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Reflections on the DOE/USDA report on the technical feasibility of a billion-ton annual supply of biofeedstocks Robin L. Graham Oak Ridge National Laboratory Workshop on Critical Issues in Climate Change Biotechnologies: Land, Production, Transformation and Economics Snowmass, Colorado August 2, 2006 http://www1.eere.energy.gov/biomass/pdfs/final_billionton_vision_report2.pdf WHAT WAS THE PURPOSE OF THE STUDY? • To determine whether the land resources of the U.S. are capable of producing a sustainable supply of biomass sufficient to displace 30% of the country’s present petroleum consumption – approximately equivalent to one billion dry tons. • Goal was set by a joint advisory committee to the DOE and USDA as a vision for making a major contribution to U.S. energy needs by 2030 – 5% of the nation’s power – 20% of the nation’s transportation fuels – 25% of the nation’s chemicals & materials from biobased products WHAT WAS THE Motivation OF THE STUDY? • In 2004, estimates of current and future biomass availability in the US were a confusing (a mess?) – Existing vs potential? – Physically available vs economically available? – Wet wt vs dry wt; mass vs energy content – Lots of resource type specific studies with differing underlying assumptions. ( e.g. differing resource estimates double counting the land base) – Regional vs national studies – Confusion between stocks and annual supply - especially for forest-derived resources – Often assumptions not given – Environmental and/or operational constraints to collection often not accounted for National level -Ugarte et al 2004 – energy crops w/ price & competition -Graham et al 1997- energy crop yield, acreage, cost -Graham 1994 – energy crop land base & yield -Gallager et al 2003 – residues w/price & competition -Haq 2002- all resources w/price WHAT WAS THE Motivation OF THE STUDY? • In 2004, because of the confusion concerning resource availability, it wasn’t clear whether or not bioenergy could play a significant role in the US energy. Nor was it clear what types of resources were most worthy of pursuit from the perspective of potential quantity. – Lots of “pet” resources – Need to target R&D on nationally significant resources • Need for a document which – Addressed ALL resources – Clearly stated assumptions – Was acceptable to USDA – Was written for a wide audience RESOURCE ANALYSIS APPROACH • Did not consider resource costs or policy changes required for land use, agriculture, and fuels & vehicles – Viewed our study as the first step. – Wanted to be viewed as neutral, not pushing a viewpoint. – RBAEF study ongoing and we wanted to be complimentary • Took a conservative tactic to answering the question – assumed business-as-usual in both the Ag and forest sector – Felt we needed to answer the question from a conservative viewpoint – Felt the knowledge base was adequate to answer the question we posed – Wanted the numbers to be transparent Overview of RESOURCE ANALYSIS APPROACH • Forest resource estimates based on analysis of existing resources, uses, and trends in the demand for forest products – Timberlands and other forestlands (public and private) – Provides multiple-use benefits (e.g., wildlife habitat, recreation, and ecological and environmental services) – Managed less intensively, more inertia to rapid change • Agricultural resource estimates based on scenarios extrapolated from current food/feed trends and R&D – Active cropland managed intensively on year-to-year basis – Idle cropland and pasture for perennial crops (grasses and woody crops) THE BIOMASS FEEDSTOCK RESOURCE BASE • About one-half of the land in the contiguous U.S. – Forestland resources: 504 million acres of timberland, 91 million acres of other forestland – Agricultural resources: 342 million acres cropland, 39 million acres idle cropland, 68 million acres cropland pasture • Forest resources • Agricultural resources – Logging residues – Crop residues – Forest thinnings (fuel – Grains to biofuels treatments) – Perennial grasses – Fuelwood – Perennial woody crops – Primary wood processing mill – Animal manures residues – Food/feed processing residues – Secondary wood processing – MSW and landfill gases mill residues – Pulping liquors – Urban wood residues THE BIOMASS FEEDSTOCK RESOURCE BASE Target 1+ Billion Tons of Biomass Resources Available for Bioenergy and Bioproducts (Excludes conventional Food/Feed/Fiber) Biomass from Other Secondary and Biomass from Currently Agricultural Tertiary Biomass from Forest Lands Collected Lands Ag. and Forest Lands and Used Wood and Residues MSW and to Pulp & Paper and Grain Crops Urban Wood Forest Product Mills Waste Animal Oil Crops Fuel Wood Manures Food Processing Logging and Agricultural Wastes Other Removal Residues Residues Fuel Perennial Treatments Grasses Energy crops Woody