View
227
Download
1
Category
Preview:
Citation preview
Biorefineries based onlignocellulosics part 2. Analysis
CARLOS ARIEL CARDONA ALZATE M.S c PhD.
RESEARCH GROUP ON CHEMICAL , CATALYTIC AND B IOTECHNOLOGICAL PROCESSES
UNIVERS IDAD NACIONAL DE COLOMBIA SEDE MANIZALES
Outline 1
1. Types of Biorefineries and added value. Examples
2. Design of Biorefineries: Conceptual Synthesis
3. Energy analysis.
4 Technoeconomic analysis
5. Environmental assessments and Social analysis
6. Influence of the scale
Outline 2➢ Biorefinery concept
➢Types of biorefinery
➢Suitable feedstocks for a biorefinery
▪ Feedstocks classification
▪ Food Security
➢ Technologies in a biorefinery
▪ Technologies
▪ Hierarchization, sequencing and integration
▪ Green Biorefinery
▪ Biorefineries specification form
Feedstock separation in more treatable fractions
(Platforms)
Each platform → ProductLine
Different technologies allowthe conversion of biomass
into:• Commodities (Biofuels,
electricity, etc)• Specialties (Chemical
building blocks)
These combinations create a complex system able to exchange material (waste streams, platforms and products) and energy streams to supply their requirements and achieve self-sufficiency
General Biorefinery
Scheme
5
Combustion Gasification Pyrolysis Digestion Fermentation
Thermochemical Biochemical
Pretreatment
Biomass sources
Steam Syngas Oil/Charcoal Biogas Distillation
BIOFUELSELECTRICITYHEAT
Figura 5. Tipos de gasificadores
Figura 4. Tecnologías para la
conversión de biomasa
6
Figura 6. thermochemical processes
Figura 7. Products from gas
fermentation
Types of Biorefineries
Type I - Dry-milling bioethanol plantsusing wheat or corn
Type II - wet-milling plantusing corn and various processes with the capability to adapt multiple productions
Type III – These biorefineries are under extensive research and development
FOR THE SAME SYSTEMS :ENERGY DRIVEN OR PRODUCT DRIVEN
Energy driven or product driven
Energy driven most. Based mainly on biofuels and bioenergy production
Product driven …. Few. Based on products without priority in energy production
Energy driven usually low added value
Product driven usually higher added value
Biorefinery Feedstock
Biomass
Plant Location
PotentialAvailability
Starting point for planning and design of a biorefinery
Process Scale
BiomassNature
Platforms and Products
Processes
Biomass
“Any organic matter that is available on a renewable or recurring basis, including dedicated
energy crops and trees, agricultural residues, algae and aquatic plants, wood and wood residues,
animal wastes, wastes from food and feed processing and other waste materials usable for the
production of energy, fuels, chemicals, materials.”
CarbonNeutral
Capture CO2 fromthe atmosphere in the photosynthesis
Biorefinery is an effective way to alleviate climate change
Elemental analysis
Correlaciones teórico –experimentales
FC = Fixed carbonVM = volatile mat.
ASH = Cenizas
Easy method with good accuracy
Shen, J., Zhu, S., Liu, X., Zhang, H., Tan, J., 2010. Theprediction of elemental composition of biomass based onproximate analysis. Energy Convers. Manag. 51, 983–987.
Heating valueHigh (HHV) Low (LHV)
25°C, includes enthalpy of vaporization 150°C, no enthalpy of vaporization is considered.
