Production of Transportation Fuels from Biomass at Pulp and Paper

Production of Transportation Fuels from Biomass at Pulp and Paper Mills - the Finnish Approach

Paterson McKeough and Esa KurkelaVTT, Finland

7th International Colloquium on Black Liquor Combustion and GasificationJyväskylä, Finland 31.7 - 2.8.2006

2

The Finnish Approach

Development and commercialisation of technology for producing multi-purpose synthesis gas (syngas) from solid biofuels:

– fluidised-bed gasification, applicable to a wide range of fuels:– woody biofuels, peat– straw and other agro-biomasses– waste-derived fuels

– novel catalytic gas reforming and conditioning

Envisaged commercial scale: 200 – 300 MWfeed; preferably integrated with energy-consuming paper mills

The long-term objective is no less than to develop superior bio-syngastechnology for export markets; e.g. a target cost of < 50 c/l has been set for Fischer-Tropsch diesel production based on this technology.

3

The Finnish Development Path

Current development stage led by VTT (Esa Kurkela): 0.5 MW process development unit (PDU) 2006 – 2007

Total budget ca. 4 MEUR, duration: 1.1.2004 – 31.3.2007

Current industrial consortium: Foster-Wheeler, Neste Oil, Andritz, Vapo, PVO, UPM, M-real, Metsä-Botnia, Stora-Enso

Demonstration of bio-syngas process planned for the period 2008 – 2010– size of demonstration plant: 20 – 50 MW feedstock input– operation of plant to be economically profitable: replacement of natural gas or

fuel oil– plant design studies already under way

The subsequent step: pre-commercial plant; 200 MW; commissioning 2013

4

Pressure control valve

0.5 MW Pressurized Fluidized Bed Gasifier (VTT PDU)

Fuel feedingequipment

Bedmaterial

Additive

FILTER

PFB GASIFIER

Gascooler

CATR

Bed removal

Ash removal

Heating elements Heating

elementsFurnace

Air

Nitrogen

Steam

Oxygen

To slip stream testing facilities

Biomass Gasification& Reforming

Gas Cleaning

GasConditioning

Synthesis/Separation Main

Product

HP Steam CO shift,CO2 removal

MPSteam

Off-gas

1 – 30 bar

850 °C

1 – 30 bar

40 - 280 °C (final)(IGCC: 500 °C)

30 bar

40 - 350 °C(initial)

FT, SNG, H2: 20 – 30 barCH3OH, DME: 100 bar

FT, CH3OH, DME, SNG, H2/trad:200 – 300 °CH2/PSA: 40 °C

Abbreviations: CC Combined-Cycle energy productionFCCC Fuel-Cell Combined-Cycle energy productionFT Fischer-Tropsch liquid fuelsSNG Synthetic Natural Gas (CH4)CH3OH MethanolDME Di-Methyl EtherH2/trad Traditional process for H2 production from syngasH2/PSA H2 production based on separation by Pressure Swing Absorption

General Layout of Processes for Bio-Syngas Production and Conversion

LPSteamLP Steam

Drying

Heat CC, FCCCApplications

6

Modelling of Bio-Syngas ConversionApplications Examined and their Abbreviations

FT: Fischer-Tropsch primary liquids (C5+); once-through

FT/R: Fischer-Tropsch primary liquids (C5+); with reforming loop

CH3OH: Methanol; high-conversion gas-phase synthesis

SNG: Synthetic natural gas; mainly CH4; H2 (e.g. 2 vol. %)and inerts (e.g. 1 vol. %) also present; delivered at 30 bar

H2/trad: Hydrogen via traditional method; CH4 (e.g. 2 vol. %) andinerts (e.g. 1 vol. %) also present; delivered at 30 bar

H2/PSA: Hydrogen via separation by Pressure Swing Adsorption;high-purity; delivered at 30 bar

7

Biomass Gasification,Reforming &Gas Cleaning

Proportionof CO + H2

MainProductConversion

of CO + H2

Synthesis(+ Shift)

ColdGas

CO + H2

ConvertedCO + H2

SynthesisProducts Selectivity to

Main Product

HP Steam LP Steam

CH4 UnconvertedCO + H2

Exotherm LightHCs

Gasificationefficiency, G %

(Cold-gas LHV basis)

(CO + H2)in cold gas,

P % of gas LHV

(CO + H2)conversion

C %

Chemical energyuptake, U %(LHV basis)