Crops CORN STOVER - LARGEST RESIDUE RESOURCE Amount is dependent on crop yield, collection equipment, tillage practices, and environmental restrictions SWITCHGRASS PRODUCED IN 10 YEAR ROTATIONS WITH ANNUAL HARVEST, USING CONVENTIONAL AGRICULTURAL EQUIPMENT POPLARS GROWN ON CROPLAND AT 8-12FT SPACINGS, 6-10 YR ROTATIONS, HARVESTED WITH FORESTRY EQUIPMENT Early 2nd yr poplar growth WILLOW PRODUCED ON CROPLAND AT 1-3 FT SPACINGS, HARVESTED IN 3 YEARS WITH SPECIALIZED EQUIPMENT Willow at harvest age Fuel treatment thinning operations Forest resources • Logging residues – From conventional harvest – tops, branches NOT needles/leaves – Forest management ( rough & rotten wood) and land clearing for logging roads etc • Fuel treatments – forest thinning to reduce susceptibility to catastrophic wild fire • Fuelwood – e.g. for wood stoves • Wood residues from forest products – Primary residues -fine (e.g. sawdust) ,coarse ( e.g. slabs), bark – Secondary residues ( fine & coarse) • Pulping liquor • Urban wood waste – Discarded wood waste ( pallets, packaging materials, wood scraps) – Yard trimmings – Construction & demolition RESIDUES FROM LOGGING, SILVICULTURAL OPERATIONS & CLEARING OF TIMBERLANDS • Timber Product Output database • 70 million dry tons generated annually • Collected concurrently with operations • 50% to 65% of biomass is recoverable (public vs private lands) • All recovered material (~ 41 million dry tons/year) for biomass uses • Estimated to increase to ~ 64 million dry tons/year RESIDUES FROM FUEL TREATMENT OPERATIONS • Timberlands – Fuel Treatment Evaluator used to identify biomass requiring removal – Recovery of 85% of the identified biomass – Accessibility – 60% for public lands and 80% for private lands – Biomass fraction – 30% (70% conventional forest products) – Collection cycle – 30 years • Other forestlands – Forest Inventory Analysis database used to identify biomass (50% removal) – Recovery of 85% of the identified biomass – Accessibility – 60% for public lands and 80% for private lands – Biomass fraction – 90% – Collection cycle – 30 years FOREST RESOURCE SUMMARY ~ 368 M ton/yr in 2030 Logging and other removal residue Fuel treatment thinnings - timberlands Fuel treatment thinnings – other forestland AGRICULTURAL RESOURCES • Took a scenario approach because – Unlike forests, cropland is intensively managed and on a short time frame so over the next 30-50 years there are lots more “options” – Needed to include the possibility of energy crops and currently there are none so you can’t really extrapolate • Did ground the scenarios utilizing USDA research data and expert opinion – USDA-NASS: Agricultural Statistics 2003 (2001 crop data) – USDA-OCE: Baseline Projections to 2012 & 2013 – USDA-ARS: National Agronomy Manual – USDA-ARS: R&D on forage soybeans yield and residue – USDA-NRCS: Soil Conservation Index version 25 – USDA-ERS: Confined animal and manure data – Corn & wheat residue analyses (Graham et al) – Corn planting density effects research (U. of Nebraska & Pioneer Hi-Bred) – DOE - Roadmap for Agricultural Biomass Feedstock Supply – FAO and UN population and crop yield projections – Literature - yield potential and crop residue management Agricultural biomass resources • Other residues – MSW & animal fats & corn fiber not used for animal feed • Manures - from confined feedlots in excess of what can be applied on farm • Grain to fuel – sugars, starch and oils • CRP biomass – harvest 1 ton/acre, no harvest on CRP for wildlife • Other crop residues – rice, cotton lint • Soybean residues – development of new varieties with much higher residue/grain ratio ( e.g. much lower harvest index) • Small grain residues other than wheat – barley, oats • Wheat straw • Corn stover • Perennial energy crops – switchgrass, poplar, willow (ylds 5 or 8 dry tons/acre) AGRICULTURAL RESOURCES considered by scenario Current Mod yld High yld Mod yld High yld No energy No energy Energy crop Energy crop Other Yes Yes Yes Yes Yes residues Manures Yes Yes Yes Yes Yes Grain to fuel Yes Yes Yes Yes Yes CRP biomass Yes Yes Yes Yes Other crop Yes Yes Yes Yes Yes residues Soybean Yes Yes residues Small grain Yes Yes Yes Yes Yes residues Wheat straw Yes Yes Yes Yes Yes Corn stover Yes Yes Yes Yes Yes Perennial Yes Yes energy crops AGRICULTURAL RESOURCE ANALYSIS • Approach (“what if”) based on available information & expert opinion on potentials (e.g., crop yields, equipment efficiency, etc.) • Crop yields (annual and perennial crops) – 15% to 50% for annual crops – 5 to 8 dry tons/acre/year for perennial crops • Residue to grain ratios – Vary by crop; only soybean ratios change in scenarios • Harvest/collection efficiency – 40%, 60%, 75% • Tillage practices (no-till) – Current tillage with changes up to 100% no-till • Allocation of cropland acres – Perennial crops accommodated with reductions in active