i

EGE UNIVERSITY INSTITUTE OF NATURAL AND APPLIED SCIENCES

(MASTER THESIS)

COPYROLYSIS OF OIL SHALES WITH BIOMASS

Serhat KARAKAYA

Supervisors: Doç. Dr. Yurdanur AKGÜL

Chemistry Department

Code of Discipline: 405.02.01 Presentation Date:07.06.2012

Bornova-İZMİR

2012

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Sayın Serhat KARAKAYA tarafından Yüksek Lisans tezi olarak sunulan “Copyrolysis of Oil shales and Biomass” başlıklı bu çalışma E.Ü. Lisansüstü Eğitim ve Öğretim Yönetmeliği ile E.Ü. Fen Bilimleri Enstitüsü Eğitim ve Öğretim Yönergesi’nin ilgili hükümleri dikkate alınarak tarafımızdan değerlendirilerek savunmaya değer bulunmuş ve 07.06.2012 tarihinde yapılan tez savunma sınavında aday oybirliği/oyçokluğu ile başarılı bulunmuştur.

Jüri Üyeleri İmza

Jüri Başkanı : Doç. Dr. Yurdanur AKGÜL .............................

Raportör üye : Prof.Dr. Jale YANIK ..............................

Üye :Prof.Dr. Levent BALLİCE ..............................

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v

ÖZET

Bitümlüşist ve Biyokütlenin Beraber Pirolizi

KARAKAYA, Serhat

Yüksek Lisans Tezi, Organik Kimya Anabilim Dalı

Tez Yöneticisi: Doç. Dr. Yurdanur AKGÜL

Haziran 2012, 56 Sayfa

Bu çalışmada, bitümlüşistin ve biyokütlenin ve bunların beraber olarak sabit

yatak reaktöründe ısısal dönüşümü çalışılmıştır. Biokütle olarak çitlenbik

kullanılmıştır. Bitümlüşist olarak Göynük bitülüşisti seçilmiştir. Bitümlüşist, sabit

yataklı reaktörde 500, 600 ve 700 °C’de; biokütle ise 400, 500 ve 600 °C’de azot

atmosferi altında pirolizlenmiştir. Piroliz ürünleri gaz, sıvı (su fazı +biyoyağ/tar)

ve katı olarak ayrılmıştır. Bitümlüşist ve biokütlenin birlikte piroliz deneyleri 500

°C 'de 3:1, 1:1, 1:3 gibi bitümlüşist:biokütle oranlarında yapılmıştır. Bitümlüşistin

ısısal dönüşümünde biokütlenin farklı oranlarda karışımının ürün dağılımı üzerine

etkisi ve ürünlerin yakıt özellikleri incelenmiştir.

Anahtar Sözcükler:Çitlenbik, Bitümlüşist, bioyağ - tar, birlikte piroliz

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ABSTRACT

COPYROLYSIS OF OIL SHALES WITH BIOMASS

Master in Chemistry

Supervisor: Doç. Dr. Yurdanur AKGÜL

June 2012, 56pages

In this study, thermal conversion of lignocellulosic biomass, oil-shale and

their blends were investigated in a fixed bed reactor. Terebinth berry was used as

lignocellulosic biomasses. Goynuk oil-shale was selected as oil shale. The

pyrolysis temperatures were selected as 400, 500 and 600 °C for biomass samples

and 500 , 600 and 700 °C for oil shale. Pyrolysis products were separated as gas,

liquid (aqueous phase + oil/tar) and char.The effect of temperature on yields and

properties of pyrolysis products was investigated. Copyrolysis experiments were

carried out at 500 °C with the blends consisted of oil shale/ biomass in weight

ratio of 1:3, 1:1 and 3:1. The effect of different ratios of biomass in the

biomass/oil shale blends on the thermal degradation of oil shale was investigated

in terms of both product distribution and fuel properties of products.

Keywords:terebinth berry, oil shale, bio oil - tar, copyrolysis

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ACKNOWLEDGMENT

I gratefully acknowledge Doç. Dr. Yurdanur AKGÜL for her considerable

contributions, supports, helpful suggestions and supervision during my study and

for her interest in its progress.

I am also grateful to Prof. Dr. Jale YANIK, Pelin SEÇİM and Gözde

DUMAN for their valuable suggestions, criticism, technical help and supports in

interpretation of research.

My special thanks is to my family for their care and patience during the

preparation of this thesis.

Serhat KARAKAYA

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CONTENTS

Page

ÖZET ........................................................................................................ V

ABSTRACT .......................................................................................... VII

ACKNOWLEDGMENT ......................................................................... IX

CONTENTS ............................................................................................ XI

LIST OF FIGURES .............................................................................. XIV

LIST OF TABLES ................................................................................ XVI

SYMBOLS AND ABBREVIATIONS ............................................. XVIII

1. INTRODUCTION ................................................................................. 1

1.1 Oil shale ............................................................................................... 1

1.2 Biomass Energy ................................................................................... 8

1.2.1 Biomass conversion process ........................................................... 10

2. LITERATURE REVIEW .................................................................... 20

2.1 Oil shale and coal pyrolysis ............................................................... 20

2.2 Biomass pyrolysis .............................................................................. 21

2.3 Copyrolysis of oil shale or coal and biomass ................................... 23

3. MATERIAL AND METHODS ........................................................... 29

3.1 Material .............................................................................................. 29

3.1.1 Feed stocks ..................................................................................... 29

3.1.2 Chemicals ....................................................................................... 29

3.2 Methods ............................................................................................. 30

3.2.1 Pyrolysis ......................................................................................... 30

3.2.2 Analysis .......................................................................................... 32

xii

CONTENTS (continue)

Page

4. RESULTS AND DISCUSSION .......................................................... 36

4.1 Oil shale Results................................................................................. 36

4.1.1 Thermogravimetric Analysis Results .............................................. 36

4.1.2 Pyrolysis Results ............................................................................. 37

4.2 Biomass Results ................................................................................. 38

4.2.1 Thermogravimetric Analysis Results .............................................. 38

4.2.2 Pyrolysis Results ............................................................................. 40

4.3 Copyrolysis of oil shale and terebinth berry ...................................... 42

4.3.1 Composition of oil phase ............................................................... 43

4.3.2 FT-IR Results .................................................................................. 44

4.3.3 H-NMR results ................................................................................ 46

4.3.4 Fuel characterization of oil and tar ................................................. 48

4.3.5 Composition of aqueous phase ....................................................... 49

4.3.6 Fuel characterization of char ........................................................... 50

4.3.7 Composition of gas products .......................................................... 51

5. CONCLUSION .................................................................................... 52

REFERENCES......................................................................................... 54

xiii

LIST OF FIGURES

Figure Page

1.1 General composition of oil shale ......................................................... 3

3.1 Fixed bed reactor ............................................................................... 31

4.1 Tg curve of oil shale .......................................................................... 36

4.2 DTG curve of oil shale ...................................................................... 37

4.3 Product yields (wt.%) from pyrolysis of oil shale ............................. 37

4.4 Composition of liquids obtained from pyrolysis of oil shale ........... 38

4.5 TG curve of biomass .......................................................................... 39

4.6 DTG curve of biomass ....................................................................... 39

4.7 Product yields (wt.%) from pyrolysis of biomass ............................. 40

4.8 Composition of liquids obtained from pyrolysis of biomass ............. 41

4.9 FT-IR spectrums of pyrolysis oil and tar ........................................... 45

4.9 Assignments of the bands in the 1H-NMR spectra of bio-oil and tar samples ................................................................. 47

4.11 Composition of gas products ........................................................... 51

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LIST OF TABLES

Table Page

1.1 Economic oil shale reserves and production in 1999 as reported bt WEC ............................................................................ 6

1.2 Main oil reserves in Turkey ................................................................ 7

1.3 Characteristics of the major oil shale deposits in Turkey ................... 7

1.4 Reactor types and heat transfer ......................................................... 17

3.1 Oil shale properties ........................................................................... 29

3.2 Biomass properties ............................................................................ 30

4.1 Products distributions from the oil shale and copyrolysis of oil shale and biomass ............................................... 43

4.2 Composition of oil phases ................................................................. 44

4.3 H-NMR results of pyrolysis oil and tar ............................................. 46

4.4 Some properties of pyrolysis oil and tar ........................................... 48

4.5 Composition of aqueous phase ........................................................ 49

4.6 Properties of char .............................................................................. 50

xv

SYMBOLS AND ABBREVIATIONS

Abbreviation Explanation

Db Dry basis

DTG Differential Thermo gravimetric Analysis

EU European Union

GC-FID Gas Chromatography Flame Ionization Detector

GC-TCD Gas Chromatography Thermal Conductivity Detector

GCV Gross Calorific Value

GW Giga watt

L Liter

Mg Milligram

mL Milliliter

TGA (TG) Thermo gravimetric Analysis

GOS Goynuk Oil shale

TB Terebinth berry

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1

1. INTRODUCTION

Rapid increase in world population and energy demand is continuously

increasing in line with developing technology. Energy sources will play an

important role in the world’s future. The energy sources have been split into three

categories: fossil fuels, renewable sources and nuclear sources. Increasing demand

for fuels and for chemical feedstock and the awareness of the finite nature of

petroleum deposits results in great interest in alternate sources of fossil fuel, such

as coal, asphaltite and oil shales.

Oil shale represents the main source of solid fossil hydrocarbon compounds

in the form of kerogen (M. Sert et al, 2009). Oil can be obtained from kerogen by

pyrolysis and retorting processes. The estimated amount of oil recoverable from

oil shale is much higher than the resources of crude oil.

Like conventional natural energy resources, most organic waste materials

such as municipal solid waste (MSW), lignocellulosic waste, and plastic are also

potential energy resources. Today, biomass is considered as a renewable resource

with high potential for energy production. There are a number of waste and

biomass sources being considered as potential sources of fuels and chemical feed

stocks. Biomass can be converted to various forms of energy through numerous

thermo chemical conversion processes, depending upon the type of energy

desired.

One of the approaches in utilization of oil shale is coprocessing. The oil

shale/biomass co-processing is the one of the most promising options for

enhanced oil shale liquefaction and preferable liquefaction products.

Coprocessing can also provide the environmental benefits leading to reduction in

CO2 emissions.

1.1. Oil Shale

Oil shale, an organic-rich fine-grained sedimentary rock, contains

significant amounts of kerogen (a solid mixture of organic chemical compounds)

from which liquid hydrocarbons called shale oil can be produced. Shale oil is a

substitute for conventional crude oil; however, extracting shale oil from oil shale

is more costly than the production of conventional crude oil both financially and

2

in terms of its environmental impact. Deposits of oil shale occur around the world,

including major deposits in the United States of America. Estimates of global

deposits range from 2.8 trillion to 3.3 trillion barrels (450×109 to 520×109 m3) of

recoverable oil (Survey of energy resources, 2007).