SelectivityS %

Electricity

Off-gas

Modelling of Bio-Syngas Conversion

Boundary of syngas-conversion model

8

85959895H2/PSA

1009510095H2/trad1007810095SNG100839595CH3OH

89808095FT/R

91808095FT

SelectivityS, %

Energyuptake

(LHV basis)U %

(CO + H2)conversion

C, %

(CO + H2)proportion

(LHV basis)P, %

Modelling of Bio-Syngas ConversionSummary of Model Inputs for Base Cases

9

Modelling of Bio-Syngas ConversionEstimated Production Efficiencies of Base Cases

Feedstock drying from 50 % to 15 % moisture using by-product steam

Efficiency = (product LHV-flow / feedstock LHV-flow) x 100; electricity input ignored

0102030405060708090

100

FT FT/R CH3OH SNG H2/trad H2/PSA

LHV

-Effi

cien

cy fo

r Mai

n P

rodu

ct, %

10

Modelling of Bio-Syngas ConversionEfficiencies to Main Product and Net High-Grade Energy (Base Cases)

Electricity inputs ignored. High-grade energy products: fuel gas, steam (4 bar and higher)

010

20304050607080

90100


Ove

rall

LHV-

Effic

ienc

y, %

11

Modelling of Bio-Syngas ConversionRationale for Application of Model to Cost Comparisons

Investment costs are dominated by those of the front-end section, comprising pre-treatment, O2 plant, gasification, gas reforming, gas cooling and initial gas cleaning. The total investment costs for the alternative syngas production and conversion plants would differ from each other by less than 20 %, which means a maximum effect of ± 10 % on the production costs.

In fact, to reduce this inaccuracy in the present analysis, differences in the syngas-conversion sections were taken into account when assigning investment costs to the different cases.

The following estimates of the total investment costs of 300 MWfeed plants, employing mature technology, were derived:

FT: 210 MEURFT/R: 235 MEURCH3OH: 220 MEURSNG: 210 MEURH2/trad: 195 MEURH2/PSA: 195 MEUR

12

Capacity of plant: 300 MW of feedstock (LHV basis)Annual operating time: 8000 h/aInterest on capital: 10 % for 20a O&M costs: 4 % of investment Base values for purchased/sold energy (other values applied in sensitivity cases):

– feedstock: 10 EUR/MWh (LHV)– electricity: 30 EUR/MWhe

– HP steam: 16 EUR/MWh of transferred heat– MP and LP steam: 13 EUR/MWh of transferred heat– fuel gas: 14 EUR/MWh (LHV)

Modelling of Bio-Syngas ConversionImportant Bases of the Cost Estimates

13

0

10

20

30

40

50

60

70

80


Prod

uctio

n co

sts,

EU

R/M

Wh

Feed 0 EUR/MWh

Feed 5 EUR/MWh

Feed 10 EUR/MWh

Feed 15 EUR/MWh

Feed 20 EUR/MWh

Modelling of Bio-Syngas ConversionComparison of Costs; Effect of Feedstock Price

Level of excise tax on diesel and gasoline

Current Finnish price level of diesel and gasoline (excluding taxes and distribution)

Cost of final upgrading of FT primary liquids: about 4 EUR/MWh.

For diesel fuel, 1 EUR/MWh ~ 1 c/l.

14

Modelling of Bio-Syngas Conversion; Example of Sensitivity StudyEffect of Unreformed CH4; Feedstock Price 10 EUR/MWh

0

10

20

30

40

50

60


Prod

uctio

n C

osts

, EU

R/M

Wh

Base (1 vol% CH4)

2 vol% CH4

15

By-Product Energy of Synthesis-Gas Conversion Processes

Processes for producing and converting synthesis gas yield significant by-product energy in the form of steam and off-gas.

This is illustrated by examples in following slides. A plant producing Fischer-Tropsch (FT) liquids yields significantly more by-product energy than a methanol plant.

A large amount of by-product energy means that significant synergy -and so lower costs - can be derived by integrating these processes with pulp and paper manufacturing.

A feature of the Fischer-Tropsch process is that the ratio of liquid product to gas product can be varied by altering the degree of recycle of off-gas to the gas-reforming step (two different cases shown in the following slides). This allows significant flexibility when integrating a FT plant with a paper mill.


