Techno-economic and ecological evaluation of a wood biorefinery

Transcription

1 Techno-economic and ecological evaluation of a wood biorefinery Martina Haase 1, Magnus Fröhling 1, Jörg Schweinle 2, Birgit Himmelreich 3 1) Industrial Production, Universität Karlsruhe (TH) 2) Johann Heinrich von Thünen-Institute, Institute of Forest Based Sector Economics 3) Bayer Technology Services GmbH Industrial Production (IIP) Biorefinica 2009, January 27-28, DBU Osnabrück, Germany

2 Content Introduction Methodology for the evaluation of process chains for biomass utilization Reference configuration of the modelled biorefinery Modelling of material and energy flows along the whole value chain Economic evaluation of the wood biorefinery Ecological evaluation of the wood biorefinery Summary Industrial Production (IIP) 2

3 Increasing use of biomass in fossil based industries Replacement of limited fossil raw materials Increasing prices for non-renewable raw materials Reduction of dependency on crude oil imports and securing of raw material supply Reduction of greenhouse gas emissions Increase of competition for biomass and arable land through new biomass utilization concepts Enhancement of research and development regarding new conversion technologies Industrial Production (IIP) 3

4 Possible process steps and potential products of a wood biorefinery Feedstock Precursors Platform chemicals Lignocellulosic Biomass Disintegration, Separation Cellulose Hemicellulose Lignin Enzymatic conversion Chemical conversion Glucose Xylose Furfural Phenolderivatives Wood chips Bark Possible solvents: - Ethanol/Water - Ionic Liquids - H 2 SO 4 Potential material utilisation, e.g. - Binding agents - Fillers - Polymer compounds - Pulp - Cellulose derivatives e.g. chemical or enzymatic hydrolysis Subsequent processing to various products, e.g. - Fuel additives - Polyethylene - PLA - Acrylic acid Industrial Production (IIP) 4

5 Objectives of the techno-economic economic and ecological evaluation Estimation of production costs and environmental effects of a process chain for the use of biomass at an early stage of process development Determination of economic and ecological key parameters and their influence on the sustainability of the process chain Identification of cost-effective and environmentally sound process configurations Industrial Production (IIP) 5

6 Methodology for the evaluation of process chains Determination of a reference configuration Modelling of material and energy flows along the whole value chain (e.g.: Material flow analysis, process simulation) Estimation of raw and auxiliary material flows, energy demand, waste streams, products and emissions for different scenarios Estimation of investments and production costs Investment related costs, operating costs, costs for disposal, labor,... Estimation of environmental impacts E.g. acidification, global warming potential, eutrophication, CED,... Location and logistics planning Availability of raw materials, infrastructure, consideration of different plant sizes,... Sensitivity analysis Industrial Production (IIP) 6

7 Reference configuration of the modelled biorefinery Plant capacity: t dry wood/year Load: 50 t dry wood/h (8000 h/year) Feedstock properties : Wood chips of residual wood (P100, 50% water content), 42 % cellulose, 29% hemicellulose, 24% lignin, 5% others Organosolv pulping: Ethanol/Water mixture (50/50) T = 180 C, p = 18bar Ratio wood : solvent = 1 : 6 Enzymatic conversion of cellulose: Conversion rate to glucose: 82% Cellulase and beta-glucosidase enzymes Hemicellulose fraction: Solute hemicellulose fragments after organosolv pulping are subsumed to xylose Final products: Main product: Glucose (solution ~16 mass-%), Byproducts: Xylose (solution ~5 mass-%), lignin (dry) Industrial Production (IIP) 7

8 Major process steps for the production of glucose from wood CO 2, H 2 O, solar radiation Forest production Transport Disintegration Separation of components Biological production, Forest maint. Wood harvest/ chipping Lorry EtOH, H 2 O T = 180 C p = 18 bar Precipitation Filtration Centrifugation Solvent recovery Enzymatic hydrolysis Glucose Xylose Lignin Flash- Separator Cellulase Distillation β-glucosidase Industrial Production (IIP) 8

9 Modelling of material and energy flows along the whole value chain Umberto material and energy flow network Transport P12: Emissions, waste materials P6: Energy Disintegration and separation of components P12: Emissions, waste materials P6: Energy P18: Solvent P2:Raw and auxiliary materials P9:Wood chips P13: UPR T10:Transport T1: Disintegration and separation of components P15: Wood P5: Cellulose fraction P10: Lignin fraction T12: Forest production P12: Emissions, waste materials P2:Raw and auxiliary materials P7: Cellulose fraction T4: Water addition T11: Dryer P12: Emissions, waste materials P6: Energy P6: Energy P2:Raw and auxiliary materials P2:Raw and auxiliary materials T8: Enzymatic conversion Forest production P6: Energy P12: Emissions, waste materials P3:Glucose P8:Xylose Further processing of components P25: Lignin Industrial Production (IIP) 9

10 Subnet Disintegration and separation of components (Sankey Diagram) P16: Steam P6: Energy P12:Effluents P2:Raw and auxiliary materials P18: Solvent T15: Distillation P6: Energy T3: Solvent compression P9: Lösung T5: Heat exchanger P13: Steam T9: Flash P24: Solution P8: Hemicellulose fraction P7: Solvent P4:Water P30: Wood chips P17:Solvent mixture P11: Suspension T2: Disintegration reactor T6: Centrifuge/decanter T8: Lignin precipitation P14: Residue P20 T13: Centrifuge/ decanter P22 P6: Energy P10:Lignin fraction T4: Heat exchanger P5: Steam T1: Pressure release/ decanter P3 P2:Raw and auxiliary materials P16: Steam P6: Energy P1: Residue P12:Effluents T14: Cellulose washing P31: Cellulose fraction P2:Raw and auxiliary materials Ethanol Water Wood / -components Industrial Production (IIP) 10