Oil shale contains a lower percentage of organic matter than coal. In

commercial grades of oil shale the ratio of organic matter to mineral matter lies

approximately between 0.75:5 and 1.5:5. At the same time, the organic matter in

oil shale has an atomic ratio of hydrogen to carbon (H/C) approximately 1.2 to 1.8

times lower than for crude oil and about 1.5 to 3 times higher than for coals.(Arvo

Ots, 2007)

Geologists can classify oil shales on the basis of their composition as

carbonate-rich shales, siliceous shales, or cannel shales(Sunggyu Lee, 1991).

Another classification, known as the van Krevelen diagram, assigns kerogen

types, depending on the hydrogen, carbon, and oxygen content of oil shales'

original organic matter. Type I refers to kerogen content with a high initial H/C,

but a lower O/C ratio. Type I kerogen are mostly aliphatic chains. Oil shales

containing type I kerogen provide the highest yield of oil and are the most

promising deposits in terms of conventional oil retorting. Type II kerogen is

common in many oil shale deposits. This type is also characterized with relatively

high H/C and low O/C ratios. In type II kerogen, the poly aromatic nuclei, the

hetero atomic ketone and carboxylic groups are more significant than in type I,

but still less than type III. Type III kerogen refers to a low H/C ratio, but a high

O/C atomic ratio that is derived from terrestrial higher plants. Another distinct

characteristic is their relatively higher proportion of polyaromatic nuclei,

heteroatomic ketone and carboxylic acid groups.

Although resources of oil shale occur in many countries, only 33 countries

possess known deposits of possible economic value (K. Brendow, 2003). Well-

explored deposits, potentially classifiable as reserves, include the Green River

deposits in the western United States, the Tertiary deposits in Queensland,

Australia, deposits in Sweden and Estonia, the El-Lajjun deposit in Jordan, and

deposits in France, Germany, Brazil, China, southern Mongolia and Russia. These

deposits have given rise to expectations of yielding at least 40 liters of shale oil

per tonne of oil shale, using the Fischer Assay.

3

Figure 1.1 General composition of oil shales (N. E. Altun, 2006)

A 2005 estimate set the total world resources of oil shale at 411 giga tons

enough to yield 2.8 to 3.3 trillion barrels of shale oil (Survey of energy resources,

2007).This exceeds the world's proven conventional oil reserves, estimated at

1.317 trillion barrels (209.4×109 m3), as of 1 January 2007. The largest deposits in

the world occur in the United States in the Green River Formation, which covers

portions of Colorado, Utah, and Wyoming; about 70% of this resource lies on

land owned or managed by the United States federal government. Deposits in the

United States constitute 62% of world resources; together, the United States,

Russia and Brazil account for 86% of the world's resources in terms of shale-oil

content ( K. Brendow, 2003).

Extraction and processing

Oil shale is mined either by traditional underground mining or surface

mining techniques. There are several mining methods available, but the common

aim of all these methods is to fragment the oil shale deposits in order to enable the

transport of shale fragments to a power plant or retorting facility. The main

methods of surface mining are open pit mining and strip mining.

OIL SHALE

- Quartz

- Feldspars

- Clays(mainly illite and chlorite)

- Pyrite and others

- Solubles in CS2 - Insolubles in CS2

- Containing U, Fe, V, Ni, Mo

4

The extraction of the useful components of oil shale usually takes place

above ground (ex-situ processing), although several newer technologies perform

this underground (on-site or in-situ processing) (A.K.Burnham, 2006). In either

case, the chemical process of pyrolysis converts the kerogen in the oil shale to

shale oil (synthetic crude oil) and oil shale gas. Most conversion technologies

involve heating shale in the absence of oxygen to a temperature at which kerogen

decomposes (pyrolysis) into gas, condensable oil, and a solid residue. This usually

takes place between 450 °C and 500 °C The process of decomposition begins at

relatively low temperatures (300 °C), but proceeds more rapidly and more

completely at higher temperatures. In-situ processing involves heating the oil

shale underground. Such technologies can potentially extract more oil from a

given area of land than ex-situ processes, since they can access the material at

greater depths than surface mines can.

Applications and products

Industry can use oil shale as a fuel for thermal power-plants, burning it (like

coal) to drive steam turbines; some of these plants employ the resulting heat for

district heating of homes and businesses. Sizable oil-shale-fired power plants

occur in Estonia, which has an installed capacity of 2,967 megawatts (MW), Israel

(12.5 MW), China (12 MW), and Germany (9.9 MW).

In addition to its use as a fuel, oil shale may also serve in the production of

specialty carbon fibers, adsorbent carbons, carbon black, phenols, resins, glues,

tanning agents, mastic, road bitumen, cement, bricks, construction and decorative

blocks, soil-additives, fertilizers, rock-wool insulation, glass, and pharmaceutical

products (A study on the EU oil shale industry-viwed in the light of the Estonian

experience, May 2007)

Based on the EC 2007 report, Estonia was the world’s largest producer of

shale oil, producing 345,000 ton of shale oil per year. Approximately 8000 ton of

shale oil was utilized for domestic electricity generation; 98,000 ton of oil for heat

generation and the remaining 222,000 was exported. In Estonia the solid semicoke

byproduct of shale oil production is mostly disposed of in open dumps; currently

approximately 300 million ton of solid semi coke waste is present in such dumps.

5

Table 1.1 gives the the reserve amounts, oil-yield potentials and shale-oil

production figures for 1999 (WEC, 2001).

Environmental considerations

Both mining and processing of oil shale involve a variety of Environmental

impacts, such as global warming and greenhouse gas emissions, disturbance of

mined land, disposal of spent shale, use of water resources, and impacts on air and

water quality.

Oil shale potential in Turkey

Oil shale comprises the second largest potential fossil fuel in Turkey. The

main oil shale resources are located in middle and western regions of Anatolia.

The amount of proved explored reserves is around 2.22 billion tons while the total

reserves are predicted to be 3 to 5 billion tons. Despite this vast potential, the

stated amount cannot be accepted as a the amount of commercial reserves. The

deposits vary from 500 to 4500 kcal/kg in calorific value, revealing that each

deposit requires a detailed study regarding its possible use (N. E. Altun, C. et al.,

2006). In Turkey, the current total reserves of oil shale are the second place, after

the lignite reserves.

The main oil shale deposits in Turkey are shown in Table 1.2 with the

amounts of their geological (proved) and possible reserve. Among the potential

resources, Beypazarı (Ankara), Seyitömer (Kütahya), Himmetoğlu (Bolu) and

Hatildağ (Bolu) deposits are of major importance in terms of quality, amount and

exploitability. The characteristics of these four deposits, which constitute around

50% of the total oil shale potential of Turkey are given in Table 1.3

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Table1.1 Economic oil shale reserves and production in 1999 as reported by

WEC

Reg

ion/

Cou

ntry

Rec

over

y m

etho

d

Prov

ed O

il sh

ale(

x106

tons

)

Prov

ed re

cove

rabl

e oi

l

pote

ntia

l (x1

06 tons

)

Ave

rage

shal

e oi

l yie

ld (k

g

oil/t

on)

Estim

ated

add

ition

al o

il

pote

ntia

l

(10

6t

)Sh

ale

prod

uctio

n in

199

9

(x10

3 tons

)

African/Morocco Surface 12300 500 50-64 5400 -

Africa/S.Africa In situ 73 10 -

N.America/USA Surface 3340000 60000-

80000

57 62000 -

Asia/Thailand In situ 18668 810 50 -

Asia/Turkey Surface 1640 269 56 -

Europe/Albania Surface 6 5

Europe/Estonia Surface 590 167 167 151

In situ 910 -

Europe/Ukraine In situ 2674 300 126 6200

Middle

East/Israel

Surface 15360 600 62

Middle

East/Jordan

Surface 40000 4000 100 20000

Oceania/Australia In situ 32400 1725 53 35260

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Table 1.2 Main oil shale reserves in Turkey

Name of the

deposits

Geological

Reserves (x106

tons)

Possible reserves

(x106 tons)

Total reserves

(x106 tons)

Beypazarı 327.68 - 327.68

Seyitömer 83.32 38.85 122.17

Himmetoğlu 65.97 - 65.97

Hatıldağ 78.37 289.2 467.57

Mengen - 50 50

Ulukışla - 130 130

Bahçecik - 42 42

Burhaniye - 15.6 15.6

Beydili - 300 300

Dodurga - 138 138

Demirci - 172 172

Sarıcakaya - 330 300

Çeltik - 90 90

TOTAL 555.34 1665.65 2220.99

Table 1.3 Characteristics of the major oil shale deposits in Turkey

Deposit Upper

calorific

value

kcal/kg

Total

organic

carbon %

Oil

content %

Oil

content l

Total

sulphur %

Beypazarı 812.67 4.8 5.4 60 1.4

Seyitömer 847.90 6.9 5 54.3 0.9

Himmetoğlu 1991.88 30.9 43 482 2.5

Hatıldağ 773.86 5.6 5.3 58 1.3

8

Göynük Himmetoğlu deposit

The Himmetoğlu oil shale deposit is located in the southwestern part of

province of Bolu, in the neighborhood of the Beypazari, Hatildağ Mengen oil

shale deposits. The Himmetoğlu oil shale basin is of Neogene age, and volcanism

and tectonic activity have considerable influence on the environmental conditions

during the deposition period. The Himmetoğlu oil shale consists of more than

50% liptinite, 20–50% huminite and 0–20% inertinite maceral groups and is

characterized by its high organic content. The origin of the organic matter is

mainly algae and land plants. The major inorganic constituents in the organic-rich

zones are calcite, dolomite, silica, and considerable amounts of pyrite. The

average calorific value of the EGOS zone is around 4900 kcal/kg. The in-place

shale oil content of the Himmetoğlu oil shale is 43% by weight or approximately

482 l/ton of shale. However, the average total sulphur content is high (2.5%) due

to considerable pyrite. The Himmetoğlu oil shale zone is being excavated (2005)

to exploit a underlying high-quality lignite seam utilized for domestic heating. On

account of its high thermal quality, the Himmetoğlu oil shale alternative for power

generation in Turkey, which relies mostly on poor-quality lignites.