𝐿𝐻𝑉 = 𝐻𝐻𝑉 − ℎ𝑓𝑔𝐹𝑎𝑔𝑢𝑎
𝐹𝐵𝑖𝑜𝑚𝑎𝑠𝑎
ℎ𝑓𝑔 = Enthalpy of vaporization𝐹𝑎𝑔𝑢𝑎
𝐹𝐵𝑖𝑜𝑚𝑎𝑠𝑎= water content
Experimental o teórico
High heating value (HHV)
Experimental
- proximal analysis
- Elemental analysis𝐻𝐻𝑉 = 0.335𝐶 + 1.423𝐻 − 0.154𝑂 − 0.145𝑁
- composition𝐻𝐻𝑉 = 0.1739 ∗ 𝐶𝑒𝑙𝑙𝑢𝑙𝑜𝑠𝑒 + 0.2663 ∗ 𝐿𝑖𝑔𝑛𝑖𝑛 + 0.3219 ∗ 𝐸𝑥𝑡𝑟𝑎𝑐𝑡𝑖𝑣𝑒𝑠
Theoretical
Heat pump
best correlation
Food Security Current Status
Food Crops = Corn, Wheat, Sugarcane
and oil seeds
Bioethanol and Biodiesel
¿Should be usedfood and feed for
biofuels?
Social ImpactEconomic
Impact
EnvironmentalImpact
Lignocellulosic residues as an alternativeEnsure Food
Security
Lignocelulosic biomass as a promising alternative
AdvantageDrawback
Technological barriersto break down theircomplex structure
• Cheap• No need additional
land for production
Pathways underdevelopment to reduce the
environmental footprint
Processes and Platforms
Fractionation and upgrading allows
an efficient use of biomass
feedstock and generation of value-
added products through
valorization.
Conversion Platforms
Biorefinery Products
Defining the product portfolio will depend
on their potential to generate revenues and
potential for avoided emission by replacing
similar functionality fossil-derived products.
Energy Carriers (biofuels, heat and electricity)
Materials for differentindustries (chemicals, foodingredientes, polymers, etc)
Design Strategies of a Biorefinery
Hierarchization
IntegrationSequencing
FeedstockProducts
Technologies
Technologies Hierarchy
Utilities
HeatExchangerNetwork
Separationand Recycling
Reaction
The hierarchy decompositionlevel is based on the processwhich has the highestimplication of the entirefacility.
Sequencing in a BiorefineryThe term sequence is used to establish a logical order to relate technologies and products. Last also considers the hierarchy definition described above. This leads to involve certain restrictions in the order and production lines.
Mechanical Sugar Extraction
Sugar for human consumption
Bioethanol Production
Non-convertedsugars
Ensure FoodSecurity
Integration in a Biorefinery
Integration makes reference to the maximum use of resources withinthe same plant. Integration can be performed between raw materials, technologies and even products.
The integration levels enhance the overallperformance of the entire biorefinery.
Integration in a Biorefinery
Green BiorefineriesPrinciples
Integrated technologies should have priority over separated technologies.
Feedstocks from Natural Sources, looking for first, second and third generation integration.
Reduce wastes, integrating products with feedstocks in multiprocessing biorefineries.
Preserve Ecosystems and biodiversity
Innovative Engineering Solutions
Social Impact and evaluation is essential
Adopt the term of Life Cycle.
Reduce as possible energy consumption and byproducts with low added value.
Use tools and strategies of analysis and evaluation for environmental, technical and economic impact.
Supply chain and logistics should be an essential part of a green biorefinery
Biorefinery Performance
Indicator Definition
Energy Conversion efficiencyRatio between net energy output (as valuable products, includingelectricity, steam, fuels and other streams contributing to energygeneration) to energy input (e.g., total biomass calorific value).
Land UseAmount of land used per unit biomass feedstock production.
Lignocellulosic feedstocks are chosen to reduce land use.
Water Use Amount of freshwater depletion, beyond recovery.
Greenhouse gases Gases causing greenhouse effect, i.e., with global warming potential.
Economic Margin Revenue potential of a biorefinery.
