Switchgrass and Perennial Grasses, Biomass, and Biofuels- 2012 Ken Vogel USDA-ARS,Lincoln, NE

Main Conclusion U.S. can displace over 30% of current petroleum consumption by 2030 using crop residues and other sources including biomass from perennial herbaceous crops for the production of cellulosic ethanol. Emphasis on cellolosic energy because of food vs fuel problem.

http://feedstockreview.ornl.gov/pdf/billion_ton_vision.pdf 2007 Energy Independence and Security Act (EISA) • EISA requires EPA to revise the Renewable Fuels Standards (RFS) program to increase renewable fuel blended into transportation fuel from 9 billion gallons in 1998 to 36 billion gallons per year by 2022. • Revised standards (RFS2) was finalized in 2010.

Renewable Fuel Standard revised 2010 (RFS2) • The RFS goal is 36 billion gallons per year for renewable fuels by 2022. • RFS2 limits the amount of corn ethanol that counts toward the requirement to 15 million gallons per year. • The remaining 21 billion gallons must come from other non-food or cellulosic sources • Other sources are corn stover, perennial grasses, woody biomass, and algae. U.S. Billion-Ton Update 2011

• Increased emphasis on dedicated energy crops including herbaceous perennials such as switchgrass, other grasses and woody species. • Sustainable use of crop residues.

Some Questions

• Why not just use corn stover? • Why switchgrass? • Why other perennial grasses? • How are we going to get fuels out of this stuff? • Where are we at on management, cultivars, and other improvements? Long term Carbon sequestration Study- Corn & Switchgrass, Mead, NE • Quantify carbon sequestration on cropland converted to switchgrass.

• Compare to no-till corn.

• Experiment in eastern NE established in 1998.

• In 2000, plots split and stover removed (50%) on split half of corn plots.

Corn Grain Yield – Effect of removing ½ of stover

Corn Grain Corn Grain after removal

25

20 - 7.2% grain

15 ½ stover removed stover ½ 10

5 Grain Biomass (Mg/ha) Grain Biomass 0 2000 2001 2002 2003 2004 2005 2006 2007 Mean Wally Wilhelm Gary Varvel Factors Limiting Crop Biomass Removal

8

)

1 - Soil organic carbon 6 Water erosion 5.58 Wind erosion

4 3.38 3.56 3.52

2.34 2 1.39 1.22 0.77 0.29 0.43 0.15

Stover to (tonac retain Stover 0.06 0 Moldboard No or Moldboard No or plow conservation plow conservation tillage tillage

Continuous corn Corn-soybean

Wilhelm et al., 2007. Agron. J. 99:1665-1667. ARS-REAP Switchgrass Biomass Feedstock Research • 1980’s, : Oak Ridge National Laboratory, DOE, in cooperative work with Universities & USDA-ARS. Species evaluations. Selected switchgrass & hybrid popular & willow. • 1990’s, 2000-2002. Funded research at Univ. & ARS. • 2002. DOE switchgrass work discontinued. All feedstock and conversion research switched to corn stover and crop residues. • 2002 to present. New thrust by USDA-ARS. Perennial energy crop research. A few land-grant universities continue programs. • 2006 – present. DOE renews major funding effort with focus on basic biology & conversion. New USDA funding. Private Companies funding inhouse research.

Why Switchgrass?

• Native to N. America • Low energy input east of Rocky Mtns. • Increased carbon • Adapted germplasm storage. available. • Soil and water • High yield potential conservation benefits. • Can harvest and grow • Excellent wildlife like hay using farm habitat. equipment. • Buffer strips, wetlands • Multiple uses on/off • Seed easy to plant farm

Switchgrass Panicum virgatum L.

Upland switchgrass plant Natural distribution of switchgrass In North America USDA-ARS Grain, Forage, & Bioenergy Research Unit, Lincoln, NE Switchgrass research 1930’s to present • Native prairie species, domestication, breeding & management work to revegetate grasslands after drought of the 30’s • Use by livestock was emphasized • 1990 - began work to develop switchgrass into a biofuel crop. • 2000 - Information used for farm scale production trials Biomass Power Back to the Future

• 1920 - 27,000,000 horses & mules, USA • 1954 - < 5,000,000 • Resulted in major land use change. • 80 million acres of pasture & hayland (biomass) released for other uses.

Horse power to tractor power – land use changes, government programs, & bioenergy

Fields in northeast Nebraska • Marginal land previously in pasture converted to grain crops. Severe erosion. • Crop surpluses depressed prices requiring farm subsidizes • Conservation Reserve Program (CRP): over 35 million acres in CRP. • Annual cost is $1.7 billion. Switchgrass field in same region • CRP land east of 100o W. Long. could be used for perennial biomass energy crops (switchgrass). • All conservation benefits would be retained. • Equivalent amount of marginal cropland in USA.