1.2 Biomass Energy

Biomass is the name to given all Earth’s living matter. Biomass is general

term for material derived from growing plants or from animal manure which is

effectively a processed form of plant material such as wood from natural forests,

waste from agricultural and forestry processes, and industrial, human or animal

wastes. The stored energy in the plants and animals, or the waste that they

produce is called biomass energy.

Plants absorb solar energy, using it to drive the process of photosynthesis,

which enables them to live. The energy in biomass from plant matter originally

comes from solar energy through the process known as photosynthesis. The

energy, which is stored in plants and animals (that eat plants or other animals), or

in the wastes that they produce, is called biomass energy. This energy can be

recovered by burning biomass as fuels. During combustion, biomass releases heat

and carbondioxide that was absorbed while the plants were growing. Essentially,

9

the use of biomass is the reversal of photosynthesis. Is biomass energy a variety of

chemical energy? In nature, all biomass ultimately decomposes to its molecules

with the release of heat. The release of energy from the combustion of biomass

imitates natural process. Therefore, the energy obtained from biomass is a form of

renewable energy and, in principle, utilizing this energy does not add

carbondioxide to environment, in contrast to fossil fuels. Of all the renewable

sources of energy, biomass is unique in that it is effectively stored solar energy.

Furthermore, it is the only renewable source of carbon and is able to be converted

into convenient solid, liquid and gaseous fuels . Biomass can be used directly (e.g

burning wood for heating and cooking) or indirectly by converting it into a liquid

or gaseous fuel (e.g. alcohol from sugar crops or biogas from animal waste).The

net energy available from biomass when it is combusted ranges from about

8MJ/kg for green wood, to 20MJ/kg for dry plant matter, to 55MJ/kg for methane,

as compared with about 27 MJ/kg for coal.

Many biomass fired electricity generators use waste materials, such as straw

or domestic refuse. Other schemes are based on the idea of cultivating crops of

various kinds, especially to provide biomass for fuel.

The conversion of biomass to energy (also called bioenergy) encompasses a

wide range of different types and sources of biomass, conversion options, end-use

applications and infrastructure requirements (McKendry, 2002). Although a wide

variety of biomass sources, most importants of their used for energy are: Wood,

Vegetable sources, Grease seed crops (sunflower, colza, soybean...),

Carbohydrate crops (potato, wheat, corn, beet...), Energy (C4) crops (eucalyptus,

sweet corn, miscanthus ...), Aquatic plants (water hyacinth, algae, marine algae,

some water grass...), Crop residues (brunch, stalk, straw, root,shell...), Animal

wastes, Urban and industrial wastes (Balkanlı, 2001).

Biomass is the fourth largest source of energy in the world after coal,

petroleum and natural gas, providing about 14% of the world’s primary energy

consumption. Since the energy crisis in the mid-1970s, the energy utilization from

biomass resources has received considerable attention (Bridgwater, 1999).

10

This type of biomass-based resources through different processes of

conversion is used to produce biofuels such as biodiesel, ethanol, in heating, in

cooking and is used to produce electricity. Biomass energy due to has an

extremely important role, renewable and easy availability, socio-economical

contribution to development and environmentally friendly.

1.2.1 Biomass conversion process

Biomass cn be converted to fuels and chemical by thermochemicals and

biochemical ways. The thermochemical conversion processes have two basic

approaches. The first is the gasification of biomass and its conversion to

hydrocarbons. The second approach is to liquefy biomass directly by high-

temperature pyrolysis, high-pressure liquefaction, ultrapyrolysis, or supercritical

extraction. These processes convert the waste biomass into energy rich useful

products. Choice of conversion process depends upon the type and quantity of

biomass feedstock, the desired form of the energy, i.e., end use requirements,

environmental standards, economic conditions and project specific factors.

Different thermochemical conversion processes include combustion, gasification,

liquefaction, hydrogenation and pyrolysis. Although pyrolysis is still under

developing stage but during current energy scenario, pyrolysis has received

special attention as it can convert biomass directly into solid, liquid and gaseous

products by thermal decomposition of biomass in the absence of oxygen.

Pyrolysis offers efficient utilization of particular importance for agriculture

countries with vastly available biomass by-products. Pyrolysis will be explained

in another section.

1.2.1.1 Combustion

The burning of biomass in air, i.e. combustion, is used over a wide range of

outputs to convert the chemical energy stored in biomass into heat, mechanical

power, or electricity using various items of process equipment, e.g. stoves,

furnaces, boilers, steam turbines, turbo generators, etc. The technology is

commercially available and presents minimum risk to investors.

11

Combustion of biomass produces hot gases at temperatures around 800–

1000˚C. It is possible to burn any type of biomass but in practice combustion is

feasible only for biomass with a moisture content <50%, unless the biomass is

pre-dried. High moisture content biomass is better suited to biological conversion

processes.

1.2.1.3 Gasification

Gasification is the conversion of biomass into a combustible gas mixture

either by the partial oxidation or by steam or pyrolysis gasification of biomass at

high temperatures, typically in the range 800–900 ˚C. The low calorific value

(CV) gas produced (about 4–6 MJ=N m3) can be burnt directly or used as a fuel

for gas engines and gas turbines. The product gas can be used as a feedstock

(syngas) in the production of chemicals e.g. methanol (McKendry, 2001).

The process of gasification is a sequence of interconnected reactions; the

first step, drying evaporate moisture, is a relatively fast process. The second step,

pyrolysis, is also relatively fast but it is a complex process that gives rise to the

tars that cause so many problems in gasification processes. Pyrolysis occurs when

a solid fuel is heated to 300–500 ºC in the absence of an oxidizing agent, giving a

solid char, condensable hydrocarbons or tar and gases. The relative yields of char,

liquid and gas mainly depend on the rate of heating and the final temperature.

In gasification by partial oxidation, both the gas and liquid and solid

products of pyrolysis then react with the oxidizing agent – usually air, although

oxygen can be used – to give the permanent gases CO, CO2, H2, and lesser

quantities of hydrocarbon gases. In steam or pyrolytic gasification, the char is

burned in a secondary reactor to reheat the hot sand which provides the heat for

the gasification.

12

1.2.1.3 Liquefaction

Liquefaction is the conversion of biomass into a stable liquid hydrocarbon

using low temperatures and high hydrogen pressures (McKendry, 2001). In this

process, liquid is obtained by thermo-chemical conversion at low temperature and

high pressure using a catalyst in the presence of hydrogen. The interest in

liquefaction is low because the reactors and fuel-feeding systems are more

complex and more expensive than pyrolysis processes.

In liquefaction, feedstock organic compounds are converted into liquid

products. In case of liquefaction, feedstock macromolecules compounds are

decomposed into fragments of light molecules in the presence of a suitable

catalyst. These unstable and highly reactive fragments repolymerize into oily

compounds having appropriate molecular weights, whereas in pyrolysis, catalysts

are not used and light decomposed fragments are converted to oily compounds

through homogeneous reactions in the gas phase. It is an expensive process and

also the product is a tarry lump, which is difficult to handle.

1.2.1.4 Supercritical fluid extraction

SCFs have both gas and liquid like properties. They possess gas like mass

transfer properties and the salvation characteristic of liquids. Their high

diffusivity allows them to penetrate solid materials, and their liquid like densities

enable them to dissolve analyses from a solid matrix. SCFs are compressible, and

small pressure changes produce significant changes in their density and in their

ability to solubilise compounds. Also SCFs have almost no surface tension. Thus,

they can penetrate low porosity materials. In addition, their low viscosity provides

favorable flow characteristics. These properties enable SCFs to provide excellent

extraction efficiency and speed.

Supercritical fluid extraction is a fast and efficient method to extract all

manner of organic compounds from a wide variety of solid sample matrices. Due

to the marked change in its polarity with temperature, water is an interesting

13

alternative to carbondioxide as the extraction fluid. By merely adjusting the

temperature, selectivity can be achieved for inorganic or organic compounds and

for polar and non-polar organic compounds. Many organic compounds are

sufficiently soluble to be extracted under subcritical conditions and in this way,

instrumental and other problems, such as the high corrosiveness of supercritical

water, can be avoided. Instrumentation for sub- and supercritical water extraction

was developed and modified in several ways with the aim of simplifying the

procedure while maintaining good recoveries.

1.2.1.5 Pyrolysis

Pyrolysis is the chemical and pysical decomposition of organic material that

occurs at high temperatures in the absence of oxygen. The conditions created

during pyrolysis cause complex organic molecules to break down into simpler

molecules and thus fundamentally and irreversibly alter their properties at a

molecular level.

Type of pyrolysis

a. Slow pyrolysis

Conventional slow pyrolysis has been applied for thousands of years and

has been mainly used for the production of charcoal. Slow pyrolysis is defined as

the pyrolysis that occurs under a slow heating rate. This condition permits the

production of solid, liquid, and gaseous pyrolysis products in significant portions.

In slow pyrolysis, biomass is heated to about 500 °C. The vapor residence time

varies from 5 min to 30 min. Because of long residence time of vapor,

components in the vapor phase continue to react with each other, as the solid char

and any liquid are being formed. The heating rate in conventional pyrolysis is

typically much slower than that used in fast pyrolysis. A feedstock can be held at

constant temperature or slowly heated. Vapors can be continuously removed as

they are formed.

14

b. Fast pyrolysis

Fast pyrolysis occurs in a time of a few seconds or less. Therefore heat and

mass transfer processes and phase transition phenomena, as well as chemical

reaction kinetics, play important roles. The critical issue is to bring the reacting

biomass particles to the optimum process temperature and minimize their

exposure to the intermediate (lower) temperatures that favour formation of

charcoal. One way this objective can be achieved is by using small particles, for

example in the fluidized bed processes. Another possibility is to transfer heat very

fast only to the particle surface that contacts the heat source as applied in ablative

pyrolysis. A critical technical challenge in every case is heat transfer to the reactor

of char. The higher yield of desirable liquid product can be obtained by fast

pyrolysis. It involves rapid heating of biomass but not as fast as flash pyrolysis.

Heating rate is somewhere about 300 °C/min. Generally, fast pyrolysis is used to

obtain high-grade bio-oil. Fast pyrolysis is successful with most of fluidized bed

reactors as it offers high heating rates, rapid devolatilization, easy control, easy

product collection, etc.

Various reactors like entrained flow reactor, wire mesh reactor, vacuum

furnace reactor, vortex reactor, rotating reactor, circulating fluidized bed reactor,

etc. were designated for performing fast pyrolysis. Many researchers have

contributed in the field of fast pyrolysis of biomass using various reactors.

