Academia Nacional Ingenieria, Uruguay 2018 CAETS, Montevideo, Uruguay Biorefining: Engineering, Science, and Economics Michael R. Ladisch Purdue University September 12, 2018 Montevideo, Uruguay
Acknowledgements National Academy of Engineering, US National Academy of Engineering, Uruguay Purdue University College of Engineering College of Agriculture
3 Grand Challenges Food Society Water Energy
The Grand Challenges for Engineering Make solar energy economical Provide energy from fusion Develop carbon sequestration methods Manage the nitrogen cycle Provide access to clean water Restore and improve urban infrastructure Advance health informatics Engineer better medicines Prevent nuclear terror Secure cyberspace Enhance virtual reality Advance personalized learning Engineer the tools of scientific discovery Reverse engineer the brain Engineering for the Future, The Third Global Grand Challenges Summit, July, 2017
GLOBAL CLIMATE CHANGE AND SUSTAINABLE CITIES Atmospheric greenhouse gas concentrations, global temperatures, and risks to human populations are all increasing, stated Ding • Extreme weather and climate events • Failure to mitigate and adapt to climate change • Large-scale loss of biodiversity and collapse of ecosystems • Large-scale natural disasters • Anthropogenic environmental damage and disasters Engineering for the Future, The Third Global Grand Challenges Summit, July, 2017
America’s Energy Future: Technology Opportunities, Risks, and Tradeoffs July 2009 http://w w w.nationalacademies.org/energy October 2008 May 20, 2009 June 15, 2009 Est. September, 2009
Basic Concerns/Motivations ● Environmental concerns emanating from the burning of fossil fuels with inadequate accounting for the serious externalities involved. ● National security concerns emanating from our falling production of petroleum, our dependence on fragile supply chains, the vulnerability of our electrical grid and transportation sector, and nuclear safety and proliferation. ● Economic competitiveness in the face of volatile prices for energy supplies and uncertainties that surround the various supply chains. National Academies, 2009 2
AEF “Global” Conclusion The only way to meet the concerns identified given our initial conditions is to embark on a sustained effort to transform the manner in which we produce and consume energy. Transforming the Energy Sector The AEF committee carefully considered some of the critical technological options (including their costs and limitations) that might be deployed in pursuing a transformation of the energy sector that would meet the identified economic, environmental and national security concerns. National Academies, 2009 4
Economics: Oil Price Trends are Uncertain $ / Bbl – EIA International Energy Outlook
Oil Prices Fluctuate http://www.macrotrends.net/1369/crude-oil-price-history-chart
CPI Correlates to Oil Prices http://www.macrotrends.net/1373/oil-prices-vs-the-cpi-historical-chart
Energy Consumption in other Countries is Increasing (in Quadrillion Btu)
Renaissance in US Oil Production
Global Energy Sources (and Consumption) are Increasing Pearl Gas-to-Liquid Plant, Qatar Hydro Nuclear Renewables Fossil: Oil, Coal, Gas TPES = total primary energy supply Mtoe = millions of tons of oil equivalent World Energy Council, 2013 Renewables = wind, solar, PV, biomass “Negajoule” = energy saved
Global CO 2 Emissions are Increasing Keeling Curve Scripps Institute: http://www.climatecentral.org/gallery/graphics/keeling_curve
Future of Liquid Transportation Fuels? The Wall Street Journal, 5/22/17
Two Approaches to Reduce Liquid Fuels Emissions Engine Technology More fuel with less carbon – More miles with less fuel advanced low carbon biofuels Cellulosic materials: low carbon and with long term sustainability. Combined with efficient biofuel engines, emission reductions result. Shaver, 2014, Kakosimos, 2016; Allen, 2015
18 Biorefining sustainable processing of biomass into bio-based products: food feed chemicals materials and bioenergy: biofuels power and/or heat IEA Bioenergy Task 42 on Biorefineries, 2017 Houghton, Weatherwax, Ferrell, DOE SCE 0095, 2006 https://www.iea-bioenergy.task42-biorefineries.com/en/ieabiorefinery.htm
Agricultural Residues: Collection and storage must be efficient Corn Stover - stalks US Corn Stover 1 to 2 tons (dry basis)/acre 300 million tons / year stover Some Residue left on ground with permission, Shinners, 2009 Corn Sugarcane and bagasse Brazil Sugar Cane 7 to 10 tons (dry basis)/acre; Green residue: 3 tons /acre 300 million tons / year bagasse Unica Report, 2010
