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Implications of Biofuels for Nutrient Cycling in Agriculture. Luc M. Maene and Patrick Heffer International Fertilizer Industry Association (IFA). SCOPE Biofuels Rapid Assessment Project Workshop 22-25 September 2008, Gummersbach , Germany. Contents. Evolution of Biofuel Production
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Implications of Biofuels for Nutrient Cycling in Agriculture Luc M. Maene and Patrick Heffer International Fertilizer Industry Association (IFA) SCOPE Biofuels Rapid Assessment Project Workshop 22-25 September 2008, Gummersbach , Germany
Contents • Evolution of Biofuel Production • Wastes and Co-products Generated during Biofuel Production • Impact of Biofuels on World Fertilizer Consumption • Implications of Biofuels for Nutrient Cycling • Outlook • Conclusion
Evolution of Global Biofuel Production (billion gallons) 2007 world output = 18.7 Bgal according to FAPRI 1981 2007 Source: IEA and F.O. Licht, in W. Coyle
Biofuel Production by Country in 2007 Source: F.O. Licht, in W. Coyle
Ethanol ProductionGlobal Feedstocks (2006) Tubers, mostly cassava Sugar crops, mostly sugar cane Cereals, mostly maize Source: IFA Biofuels Report, PotashCorp
Biofuels – Where Are We Going? • 2007 world output ~19 billion gallons (Bg) • Ethanol: 16.3 Bg • Biodiesel: 2.4 Bg • Very ambitious targets • USA: 9 Bg in 2008 24 Bg by 2017 • EU: 10% in vehicle fuels by 2020 • Brazil / Argentina: biodiesel targets • Realistic mandates? • Enough land and water available? • Environmental impact? • Food and nutrition security impact? A pause in biofuel expansion is likely Mandates might be revised downward Sources: FAPRI, USDA, EC
US Biofuel Outlook US Maize Uses (bill bu) 2007 US Renewable Fuel Standard (bill gallons) Total RFS RFS ethanol derived from com starch Source: USDA
Global Biofuel Outlook These projections do not take new US and EU mandates into account World Ethanol Output (Bg) World Biodiesel Output (Bg) Source: FAPRI
Relative Evolution of World Maize Uses Base 100 172 Mt Co-productsused as feed 485 Mt 85 Mt Source: IGC
Products Resulting from the Wet and Dry Milling of Maize Source: F.O. Licht
Distiller’s Dried Grains with Solubles (DDGS) • Result of a combination of coarse grains and solubles generated during ethanol production from maize (dry milling) • In the USA, 75-80% of distiller’s grains is sold to local livestock producers as DDGS • DDGS has higher protein content than maize grain (starch removed) • Can be included in feed up to: • 30% for cattle • 10-15% for poultry and swine
Biofuel Co-product Use US Consumption of DDGS • ~20 Mt of maize co-products are used as animal feed in the USA (i.e. ~9% of the US feed volume) vs. ~150 Mt maize and ~30 Mt soybean • Rapeseed conversion to diester generates 40% oilseed cake. Glycerine is another marketable co-product Poultry Swine Ruminants Source: Feedstuffs
The First Commercial-Scale Closed Loop Refinery, Mead, Nebraska, USA N2O CH4 CO2 CH4 CO2 Corn & soybean production Ethanol Plant (24 M gallons/yr) Grain8 M bu/yr= 15,000 ha Ethanol NO3 leaching Stillage 100% thermal energy CH4 Grain Distillers grain CH4 CO2 N2O CH4 Cattle Feedlot (28,000 heads of cattle) Methane Biodigestor Meat manure, urine Biofertilizer NO3 leaching Horticultural uses/organic ag? Fertilizer offset in crop production www.e3biofuels.com
Ethanol from Sugar Cane • Co-products/wastes generated during cane-based ethanol production in Brazil: • Filter cake: 12 kg/t sugar cane • Vinasse: 10-15 litres per litre of ethanol • Bagasse: ~300 kg/t sugar cane; burnt to supply energy to sugar mills and bioethanol plants • Trash: 4Mha are currently burned before harvesting; progressive conversion to mechanical harvest • Vinasse, filter cake and ashes are largely returned to the field as nutrient sources
Fertilizer Applications to Main Feedstocks in 2006/07 • Assumptions: • ~50% of Brazilian cane converted to ethanol • ~30% of US maize converted to ethanol • 10-15% of EU rapeseed converted to biodiesel • Similar application rates by crop for food, feed and biofuel uses Source: IFA
Estimates of Global Fertilizer Use on Biofuel Crops in 2007/08 (Mt nutrients) 4.2% 2.1% 1.9% Source: IFA