Research Accomplishments

• Harvest management and timing • Nitrogen fertilization rates • Cultivar evaluations, classification, and geographic adaptation • Genetic improvements and new cultivar development • Genetic diversity and gene pools • Production economics Harvest Management Vogel et al. (2002)

12

First cut 10 Second cut 8

6

4

2 Biomass Yield (Mg/ha) Yield Biomass 0 1 2 3 4 5 6 7 8 Harvest interval (late June to late August) Nitrogen Fertilization Vogel et al. (2002)

11

10 Ames, IA 9 8 Mead, NE 7 Above this point, N application rate exceeded N removal rate, increasing NO3-N

Biomass Yield (Mg/ha) Yield Biomass 6 in the soil. 0 60 120 180 240 300 Nitrogen Applied (kg/ha) Northern Plains Switchgrass Field Scale Production & Economic Trials 2000-2005

15”-17” Annual 2000-2005 Precipitation On-Farm Production Trials:15-20 acre (6- Cooperating farmers paid 9 ha) fields to manage fields as biomass energy crops.

31”-33” Annual Precipitation

DOE/USDA Biomass Feedstock Stage Gate Review Meeting March 14-16, 2005

• Improved Plant & Production Practices for Grasslands & Biomass Crops in the Mid- Continental USA

Kenneth P. Vogel USDA-ARS, Lincoln, NE

Plant Genomics for Biofuels" BP-DOE Office of Science Review June/05 Ari Patrinos (DOE) & Steve Koonin (BP) • Participants • Speakers – Justin Adams, BP – Chris Somerville – John Pierce, DuPont – Richard Flavell – C. Saunders, Pioneer – Elliott Meyerowitz – Don Doering, Winrock – Craig Venter – Jim Barber, Metabolix – Jerry Tuscan – Biotechnology Ind. Org. – Steve Straus Reps. – Ed Buckler – Other invited industry reps. – Ken Vogel – USDA & DOE Senior – 4 others Executives

Science editorial: 1/27/ 2006 Steve Koonin, BP Chief Scientist endorses biofuels from cellulosic sources such as switchgrass.

Science 2006 cover story. Tillman et al. Science 2006 314:1598- 1600. Low input-high diversity grasslands for biofuels. Switchgrass for Bioenergy – On farm economic study in NE, SD, ND.

• Field shown at left had a five Switchgrass field in NE South Dakota year cumulative average cost in 2005. Yields averaged 4T/acre. of $33/T switchgrass biomass including land & money costs.

• Average costs for 10 farms was $60/T; two experienced farmer’s costs were $39/T.

• Each big bale (left) represents a 50 gal barrel of ethanol at conversion rate of 0.38 L/kg with average farm gate cost of $0.64/gal. Low cost producers = $0.53/gal at the farm gate. Perrin et al. 2008 BioEnergy Research 1:91-98 (US units)

Take Home Lessons

• Economic production efficiency can be improved via research and producer training. • Adaptation and production trials in potential biomass production areas are needed. • Improved high yielding cultivars/hybrids with improved conversion efficiency will be needed. • Additional agronomic research on fertility, establishment, seed quality, & other factors. • Feedstock harvesting and storage research needed.

Net energy and petroleum inputs from corn and cellulosic (switchgrass) ethanol (Ferrell et al. Science 2006 311:506-508)

Ignored co-products & Used outdated agronomics

Models over-estimate switchgrass inputs

15

) Estimated Inputs -1 12 Actual farm inputs from 5-yr Other USDA study 9 Machinery & Labor Herbicide 6 Seed Diesel Fertilizer

3 Agricultural Inputs (GJ ha (GJ Inputs Agricultural 0 Estab. Post. Farrell et al., Pimentel & Wang et al., 2006 Patzek 2005 1999 On-farm Switchgrass Production in the Great Plains – Net Energy • Previous models over-estimated the energy inputs for switchgrass production by as much as 2X • Switchgrass produced 13X more energy as ethanol than was required as energy from petroleum • Switchgrass produced 540% more renewable than non-renewable energy consumed on marginal land when properly managed • Switchgrass biofuel production systems are economically feasible, environmentally sustainable, and energetically positive on marginal cropland in the central USA east of the 100th Meridian

Schmer et al. 2008 – Proceedings of the National Academy of Science Ethanol from switchgrass: Input - output illustration.