20 Iowa Cornstover Collection Study, 2008-2012 Biomass Program Overview, Poet / DSM 2008-2012
Corn Cobs: Large scale harvest and storage 200,000 tons / year in the Yucheng area - China Yinbu Qu, Shandong U., 12/4/2008
Global Agriculture = Water Requires Large Amounts of Water (Rainfall and Irrigation) Fertilizer, biotechnology (traits of productive crops) Irrigation = 70% of global fresh water consumption Research: drought tolerance or submergence (water) tolerance Nitrogen (Fertilizer) via Haber – Bosch Process (uses 3% of global gas production) 118 million metric tonnes / yr ($100 Bn / yr) ammonia Research: nitrogen fixing crops (plants and soils) Phosphorous Bioavailable orthophosphate; only 30 % of amount applied is actually used by plants (reacts with soils) Research: increase efficiency of phosphorous use and delivery of fertilizer Holistic Approach: Research: Precision Agriculture, Phenotyping, Genotyping, Stacked Traits Jez et al, Science, 353, 6305, 1241, 2016; Farinas, 2016; Plaut, 2015
SOIL HEALTH PRACTICES (Sequester Carbon) Crop Rotation Biosolids Application No Till Rotational Grazing National Academies Land Management Practices for CO 2 Removal…, 2018
Soil Carbon Sequestration 2-3 times more carbon in soil than in atmospheric (Stocker et al., 2013) 1.4 billion metric tonnes (G + C) can be stored annually agricultural soils 80% of potential G + C could be reached at $100 / ton CO 2 (Smith et al., 2008) But soil organic carbon will only increase over a finite period until new equilibrium occurs National Academies Land Management Practices for CO 2 Removal…, 2018
Gen 2 Second Generation (Cellulosic) Biofuels Major sources of uncertainty for cellulosic biofuels: Future oil prices, Feedstock costs and availability by region, Conversion costs and efficiencies, Environmental impacts, Government policy. The combination of all of these uncertainties makes analysis of biofuels impacts highly uncertain . Current condition of the financial markets causes difficult conditions for cellulosic biofuel investment Tyner, 2013
1. Biochemical vs Chemical Conversion David Dayton, NREL, IEA, 2007
Composition of Lignocellulosic Biomass Hardwood composition Ash 2% Extractive 2% Acetyl groups Similar Compositions 3% Corn residue Sugar Cane Bagasse Switch grass Hardwoods Glucan Lignin 44% 32% Lignin under-utilized Inhibits hydrolysis Protects structural Xylan carbohydrates 17% Ko, Kim, 2014
Biochemical Conversion of Cellulose Microbes Fuel, (Yeast, Bacteria) Chemicals Enzymes Feedstock 1 Feedstock 2 3 4 5 Pretreatment Hydrolysis Fermentation Separations Preparation CO 2 Catalysts 6 Combustion or Energy Residue Gasification Co-products Aqueous based, microbial/protein catalysts, mild conditions
29 2. Pretreatment Pretreatment disrupts biomass for better enzyme access Approximately 18% of total cost Mosier et al., 2005
Feedstock preprocessing needed for operability Liquefy (from slurry) if possible Minimize addition of chemicals Simplify pumps / pumping Understand inhibition / inhibitors Minimize hydrolysis during liquefaction (minimizes enzyme) Chose microorganism wisely Pictures of corn stover at 22% weight of solids / volume of water Modeling of liquefaction of lignocellulosic biomass (to start in 2018) Ladisch, Kim, Ximenes 2009; Ximenes et al 2010,2011; Cuhna, 2014; Ladisch, Wassgren, Mosier, Sharma, et al 2017
Addition of BSA to Enzyme High Yield at Lower Enzyme Loading and High Severity BSA Added No BSA Added No Pretreatment Kim et al, 2014 Cellic Ctec2 of 5 FPU (8 mg protein)/g glucan, pH 4.8, in 50 mM citrate buffer, 50°C, 200 rpm for 168 hrs. Equivalent to 3.5 mg/g total solids prior to pretreatment
32 Diluting Enzyme with Non Catalytic Protein Increases Yield As specific activity decreases, conversion increases Kim et al, 2014 Cellulase loading fixed at 1.8 FPU / g glucan, equivalent to 1.3 FPU / g pretreated solids
33 Pretreatment and Cost Effective Enzymes are Key Pretreatment: - makes substrate susceptible - decreases enzyme usage (increases yield) - releases enzyme inhibitors (increases enzyme usage) xylo-oligosaccharides phenols, tannic acids - may form fermentation inhibitors acetic acid aldehydes (fufural) phenols Science led to strategies for managing inhibition due to lignin. Engineering reduced enzyme requirement (and cost) by 5X.
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