Impact of Biofuel Production on Fertilizer Demand • Impact on nutrient requirements (larger cultivated area, more fertilizer-intensive crops, higher yields) • Changes in nutrient flows through recycling of wastes (vinasse) and co-products (DDGS, oilseed meals) • Strong impact on prices of feedstock (maize, oil crops, sugar crops) and other crops through competition for land • Higher crop prices Higher fertilizer application rates
Where Do Nutrients End Up ? • Ethanol and biodiesel do not contain N, P and K • In biofuel production processes, N, P and K end up in wastes and co-products • With maize-based ethanol and rapeseed-based biodiesel, most of the N, P and K is in distiller’s grains and oilseed meals, which serve as animal feed • Part of the N, P and K in animal feed goes back to the soil through manure applications • With cane-based ethanol, a large share of the N, P and K in the wastes is recycled directly to the soil
Nutrient Content of DDGS 1 Conversion factor protein to N: 0.16 (6.25 kg protein contains 1 kg N) Source: US Grains Council
Estimated Amount of Nutrients in Ethanol Co-products Used as Animal Feed in the USA • Assumptions: • ~20 Mt of the maize co-products are used as animal feed in the USA • The co-products are mostly DDGS
Estimated Amount of Nutrients in Ethanol Co-products Used as Animal Feed in the USA • ~1.2 Mt N+P+K from ethanol co-products are used as animal feed in the USA • Equivalent to ~15% of the fertilizer nutrients applied to US maize (7.9 Mt N+P+K) • Equivalent to ~16% of the N, ~20% of the P and ~9% of the K applied to maize as fertilizers • This amount will increase with ethanol production expansion • Feed use efficiency and recycling through manure application should be improved to reduce nutrient losses
Potential for Recycling Nutrientsin Ethanol Co-products Production in Brazil • Half of the sugar cane is used for ethanol production • A large share of the nutrients contained in filter cake, vinasse, trash and ashes is already returned to the soil • Substantial N losses are still due to cane burning and manual harvesting Half of this amount comes from ethanol production; the other half from sugar production Calculated from : VII e VIII Seminarios de Tecnologia Agronômica Copersucar
Local vs. Trans-boundary Impacts • US ethanol is mostly produced from domestic maize • Impact mostly local through nutrient accumulation spots, relocation of feedlots next to ethanol plants… • Trans-boundary impact through smaller maize exports • Brazilian ethanol is exclusively produced from domestic cane • Mostly local impact; limited due to good nutrient recycling • EU biodiesel is mostly produced from domestic rapeseed • Impact mostly trans-boundary through changes in vegetable oil and oilseed meal trade (likely less soybean meal and more palm oil imports in the medium term)
Ligno-Cellulosic Ethanol • Ligno-cellulosic materials (maize stover, cane, grass, forestry material) all export large amounts of K • K supply/demand balance is very tight • Process and management should allow for optimum recycling of K, otherwise large additional K fertilizer production capacities would be required Source: IFA World Fertilizer Use Manual
Biodiesel – Emerging Feedstocks • Oil palm • Attempts to produce biodiesel from palm oil in SE Asia, and to export feedstock to the EU • Large K (and Mg) requirements recycling needed • Soybean • Development of biodiesel from soybean in the USA, Brazil and Argentina • Will increase soybean acreage and soybean meal availability • Jatropha • Tolerant to drought, but productive only under favourable conditions will require appropriate nutrient supply
Conclusion • Currently, potential for recycling: • US maize-based ethanol: ~1.2 Mt N+P+K from distiller’s grains (mostly N) • Brazilian cane-based ethanol: ~0.5 Mt N+P+K from cane co-products (mostly K) • EU rapeseed-based biodiesel: smaller amounts (~5.5% N and 0.8% P in rapeseed cakes) • Amounts expected to rise quickly • Use of ligno-cellulosic material and palm oil as feedstocks will require careful K management
Contact for further information pheffer@fertilizer.org www.fertilizer.org