Gas Cleaning

GasConditioning


Product

HP Steam

CC, FCCCApplications

CO shift,CO2 removal

MP Steam

Off-gas

LP SteamLP Steam

1 – 30 bar

850 °C

1 – 30 bar

40 - 280 °C (final)(IGCC: 500 °C)

30 bar





Drying

Heat

Fischer-Tropsch Liquids Example / Once-Through

LP Steam

260 MW

38 MW

44 MW8 MW

30 MW

67 MW

126 MW

7 MW

Electricity consumption: 21 MWe

8 MW

MP Steam 8 MW



Gas Cleaning

GasConditioning


Product

HP Steam

CC, FCCCApplications

CO shift,CO2 removal

MP Steam

Off-gas

LP Steam

1 – 30 bar

850 °C

1 – 30 bar

40 - 280 °C (final)(IGCC: 500 °C)

30 bar





LP Steam

Drying

Heat

Fischer-Tropsch Liquids Example / Reforming Loop

LP Steam

260 MW

38 MW

39 MW

9 MW

161 MW

9 MW

Electricity consumption: 25 MWe

10 MW52 MW10 MW

Reforming Loop

MP Steam 14 MW


18

Levels of Integration

Co-Production of Syngas Derivatives at Pulp and Paper Mills

Several different levels of integration are possible:

utilisation of mill secondary/waste heat for feed-stock drying

utilisation of the off-gas of the conversion process in the mill. This is particularly beneficial when fossil fuel is replaced in lime kilns, paper dryers, etc.

integration of the steam system of the conversion process with that of the paper mill. To gain the full integration benefit, this would be carried out in conjunction with a rebuild of the mill power boiler(s).

19

Example of Mill Energy Balances Before and After the Integration of a Plant Producing Fischer-Tropsch (FT) Liquids

The next three slides (BEFORE, AFTER, NET CHANGES) show how the incremental energy balance is arrived at for one particular example of integration of an FT plant with a paper mill.

The NET CHANGES do not depend on the size of the original power-boiler process provided that the capacity of this process exceeds a certain minimum value. The minimum value corresponds to about half of the feedstock input to the FT plant. For example, if the latter is 260 MW, as in the following example, the minimum value for the fuel input to the original power-boiler process is about 130 MW.

If the fuel input to the original power-boiler process is less than this minimum value, the benefit of integration will be somewhat smaller than that in the following example.

20

BEFORE INTRODUCTION OF FT PLANTPower-Boiler Energy flows (LHV basis)

Bark, etc

Black liquor

Purchased biofuel

P&P products

151 MW

Wood for fibre,purchased fibre


Powerboiler

Electricity

Primary heat100 MW

31 MWe

21

Bark, etc

Black liquorP&P products

Purchased electricity FT primary liquids 161 MW

25 MW


25 MWe

Powerboiler

FT plant

Purchased biofuel 260 MW

Electricity

Primary heat100 MW

21 MWe

285 MW


AFTER INTRODUCTION OF FT PLANT (260 MWfeed)Integration of steam system in conjunction with power boiler rebuild

Secondary heat used for biomass dryingEnergy flows (LHV basis)

22

Bark, etc

Black liquor

Purchased biofuel

P&P products

Purchased electricityFT primary liquids

+ 161 MW

+ 134 MW*


IntegratedPulp and Paper Mill

orStand-AlonePaper Mill

+ 35 MWe**

* 134 MW = (285 – 151) MW

** 35 MW = (31 – 21 + 25) MW


NET CHANGES WITH INTRODUCTION OF FT PLANT (260 MWfeed)Integration of steam system in conjunction with power boiler rebuild

Secondary heat used for biomass dryingIncremental energy flows (LHV basis)

Nominal overall efficiency = 100 x 161/(134 + 35/0.4) = 73 %(purchased electricity generated from biomass at 40 % η)

23

Bark, etc

Black liquor

Purchased biofuel

P&P products


+ 126 MW

+ 114 MW




+ 13 MWe


FT ALTERNATIVE WITH LOWER ELECTRICITY INPUTPower boiler replaced by combined-cycle plant fired by FT off-gas

Secondary heat used for biomass dryingIncremental energy flows (LHV basis)

Nominal overall efficiency = 100 x 126/(114 + 13/0.4) = 86 %(purchased electricity generated from biomass at 40 % η)

24

Bark, etc

Black liquor

Purchased biofuel

P&P products


+ 134 MW




+ 35 MWe

600 000 t/a

161 MW105 000 t/a

Potential Profitability of FT-Liquids Co-Production at Paper Mill Paper production 600 000 t/a; FT-liquids production 105 000 t/a

Economic performance of paper-production process:- Income: 360 MEUR/a (product value 600 EUR/t)- Operating profit (@ 12.5 % of income): 45 MEUR/a- Internal interest rate for greenfield plant (700 MEUR): 10 %

Economic performance of FT plant:- Income: 79 MEUR/a (product value 750 EUR/t, 60 EUR/MWh*)- Operating profit: 45 MEUR/a (purchased biofuel @ 12 EUR/MWh)- Internal interest rate (incremental investment 220 MEUR): 27 %

* expected value once biofuel addition to automotive fuel is made obligatory in Finland

Profit from co-production of FT liquids could be of similar magnitude to that from paper production.