Methodology for Biorefineries design
1. Feedstock Selection
2. Products Selection
3. Potential Product Scenarios
4. Mass and Energy Integration
5. Generation of the superstructure
6. Techno-economic, energetic, environmental and social assessment
Feedstock Selection
Raw Material
FeedstockClassification
First Generation
Food Security?FeedstockAvailabilitySecond Generation
Thrid Generation
Decision Criteria
Feedstock Characteristics
Chemical Composition Heating Value
Proximate and Ultimate Analysis Density and Particle Size
Moisture Content Digestibility Parameters
Ash Content
Products
Based on the products and thehierarchical of the feedstock
Selection of the posible productsbased on the characteristics of
the feedstock
Potential Product Scenarios
Biorefinery Process• Mechanical/physical
• Biochemical• Chemical
• Termochemical
Which processes are required to convert feedstock in the selected
products?Hierarchization
Sequence of the Biorefineryscenarios
Biorefinery Schemes
IntegrationMass and Energy Integration
of process streams
Solid Residues for cogenerationPinch methodology for energy
integrationWastewater Treatment
SuperstructureGeneration
Techno-economic, environmentaland social evaluation
Optimization
Techno-economic Assessment
Economic Performance of thebiorefinery
Net Present Value (NPV)
Production Costs vs Maket Price
Economic assessment
Tasa de impuesto/Tax rate. Es el porcentaje de las ganancias pagado como impuesto, o el porcentaje del valor de un bien, servicio o activo pagado como impuesto. Para el contexto Colombiano es del 25%.
Tasa de interés anual/Interest rate. Conocida también como Tasa de Interés, Tasa de Interés Efectiva Anual, Tasa Efectiva Anual, es un monto de dinero que se cobra sobre una deuda prestada. Para el contexto Colombiano es del 17%.
Servicios o utilities. Conocida también como Fluidos de servicio, son fluidos ya sea de enfriamiento (Ej. Refrigerantes, agua, etilenglicol, etc.) o calentamiento (Ej. Vapor de alta, media o baja presión, aceites, etc.) que se usan en intercambiadores de calor, reactores enchaquetados, etc.
Periodo. Es el tiempo de operación de una planta y en Aspen Plus está definido como 8000 horas. Costo total (USD/periodo). Es la suma de Raw material costs, Utilities cost, Operating labor cost, Maintenance cost, Operating cost, Plant overhead, General and administrative cost y Depreciation.
Economic assessmentDepreciación (USD/periodo). Se refiere a una disminución periódica del valor de un bien material o inmaterial, en estecaso está asociado a la disminución del valor de los equipos considerados en el proceso.
Producción total (Kg/periodo). Es el flujo másico, molar o volumétrico del producto(s) principal(es) en el periodo deoperación. El flujo por corrida (kg/h) debe ser multiplicado por el periodo (8000h/periodo) para obtener el flujo total(kg/periodo).
Costo de producción (USD/kg). Es definido como la relación entre el Costo total y la Producción total.
Precio de venta (USD/kg). Es el valor monetario que se le asigna a un producto en el mercado.
Margen de ganancia (%). Indica la rentabilidad de un producto, servicio o negocio. Mientras más alto sea el número,más rentable es el negocio. En fórmula es: ((Precio de venta-costo de producción)/precio de venta)*100.
Valor Presente Neto (VPN). Es el método más conocido a la hora de evaluar proyectos de inversión a largo plazo. ElValor Presente Neto permite determinar si una inversión cumple con el objetivo básico financiero: MAXIMIZAR lainversión en un periodo de tiempo.
Tasa Interna de Retorno (TIR). Es aquella Tasa de Descuento que al utilizarla para actualizar los flujos Futuros deIngresos netos de un proyecto de Inversión, hace que su VPN sea igual a cero. Es decir, la Tasa Interna de Retorno (TIR)es una medida de la Rentabilidad de una inversión, mostrando cuál sería la tasa de Interés más alta a la que el proyectono genera ni pérdidas ni Ganancias
Process Scale
The optimum size of a biorefinery involves tradeoffs
between economies of scale with larger plants and
increased costs of feedstock transportation.
A critical component of economic profitability of biorefinery
processes is a secure and reliable feedstock supply system.
Ample feedstock should be available to biorefineries at the
appropriate time and at competitive prices, while assuring
reasonable, steady profits to the biomass suppliers.
