1. Lund University Experience onTechnology Assessment for 2nd Generation Bioethanol Production Guido Zacchi, Chemical Engineering Lund University www.chemeng.lth.se Workshop Virtual Sugarcane Biorefinery Campinas August 13-14

2. Schematic process Steam pretreatment Acid hydrolysis Fermentation of all sugars (incl. Pentoses) Simultaneous saccharification and fermentation (SSF) Energy integration Integration with other processesBiomassPre- EnzymaticFerment-EthanolhydrolysisDistillationtreatmentation SSFLignin 3. Steam pretreatment unit10 litre reactor160 - 230 CImpregnation withH2SO4 or SO2Main purposesHydrolysis of hemicelluloseImprove the enzymatichydrolysis of cellulose 4. Equipment for enzymatic hydrolysis and fermentation (SSF) 5. Techno-Economic Evaluation Experimental Aspen Plusdata Mass & energy balances Thermodynamic calculationsVendorSwedish quotations conditionsIcarus Process EvaluatorProduction Sizing & cost estimation ofcost (SEK/L) process equipment 6. High quality data are crucial Experimental data for all conversions Physical data Phase equilibria Cost data EtcRubish in = Rubish out (Independent of how good the model is) 7. Useful for Sensitivity analysis(solid content in SSF) Compare different process configurationsone versus two stage pretreatmentreplace evaporation of stillage with biogas production Internal process integrationrecirculation of process streams External process integrationwith heat and power productionwith 1G ethanol production 8. Overall process heat demand as function of the WIS concentration in SSF2826 Heat duty (MJ/L ethanol) Salix24 Corn stover22 Spruce201816141210 7 8 910111213 14 15 WIS concentration in SSF (%)Sassner, Thesis LU 2007 9. Ethanol production cost as functionof the WIS concentration in SSF6,50 krEthanol production cost (SEK/L) Salix6,00 kr Corn stover Spruce5,50 kr5,00 kr4,50 kr4,00 kr3,50 kr7 8 9 10 11 12 1314 15 WIS concentration in SSF (%)Sassner, Thesis LU 2007 10. Fed-batch SSF yeast cultivated on hydrolysate Above 45 g/l etanol 2 g/l yeast12 % Fibres Fed-Batch SSF 50 45Concentrations (g/L) 40 35 30Glucose 25 20Ethanol 15 10500 50 100 150 200Time (h) 11. SSF of pretreated and delignified aspen9080 20% WIS New reactor70Ethanol concentration (g/l)60 15% WIS5040Conventional 10% WISfermentor302010 0 0 24 487296 120 144 Time (Hours) 12. 2-step pretreatment Experimental set-upRaw materialPretreatment Pretreatment step 1 solid step 2 liquidslurryFermentationEnzymaticSSFtesthydrolysis 13. Recovery after pretreatment (%) 20 40 60 80 1000 GlucoseTotal MannoseSolidOSLiquidTotal Glucose MannoseTS+WTotal Glucose Comparison yields MannoseTS-WTotal 14. Economic evaluationCatalyst HX2 HX6 SteamCatalyst SteamHX7 HX5 HX177.0% HX3Woodno flashingNo flashing HX450% WIS Cooling no washing50% WIS To SSFto 20C To SSF 71.8% HX874.6% First stepOptional second step 15. Ethanol cost (SEK/L) 4.3 4.2 4.1Ethanol cost (SEK/L) 4.0 3.9 3.8 3.7 3.6 3.5 BC one-step BC two-step Worst case No flash case Optimistic case 16. The Process Replacement of evaporation with Biogas productionPellet Pelletsproduction Enzymes &Raw material Steam Ethanol Water &nutrients SO2base DryingFeedstock Pre- SSF & yeast Distillationhandling treatmentcultivation& dehydr. Process Electricty Stillage steam Excess solidsWastewater LiquidSteam & Condensates EvaporationfractionFiltrationtreatment electr. gen. Concentrated liquid Biogas (methane) 17. The Process with biogasPellet PelletsproductionEnzymes &Raw material SteamEthanol Water & nutrients SO2 DryingbaseFeedstock Pre-SSF & yeast Distillationhandling treatment