Process Integration How To Integrate? Depend On Purpose

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Process Integration Guido Zacchi, Chemical Engineering www.chemeng.lth.se LU Biofuels 23/10 2009 How to integrate? Depend on purpose Biomass Pulping Pulp Heat & Power Electricity Heat Enzymatic hydrolysis Fermentation Solids Reactor Filter Liquid Ethanol Butanol Lactic acid Other How to integrate? Depend on purpose Biomass Pulping Pulp Heat & Power Electricity Heat Enzymatic hydrolysis Fermentation Solids Reactor Filter Liquid Ethanol Butanol Lactic acid Other Fermentation Reaction Separation Furfural Acids (levulinic, Formic etc) Oligomers (Building blocks for polymers) Schematic process – Ethanol production • Steam pretreatment – Acid hydrolysis • Fermentation of all sugars (incl. Pentoses) • Simultaneous saccharification and fermentation (SSF) • Energy integration • Integration with other processes Biomass Pretreatment Enzymatic hydrolysis Fermentation Distillation SSF Lignin Ethanol Techno-Economic Evaluation TS1 TSR Aspen Plus REBREC TS Mass & energy balances Thermodynamic calculations REC TSB Vendor quotations Icarus Process Evaluator Production cost (SEK/L) Sizing & cost estimation of process equipment Energy demand 14 12 Preheating ⇒ Heat demand Secondary heat Overall 8 6 4 2 -6 g yin Dr Ev ap o ra tio n -4 Dis -2 till ati on 0 Pr etr ea t me nt Energy (MJ/L EtOH) 10 External process integration Heat and power plants Starch or sugar based ethanol Pulp and paper Power Plant Electricity Steam & electricity Lignin Biomass Ethanol Plant Heat Value-Added Chemicals District Heating Ethanol Cars Schematic flowsheet Pellets Raw material Steam SO 2 Feedstock handling Pretreatment Water & base Enzymes & nutrients Ethanol SSF & yeast cultivation Distillation & dehydr. Drying Process steam Stillage Wastewater treatment Excess solids Condensates Evaporation Liquid fraction Filtration Concentrated liquid Biogas (methane) Pellet production Steam generation No pellet production Pellets Raw material Steam SO 2 Feedstock handling Water & base Pretreatment Enzymes & nutrients Ethanol SSF & yeast cultivation Distillation & dehydr. Drying Process steam Stillage Wastewater treatment Excess solids Condensates Evaporation Liquid fraction Pellet production Filtration Electricty Steam & electr. gen. Concentrated liquid Biogas (methane) 5 Scenarios Ethanol Pellets Electricity District heating BC: base case LO: lower yield HI: higher yield A X B X X X C X X X D X E X X X X X WIS: reduced energy demand HI&WIS: combined case Sassner et al. Biotechnology and Biofuels, 2008 Energy efficiency 100% 92% Energy efficiencyLHV 90% 76% 80% 70% 60% 70% 70% Heat Electricity Pellets Ethanol 53% 50% 40% 30% 20% 10% LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS 0% A B C D E Min. EtOH selling price 4.80 4.73 4.65 4.56 4.40 4.20 4.20 4.00 3.87 3.80 3.60 3.40 3.20 3.00 LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS LO BC HI WIS HI&WIS MESP (SEK/L) 4.60 A B C D E Integration of 1st and 2nd generation ethanol Starch based process Solid material water & steam Raw material Enzymes Water Liquefaction Enzymes Yeast Saccharification Fermentation Ethanol Solid material Centrifugation Distillation SSF Liquid 1 Steam Raw material 3 Water Pretreatment 2 4 Enzymes Yeast Enzymatic hydrolysis Fermentation Ethanol Solid material Filtration Distillation SSF Liquid Solid material Cellulose based process Energy demand (kW/kg EtOH) Energy demand in distillation 12 10 8 6 4 2 0 0% 1% 2% 3% 4% 5% 6% Ethanol concentration in feed (% [w/w]) 7% 8% SSF of wheat straw – wheat meal (5% WIS) 60 2.5% straw + 2.5% meal Yield 92% Ethanol concentration [g/l] 50 40 30 5% straw 81% 20 10 0 0 20 40 60 Time [hour] Final aim? 80 100 Thanks for your attention! www.chemeng.lth.se