11 Methodology for economic analysis Estimation of investments: - +/- 30% accuracy - Site infrastructure completely available and useable (outside battery limits neglected) Determination of glucose production costs: - Variable costs and credits o Costs for raw and operating materials (wood chips, ethanol, water, enzymes) o Energy costs (electricity, steam, cooling) o Costs for sewage disposal o Credits for by-products (lignin as high grade product, xylose) - Investment related costs (depreciations, taxes and insurance, reparation and maintenance, costs of capital) - Labour costs Costs for sales, administration and research are not yet determined Industrial Production (IIP) 11

12 Structure of costs and credits for the base scenario 400 Enzymes 200 EtOH Costs [ /t Glucose] 0 Wood Water Electricity Cooling Steam Capital costs Rep./Maint. Tax./Ins. Depr. Admin. Labour Effluents Lignin -200 Xylose -400 Input materials Energy Invest. dep. costs Other costs Credits Industrial Production (IIP) 12

13 Estimation of glucose production costs for different scenarios Consideration of different wood : solvent ratios Requirement for economic efficiency: production costs << market price for glucose 400 ~ Glucose market price Input materials Energy Invest. dep. costs Other costs /t Glucose 0 Credits Production costs Market price glucose Scenario -400 Base Wood : solvent 1:6 1:8 1:4 1:4 opt Industrial Production (IIP) 13

14 Sensitivity analysis for the base scenario Prices for wood chips and lignin mainly influence glucose production costs Production costs variation [%] Parameter variation [%] Lignin price Wood chips price Ethanol price Enzymes price Investment Steam price Industrial Production (IIP) 14

15 Methodology for ecological evaluation Methodology for life cycle assessment (LCA) according to the international standard DIN EN ISO and Goal and scope definition and life cycle inventory analysis - Cradle to gate analysis including forest production (wood maintenance, wood harvest/chipping), wood transport and the biorefinery processes - Integration of supply chains for the provision of energy and operating materials (ecoinvent v2.0 LCI database) Selection of impact categories, e.g. global warming potential, acidification, eutrophication Life cycle impact assessment (e.g. allocation of emissions to the corresponding impact categories and conversion to indicator values, e.g. CO 2 equivalents) Industrial Production (IIP) 15

16 Ecological evaluation Examples (1) Determination of proportions of particular process steps to the emission equivalents of selected impact categories (base scenario) 100% Fuel provision (forest mainten., wood harvest) Fuel combustion (forest mainten., wood harvest) Provision of diesel fuel (wood transport) 50% Fuel combustion (wood transport) Provision of electricity (process plant) Provision of steam (process plant) 0% CO2 equiv. SO2 equiv. PO4 equiv. Provision of auxiliary materials for the process plant (enzymes, ethanol, water) Global warming potential Acidification Eutrophication Uncertainties for contributions caused by enzymes production especially for PO 4 -Eq. Industrial Production (IIP) 16

17 Ecological evaluation Examples (2) Comparision of indicator values (CO 2 - and SO 2 - equivalents) for different scenarios Different scenarios result in different conclusions for several impact categories CO2-Equivalents SO2-Equivalents t CO2-Equiv./h kg SO2-Equiv./h 0 0 Base scenario Scenario "wood for Base scenario 1 : 6 steam generation" 1 : 6 Scenario "wood for steam generation" Prov. of auxiliary materials for the process plant (enzymes, ethanol, water) Provision of electricity (process plant) Provision of diesel fuel (wood transport) Provision of steam (process plant) Fuel combustion (wood transport) Fuel combustion (forest mainten., wood harvest) Fuel provision (forest mainten., wood harvest) Industrial Production (IIP) 17

18 Ecological evaluation Examples (3) Comparison of CO 2 - and SO 2 - equivalents of the biorefinery with the production of potential reference products Assumptions: - Sugar from a sugar refinery as reference product for xylose and glucose - Phenol from a phenol plant as reference product for lignin Consideration of different wood : solvent ratios Biorefinery causes lower environmental effects compared to the reference processes t CO2 equiv./ h 25 kg SO2 equiv./ h Biorefinery 1:6 Biorefinery 1:8 Biorefinery 1:4 Biorefinery 1:4opt Reference processes 0 Biorefinery 1:6 Biorefinery 1:8 Biorefinery 1:4 Biorefinery 1:4opt Reference processes Lignin Xylose Glucose Sugar from sugar refinery Phenol from phenol plant 1 Values for reference processes derived from the ecoinvent v2.0 LCI database Industrial Production (IIP) 18

19 Summary Development of new concepts for the non-energetic use of biomass, e.g. wood biorefineries producing platform chemicals Modelling of mass and energy flows of a wood biorefinery along the whole value chain for different scenarios Early-stage techno-economic and ecological evaluation for the identification of sustainable production processes Economic efficiency highly depends on prices for raw materials and the sales price for lignin Further improvement of process design is necessary to enhance economic efficiency Steam and electricity generation are crucial for the extent of GHG emissions Analysis of different impact categories may lead to different conclusions Industrial Production (IIP) 19

20 Thank you for your attention! Industrial Production (IIP) Hertzstr Karlsruhe Dipl.-Umweltwiss. Martina Haase +49 (0) Dr. rer. pol. Magnus Fröhling +49 (0) This work is part of the research project Pilotprojekt Lignocellulose Bioraffinerie, supported by the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) and attended by the FNR. Industrial Production (IIP)