Although fast pyrolysis of biomass has achieved commercial status, there

are still many aspects of the process which are largely empirical and require

further study to improve reliability, performance, product consistency, product

characteristics and scale-up. A wide range of reactor configurations have been

investigated that show considerable diversity and innovation in meeting the basic

requirements of fast pyrolysis. The `best' method is not yet established with most

processes giving between 65±75% liquids based on dry wood input. The essential

features of a fast pyrolysis reactor are: very high heating and heat transfer rates;

moderate and carefully controlled temperature; and rapid cooling or quenching of

the pyrolysis vapours. Commercial operation is currently only being achieved

from a transport or circulation fluid bed system that are used to produce food

15

favourings. Fluid beds have also been extensively researched and have been

scaled up to pilot plant size with plans in hand for demonstration in several

locations. Substantial developments can be expected in performance and cost

reduction in coming years.

The penalties and interactions are summarized in Table 2.2 below with

some speculations on heat transfer modes. The two dominant modes of heat

transfer in fast pyrolysis technologies are conductive and convective. Each one

can be maximized or a contribution can be made from both depending on the

reactor configuration (Bridgwater, 1999)

Bubbling fluid beds – usually referred to as just fluid beds as opposed to

circulating fluid beds – have the advantages of a well understood technology that

is simple in construction and operation, good temperature control and very

efficient heat transfer to biomass particles arising from the high solids density.

Fluid-bed pyrolyzers give good and consistent performance with high liquid

yields of typically 70–75% wt from wood on a dry-feed basis. Small biomass

particle sizes of less than 2–3mm are needed to achieve high biomass heating

rates, and the rate of particle heating is usually the rate-limiting step. Residence

time of solids and vapours is controlled by the fluidizing gas flow rate and is

higher for char than for vapours. As char acts as an effective vapour cracking

catalyst at fast pyrolysis reaction temperatures, rapid and effective char

separation/elutriation is important. This is usually achieved by ejection and

entrainment followed by separation in one or more cyclones so careful design of

sand and biomass/char hydrodynamics is important.

Fluidized bed pyrolysis and circulating fluid beds which transfer heat from

a heat source to the biomass by a mixture of convection and conduction. The heat

transfer limitation is within the particle, thus, requiring very small particles of

typically not more than 3 mm to obtain good liquid yields. Substantial carrier gas

is needed for fluidization or transport. Circulating fluid beds (CFBs) have many of

the features of bubbling beds, except that the residence time of the char is almost

the same as for vapours and gas, and the char is more attrited due to the higher gas

16

velocities, which can lead to higher char contents in the collected bio-oil. An

added advantage is that CFBs are potentially suitable for very large throughputs

even though the hydrodynamics are more complex – this technology is widely

used at very high throughputs in the petroleum and petrochemical industries.

However, heat transfer at higher throughputs has not been demonstrated and

offers some challenges. Heat supply is usually from recirculation of heated sand

from a secondary char combustor, which can be either a bubbling or circulating

fluid bed.

In this respect the process is similar to a twin fluid-bed gasifier except that

the reactor (pyrolyser) temperature is much lower and the closely integrated char

combustion in a second reactor requires careful control to ensure that the

temperature and heat flux match the process and feed requirements.

Ablative pyrolysis is substantially different in concept compared with other

methods of fast pyrolysis. In all the other methods, the rate of reaction is limited

by the rate of heat transfer through the biomass particles, which is why small

particles are required. The mode of reaction in ablative pyrolysis is like melting

butter in a frying pan – the rate of melting can be significantly enhanced by

pressing the butter down and moving it over the heated pan surface. In ablative

pyrolysis, heat is transferred from the hot reactor wall to ‘melt’ wood that is in

contact with it under pressure. The pyrolysis front thus moves unidirectionally

through the biomass particle. As the wood is mechanically moved away, the

residual oil film both provides lubrication for successive biomass particles and

also rapidly evaporates to give pyrolysis vapours for collection in the same way as

other processes.

17

Table 1.4 Reactor types and heat transfer (Bridgwater, 1999).

Reactor type Suggested mode of heat

transfer

Advantages/disadvantages/features

Ablative 95%Conduction, 4%

convection; 1% radiation.

Accepts large size feedstocks;

very high mechanical char abrasion

from biomass; compact 1% radiation

design; heat supply problematical;

heat transfer gas not required;

particulate transport gas not always

required.

Circulating fluid

bed

80%Conduction, 19%

convection; 1% radiation.

High heat transfer rates; high

char abrasion from biomass and char

erosion leading to high char in

product; char/solid heat carrier

separation required; solids recycle

required; increased complexity of

system; maximum particle sizes up to

6 mm; possible liquids cracking by

hot solids; possible catalytic activity

from hot char; greater reactor wear

possible.

Fluid bed 90%Conduction , 9%

convection; 1% radiation

High heat transfer rates; heat

supply to fluidizing gas or to bed

directly; limited char abrasion; very

good solids mixing; particle size limit

< 2 mm in smallest dimension; simple

reactor configuration

Entrained flow 4%Conduction , 95%

convection; 1% radiation

Low heat transfer rates; particle

size limit < 2 mm; limited gas/solid

mixing

18

The rate of reaction is strongly influenced by pressure, the relative velocity

of the wood and the heat exchange surface and the reactor surface temperature.

The key features of ablative pyrolysis are therefore as follows:

• High pressure of particle on hot reactor wall, achieved due to centrifugal

force

• High relative motion between particle and reactor wall

• Reactor wall temperature less than 600 °C.

As reaction rates are not limited by heat transfer through the biomass

particles, large particles can be used and, in principle, there is no upper limit to the

size that can be processed. In fact, the process is limited by the rate of heat supply

to the reactor rather than the rate of heat absorption by the pyrolysing biomass, as

in other reactors. There is no requirement for inert gas, so the processing

equipment is smaller and potentially lower cost. However, the process is surface-

area-controlled so scaling is more costly and the reactor is mechanically driven,

and is thus more complex.

Entrained flow fast pyrolysis is, in principle, a simple technology, but most

developments have not been as successful as had been hoped, mostly because of

the poor heat transfer between a hot gas and a solid particle. High gas flows are

required to affect sufficient heat transfer, which requires large plant sizes and

entails difficult liquid collection from the low vapour partial pressure. Liquid

yields have usually been lower than fluid bed and CFB systems (Bridgwater,

2006).

c. Flash pyrolysis

Flash pyrolysis is the process in which the reaction time is of only several

seconds or even less. The heating rate is very high. This requires special reactor

configuration in which biomass residence times are only of few seconds. Two of

appropriate designs are entrained flow reactor and the fluidized bed reactor. Flash

19

pyrolysis of any kind of biomass requires rapid heating and therefore the particle

size should be fairly small, i.e., approximately 105–250 mm (Goyal et al., 2008).

d. Vacuum pyrolysis

Vacuum pyrolysis has slow heating rates but removes pyrolysis products as

rapidly as in the previous methods which thus simulates fast pyrolysis. Larger

particles are needed and the vacuum leads to larger equipment and higher costs. It

limits the secondary decomposition reactions, which in turn gives high oil yield

and low gas yield.

The Factors that affect Pyrolysis

The factors that affect pyrolysis are pyrolysis temperature, heating rate,

catalyst, particle size, reaction conditions of the products and pressure.

The amount of volatile matter increase with increasing heating rate. Tar

decomposed at high temperatures so that the amount of gas products increase.

With Increasing pressure, retention time of volatile substances decreases. The

amount of tar increase at middle temperatures with low pressure. Pyrolysis

temperature is the important parameter affecting the quantity and composition of

volatile substances. Liquid, gas and activated carbon (solid) change by pyrolysis

temperature and their chemical composition is also quite different. With the

increase in temperature of pyrolysis, H / C and O / C ratio of the liquid product

and activated carbon decrease. Volatile products decomposition and again carbon

waste gasification observed in long retention times.

The pyrolysis process in short retention times, there is a direct correlation

between temperature and chemical composition. With the increase temperature,

oxygen content in the structure and C / N ratio decrease.

With the increase particle size, volatiles migration accelerate to gas

atmosphere so that it is possible that the mass transfer limitation. Volatiles interact

longer with the surface and may cause formation of secondary reactions.

20

Polymerization decreases the efficiency of whole pyrolis process,and

decompositon reactions on the suface reduces the liquid efficiency while

increasing the gas efficiency.

21

2. LITERATURE REVIEW

2.1 Oil shale and Coal Pyrolysis

Hans Luik et al. studied two different Estonian oil shales, peat, and willow

biomass were submitted to supercritical water conversion at unified operating

conditions. The yield and chemical composition of conversion products were

investigated by chromatographic, FTIR-spectroscopic and ultimate analysis

techniques. The results reveal significant difference in products yield and

composition those depending on the feedstock origin and its chemical

composition. Common and specific features in conversion of fossil and renewable

matter were described. The maximum and the minimum oil yield per organic

matter, 62.7 and 18.6%, respectively, were obtained in conversion of oil shales.

Willow biomass conversion resulted in the highest yield of gas andwater (50 %).

The solubility of oils despite original feedstock increases with solvents used in the

raw: dimethyl ketone < water < benzene. The investigation on group composition

of the benzene-soluble compounds demonstrated that various oxygen compounds

dominate over hydrocarbons in all cases. The majority of hydrocarbons was

represented by polycyclic aromatic ones. Aliphatic hydrocarbons, making 6–11%

of the benzene-soluble oil were represented by n-alkanes up to C33. Conversion

gases, especially those of peat and willow were characterized by high carbon

dioxide content. Supercritical water conversion can be used as an alternative

method for the liquefaction and gasification of different feed stocks.

Omar S. et al. investigated a modified first order kinetic equation with

variable activation energy is employed to model the total weight loss of Ellajjun

oil shale samples. Fixed bed retort with 400 g of oil shale sample size is used in

this study in 350–550 0C temperature range. Variable heating rate, h, in the range

2.6–5 0C min-1 are tested. Activation energy was allowed to vary as a function of

oil shale conversion. The value of the activation energy increased from 98 to 120

kJ mol-1 while the corresponding frequency factor changed from 9.51 -105 to 1.16

- 106. Fischer Assay analysis of the studied samples indicated 12.2 wt.% oil

content. The oil shale decomposition ranged from 3.2% to 28.0%. The obtained

22

kinetic data are modeled using variable heating rate, pyrolysis temperature and

variable activation energy principle in a nitrogen sweeping medium. Good fit to

the obtained experimental data is achieved.