Big round bale of switchgrass – 0.7 ton (0.63 Mg). Conversion rate of 80 gal/ton (330 L/Mg)

Output Input Net energy 8 gal.(30 L) 50 gal (180 L)

Based on Schmer et al., 2008. PNAS105: 464-469. Managed switchgrass produced 97% more ethanol yield than man-made prairies USDA study Low yielding farms 4000

Mean yield ) -1 High yielding farms 3000

Tilman et al., 2006 2000

1000 Ethanol Yield (L ha

0 Switchgrass LIHD LI-SW Corn grain (Field-scale) (NGP) Switchgrass grown for bioenergy: Soil carbon storage in 5 years: 0-120 cm Switchgrass Soil Carbon Sequestration when grown and managed as a biomass energy crop • Field at left for period Douglas, Nebraska Field 2000 to 2005 - 0 to 30 cm: 5 Mg C/ha increase in soil carbon (2.2 t/A) - 0 to 120 cm: 18.4 Mg C/ha increase in soil carbon (8.2 t/A) (Liebig et al., Agron. J. 2008). Coffee Break – Stretch Break

• After break topics – Adaptation – Yield – Breeding & new cultivars – Other species – Conversion methods – Biomass quality – Improve Agronomic and Genetics

Ecoregions Geographic regions for which thermal and moisture (amount and season) determine dominant plant populations.

Ecoregions of the USA 1990 USDA Plant Hardiness Zones growing season length, temperatures.

Plant Adaptation Regions of the USA USDA Hardiness Zones

Vogel et al., 2005

Bailey’s Ecoregions Target Plant Adaptation Regions 251-HZ 4&5 Prairie Parkland 332-HZ 4&5 Great Plains Steppe 331-HZ 4&5 Great Plains-Palouse Dry Steppe Switchgrass Adaption

• Switchgrass is photoperiod sensitive (Benedict, 1941) and is a determinate species. • Photoperiod requirements are based on the latitude-of- origin of individual ecotypes. Flowering is induced by decreases in daylength following the summer solstice. Photoperiod also affects winter sensence. • When grown in the central Great Plains, switchgrasses from the Dakotas (northern ecotypes) flower and mature early and are short in stature while those from Texas and Oklahoma (southern ecotypes) flower late and are tall (Cornelius and Johnson 1941; McMillian 1959). Switchgrass Adaption (cont.)

• In North America, moving northern ecotypes south exposes them to a shorter-than-normal daylength during summer month, which causes early flowering, reducing biomass yield. • The opposite occurs when southern ecotypes are exported north. They remain vegetative for a longer period of time, with a longer photosynthetically active period, often producing more forage than northern ecotypes (Newell, 1968). • The physiological development of switchgrass as determined by a maturity staging system is highly correlated to Day of Year and Growing Degree Days with DOY being the most important.

Switchgrass General Adaptation Rule • Switchgrass strains should not be exported more than one USDA Plant Hardiness Zone north or south of their area of origin for long term survival under biomass production conditions. • East-west adaptation is a function of disease resistance (more humid conditions – more disease pressure) or drought tolerance. • Plant Adaption Region (PAR) of origin is a good indicator or where switchgrass strain can be used. In current environmental conditions, switchgrass strains can be used in origin PAR and adjacent PAR. Some cultivars have wider adaptation zones. Revised USDA Plant Hardiness Zone Map 2012 Plant Hardiness Zones have shifted ½ zone north since 1990

PHZ 4b

PHZ 5a Adaptation and Breeding and Management for Biomass Yield • The easiest way to breed for improved biomass yield is to use southern ecotypes to extend the effective length of the pre-flowering growing season. • Problem is winter survival. Plants need to move storage carbohydrates to the roots for winter survival. Because of photoperiod, southern ecotypes may start this too late in northern latitudes and winter kill. • Basic research on physiology and genetics of fall sensence and spring green-up being conducted by G. Sarath. • If climate warming continues, it will affect adaptation and also pathogen and insect populations. • Regional trials are being used to track adaptation and productivity.

Land required to produce feedstock for a 50 million gallon (190 ML) cellulosic ethanol plant in a 25 mile (40 km radius).

Feedstock Yield Acres (Mg/ha) % of Land Area tons/acre (Mg/ha) 1 (2.2) 625,000 (250,000) 50

2 (4.5) 312,500 (125,000) 25

3 (6.7) 208,333 (85,000) 17

4 (9.0) 156,250 (63,000) 12

5 (11.2) 125,000 (50,000) 10

7.5 (16.8) 83,333 (34,000) 6.6

10 (22.4) 62,500 (25,000) 5

A 50 million gallon plant requires 625,000 tons (567,00 Mg) of feedstock/year at 80 gal/ton or 330 L/Mg conversion rate.

