integration of biorefinery concepts in process industries
TRANSCRIPT
Integration of Biorefinery concepts in Process Industries
Thore Berntsson, Professor Department of Energy and Environment Division of Heat and Power Technology
CHALMERS UNIVERSITY OF TECHNOLOGY
What is a Biorefinery?
Two examples of definition: • “Biorefining is the sustainable processing of biomass into a
spectrum of marketable products and energy.” From IEA • “A biorefinery is a facility that integrates biomass
conversion processes and equipment to produce fuels, power, and chemicals from biomass.” From NREL
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Research Theme: Biorefineries - Process Integration Issues
Biorefinery Plant Industrial Process Plant
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Cellulose & Lignin wood, black liquor,
grass
Starch wheat, corn, potatoes
Sugar
Oil rapeseed, palmoil, soy
Rest flows from agriculture, forstry,
industries, societal waste etc, e.g. straw, sawdust,
manure, sludge, food waste.
Fermentation of sugar
Ethanol
BIOMASS CONVERSION PROCESS ENERGY CARRIER
Electricity Combustion
Methane
Hydrogen
Fischer-Tropsch Diesel
DME (Dimehtyleter)
Methanol
Gasification to syngas
(CO and H2)
Cracking Bio-oils treated with
hydrogen HVO
Pressing and esterification
FAME
Anearobic digestion
Biogas
Example of biofuels and conversion processes
Acid or enzymatic hydrolysis
Gasification Pyrolysis
Fermentation Catalytic conversion Upgrading
Liquid fuels Hydrocarbons, methanol, hydrogen,
SNG chemicals, materials etc.
Bio-oils Syngas
(H2, CO, CO2, H2O) Heat
Electricity Sugars
Ethanol, butanol
Woody biomass
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Woody biomass
Gasification of biomass
6 (Milne et al 1998)
H2, CO, CO2, H20, CH4, (N2), tars
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Example of a Fermentation Route
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Degrees of Freedom
The biomass feedstock • Forest biomass • Agricultural biomass • Organic waste • Algae • Etc
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Degrees of Freedom
The conversion processes • Gasification • Fermentation • Pyrolysis • Torrefaction • Drying • Hydrolysis • Separation technologies • Gas cleaning • Etc
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Degrees of Freedom The end products • Bulk Products, high value materials, specialty chemicals • Examples of bulk products: • Fischer-Tropsch diesel • SNG • DME • Methanol • Ethanol • Hydrogen • Furfural • Carbon fibres • Polyethylene • Green electricity • Heat
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Several New Approaches for Strategic Decision-Making for Biorefineries
Some Examples: • Systematic screening of biorefinery concepts • Value and supply chain management and evaluation • Optimal synthesis of biorefinery concepts • LCA-based evaluation of biorefinery concepts • Future scenarios for evaluation of biorefinery concepts • Decision-making under uncertainty regarding future prices
and policy instruments
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The Advanced Composite Curves below the pinch are: • Cold Utility curve, representing the composite of the
cooling media • Actual Cooling Load Curve, representing the highest
possible temperatures of the excess heat without additional internal heat exchanging
• Theoretical Cooling Load Curve, representing the highest temperature levels at the actual level of hot utility (not equal to the GCC below the pinch)
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Advanced Composite Curves
Pinch divides process into heat source and heat sink
QHmin
QHmin
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Advanced Composite Curves
With heat exchanger additions, the temperature levels of the excess heat can be increased compared to existing levels. The advanced composite curves identify the theoretically highest possible level at given levels of hot and cold utility. In the same way, the advanced composite curves identify the lowest possible temperature levels for heat transfer to the system above the pinch. Both aspects are crucial for identifying true process integration opportunities in biorefineries.
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Advanced pinch curves for the background process
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Optimization
Complicated, many optimization parameters • Technical parameters, e g feedstock, upgrading processes,
type of products • Economic parameters, e g energy prices, investment costs
for new technologies, feedstock and product prices • Policy instruments, e g CO2 charge, green certificates,
energy taxes • Build margin technology for e g power production, use of
biomass
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Optimization
All optimization parameters will change considerably during the service life of a biorefinery. With the ENPAC tool, the economy and environmental performance for a biorefinery can be evaluated at different scenarios for future changes and “robust” options can be identified.
