Converting Red Liquor, Pulp, and Sludge to Ethanol Spring 2009 Design Class Paper Science & Engineering 487 College of Forest Resource University of Washington 11 June 2009

Agenda Background Red Liquor to Ethanol Production Process Overview Process Detail Mill Integration Process Economics Environmental and Safety Conclusions and Recommendations Pulp to Ethanol Production Sludge to Ethanol Production Process Comparison Conclusion

Background Ethanol – Production Benefits: Environmental Economical Efficient Project Objective: Integrate the production of ethanol into the KC Everett mill. Group Objectives: Production of ethanol from Red Liquor, Pulp, and Sludge

Fermentation Options Three Fermentation Microorganisms Escherichia coli Genetically engineered strain KO11  Yield 0.44 g ethanol /g sugar  Metabolize 5 and 6 carbon sugars Zymomonas mobilis Genetically Engineered Strain ZM4:ZB5  More tolerant of acetic acid  Yield 0.47g ethanol/g sugar  Metabolize 5 and 6 carbon sugars Saccharomyces cerevisia Strain 424A(LNH-ST)  Yield 0.41 g ethanol/g sugar  Metabolize only 6C sugars  Proven performance with red liquor

Red Liquor to Ethanol Chris Ardales, Colynn Boyd, Sabrina Burkhardt, Danielle Greenwood Paper Science & Engineering 487 College of Forest Resource University of Washington

Process Overview Assumptions Neglect Inhibitors 86% Fermentable Hexoses converted 77% Fermentable Pentoses converted Mill is capable of handling increased steam production Critical Unit Operations Raise pH with Ammonium Hydroxide prior to fermenting Lower Temperature prior to fermenting Use of Zymomonas mobilis as fermenting agent Nutrients: corn steep, diammonium phosphate SSL taken from 5 th MEE, remaining liquor returns to 1 st MEE Flow Diagram Follows:

Process Detail - WinGEMS

Process Detail – Inputs to Process SSLSWHW Total Mass Flowrate (klb/hr) Total Dissolved Solids (klb/hr)56.06 Total Sugars (klb/hr) Fermentable 6 C Sugars (klb/hr) Fermentable 5 C Sugars (klb/hr) Other Solids (klb/hr) Lignin Mass Flowrate (klb/hr) Water (klb/hr) Temperature (deg F) 149 pH 2.6

Process Design Fermenter Outflow to Beer Column SoftwoodHardwood Ethanol concentration (%) Ethanol (gpm) Total solids (kpph) Water (gpm)404413

Process Design SoftwoodHardwood Dissolved Solids (%) Lignin and extractives (kpph) Sugars (kpph) Water (kpph)234 Beer column outflow to evaporator stage 1

Beer column flow to rectifier and sieve Process Design SoftwoodHardwood Ethanol concentration (%)93.0% Ethanol (gpm) Water (gpm) SoftwoodHardwood Ethanol concentration (%)99.8% Ethanol (gpm) Ethanol (MM gal/yr) Water (gpm)0.004 Outflow from rectifier and sieve

Process Detail – Results from WinGEMS Ethanol Production (WinGEMS Simulation) SoftwoodHardwood Ethanol (MM gal/yr) Ethanol Production (calculated) SoftwoodHardwood Ethanol (MM gal/yr)7.36.4

Steam Production from Red Liquor Without Fermentation After Fermentation Wingems Simulation 268 KPPH KPPH197 KPPH  31%-53% reduction in steam from red liquor  Distillation requires 33 KPPH  Other fuels must be burned to makeup the steam requirement  Wingems simulation is optimistic Process Design Without FermentationAfter Fermentation Change in power production from WINGEMS

Process Economics Capital Costs Fermentation $ 2,600,000 Distillation $ 5,900,000 Storage $ 800,000 Utilities $ 200,000 Total Installed Equipment Cost $ 9,500,000 Added Costs $ 7,000,000 Total Project Investment $ 16,500,000 Estimated based on NREL corn ethanol process Exclude non-applicable operations 2008$ using ppi Installation factors, cost relationships used by NREL Scaled based on production level

Process Economics Operating Costs (cents/gal ethanol) Variable Operating Costs Chemicals2.0 Fermentation Nutrients1.4 Steam49.5 Fixed Operating Costs16.9 Total69.8 Equivalent annual worth values 20 year projection, 20% rate of return Estimated based on NREL corn ethanol process Chemicals vary from NREL process Fixed costs based on production as in NREL

Process Economics Steam Use (klb/hr) Process Demand33 Steam Production from SSL loss112 Total145 Value at $2.2/gal ($/yr) $ (2,800,000) Cost of Natural Gas Replacement ($/yr) $ (3,400,000) Natural gas cost: $4/MM Btu

Profitability 20 year projection (pre-tax) Ethanol selling price of $1.50/gal Ethanol production of 7.1 MM gal/yr Desired rate of return at 20% Net Present Value = $17.3 MM Break Even Ethanol Price: $1.06/gal

Environmental and Safety Displacement of Carbon released from gasoline Calculated using guide lines from The Intergovernmental Panel on Climate Change Ethanol MM gal/yr Gasoline replaced MM gal/yr CO 2 released lbs/gal Carbon saved MMlbs/yr Carbon saved tons/yr

Environmental and Safety Money in CO 2 ? European Union Results in an additional earning of 1.6Million dollars/year at $35/ton

Environmental and Safety Storage Tank labeling Materials resistant to ethanol corrosion Unplated and Stainless Steel Black Iron Bronze Nonmetallic Thermoset Reinforced Fiberglass Thermo Plastic Piping Neoprene Rubber Nitrile Teflon Hazard Rating 4-Extreme 3-Severe 2-Moderate 1-Slight 0-Minimal Health2 Flammability3 Reactivity0

Environmental and Safety Odor Control Water Scrubber Off fermentation and any vents that would contain Ethanol  Majority of the CO 2 and 0.2% of the ethanol is vented  Contains 83.7% CO 2, 12% ethanol, 4% water  Effluent is fed to the first distillation column  Over 99% of the ethanol to scrubber is recovered

Recommendations Further testing on Z. Mobilis Genetically engineered bacteria my not hold up in SSL New strains could be more effective Consider yeast Proven to work well with 6 carbon sugars Will lose the fermentation of 5 carbon sugars Rework analysis for 6 carbon sugars alone

Conclusions Ethanol production = 7.1 MM gal/yr Net Present Value = $17.3 MM Assuming mill can handle increase in steam demand Z. mobilis yield is accurate and is hardy enough for SSL