Yahya H. et al. investigated In this investigation, spectroscopic (FT-IR,

UV–Vis, 1H NMR) and chromatographic (GC) techniques were used to analyze

two Jordanian shale oils, Sultani and El-Lajjun. The oils were extracted at

different pyrolysis temperatures (400–500 0C) using a fluidized bed reactor. The

spectroscopic and chromatographic analyses show that the variation of pyrolysis

temperature has no significant effect on the composition of the produced oil. The 1H NMR results indicate that the protons of methyl and methelyene represent the

bulk of the hydrogen (90%) in most shale oil samples. GC analysis reveals that

the oil samples contain n-alkanes with a predominant proportion of n-C25.

2.2 Biomass Pyrolysis

G.A. Romeiro et al. investigated the low temperature conversion (LTC)

process applied to a castor seed sample at 380 8C produced pyrolysis oil

(50%,w/w), pyrolytic char (29%, w/w), water (13%, w/w) and gas (8%, w/w)

fractions. The oil fraction was subjected to analysis of by FTIR, 1H NMR, 13C

NMR, GCMS and physical–chemical analysis such as sulfur content, distillation,

density, flash-point, kinematic viscosity, Ramsbottom carbon residue, ash content,

corrosivity to copper, water content and sediment, cold filter plugging point, and

gross calorific value. They were found as conclusion The need for an efficient and

renewable source of biomass makes castor seeds an excellent material to be used

in the LTC process. After separation of the fractions, the pyrolysis oil was

analyzed by FTIR, 1H, 13C NMR and GCMS, demonstrating that the oil possesses

long-chain hydrocarbons and also polar components.

Nurgul O. et al. investigated apricot pulps was pyrolyzed in a fixed-bed

reactor under different pyrolysis conditions to determine the role of final

temperature, sweeping gas flow rate and steam velocity on the product yields and

liquid product composition with a heating rate of 5 C/min. Final temperature

range studied was between 300 and 700 0C and the highest liquid product yield

was obtained at 550 0C. Liquid product yield increased significantly under

23

nitrogen and steam atmospheres. For the optimum conditions, pyrolysis of peach

pulp was furthermore studied. Liquid products obtained under the most suitable

conditions were characterized by FTIR and H-NMR. In addition, gas

chromatography/mass spectrophotometer was achieved on all pyrolysis oils.

Characterization showed that bio-oil could be a potential source for synthetic fuels

and chemical feedstock.

Putun E. et al. were studied pyrolysis of hazelnut shells in a fixed-bed

tubular reactor. Fixed-bed pyrolysis experiments have been conducted on a

sample of hazelnut shells to determine the possibility of being a potential source

of renewable fuels and chemical feedstocks. The effects of pyrolysis temperature

and well-sweep gas atmosphere (N2) on the pyrolysis yields and chemical

compositions have been investigated. The maximum bio-oil yield of 23.1 wt.%

was obtained in N2 atmosphere at a pyrolysis temperature of 500°C and heating

rate of 7 K min-1. The pyrolysis products were characterized by elemental

analysis and various chromatographic and spectroscopic techniques and also

compared with currently utilised transport fuels by simulated distillation. Bio-oil

was then fractionated into pentane soluble and insoluble compounds

(asphaltenes). Pentane soluble was then solvent fractionated into pentane, toluene,

ether and methanol subfractions by fractionated column chromatography. The

aliphatic and low-molecular-weight aromatic subfractions of the bio-oil were then

analyzed by capillary column gas-liquid chromatography and GC:MS. Further

structural analysis of bio-oil and aromatic and polar subfractions FTIR and 1H-

NMR spectra were obtained. The chemical characterization has shown that the

bio-oil obtained from hazelnut shells was quite similar to the crude oil and shale

oil.

2.3 Copyrolysis of biomass with coal or oil shale

Hans Luik et al. (2007) investigated pyrolysis of different types of forest

residual biomass such as pine wood, pine bark and spruce needles, and Estonian

Kukersite oil shale. Pyrolysis of the individual samples was carried out in a

Fischer assay in standard for oil shales semi-coking conditions (under the heating

rate 5 min-1 up to 520 0C). The elemental composition of the selected products

24

was examined with ‘‘Elementar Vario EL’’ analyzer. The functional group

composition of liquid fractions was investigated by FTIR-spectroscopy. The

group composition of the benzene-soluble fraction was determined by thin-layer

chromatography (TLC). The individual composition of volatiles was analyzed by

gas chromatography in columns of different polarity with temperature

programming. Gas composition, characterizes the bio-gas as especially rich in

CO2. The content of CO is considerable also.

Common and specific features in biomass and oil shale semi-coking have

been described. In comparison with oil shale, the biomass yielded less oil and

more gas. Specifically large amounts of reaction water and carbon dioxide were

obtained in biomass pyrolysis resulting in formation of significantly deoxygenated

liquid and solid products. Bio-oils can be distinguished by the solubility in

conventional solvents. Kukersite shale oil and the benzene-soluble fractions of

different bio-oils were characterized by similar group composition.

Xiumin Jiang et al. (2009) were studied the pyrolysis experiments of the

mixture fuels of Huadian oil shale and its shale char prepared at a retorting

temperature of 520 0C were conducted using a thermo gravimetric analyzer. Oil

shale samples were crushed and sieved to size range of 0-0.6 mm. 50 g of oil shale

samples was placed inside a sealed aluminum crucible and heated from room

temperature to the retorting temperature of 520 0C in a pure nitrogen atmosphere.

In the heating process, steam, hydrocarbon gases, and shale oil evaporation were

formed and conducted into a conical flask immerged in a low-temperature trough;

after the retorting temperature was kept for a specified residence time of 20 min,

the experiment ceased and the standard shale char was obtained. According to The

ultimate and proximate analysis of Huadian oil shale and its shale char it was

found that, as a result of char production, carbon content (C%) decreases about

10%, but fixed carbon content (FC%) increases almost 2.5 times. carbon element

in organic matter is released with the release of volatile matter. As a result, the

increase of the mass of fixed carbon and the great decrease of the mass of the

sample make FC% of shale char almost 2.5 times as great as that of oil shale.

The obtained shale char was mixed with oil shale samples adequately in

certain proportions to five samples labeled with S1-S5 in turns with the increase

of shale char fraction. Some previous investigations on copyrolysis for thermo

25

gravimetric studies showed the lack of interactions, which have low heating rates.

Under very low heating rate conditions, the temperature ranges for pyrolysis of

two components differ considerably, indicating that the two processes are well

separated and, therefore, obvious synergies cannot be found.

According to the thermo gravimetric analysis, the following conclusions can

be obtained. The copyrolysis of oil shale and shale char was a complicated

multistage process. The release of organic matter tended to decrease while the

decomposition of inorganic constituents tended to increase slightly with

increasing shale char fraction. At temperatures ranging from 250 to 600 0C, the

reactivity of the samples tended to decrease with the increase of shale char

fraction due to the lower volatile content and carbon condensation structures in

shale char. For each sample, the reactivity increased first and then decreased as

the temperature increased, which was attributed to the rearrangement of internal

structure of sample particles and forming carbon condensation structures due to

the decomposition and release of volatile matter. Between 600 and 800 0C,

different ash shells formed inside sample particles of different mixing ratios after

the previous pyrolysis, which made the decomposition of minerals more

complicated.

Sang Done Kim et al. (2010) investigated copyrolysis characteristics of

sawdust and coal blend in TGA and a fixed bed reactor. Particle size of the

sample was less than 1.0 mm in diameter. The blending weight ratio of

sawdust/(sawdust + coal) was 0.4 in the TGA experiments. In a fixed bed reactor,

six blending ratios (0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were employed. The fixed bed

reactor was heated to a desired temperature under N2 flow. At a desired

temperature, the reactor was purging by N2 to eliminate O2 for more than 10 min,

thereafter sample (20 g) was fed into reactor under N2 flow of 0.2 m/s for 30 min.

The concentrations of CO2, CO and CH4 were analyzed by infrared gas analyzer

(and H2 concentration was determined by thermal conductivity gas analyzer.

Thermal decomposition of coal appears to start at around 300 0C, and it

continued over the whole temperature range at are latively low and constant rate.

The maximum weight loss rate is found to be 0.015 min-1 at 460 0C and the total

amount of volatiles from coal pyrolysis is 26 wt.% of the initial sample weight on

the dry basis. On the other hand, thermal decomposition of sawdust starts at

26

around 200 0C and the maximum weight loss rate is 0.168 min-1 at 3700C. The

total volatiles are produced approximately 80 wt.% of the initial sample weight on

the db. Cellulose and lignin in the macromolecular structure of biomass are linked

together with relatively weak ether bonds (RAOAR, bond energy of 380–420

kJ/mol) that will broken at lower temperature. The backbone of coal structure is,

however, made of

dense polycyclic aromatic hydrocarbons and linked by alternate single and double

bonds with extra resonance stability and is more resistant to thermal

decomposition with high bond energy of 1000 kJ/mol.

Consequently, more volatiles are produced from thermal decomposition of

the blend than that from the individual thermal decomposition of coal and

sawdust. From copyrolysis of sawdust and coal blend in TGA, the synergy effect

to produce more volatiles from coal pyrolysis is pronounced above 400 0C and

the catalytic effect of inorganic species in sawdust ash is observed at 700 0C.

From the fixed bed reactor experiments, gas products increase up to 39% than that

from the additive model by the synergy effect of reduction in char and tar yields.

Calorific value of the product gas increases up to 68% with the increase of CO

and CH4 yields and it is 35% higher than that of sawdust pyrolysis only.

Anup Kumar Sadhukhan (2008) were studied modelling of lignite coal-

biomass such as waste-wood fines blends using thermogravimetric analysis.

Lignite coal of Indian origin and waste-wood fines obtained from local saw mills

were used in the study. Coal sample was crushed and sieved in the size range of

149–210 lm, while the sawdust used was in the range of 354–500 lm. Both coal

and wood sample were dried in crucibles in an oven at a temperature of 100 0C for

2 h. The samples were then mixed with appropriate proportions to make the

blends and then kept in packed condition in desiccators. Blended samples were

prepared with coal and biomass ratios of 100:0, 50:50, 40:60, 10:90, and 0:100,

respectively. A Perkin Elmer, Pyris Diamond TG/DTA apparatus was used to

record the sample mass change with temperature over the course of pyrolysis

reaction. The runs were performed with the prepared samples at a slow heating

rate of 40 °C/min. For all runs 5 mg sample were used with N2 flow of 0.1 L/min

to ensure inert atmosphere. Intermolecular dehydration leads to intermediate char

27

formation along with the formation of primary volatiles and char by cracking,

cross-linking and re-polymerization reactions. The char further undergoes

cracking reaction at high temperature to form gases like CH4, C2H4, and HCN,

collectively called secondary volatiles, leaving behind the residual char.

