All Biomass Is Local: Using Life Cycle Analysis to Enhance Biofuel - PowerPoint PPT Presentation

All Biomass Is Local: Using Life Cycle Analysis to Enhance Biofuel Sustainability Seungdo Kim and Bruce E. Dale Michigan State University 3rd International Conference on Life Cycle Management Zurich, August 27-29, 2007

Mature vs. Immature Industries • Life cycle analysis plays a somewhat different roles for mature industries (eg, petroleum refining) than it does for immature industries (eg, bioethanol production) • For mature industries the purpose of LCA is primarily to document & drive incremental environmental improvement • For immature industries, the purpose of LCA is to understand & guide revolutionary environmental improvement

Objective • Understand & improve the overall environmental performance of corn based ethanol production – Identify roles of N 2 O and of carbon sequestered by soil in GHG profile – Estimate local environmental effects due to farming sites on the ethanol fuel system – Determine the effects of alternative agricultural management practices, eg. cover crops, for reducing nitrogen losses from soil during corn cultivation – This represents a “ revolutionary ” change in agricultural practice (large departure from status quo )

Scope • Functional unit: bioethanol derived from corn grain used in an E10 fueled vehicle – reference flow: one gal of ethanol • Overall system boundary – Corn production, dry milling, E10 fueled vehicle operation • Environmental impacts – nonrenewable energy consumption, greenhouse gas emissions: global impacts – acidification, eutrophication and photochemical smog formation: these “ local ” impacts estimated by the TRACI model (USEPA)

System Boundary Agriculture process • Corn culture • Transportation of corn grain Biorefinery • Dry mill • Alternative product systems for DDGS (i.e., corn grain & soybean meal) Vehicle operation • Distribution of ethanol • Gasoline production • E10 fueled vehicle operation

Farming sites • 38 counties in eight states (Indiana, Illinois, Iowa, Michigan, Minnesota, Missouri, Nebraska and South Dakota) – To determine soil organic carbon and soil nitrogen dynamics in corn cultivation • Eight counties are chosen – To determine soil organic carbon and soil nitrogen dynamics in other cropping systems – To estimate environmental performance of the ethanol application system. – Each county has an existing ethanol plant

Ethanol Plants Freeborn, MN (FMN) Morrison, MN Tuscola, MI (MMN) (TMI) Codington, SD (CSD) Fulton, IL Hamilton, (FIL) NE (HNE) Macon, Mo Hardin, IA (MMO) (HIA)

Soil Organic Carbon and Nitrogen Dynamics • Simulated by the DAYCENT model – Predicting • Soil organic carbon level - leaching • N 2 O and NO x emissions from soil, NO 3 – Information required • County-based soil textures – clay, slit, sand • County-based data – Daily maximum and minimum temperature – Daily precipitation • Cropping management – Tillage, application rate of nitrogen fertilizer, irrigation, etc

Soil Organic Carbon Submodel Source: Natural Resource Ecology Laboratory, Century soil organic matter model: user's guide and reference, Colorado State University

Overall Carbon Sequestration* in Corn Agriculture: 8 Counties 500 444 450 C sequestration [CO2 kg/ha] 400 359 350 317 305 300 275 247 250 200 146 150 82 100 43 50 0 Hardin Fulton Tuscola Morrison Freeborn Macon Hamilton Codington Avg * Current tillage practices- “averages” are simply inadequate to represent system

Cropping Systems • Conventional corn cultivation (referred as CORN ) – Under current tillage practices • Planting winter cover crops in the CORN system (referred as COVER ) – Plant winter cover crops after corn harvest, kill cover crop before planting corn in the subsequent growing season – Winter wheat

Winter Cover Crops in Corn Rotation Winter cover crop May 5, 2005 Holt, MI

Bare Corn Field- Holt, Michigan May 5, 2005

Dry Milling • Process information: ASPEN PLUS models (NREL study, 2000) – Ethanol yield: 2.7 gal per bushel – DDGS: 8.4 kg per bushel – Energy consumption • Electricity: 0.80 kWh per gallon • Natural gas: 32,329 Btu per gallon • Allocation: System expansion approach – Introducing alternative product systems for co- products: DDGS: corn grain and soybean meal

GHG Profile in the CORN System 12000 N2O from soil 10000 C-seq GHG [kg CO2 eq./ha] Others 8000 4838 6000 3472 4169 3062 3194 2794 2757 2718 2338 2520 2652 2486 2422 2354 2310 2336 2241 4000 2115 2011 2249 2180 2217 2150 1967 1935 2115 2042 1789 1830 1957 1855 1689 1673 1832 1884 1647 1481 1214 2000 0 -2000 IA1 IA2 IA3 IA4 IA5 IA6 IA7 IA8 IA9 IA10 IA11 IA12 IL1 IL2 IL3 IL4 IL5 IL6 IL7 IL8 IL9 IL10 IL11 IN1 IN2 IN3 IN4 IN5 IN6 IN7 MI1 MN1 MN2 MO NE1 NE2 NE3 SD1 Counties GHG of corn production: 1.2 ~ 4.8 ton CO 2 per ha C-seq : carbon sequestration by soil Others: GHG emissions associated with agronomic inputs and fuel consumption