Breeding Progress for Conventional Switchgrass Cultivars Yield Trial Mead, NE 2003-2005

Cultivar Year released Biomass yield - IVDMD Ton/a (Mg/ha) (%) (mature) Trailblazer 1984 6.3 (14.1) 52.5

Shawnee 1995 6.5 (14.5) 54.8 NE Late YD 7.0 (15.7) 55.2 C4* Improve biomass yields – hybrid cultivars

Strain Yield T/A (Mg/ha) Kanlow & 9.4 (21) Summer F1’s Kanlow 7.1 (16) Summer 6.1 (14)

• Improved hybrid cultivars with modified cell walls could improve ethanol yields & reduce costs.

USDA switchgrass study 10 locations 165 acres seeded Seeded with commercial drills Man-made prairies Dryland sites One location Harvested entire field Small-plots with commercial hay Hand-seeded equipment Irrigated during establishment Hand-weeded Hand-harvested using 4” strips 14% to 78% more annual precipitation than USDA switchgrass fields Biomass Energy Crops for the Central USA

Switchgrass

• Perennial grasses such as switchgrass and big bluestem. • Biomass sorghums. • Corn stover Big bluestem

Biomass Corn Sorghum Stover Other Prairie Species with Biomass Energy Potential Illinois ‘Scout’ Indiangrass Bundleflower PAR germplasm releases pending

Partridge Pea – germplasm Big bluestem cv Goldmine release Switchgrass seed – a principal attribute

• Switchgrass seed is easy to harvest and plant. • Seed yields can be high 400 to 1000 lbs/acre. Seed cost less than for other native species. • Limited amounts (3-4.5 lbs PLS) needed to plant a field. • Other natives have chaffy seed requiring special processing and planters.

Biofuels from Biomass

Biological Conversion Saccharification Fermentation Ethanol Sugar Butanol

Perennial grasses Thermochemical Conversion Fischer- Gasification Synthesis Tropsch gas Methanol Crop residues Jet Fuel Heat Gasification Power Gasoline Pyrolysis Diesel Bio-oil Manure Hydrotreating-

Hydrocracking Lignocellulosic Biomass Lignocellulosic Liquid Phase Chemical Processing Saccharification Gasoline Wood waste Sugar Liquid Phase Kerosene Processing Biological Catalytic Starch Jet Fuel Glycerol Thermochemical Liquid Phase Diesel Processing

Biological Conversion of Biomass

Swithchgrass

Saccharification Fermentation Ethanol Corn stover Sugar Butanol

Manure Lignocellulosic Biomass Lignocellulosic Status: Pilot plants are in operation, first full scale biorefineries will go into operation next year using crop residues and perennial grasses Wood waste

Biological

Thermochemical Conversion of Biomass

Swithchgrass Fischer- Gasification Tropsch Synthesis Methanol gas

Corn stover Heat Gasoline Gasification Power Diesel Pyrolysis Deoxygenation Bio-oil Jet Fuel Hydrotreating-

Manure Hydrocracking Lignocellulosic Biomass Lignocellulosic

Status: Pilot plants in operation; Thermochemical Some scale up next year. Several Wood waste Catalytic Companies with major funding: CoolPlanet, LanzaTech, & others Why fast pyrolysis? Rapid thermal decomposition of organic compounds in the absence of oxygen to predominately produce liquid product known as bio-oil.

Biochar Co-product biochar is produced at yields of 12-20 wt% Fast pyrolysis can be built at small biomass. scales suitable for distributed processing. Bio-oil is refined like petroleum into synthetic gasoline and biodiesel.

Biorefineries and Biomass Feedstock Quality

ETO yield now about 330 L Mg-1 Potential yield = 450 L Mg-1.

(source: Nebraska Ethanol Board) Genetic effects on lignin, anatomy & ethanol yield from switchgrass cellulose

Thick, lignified layer ↓ Mean Ethanol Yield mg/g

80 78 Stem Lignin 63.2 g/kg 76 74 72 70

68 Ethanol(mg/g) yield 66 64 C-1 Hi Lig C-1 Lo Lig C+3 Hi Lig C+3 Lo Lig Population Stem Lignin 50.7 g/kg Current switchgrass cultivars & agronomics equivalent to 1960’s corn system

Switchgrass technology similar to1960’s corn and Volkswagen – a basic, good system with improvement potential. Corn yield improvement 50% genetic-50% agronomics Bottom Line

• Switchgrass is an economically feasible biomass energy crop for use on marginal cropland. • Improvements in genetics and agronomics will improve: – biomass yields – biomass quality – conversion – ethanol or biocrude yield per acre Conversion information

Biomass to ethanol Corn grain to ethanol 80 gallon/US ton 2.5 to 2.9 (Current technology) gallon/bushel 110 gal/ton potential. Feedstock cost per Feedstock cost per gallon gallon $ bushel/2.9 gal. $ton/80 gal. $2.50 bu/ 2.9 gal $40 ton/ 80 gal = $0.50 =$0.86/gallon gallon feedstock cost. feedstock cost. $3.50 bu = $1.21/gal cost.