A new generalized model was proposed for pyrolysis of biomass with

parallel-series reaction scheme, which predicted well the pyrolysis behaviour of

biomass over a wide range of temperature covering two thermal events for

biomass and one for coal. The weighted average of TG data of pure coal and

biomass agreed closely with the TG data of the blends signifying a lack of

synergistic effects. Measured TG data indicated a linear relationship between final

char yield and fraction of biomass in the blend.

Li Zhang et al.(2006) were studied copyrolysis of biomass and coal in a free

fall reactor under atmospheric pressure with nitrogen as balance gas. The coal

sample selected was Dayan lignite, while the biomass used was legume straw. The

operation temperature was over a range of 500–700 0C, and the blending ratio of

biomass in mixtures was varied between 0 and 100 wt.%. the char yields decrease

and consequently the liquid yields increase compared with the calculated values,

even the compositions of the gaseous products (e.g. H2, CH4, CO and CO2, etc.)

from the blended samples are not in accordance with those of their parent fuels,

suggesting that there exist synergetic effects between biomass and coal under the

experimental conditions. The largest degree of synergetic effects on the products

yields was observed under 600 0C and the blending ratio of 73 wt.% in the

copyrolysis of LS/DY. Therefore, it can be concluded that both the higher

blending ratio (around 70 wt.%) and the relatively lower temperature (around 600 0C) are more in favor of obvious synergies during the copyrolysis of biomass and

coal in the free fall reactor.

J.M. Jones et al. (2005) investigated of devolatilisation characteristics of

coal and biomass blends. Three coals and pinewood were used in this study,

together with cellulose, lignin, xylan and polywax model compounds. All samples

were surface and sieved to 75–90 mm size fractions and dried at 60 0C for 12 h

prior to analysis. The coal:biomass blends were prepared in 25:75, 50:50 and

75:25 mixtures. Pyrolysis–GC was performed on each of the fuels, blends and

model compounds using GC–MSD gas chromatograph. Slow heating rate

28

pyrolysis tests were performed for some of the fuel mixtures. One hundred grams

of fuel was pyrolyzed under nitrogen in a static reactor at 520 0C for 1 h at a

heating rate of 10 0C min-1. The condensed tars were collected in an ice trap and

analyzed by GC–MS. The tars were subjected to open column chromatographic

separation by gradient elution from an alumina packed column to produce three

fractions—aliphatic (from a hexane eluent), aromatic (from a toluene eluent) and

polar (from a THF eluent). Thermo gravimetric analysis (TGA) was performed for

the individual fuels, the blends and the model compounds. Approximately, 15 mg

of sample was heated in nitrogen at a rate of 25 0C min-1 to 900 0C.

Nasir Ahmad et al were studied influence of particle grain size on the yield

and composition of products from the pyrolysis of oil shales. Oil shales from two

regions of Pakistan have been pyrolyzed in a fixed bed reactor in relation to

particle grain size. Five size ranges were investigated, B 0.5, 0.5–1.0, 1.0–1.7,

1.7–2.8 and 6.0–10 mm. The gases were analyzed for their content of CO, CO2,

H2, CH4 and other hydrocarbons up to C4. The derived pyrolysis oil was

condensed in a series of cold traps and the total oil yield determined. In addition,

experiments were carried out on a thermo gravimetric analyzer using the three

smallest particle grain sizes under identical heating conditions to the fixed bed

reactor. It was found that increasing the particle size up to the largest size used of

10 mm resulted in an increase in oil yield. The total gaseous yield was decreased,

reflecting a decrease in concentration for H2, CO, CO2 and the majority of the

hydrocarbon gases. The raw oil shale samples of various particle size ranges were

analyzed to determine the elemental composition and surface area to determine

their influence on the compositional changes in oil and gaseous yield with particle

size range.

H.B. Vuthaluru investigations into the thermal behavior during copyrolysis

of coal, biomass materials and coal/ biomass blends prepared at different ratios

(10:90, 20:80, 30:70 and 50:50) have been conducted using a thermo gravimetric

analysis (TGA) apparatus. Three thermal events were identified during the

pyrolysis. The first two were dominated by the biomass pyrolysis, while the third

was linked to the coal pyrolysis, which occurred at much higher temperatures. No

interactions were seen between the coal and biomass during copyrolysis. The

pyrolytic characteristics of the blends followed those of the parent fuels in an

additive manner.

29

3. MATERIALS AND METHODS

3.1 Materials

3.1.1 Feedstocks

Oil shale sample from the Göynük Himmetoğlu deposit and terebinth

berries were grind in 1 mm particle size according to ASTM D2013 and used in

experiments as received. The Göynük oil shale consists of more than 50%

liptinite, 20–50% huminite, and 0–20% inertinite maceral groups and is

characterized by its high organic content. The origin of the organic matter is

mainly algae and land plants and the kerogen of the Göynük Himmetoglu oil shale

was classified as type I. Some properties of GOS and TB are given in Table 3.1

and 3.2, respectively.

3.1.2 Chemicals

The used chemicals, methanol, n-hexane and dichloromethane, Karl Fischer

reagent, were purchased from Merck and used as received.

Table 3.1 Oil shale properties

Proximate Analysis; as GOS Moisture 7.8 volatile matter 34,5 fixed carbon 65,5 Ash 13,97

Ultimate Analysis; wt %, db C 54,86 H 6,61 N 1,59 S 3,12 O* 33,82

* calculated from difference

30

Table 3.2 Biomass properties

Type of Biomass TB

Proximate Analysis; as

Moisture 5.52 volatile matter 63.52 fixed carbon 36.48 Ash 4.33

Ultimate Analysis; wt %. db C 49.44 H 6.02 N 3.21 S 0.24 O* 41.09

Component Analysis; %wt. db Cellulose 14.41

Hemicelllulose 30.86

Lignin 40.2

Extractives 14.53

* calculated from difference

3.2 Methods

3.2.1 Pyrolysis

Pyrolysis experiments were carried out in vertical reactor. Pyrolysis reactor

was of a fixed bed design and of stainless steel with 6 cm diameter and 21 cm

high. In a typical run, 100 g of CWS or were placed into the reactor. The system

was heated to the desired pyrolysis temperature at a heating rate of 5 ºC min-1, and

hold at this temperature for 1 hour. The volatile products were swept by nitrogen

gas (25 mL min-1) from reactor to collection flasks cooled with ice where the

liquid products were condensed in the traps. Following the condensation distillate

(in first two traps), the non-condensable volatiles (gases) were vented to the

atmosphere. Experimental setup for pyrolysis is shown in Figure 3.1.

31

After pyrolysis, furnace was cooled to room temperature in a nitrogen gas

stream. All traps were weighted before and after each run. Total liquid amount

was determined by difference. The liquid and char yields were determined by

weighting. The amount of gas was determined by difference. The liquid product

consisted of two phases; water phase and oil phase. The aqueous phase in

condensate was separated from the organic phase (bio-oil) by funnel.

Figure 3.1 Fixed bed reactor

Figure 3.1 Fixed bed reactor

1 Internal thermocouple 2 Stainless steel reactor 3 High temperature oven 4 External thermocouple 5 Product outlet 6 Liquid products traps 7 Nitrogen entrance

32

3.2.2 Analysis

3.2.2.1 Component analysis of the biomass samples

The analytical methods for extractives, hemicellulose, lignin and cellulose -

results are given Table 3.2 are as follows.

i. Analysis of extractives

The dried biomass sample (G0, g) is leached with mixture of toluene/ethanol

(2:1 in volume) at a constant temperature for 3 h. After air-drying, the residue is

dried in an oven at 105–110 ºC to a constant weight. Then the residue is cooled to

room temperature in a desiccators and then weighted (G1, g). The extractive wt. %

is calculated as;

ii. Analysis of hemicellulose

Put the residue G1 from the extractive analysis above in a flask and then add

it into 150 ml NaOH solution (20 g/l). Boil the mixture for 3.5 h with recycled

distilled water. Filter and wash the residue till no more Na+, and dry it to a

constant weight. The residue is then cooled to room temperature in a desiccator

and weighted (G2, g). The hemicellulose wt. % is calculated as;

W2 (wt. %, d) = x 100 (G1–G2)

G0

W1 (wt. %, d) = x 100 (G0–G1)

G0

33

iii. Analysis of lignin

Put about 1 g of residue after extractives analysis as above into a weighed

flask and dry it to a constant weight. The sample is then cooled in a desiccator and

weighed (G3, g). Slowly pour 30 ml of sulphuric acid (72%) into the sample. Keep

the mixture at 8–15 ºC for 24 h. Then transfer it into a flask and dilute it with 300

ml of distilled water. Boil the sample for 1 h with recycled distilled water. After

cooling and filtration the residue is washed until there is no more sulfate ion in the

filtrate (detected by 10% barium chloride solution). The residue is then dried to a

constant weight, cooled to room temperature in a desiccator and weighted (G4, g).

The hemicellulose wt. % is calculated as;

iv. Analysis of cellulose;

The cellulose wt. % is calculated as;

W4 (wt. %, d) = 100-(W1+ W2 +W3)

3.2.2.2 Fixed carbon and volatile matter determination

Fixed carbon and volatile matter were determined in the 1 g product are

weighed on the sensible scale. Then it's placed into quartz crucible with cover

which was adjusted constant weight before. It is placed into pre-heated oven (850 0C) then kept for 3 min., then cooled down in the desiccator. After it's down to

room temperature, it was weighted.

W3 (wt. %, d) = x 100 G4(1–W1)

G3

34

Fixed carbon and volatile matter are calculated with the formulas below :

% Fixed Carbon =

100*12

Mmm −

% Volatile matter = 100 – ( % Fixed Carbon )

3.2.2.3 Determination of moisture

The samples were determined in terms of moisture, is placed in to

Sartorious Therma Control device ,which works infrared rays , as to be 1 g. The

moisture in the sample is then calculated as the percentage.

3.2.2.4 Elemental analysis

C, H, N, and S contents of biomass and oil shale, bio-oil, shale-oil and chars

were determined by using an elemental analyzer LECO CHNS 932 according to

ASTM D5291-96. Oxygen amount was calculated from difference.

3.2.2.5 FT-IR analysis

Fourier transform infrared (FTIR) spectra of pyrolysis oils were recorded

using a spectrophotometer (Spectrum 100, Perkin Elmer) in order to qualitatively

identify the chemical functionality of oils. Infrared spectra were recorded of the

samples placed between KBr plates.