25

Biomass-fired process(VTT concept)

Black-liquor-fired process (Chemrec)

Standard recovery-boiler as reference*

Advanced recoveryboiler as reference**

Primaryheat used

forbiomassdrying

Secondaryheat used

forbiomassdrying

Integratedpulp andpaper mill

Stand-alone

pulp mill

Integratedpulp andpaper mill

Stand-alone

pulp millη =63 %

η =70 %

η =62 %

η =66 %

η =58 %

η =60 %

Estimated Efficiencies of Methanol Production from Biomass or Black Liquor at Pulp and Paper Mills

Definition of overall efficiency:

* live-steam values: 80 bar, 480 °C** 20 % increase in electricity output compared to standard recovery boiler

η = Methanol LHV-flow out

(Incremental biomass LHV-flow in) + (Incremental electricity in)/0.4x 100 %

Note: a limitation for the biomass-fired technology is that it cannot be effectively integrated with a stand-alone market pulp mill.

26

Estimated Costs of Methanol Production from Biomass or Black Liquor at a Large Integrated Pulp and Paper Mill

0

10

20

3040

50

60

70

80

5 10 15 20Biomass Fuel Price, EUR/MWh

Met

hano

l Pro

duct

ion

Cos

ts,

EUR

/MW

hFrom black liquor(415 MW); adv.RB as ref.

From biomass(260 MW);primary heat fordryingFrom biomass(260 MW);secondary heatfor drying

Level of excise tax on diesel and gasoline

Current Finnish price level of diesel and gasoline (excluding taxes and distribution)

Note: methanol production from black liquor would typically be somewhat more economic at a stand-alone market pulp mill having the same black-liquor flow as the above case.

27

According to the present estimates, syngas derivatives could be co-produced somewhat more economically from black liquor than from solid biomass residues at integrated pulp and paper mills.

The estimated ratio of incremental investment to co-product output is almost 50 % higher for thebiomass-fired plant than for the black-liquor-fired plant. The economic advantages of the black-liquor-fired plant derive mainly from the following:

– Compared to the boiler reference case, no additional pre-treatment is necessary for black liquor, whereas drying is required for biomass residues.

– Feeding of black liquor to the pressurised gasifier is much simpler.– No separate gas-reforming step is required for the black-liquor plant (Chemrec entrained-flow

gasifier).– The black-liquor plant has a (small) scale advantage (415 MWfuel vs. 260 MWfuel).

Production of syngas derivatives from black liquor at a stand-alone market pulp mill would typically be somewhat more economic than at an integrated pulp and paper mill (same black-liquor flow).

On the other hand, biomass-fired technology has– a greater market potential (= a greater number of potential pulp and paper mill sites, wide

range of potential feedstocks + stand-alone conversion plants in the longer term)– less interaction with the pulp-mill chemical-recovery cycle (= smaller availability risk)– considerably less technical uncertainty attached to it at the present time.

Estimated Costs of Producing Syngas Derivatives fromBiomass or Black Liquor at Pulp and Paper Mills

28

The Finnish Development Path

Current development stage led by VTT (Esa Kurkela): 500 kW process development unit 2006 – 2007

Total budget ca. 4 MEUR, duration: 1.1.2004 – 31.3.2007

Current industrial consortium: Foster-Wheeler, Neste Oil, Andritz, Vapo, PVO, UPM, M-real, Metsä-Botnia, Stora-Enso

Demonstration of bio-syngas process planned for the period 2008 – 2010– size of demonstration plant: 20 – 50 MW feedstock input– operation of plant to be economically profitable: replacement of natural gas or

fuel oil– plant design studies already under way

The subsequent step: pre-commercial plant; 200 MW; commissioning 2013

Acknowledgement of funding sources: the National Technology Agency of Finland (Tekes), VTT and the companies of the consortium (above)

Documents

Production of Transportation Fuels from Biomass at Pulp and Paper