Environmental Assessment
Environmental impactindicators
Human toxicity by ingestion (HTPI), human
toxicity by dermal exposition or inhalation
(HTPE), aquatic toxicity potential (ATP), Global
warming (GWP), Ozone depletion potential
(ODP), Photochemical oxidation potential (PCOP)
and acidification Potential (AP).
Required data for the biorefinery design
Content
Introduction
Feedstock
Mechanical pretreatment
Chemical pretreatment
Fermentation
Anaerobic digestion
Thermochemical methods
Purification step (Downstream processes)
Economic analysis
INTRODUCTION
The different researches being conducted worldwide provide a wealth ofinformation that can be used in conceptual processes design to obtain avariety of value-added products. Therefore, the use of different softwarehas become so important.
Through biorefinery concept, a full use of one or more raw materials isperformed. According to the American National Renewable EnergyLaboratory (NREL) “A biorefinery is a facility that integrates biomassconversion processes and equipment to produce fuels, power, andchemicals from biomass”
The use of different software is the most powerful tool that a designerhave to evaluate from technical, economical and environmental point ofview a new unit operation or even a new production process.
FEEDSTOCK
Exist a great variety of raw materials that can be used in a biochemicalprocess, however, any material must be characterized to know itscomposition and principal attributes. For that reason, aphysicochemical, ultimate and proximate analysis must beperformed.
The principal characteristics of a lignocellulosic biomass are:
✓ Cellulose, Hemicellulose, Lignin
✓ Extractives
✓ Ash content
✓ Elemental composition
✓ Heating value
FEEDSTOCK
The following tables show some parameters that must be taken into account to evaluate the best route of processing.
Specifications of main raw material
Item Value Unit
Flow (mass, volume, molar)
Cellulose
Hemicelluose
Lignin
Extractives
Moisture
Other components
Temperature
Pressure
Physico-chemical characterization of the raw
material
Item Value Unit
Total Solids
Moisture
Volatile Solids
Ash
Particle Size
Lipids (optional)
Proteins (optional)
Elemental analysis of raw material
Item Value Unit
C % w/w
H % w/w
O % w/w
N % w/w
S % w/w
Energetic information of raw material
Higher heating value (HHV) kcal/kg
Lower heating value (LHV) kcal/kg
MECHANICAL PRETREATMENT
Generally, the feedstock in a biorefinery is a solid waste that comes fromagroindustry sector and its size cannot be appropriated to subsequentsteps in the process, for this reason a mechanical pretreatment usually isemployed.
This pretreatment consist in a particle size reduction of the raw material using a crusher. Some crusher that can be modeled in process design software are:
Figure 1. Ball and impact mill
MECHANICAL PRETREATMENT
The tables present the required information for the mechanical treatment simulation
Crusher specification
Item Value Unit
Crusher type
Input particle diameter
Output particle diameter
Ratio of cut-off size to solids outlet diameter
Bond work index (J/kg, kJ/kg, kWhr/ton)
Particle Size Distribution (PSD)
Type of sieve (e.g Tyler, ASTM, etc.)
Sieve No. Mesh width (i.e inch,
milimeters)
Weigth
of sieve
Weigth of
solids
Ratio of the solids in each
sieve to total solids
Ratio of the
accumulated
solids to total
solids
1
2
3
n
n+1
Collector
CHEMICAL PRETREATMENT
In this step of the process the raw material is submitted to different types ofreaction that search increase the accessibility of microorganism in the nextstep (i.e fermentation) also this increase on the accessibility is evidencedthrough of amount of disposal substrate to fermentation (e.g sugars). Thesereactions and its objective are:
Acid/Alkaline reaction
Acid pretreatment is used to remove hemicellulose content in lignocellulosicmaterials, hydrolyzate the cellulose to increase the fermentable sugars anddecrease the crystallinity of the raw material.
Alkaline pretreatment is used to remove the lignin content in the raw materialto facility the next hydrolysis step. For these reactions are necessaryspecify: reactor type, temperature, pressure, amount of chemical (i.eacid or base) used, pH, agitation speed, etc.