3.2.2.6 1H NMR analysis

1H NMR Spectra of oils were recorded with a Varian AS-400 using CHCl3

solvent.

35

3.2.2.7 Water determination

Water contents of bio-oil and oil phase of shale were determined by Karl-

Fischer titration.

3.2.2.8 Gas product analyses

Pyrolysis gases collected in Tedlar bags were analyzed by gas

chromatography using a HP model 5890 series II with a thermal conductivity

detector and flame ionization detector. A stainless steel packed column(6.0 m ×

1/8 in. Propac Q, 2.0 m × 1/8 in. 5A molecular sieve, serially connected to each

other) was used. The separation of CO2, C1, C2, C3 and C4 gases was achieved by

the Propac Q column and the separation of H2, N2 and CO was carried out with

the MS 5A column.

3.2.2.9 Thermo gravimetric analysis

Thermo gravimetric analysis of samples was performed in a thermo

gravimetric analyzer (Perkin Elmer Diamond TG/DTA) under N2 atmosphere.

The flow rate of purge gas (pure N2, 99.99%) was kept at 200 mL min-1. The

sample was heated from the ambient temperature up to 900 °C with heating rates

of 10 °C min-1. Both the thermo gravimetric (TG) and differential thermo

gravimetric (DTG) data were used to differentiate the pyrolysis behavior of waste

samples at different conditions. In thermo gravimetric analysis, weight loss of

sludge samples was calculated according to the below equation.

Where mi is the initial mass (g), ma is actual mass (g) of sample.

Weight loss, wt. % = x 100 (mi –ma)

mi

36

4. RESULTS and DISCUSSIONS

4.1 Oil shale

4.1.1 Thermogravimetric Result

Thermogravimetric analysis of the Goynuk oil shale revealed that major

thermal decomposition occurred around 350–520 °C as shown in Figure 4.1 and

4.2. From pyrolytic differential thermogravimetric (DTG) curves, initial weight

loss corresponds to moisture removal, followed by a second degradation event

around 330–525 °C, where the evolution of light volatile compounds occurs from

the degradation of kerogen. This is consistent with other published findings

(Aboulkasa et al., 2008. ; Yagmur, S. et al., 2006.). At 520 °C the yield of

residue was about 45 % under these test conditions. TG-DTG results showed that

organic matter in oil shale and polymer was completely decomposed at the

temperature of below 600 °C.

0102030405060708090

100

0 200 400 600 800 1000 1200

Weight

Temperature C

Figure 4.1 TG curve of Oil Shale

37

‐4,5

‐4

‐3,5

‐3

‐2,5

‐2

‐1,5

‐1

‐0,5

0

0 200 400 600 800 1000 1200

Derivative Weight %

Temperature C

Figure 4.2 DTG curve of Oil Shale

4.1.2 Pyrolysis Results

Oil shale was pyrolyzed at three different temperature (500, 600 and 700

°C) in a fixed-bed reactor. The effect of temperature on pyrolysis yields are given

in Fig 4.3. As seen from fig 4.3 oil shale product distribution did not significantly

change as pyrolysis temperature between 500-700 ºC. There was a little increase

in gas and liquid products and decrease in char product yields as the temperature

raised from 500 to 700 ºC.

0102030405060708090100

500 600 700

Yields (w

t %)

Temperature C

Liquid

Char

Gas

Figure 4.3 Product yields (wt. %) from pyrolysis of Oil shale

38

Although pyrolysis temperature had no considerable effect on product

distribution, liquid composition was changed depending on the pyrolysis

temperature. As seen Figure 4.4 tar amount in liquid product considerable

decreased (from 87.6 wt% to 71.6 wt %) by increasing the temperature from 500

to 600 °C. This shows that tar products decomposed to water soluble compounds

and water. As seen Figure4.4, the highest yield of tar was obtained at the pyrolysis

temperature of 500 °C.

Figure 4.4 Composition of liquids obtained from pyrolysis of Oil shale

4.2 Biomass

4.2.1 Thermogravimetric Results

To understand the thermal conversion behavior of lignocellulosic biomasses

under the inert atmosphere, experiment was systematically carried out by means

of TGA.

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

500 600 700

Yields (w

t%)

Temprerature °C

Tar

Aqueous Phase

39

0102030405060708090

100

0 200 400 600 800 1000 1200

Weigh

t %

Temperature C

Figure 4.5 TG curve of Terebinth berry

‐6

‐5

‐4

‐3

‐2

‐1

0

0 200 400 600 800 1000 1200

Derivative Weight %

Temperature C

Figure 4.6 DTG curve of Terebinth berry

40

The weight loss (TG curve) and derivative weight loss (DTG curve) for

terebinth berry are exhibited in Figure 4.5 and 4.6, respectively.

Generally, the occurrence of three weight-loss steps has been reported in

literature on the pyrolysis of different lignocellulosic materials (Sentorun-Shalaby

et al., 2006). The first weight-loss step is associated with the decomposition of

hemicellulose, and the second with cellulose decomposition. On the other hand,

lignin degradation occurs over a broad temperature interval (300–480 °C or

higher). It would be mainly responsible for char formation of biomass.

The main decomposition of the biomass occurred in the temperature range

between 200 and 500 °C. The sharp peak at 290 °C is attributed to hemicellulose

and a second sharp peak at 360 °C is belonged to the cellulose. A clear DTG peak

of lignin is not observed since lignin decomposes between 200 to 500 °C. The

mass of residue was ~32 wt %. at the temperature of 500 °C.

4.2.2 Pyrolysis Results

0102030405060708090100

400 450 500 550 600

Yields (w

t%)

Temperature °C

Liquid

Char

Gas

Figure 4.7 Product yields (wt. %) from pyrolysis of biomass

Biomass was pyrolyzed at three different temperatures (400, 500 and 600

°C). As seen from figure 4.7 biomass product distribution did not significantly

41

change as pyrolysis temperature between 400-600 ºC. With increasing

temperature, there was a little increase in gas and decrease in char product yields

as temperature raised from 400 to 600 ºC. However, the liquid yield (about 49

wt%) was not changed with the temperature. Similarly, Cao et al who studied the

slow pyrolysis of waste corncob, observed a faster changing in products yields

between the temperatures 350 and 400 ºC and a slower changing between the

temperatures of 400 – 600 ºC whereas the yield of the liquid was nearly constant

(Cao Q. et al., 2004.). But, in many literatures related to slow pyrolysis of

lignocellulosic materials (Ates, F. et al, 2009.; Gonzalez, J.F.et al., 2005) oil yield

reached a maximum value at 500-550 ºC, and above these temperatures oil yields

decreased while gas yield increased. Meanwhile, the char yield continuously

decreased with increasing temperature. The differences in the results obtained

from present study and previous studies may be due to the difference in the

biomass species. The yields of char and gas were approximately 25-30 wt% and

20-25 wt% between the temperatures 400 and 600 °C.

Figure. 4.8 Composition of liquid obtained from pyrolysis of biomass

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

400 500 600

Yields (%

wt)

Temperature  °C

Oil Phase

Aqueous Phase

42

Although temperature had no effect on liquid yield, oil phase slightly

increase (from 43 wt% to 48 wt %) and aqueous phase decreased (from 56 wt% to

52 wt %) as temperature raised from 400 to 500 ºC. The increase in oil amount

may be due to the degradation of lignin in biomass at high temperature.

4.3 Copyrolysis of Oil shale and Terebinth berry

As known, pyrolysis yields depend on many parameters such as

temperature, partical size, heating rate and type of feedstock. Temperature plays a

major role in biomass pyrolysis. In this study, the copyrolysis of biomass and oil

shale was carried out at 500 0C. The copyrolysis temperature was selected

according to the result of TG analysis and the results obtained from pyrolysis of

each component alone. Table 4.1 shows the char, oil-tar, aqueous fraction and gas

yields from the copyrolysis of biomass/oil shale. For comparison purpose, the

product yield from pyrolysis of terebinth berry and oil shale alone were also

presented in the same table. It is seen that the experimental yields from the

copyrolysis are not different from the theoretical ones calculated based on the

yields from the pyrolysis of the individual components of the mixtures. This

confirmed that there were no synergistic effects between the oil shale and biomass

and they had undergone pyrolysis independent of each other. Moghtaderi et al.

(2004) and Vuthaluru (2004) observed similar phenomena during the study of

pyrolysis of blends of Radiata pine sawdust and Drayton coal and blends of wood

waste and Australian coal, respectively. With addition of biomass into oil shale,

there was an increase in liquid and decrease in char from pyrolysis of oil shale.

43

Table 4.1 Product distributions from the oil shale and copyrolysis of oil

shale and biomass

GOS:TB 1:0 3:1 1:1 1:3 0:1

Exp Teo Exp Teo Exp Teo

Gaseous* 25.10 20.71 24.70 24.74 24.28 26.84 23.87 23.46

Aqueous

phase

4.12 9.95 8.31 14.57 13.33 17.40 19.18 25.84

Oil-Tar 29.04 28.87 29.03 24.93 28.20 23.26 26.55 24.07

Char 41.74 40.47 37.96 35.76 34.18 32.5 30.40 26.63

*Calculated from mass balance

4.3.1 Composition of Oil phases

The oil derived from lignocellulosic materials has a large number of oxygen

containing reactive functional groups which are fragments of cellulose,

hemicellulose, and lignin polymers. Because of this, it does not exhibit thermal

stability and cannot be effectively fractionated by conventional techniques. It is

well known that oils consist of mainly water, carboxylic acids, carbohydrates and

lignin-derived substances. On the other hand, shale tar is complex mixtures

consisting of organic compounds from wide variety of chemical groups. To

characterize the tar / oil, oil phase from pyrolysis were separated into two

fractions; hexane soluble and hexane insoluble. In the case of tar from oil sale

pyrolysis, hexane solubles and hexane insolubles are called as oil and asphaltenes,

respectively. In the case of oil from biomass pyrolysis, hexane solubles are called

as extractives which mainly contain hydrocarbons. Hexane insolubles part of bio

oil consisted of low molecular weight lignin and high molecular weight lignin

compounds.

44

In this study, the pyrolysis oil and tar were firstly extracted with hexane

separated as hexane soluble and hexane insoluble. And hexane insolubles were

dissolved totally with CH2Cl2. This shows that the compounds derived from

biomass in hexane insoluble were low molecular weight lignin compounds. It

should be noted that the bio oil from terebinth berry consisted of mainly extractive

compounds. However, most bio oil contains extractives less than 30 %. In

copyrolysis experiments, no synergic effect observed in terms of oil and tar

composition. As expected, the amount of extractives decreased with the increasing

amount of terebinth berry in blend.