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Research Theme: Scenarios for assessing profitability and carbon balances of energy
investments in industry
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Results for year ~2030 (with CCS)
BLGMF:CCS RB:ElectricityBLGCC:CCS RB:CCSLignin:Wood fuel Lignin:Oil
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Some Process Integration Principles
Two large process parts shall be integrated. This can be done at several levels: • Process integration within the biorefinery separately • Process integration of the host process separately • A total site or foreground/background analysis of the two parts • A process integration analysis treating all streams as
parts of one large process Do always the fourth level first to establish the theoretical potential. Then include practical and economic constraints.
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Examples of Industrial Biorefinery Process Integration Studies
Pulp and Paper Industry • Biomass gasification and production of electricity, methanol or Fischer-Tropsch
diesel • Black liquor gasification with production of DME or green electricity • Ethanol production using partly existing pulping equipment or docked to a pulp mill • Lignin precipitation and upgrading • Precipitation and upgrading of hemicellulose with water extraction
Oil Refineries • Biomass gasification and production of hydrogen or Fischer-Tropsch diesel
Petrochemical industry • Biomass gasification and production of methanol or SNG (which can be further
converted to e g polyethylene)
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Energy efficiency measures in a pulp mill converted to an ethanol production plant
Rickard Fornell
• Co-op with Innventia (process development).
• Process integration studies by Chalmers. Aims • Study energy efficiency measures in the conceptual process.
• Apply results in various ways (other raw-materials and different new concepts).
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Method:
Evaporation
Distillation
Background process
~
Alkalinepretreatment
Evaporation
Lignin fuel
Recoveryboiler
HPSteam
SteamTurbine
Electricity
Hydrolysis+Fermentation Fuel grade Ethanol
Condensates
Raw material
Enzymes
Distillation
Causticizing
MP/LPSteam
Acid
Yeast
Spentliquor
Molecularsieves
pH adj.
Lime kiln
CO2
Cooking liquor
dewatering
Washliquor
Distillationresidue
Step 1: Divide the process in 3 parts. Evaporation – studied in detail Distillation – studied in detail Background process – HX network Step 2: Combine different parts in energy efficient ways (Heat integration)
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Methods used Process integration studies:
- Pinch analysis (heat integration) - Targeting - Bg/Fg curves - Advanced composites - Tank curves
- Process simulations
- Evaporation (OptiVap) - Distillation (Aspen Plus) - DME (Aspen Plus)
- Economic analysis
- Previous cost information - Aspen PEE (simulations) - Scenario tool (ENPAC)
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Background process
Background process
Evap Dist
Heating demand
Cooling demand
Tem
pera
ture
[C]
Energy [MW]
1. Improve internal heat recovery in BG process:
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Background process
Background process
Evap Dist
Heating demand
Cooling demand
Tem
pera
ture
[C]
Energy [MW]
1. Improve internal heat recovery in BG process:
Improve HX network
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Background process
Background process
Evap Dist
Heating demand
Cooling demand
Tem
pera
ture
[C]
Energy [MW]
2. Improve heat integration externally:
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Background process
Evap Dist
Heating demand
Cooling demand
Tem
pera
ture
[C]
Energy [MW]
2. Improve heat integration externally:
Distillation and/or evaporation integrated with BG process
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Some General Findings
• Through Process Integration between a biorefinery concept and a process industry, energy efficiency measures can in practically all cases be found
• Energy saving opportunities for the total system are normally high, up to 25%
• The reduction of CO2 emissions through integration of biorefineries with process industries depend to a high extent on the marginal production technology of energy, especially power, in society.
• The economic benefits of integrating biorefineries are in most studied cases reasonable or high, but depend totally on future conditions regarding policy instruments, i e on future CO2 charge levels
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