cultivation& dehydr. Process Electricty Stillage steam Excess solidsWastewaterLiquid Steam & fraction Filtrationtreatment electr. gen.Biogas (methane) & sludge 18. The ProcessPellet PelletsproductionEnzymes &Raw material SteamEthanol Water & nutrients SO2 DryingbaseFeedstock Pre-SSF & yeast Distillationhandling treatment cultivation& dehydr. Process Electricty Stillage steam Excess solidsWastewaterLiquid Steam & fractionFiltrationtreatment electr. gen. SludgeBiogas VehicleBiogas upgradingfuel 19. Minimum EtOH selling price 5.004.53 kr 4.504.27 kr 4.00 3.42 kr 3.50MESP (SEK/L) 3.00 2.50 2.00 1.50 1.00 0.50 0.00Base case No Evap - Pellets No Evap - Biogas 20. Biogas productionTwo key issues:- Biogas conversion:- Yield? Rate? Concentration?- Sludge handling:- Fuel properties? Level of dewatering? 21. Recycling of process streamsSSF 22. Recirculation of processstreams in SSF4,80Overall production cost (SEK/L)4,60MaximumExperimental value4,40BeforeAfter4,204,003,80 0 2040 60 80% recycling of stream Evaporation condensate up to 100% 23. Integration with heat and powerSchematic flowsheet Pellet Pellets production Enzymes &Raw material Steam Ethanol Water &nutrients SO2DryingbaseFeedstock Pre- SSF & yeast Distillationhandling treatmentcultivation& dehydr. Process Stillage steamExcesssolidsWastewater LiquidSteam Condensates EvaporationfractionFiltrationtreatmentgeneration Concentrated liquid Biogas (methane) 24. No pellet productionPellet Pelletsproduction Enzymes &Raw material Steam Ethanol Water &nutrients SO2base DryingFeedstock Pre- SSF & yeast Distillationhandling treatmentcultivation& dehydr. Process Electricty Stillage steam Excess solidsWastewater LiquidSteam & Condensates EvaporationfractionFiltrationtreatment electr. gen. Concentrated liquid Biogas (methane) 25. 5 Scenarios A B C D EEthanolX X X X XPelletsX XElectricityX X X XDistrict heating X XBC: base case WIS: reduced energy demandLO: lower yield HI&WIS: combined caseHI: higher yield 26. Energy efficiency 100% 92% 90%Energy efficiencyLHV 80%76%70% 70% 70% 60%53% HeatElectricity 50%Pellets 40%Ethanol 30% 20% 10%0%BCBCBCBCBCLOHILOHILOHILOHILOHI WISHI&WIS WISHI&WIS WISHI&WIS WISHI&WIS WISHI&WISA B C D E 27. Min. EtOH selling price 4.804.734.654.56 4.60 4.40MESP (SEK/L) 4.20 4.20 4.00 3.87 3.80 3.60 3.40 3.20 3.00LOBCLOBCLOBCLOBCLOBCHIHIHIHIHI WISHI&WIS WISHI&WIS WISHI&WIS WISHI&WIS WISHI&WIS ABCDE 28. Effect of feedstock cost5,755,505,255,00 AMESP (kr/L)4,75 B4,50 C4,25 D4,00 E3,753,503,253,00 100 120 140160180 200 Feedstock cost (kr/MWh) 29. Effect of electricity spot price5,004,754,50 AMESP (kr/L)4,25 B C4,00 D3,75 E3,503,253,00 200 250 300 350400450 500 Electricity spot price (kr/MWh) 30. Effect of district heat credit5,004,754,50AMESP (kr/L)4,25BC4,00D3,75E3,503,253,00 100 150200 250 300 Credit, district heat (kr/MWh) 31. Integration of 1st and 2nd generation ethanolStarch based process Solid material water & EnzymesWat er EnzymesYeastEthanol Solid materialsteamRawSacchari- Centrifug- Liquefaction FermentationDistillationmaterial ficationation SSF Liquid132 4 SteamWat er EnzymesYeastEthanol Solid materialRawEnzymatic Pretreatment FermentationDistillation Filtrationmaterial hydrolysis SSF Liquid Solid material Cellulose based process 32. SSF of wheat straw wheat meal (5% WIS)Yield602.5% straw + 2.5% meal 92%50Ethanol concentration [g/l]4030 5% straw20 81%100 0 2040 6080 100Time [hour] 33. Powerful tool Assessment of improvements What if - studies Sensitivity analysis Give guidelines for experimental work Give data for LCA Basic data for process design 34. Thanks for your attention!