CHEMICAL PRETREATMENT
Detoxification reaction
This reaction has as objective eliminate all components that could be inhibitory in the fermentation step;
generally, detoxification is performed by precipitation reaction. The information necessary to specify in
this procedure are: temperature, pressure, pH, agitation speed, precipitation agent, etc
Enzymatic reaction
This reaction has as objective break different polymers that are present in the raw material (e.g cellulose,
pectin, etc) to produce free monomers that can be assimilated by the microorganisms, in this
pretreatment is necessary specify the next conditions: pH, temperature, agitation speed, residence time,
charge of enzyme, type of enzyme, enzymatic activity, etc.
CHEMICAL PRETREATMENT
The following table present the input information to perform anacid/alkaline pretreatment:
Specifications of acid/basic hydrolysis
Item Value Unit
Reactor type
Temperature
Pressure
Valid phases
Basic or Acid Hydrolysis?
Reagent Sulfuric Acid, NaOH,…
Composition %wt
Solid to Liquid Ratio %
Amount of Acid or Basic g, kg, …
CHEMICAL PRETREATMENT
The following table present the input information to perform an enzymaticpretreatment:
Specifications of enzymatic hydrolysis
Item Value Unit
Reactor type
Temperature
Pressure
pH
Agitation (type)
Rpm rpm
Energy Consumption W, kW
Enzyme 1
Enzyme 2
Enzyme n
Activity Enzyme 1
Activity Enzyme 2
Activity Enzyme n
Solid to Liquid Ratio %
Do you use a
buffer solution?YES NO
Buffer Solution Citrate Buffer, …
CHEMICAL PRETREATMENTThe following table present the input information to perform andetoxification process:
Specifications of detoxification reaction
Item Value Units
Temperature
Pressure
pH
Agitation (Type)
Revolutions rpm
Energy Consumption W, kW, …
Detoxification Reagent Calcium hydroxyde, …
Amount g, mg, kg, ---
Solid to Liquid Ratio %
Feed Stream Concentration Units
Feed Component 1 g/L, g/g, …
Feed Component n g/L, g/g, …
Feed Component n+1 g/L, g/g, …
Products Concentration Units
Product 1 g/L, g/g, …
Product n g/L, g/g, …
Product n+1 g/L, g/g, …
FERMENTATION
Fermentation is a biochemical process that use a microorganism to produce different products. Exist many
types of fermentations (i.e submerged, solid, etc.), also, different kinetics equations are employed to describe a
fermentative process, but, regardless of the type of fermentation, the following information must be taken into
account:
✓ Operation type,
✓ Initial conditions (i.e biomass, substrate, products),
✓ Charge or working volume,
✓ Specific power consumption,
✓ Temperature,
✓ pH
FERMENTATION
Specifications of fermentation block
Operation type
Batch
Fed - Batch
Continuous
Initial Conditions
Substrate g/L
Biomass g/L
Product g/L
Temperature K
pH
pH
units
Concentrations of steady state (Cs)
Substrate g/L
Biomass g/L
Product 1 g/L
Product 2 g/L
Product n g/LDilution Rate (D) Total 1/h
Flow rate into reactor (Vo) Total m^3/h
Mass flow in outlet stream of each component
(Cs*Vo)
Substrate kg/h
Biomass kg/h
Product 1 kg/h
Product 2 kg/h
Product n kg/hMass flow in outlet steam (F) Total 0 kg/h
Yields of each component
Substrate N.A
Biomass N.A
Product 1 N.A
Product 2 N.A
Product n N.A
Summatory 0 N.A
FERMENTATION
In downstream process a hydrocyclone or filter are used to separate the biomass of the broth for dispose
or recycle it to fermenter. These equipments must be specify with the following information:
✓ Diameter of hydrocyclone
✓ Inlet diameter up flow outlet diameter
✓ Down flow outlet diameter
✓ Angle of cone
✓ Efficiency
Filter Specifications: the particle diameter, mass fraction in cake of particle solids must be specified.