cropland, idle cropland, and cropland pasture • Used current trends, research directions and previous analysis results such as: – 30 yr average corn yield increase at 1.7 bu/ac – Research to develop soybeans with higher forage content (higher residue to grain ratio) – Research to develop more efficient and one-pass harvesting equipment – Increasing levels of no-till management – POLYSYS analysis indicating potential acreage available to energy crops under various market conditions. • Consultation with USDA scientists Ground rules – No perennial energy crops • Without energy crops – – Acreage of conventional crops fixed at USDA 2014 projections – Corn and soybeans could go to fuel only after food, feed and export met • Food = 2014 baseline or 137% of current ( pop increase in 50yrs) • Feed = 2014 baseline or 137% of current ( pop increase in 50yrs) • Export = 2014 baseline or higher – Tillage shifts to no-till to allow more residues removal • 200 M acres to all acres – Residue • collection efficiency increases 60% or 75% • Enough left to prevent unacceptable erosion – Crop yields increase • Corn & wheat – 25 to 50% increase • Rest – 15-30% increase – Manure – only from confined animal feed operations Ground rules – With perennial energy crops • With energy crops – – Acreage of conventional crops fixed at USDA 2014 projections except under high scenario when • Wheat acreage loses 5 M (52.3 to 47.3) • Soybeans lose 8 M (71.4 to 63.4) • Other hay loses 5 M (34.2 to 29.2) • Remaining acreage comes from cropland used for pasture, idle, and CRP used for grasses – Corn and soybeans could go to fuel only after food, feed and export met • Food = 2014 baseline or 37% higher than current ( pop increase in 50yrs - FAO) • Feed = 2014 baseline or 37% higher than current ( pop increase in 50yrs) • Export = 2014 baseline or higher – Tillage shifts to no-till to allow more residues removal • 200 M acres to all acres – Residue collection • efficiency increases 60% or 75% • Enough left to prevent unacceptable erosion – Crop yields increase • Corn & wheat – 25 to 50% increase ( 2020 & 2043) • Rest – 15-30% increase – Energy crop yields – 5 or 8 dry tons/acre/yr but 10% loss in harvesting CURRENT AVAILABILITY OF BIOMASS FROM CROPLAND • Total current availability of biomass is ~ 190 million dry tons/year • Slightly more than one-fifth is currently used • Corn stover is largest source of agriculture- derived biomass CROPLAND BIOMASS POTENTIAL WITH ENERGY CROPS • Potential from all cropland biomass resources approaches 1 billion dry tons/year • Primary sources alone are 420 – 800 million dry tons • Perennial crops average harvested yield 4.7 – 7.4 dry tons/ac; 40 - 60 million acres WHAT IS THE CROPLAND POTENTIAL? • Total resource 560 to 930 million dry tons/year – Yield increase of 25 - 50% for corn and other small grains, 15 - 30% for other crops – Change in tillage practices – Residue collection equipment – Residues from soybeans – The allocation of active cropland, idle cropland, and pasture to perennial crops so..ARE THERE potentially SUFFICIENT BIOMASS RESOURCES TO REPLACE A SIGNIFICANT FRACTION OF THE NATION’S PETROLEUM REQUIREMENTS by 2030? • Yes, land resources could provide a sustainable supply and still meet food, feed, and export demands • Estimates are reasonable given trends and time for biorefinery scale- up/deployment SUMMARY • Primary land resources (i.e., crop residues, perennial energy crops, and forest residues) are sufficient to support 30% replacement of gasoline use by 2030 • Use of cropland and forestland biomass resources could support biorefineries in all 50 States Current capacity is a small fraction of potential (map shows biochemical only – no manure, MSW) Issues • Policies needed to effect change – agriculture, land use, Conclusion and fuels & vehicles conclusion • Coordinated Technology change and RD&D needed – Yields & residue/grain ratios – Tissue quality – Reduction of nitrogen fertilizer without loss of yield • Water quality • Energy • Genetic solutions/Agronomic solutions ( e.g. rotations) – Harvesting Conclusion & on farm preprocessing – Storage of residues and grasses – Forest harvest technology Issues • Environmental uncertainties ( positives and negatives) Conclusion – Impacts of residue removal on soil carbon & wildlife and nutrientsconclusion – Impacts of energy crops on soil - enhanced sequestration – Water quality & quantity w/energy crops (quality is a generally positive; quantity?) – Wildlife impacts as a result of land use & management change – forests and croplands Unintended – Conclusion geneflow from genetically modified organisms to native populations • Some tools for evaluating these issues – EPIC, Century, SCI, RUSLE • Uncertain ownership of these issues – site specificity of response. Difficult to generalize.
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