Effects of Cover Crop in Corn System 8000 Others C-seq N2O from soil GHG [kg CO2 eq./ha] 6000 4862 3963 3062 2241 3194 4000 2354 2794 1428 1704 1647 1061 378 1800 1935 964 803 2000 0 -2000 -4000 FIL:CORN HIA:CORN HIA:COVER FIL:COVER TMI:CORN TMI:COVER MMN:CORN MMN:COVER FMN:CORN FMN:COVER MMO:CORN MMO:COVER HNE:CORN HNE:COVER CSD:CORN CSD:COVER Counties GHG emissions CORN: 1.6 ~ 4.8 ton CO 2 per ha COVER: .38 ~ 3.9 ton CO 2 per ha

Effects of Winter Cover Crops w/ o cover crop GHG ACID w cover crop 10 1% 125% 122% 120% 100% 119% 120 % 118% 10 0 % 117% 99% 115% 99% 112% 111% 111% 110% 110 % 108% 106% 98% 106% of GVO 106% 98% 98% 98% of GVO 98% 98% 10 5% 103% 103% 97% 102% 97% 97% 97% 100% 97% 10 0 % 96% % 96% 96% % 96% 96% 96% 95% 96% 90 % 95% 8 5% 94% 8 0 % 93% HIA FIL TMI MMN FMN MMO HNE CSD GVO HIA FIL TMI MMN FMN MMO HN E CSD GVO System System EUTRO PHOTO 170 % 150 % 144% 160 % 157% 140% 140 % 137% 137% 135% 150 % 130 % 127% 138% 126% 140 % of GVO of GVO 124% 123% 132% 129% 120 % 117% 130 % 116% 116% 116% % % 111% 111% 120 % 109% 110 % 113% 108% 109% 110 % 106% 100% 105% 104% 10 0 % 101% 102% 101% 100% 98% 96% 10 0 % 96% 90 % 90 % HIA FIL TMI MMN FMN MMO HNE CSD GVO HIA FIL TMI MMN FMN MMO HNE CSD GVO System System

Cover Crops Reduce Nitrogen Losses Tenfold* 600 Inorganic nitrogen losses (kg N/ha) 479.00 500 397.00 400 300 197.00 194.00 200 5 to 10x reduction 100 65.00 41.40 0 CPSN (grain) CC (grain) CC (56% ) CwCo (70% ) CwSCo (70% ) CS (54% ) Cropping system *40 year time scale, Washington County, Illinois

Conclusions • Corn field considered here releases GHG emissions: 1.2 ~ 4.8 metric ton CO 2 eq. ha -1 – Most GHG emissions come from N 2 O from soil (0.6 ~ 4.0 metric ton CO 2 eq. ha -1 ) – Carbon sequestered by soil ranges from 2.2x10 -3 to 0.5 metric ton CO 2 eq. ha -1 • Planting winter cover crops (COVER system) increases soil organic carbon level by 1.1 ~ 15 times and reduces N 2 O emissions from soil by 3 ~ 55 % – lower GHG emissions associated with the corn field cont’d

• E10 fuel reduces nonrenewable energy consumption and greenhouse gas emissions (global impacts) compared to gasoline fuel • However, E10 fuel increases acidification, eutrophication and photochemical smog formation (“local” effects) compared to gasoline fuel, primarily due to nitrogen fertilizer in corn cultivation • Environmental performance of ethanol fuel system (farm to tailpipe) varies significantly with corn production sites, particularly for local environmental impacts • Winter cover crops improve the environmental performance of ethanol fuel for all environmental impacts considered here cont’d

All Biomass Is Local • Local conditions (farm specific conditions): – strongly influence ethanol fuel environmental impacts – these impacts vary widely with location • Therefore: – using averages to represent agricultural system environmental impacts is probably not justified and should be avoided. – location specific knowledge of these impacts is required– “all biomass is local”

Acknowledgements • U.S. Dept. of Agriculture • DuPont Biobased Materials • U.S. Dept. of Energy • Nature Works, LCC • GlaxoSmithKline • Metabolix

Questions ??

To (Mis)quote the Godfather: “It’s Not Business, It’s Personal”

Cover Crop Increases Soil Fertility While Still Removing Lots of Stover 65 CPSN (grain) CwCo (70%) CC (grain) 60 CC (50%) CwSCo (70%) CwCo (70%) 55 SOC (Mg/ha) CC (grain) CwSCoS (70%) CS (54%) CS (54%) 50 CC (50 %) 45 CPSN (grain) 40 35 1994 2004 2014 2024 2034 Year