ANAEROBIC DIGESTION
Anaerobic digestion (AD) is a biological process where a organic matter is converted to
biogas and digestate. Biogas is a renewable biofuel due to this is composed by methane
(50 – 70%), carbon dioxide (25 – 40%) and other gases as hydrogen sulfide and
ammonia.
The process is performed by several microorganism (i.e hydrolytic, acidogenic,acetogenic and methanogenic bacteria). However, due to the high complexity of thesystem this process is modeled as a first order kinetic. The experimentation of thisprocess uses a inoculum that comes from a wastewater plant or Upflow AnaerobicSludge Blanket reactor (UASB). The inoculum must be characterized minimum in volatilesolids terms
ANAEROBIC DIGESTION
Item Value Units
Temperature °C, °F, …
pH
Inoculum to substrate ratio
Headspace Gas N2, CO2, He,..
Incubation time min, days,..
Does the process require
stirring? YES NO
Type of Stirring
Energy Consumed W, kW, ---
C/N Ratio
Please, specify the method used in gas measuring
Volumetric or Manometric method
Experimental yield scum/kg VS
Inoculum
Microorganism
Concentration g/L, …
Pre-incubation
Time
min,
days, …
Feedstock
Substrates Concentration Units
Substrate 1
g/g,
g/L, …
Substrate 2
g/g,
g/L, …
Substrate 3
g/g,
g/L, …
Substrate n
g/g,
g/L, …
Substrate n+1
g/g,
g/L, …
THERMOCHEMICAL METHODS
“Thermochemical pathways for biomass conversion offer opportunities for rapid and
efficient processing of diverse feedstocks into fuels, chemicals and power.
Thermochemical processing has several advantages relative to biochemical processing,
including greater feedstock flexibility, conversion of both carbohydrate and lignin into
products, faster reaction rates, and the ability to produce a diverse selection of fuels”
Gasification and pyrolysis are the two most important thermochemical routes for
transformation of biomass (i.e lignocellulosic materials) into fuels with higher value-added
(e.g syngas) and utilities as heat and power
THERMOCHEMICAL PROCESSGasification
Item Value Units
Temperature
Pressure
Gasifiyng agent air, steam, oxygen, …
Gasifier Configuration downdraft, fluidized bed …
Pyrolysis
Item Value Units
Temperature
Pressure
Type of Pyrolysis Fast, moderate or slow
Product Yield
% Liquid %Char %Gas
Pyrolysis
Gasification
Feed Stream to the process
Item Value Units
Moisture Content %wt
Particle Size mm, cm, …
Energy Content Mj/kg, Mj/kmol
Components Composition Units
Component 1 %wt, % mol, …
Component n %wt, % mol, …
Component n+1 %wt, % mol, …
Products
Components Composition Units
Component 1 %wt, % mol, …
Component 2 %wt, % mol, …
Component 3 %wt, % mol, …
Component n %wt, % mol, …
Component n+1 %wt, % mol, …
PURIFICATION STEP
The common downstream operations are:
Distillation (Azeotropic homogeneous, azeotrópic heterogeneous, extractive)
Absorption and stripping
Membranes
Molecular sieves
Decanters
Evaporators
ECONOMIC ANALYSIS
After completing the whole process of design, an economic evaluation
must be performed. This evaluation takes into account some economic
parameters of the region where the project will be located, furthermore
prices of the all raw materials must be specified.
Economic Aspects
Item Price Units
Operators USD/h, €/h, …
Supervisor USD/h, €/h, …
Tax Rate %
TIR %
Project Life years
Electricity USD/kW, …
Water USD/cum
Fuel USD/Megawatts
Low pressure steam USD/Ton
Medium pressure
steam USD/Ton
High pressure steam USD/Ton
Main raw material USD/kg, …
Reagent 1 USD/kg, …
Reagent n+1
Thank you for the attendance
Carlos Ariel Cardona Alzate M.Sc. Ph.DE-mail: ccardonaal@unal.edu.coUniversidad Nacional de Colombia Sede Manizales
Recommended