Table 4.2 Composition of tar and oil phases

Sample(GOS:TB) 1:0 3:1 1:1 1:3 0:1

Hexane Soluble 85.8 82.14 74.83 75.75 71.04

CH2Cl2Solubles 14.2 17.86 25.17 24.25 28.96

4.3.2 Fourier Transform Infrared Spectroscopy Results

Functional group compositional analysis was determined by FTIR

spectrometry, and results are shown in Figure 4.9. FTIR-spectra given in fig 4.9

emphasize rather similarity than specificity of the main functional groups in the

corresponding fractions of shale tar and bio-oil and their blends. The O-H

stretching vibrations between 3200 and 3400 cm-1 indicate the presence of

phenols and alcohols (H. Luik et al., 2007). The strong signals in the range of

2850–2920 cm-1, corresponding to aliphatic compounds, are present in all

samples. In addition, the infrared spectra of the tars and oils presents some bands

corresponding to CH2, CH3 bending (1375-1460 cm-1), alkenyl groups (C=C

stretching, 1606–1640 cm-1; –CH=CH– (trans) 960–970 cm-1; –CH=CH– (cis)

675–730 cm-1) and aromatic groups (–C=C– stretching, 1450–1464 cm-1). Except

1:1 copyrolysis spectra of tars shows the presence of CH2, CH3 bending (1260

cm-1) FTIR.

45

Figure 4.9 FTIR spectrums of pyrolysis oils and tar

46

4.3.3 H-NMR Results

The 1H NMR spectra of the bio-oil, shale tar and their blends and hydrogen

distributions are given in Table 4.3, respectively. Results of the 1H NMR analysis

show that the biomass mainly contain aliphatic protons at carbon atoms bonded to

other aliphatic carbon atoms. 1H NMR analysis for the tar also contains aliphatic

protons. Although aliphatic adjacent to oxygen is absence for oil shale and until

ratio of 1:3 copyrolysis oil, exist in ratio of 1:3 and only berry. 1H NMR results

show that oil and tar consisted of mainly paraffinic. The oils and tar obtained

from pyrolysis of oil shale and copyrolysis of some blends (3:1 and 1:1) contained

no aliphatic adjacent to oxygen. This may show that the oxygen compounds in

these oil and tar are mainly aromatic.

Table 4.3 Assignments of the bands in the 1H-NMR spectra of bio-oil and tar

samples

GOS:TB

Range

(ppm)

1:0 3:1 1:1 1:3 0:1

Aromatic 6.3-9.3 10 11 12 15 11

Alkene 4.5-6.3 7 7 3 5 5

Aliphatic

adjacent to

oxygen

3.3-4.5 - - - 5 4

Aliphatic

adjacent to

aromatic

alkene group

1.8-3.3 17 21 22 25 21

Other aliphatic

(bonded to

aliphatic only )

0.4-1.8 66 61 63 50 59

47

Figure 4.10 1H NMR spectra of pyrolysis oil and tar

48

4.3.4 Fuel characterization of oil and tar

Pyrolysis oils were brown in color with irritable odor. The main fuel

characteristics of oil and tar are given in Table 4.4. Water levels of oils are shown

irregularity. The oils from pyrolysis of individual feed stocks were contained less

amount water than that from copyrolysis. One cannot say any reason. The tars

obtained from oil shale have higher calorific value than the oils obtained from

biomass. In the case of copyrolysis oil and tar, the addition of biomass decreased

the calorie of oil obtained from oil shale. Moreover, all oils and tars can be used

as fuels for combustion systems in industry. But it is clear that they should be

upgraded to receive an improved oil composition for the direct utilization as a

transporting fuel.

Table 4.4 Some properties of Pyrolysis Oil and tar

GOS:TB 1:0 3:1 1:1 1:3 0:1

C 79.59 79.96 77.37 76.87 73.42

H 9.47 8.94 8.51 8.92 8.86

N 1.11 1.63 1.77 2.12 2.25

S 1.91 1.75 1.25 0.65 0.16

O* 7.92 7.72 11.10 11.44 15.31

H/C 0.12 0.11 0.11 0.11 0.12

Water, % 3.98 12.19 2.15 8.81 3.95

GCV, kcal kg−1

42.24 41.62 38.86 39.23 36.54

* calculated from difference

49

The properties of oil and tar are given in Table. Gross Calorific value was

calculated according to following equation (Friedl, 2005)

GCV (MJ kg-1) = (3.55 C2 - 232 C - 2230 H + 51.2 C * H + 131 N + 20600) * 10-3

As it can be seen in Table 4.4, oil and tar contain less amounts of oxygen

content than that of the original feed stocks. The significant decrease in oxygen

content of the oil and tar compared to the original feedstock is important, because

the high oxygen content is not attractive for the production of transport fuels. A

further comparison of H/C ratios with conventional fuels indicates that H/C ratios

of the oil and tar obtained in this study lie between those of light and heavy

petroleum products.

4.3.5 Composition of Aqueous Phase

Analysis of the aqueous phases showed that aqueous phases consisted of

mainly water (81-88 %). The other would be water soluble organic compounds

such as low molecular weight carbonyl compounds, phenols, alcohols, carboxylic

acids etc. To determine the amount of these compounds, aqueous phase was

extracted CH2Cl2. The amounts of CH2Cl2 solubles are given in Table 4.5. It is

seen that their amounts are not so much. But, most of CH2Cl2 soluble compounds

might be evaporated during CH2Cl2 evaporation.

Table 4.5 Composition of aqueous phase

GOS:TB 1:0 3:1 1:1 1:3 0:1

Water Content 83.33 89.35 88.34 88.08 81.36

CH2Cl2 Solubles 2.36 0.63 1.32 1.40 3.43

50

4.3.6 Fuel characteristic of chars

In principle, the char obtained from pyrolysis of materials can be used as

fuel, alone or mixed with other fuels. It can be also used as a cheap adsorbent. The

characteristic of chars obtained from pyrolysis of oil shale and biomass are mainly

depended on the composition of the biomass and oil shale. Some properties of

chars from biomass, oil shale and blend (1:1) are given in Table 4.6. GCV were

calculated according to following equation (Yanik et al, 2007).

H0 = 0,3491C + 1,1783H + 0,10005S - 0,1034O - 0,0151N - 0,0211ASH

As expected the char obtained from biomass is appropriate for household

briquette production due to the low sulphur and ash content. They can be also

burned in a steam boiler with an appropriate emission control. The GCV of char

from oil shale was increased while ash content decreased with the addition of

biomass. But, both chars from oil shale and blend contain still high sulphur

amount.

Table 4.6 Properties of chars

* calculated from difference

GOS:TB 1:0 1:1 0:1

C 57.81 58.08 77.2

H 2.60 2.42 2.68

N 1.96 2.24 2.58

S 1.99 1.07 0.04

O* 35.64 36.19 22.5

Ash 29 22.65 11.23

GCV, kcal kg−1 19.11 18.98 27.51

51

4.3.7 Composition of gas products

The compositions of gases obtained from pyrolysis of terebinth berry, oil

shale and their mixtures are given in Fig 4.11. The gases composed of mainly H2.

The content of CO2 is considerable also. The content of C1–C5 hydrocarbons,

amounting to 40% in shale-derived gas, was very low in bio-gas. By addition of

biomass to oil shale,CO2 and CO increased, while H2 decreased. Also there was

no difference in alkenes coming from oil shale and biomass gases.

Figure 4.11 Composition of gas products

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

01:00 03:01 01:01 01:03 00:01

H2COCO21‐penten2‐methyl‐2‐butenet‐2‐penten1,3‐butadienen‐pentanec‐2‐butenei‐Butylene1‐butenet‐2‐butenen‐butanei‐butanecyclopropanePropaneethyleneethanemethane

52

5. CONCLUSION

In this study, conversion of biomass and oil shale into the useful production were investigated. To predict thermal behavior of biomass and shale , thermal degradation both of them were investigated by TG/DTG. DTG curve for oil shale exhibits two weight-loss steps between 350-520 ºC. The shale, devolatilization took place a wide temperature range between 350-520 ºC with two sharp peaks. The maximum weight loss rate was observed at 520 °C. The mass of residue was ~45 wt %. In the case of biomass, DTG curve exhibited two weight loss steps between 200-500 °C; first step took place with a maximum weight loss rate at 290 ºC and second step at 360 ºC. The mass of residue was ~32 wt at 500 oC.

In the first experiments, pyrolysis of oil shale and terebinth berry were investigated by fixed bed reactor. Product distribution from pyrolysis of oil shale did not significantly change as increasing the pyrolysis temperature between 500-700 °C. There was a little increase in gas and liquid products and decrease in char product yields as temperature raised from 500 to 700 ºC . The oil yields were around 87 wt% over the range of pyrolysis temperatures. Similarly, temperature has no effect on product distribution from terebinth berry pyrolysis. Liquid yields were approximately 49 wt% in case of terebinth berry.

Copyrolysis experiments were carried out with different ratio of oil shale to biomass (1:3, 1:1, 3:1) at 500 ºC. The experimental yields from the copyrolysis are not different from the theoretical ones calculated based on the yields from the pyrolysis of the individual component of the mixtures. This confirmed that there were no synergistic effects between the oil shale and biomass and they had undergone pyrolysis independent of each other.

Functional group compositional analysis of oil/tar was determined by FTIR

and NMR spectrometry. Results of the 1H NMR analysis show that the biomass

mainly contain aliphatic protons at carbon atoms bonded to other aliphatic carbon

atoms. FTIR results also confirm that 1H NMR results.

The tars obtained from oil shale have higher calorific value than the oils

obtained from biomass. In the case of copyrolysis, the addition of biomass into oil

shale decreased the calorie of tar obtained from oil shale. Moreover, all tar/oil can

be used as fuels for combustion systems in industry. But it is clear that they

should be upgraded to receive an improved oil composition for the direct

utilization as a transporting fuel.

53

As expected the char obtained from biomass is appropriate for household briquette production due to the low sulphur and ash content. And copyrolysis of oil shale with biomass give the produce the char having better quality than pyrolysis of oil shale alone.

54

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Altun N. E., C. Hiçyilmaz , J. Y. Hwang , A. Suat Baci and M. V. Kök 2006, Oil Shales In The World And Turkey; Reserves, Current Situation And Future Prospects: A Review Oil Shale, , 23, 211–227 pp.

Arvo Ots, 2007, "Estonian oil shale properties and utilization in power plants" Energetika, 53(2), 8-18 pp.

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