Apollo Program for Biomass Liquids What Will it Take? Michael R. Ladisch Laboratory of Renewable Resources Engineering Agricultural and Biological Engineering Purdue University

Corn Source: Nicolle Rager Fuller, National Science Foundation

Supply Chain Grow Harvest Store Transport Sun Water Seed Fertilizer to Bioprocessing

Build on Existing Infrastructure for Corn Trucking the feedstock Trips of 5 to 40 miles, one way, for corn Costs about 12 cents per bushel corn 4.6 cents per gallon ethanol $ 5 / ton (dry basis) corn 10 cents per cu. ft. corn Maier and Ileleji, 2006

Corn Weighs more than Corn Stover (Cellulose) translates to larger storage volumes for cellulose feedstock for a given ethanol production Corn Corn Stover (Cellulose)

Supply Chains: Store, then Transport Sun Water Grow Harvest Seed Fertilizer Transport Store to Bioprocessing

Bioprocessing Pretreatment Hydrolysis Fermentation Fuel Ethanol Enzymes Yeast Glucose xylose Pretreatment Hydrolysis Fermentation Fuel Ethanol Distillation Delivery to markets Infrastructure

Projections: US Ethanol Production 2006 4.8 (corn) 2008 7.5 (corn + cellulose) 2015 12.0 (corn + more cellulose) 2030 60.0 (a lot of cellulose + corn) It will happen here

Ethanol Plant Locations

Biomass Resources in Tons / sq km /year Sets stage for Cellulose Ethanol From NREL Website, 2005

Corn Stover: 1 to 2 tons /acre Leaves Cobs Stalks Corn… Corn Stover are the parts of the corn plant as shown, These parts are high cellulose, hemicelluloses and lignin. Both the cellulose and hemicelluloses have the potential to yield sugars that can be fermented to ethanol. Roots

Bioethanol Production Feedstock Preparation Pretreatment Bio is…….As an intriguing substitute, sustainable bioethanol shows great market potentials. However, Bioethanol’s high cost makes it uncompetitive to petroleumCorn stover preferred (ready supply in Midwest) Hot water pretreatment -hydrates cellulose structure -minimize degradation productes Major steps in biomass-to-bioethanol process The major steps in biomass-to-ethanol process are feedstock preparation (cleaning and size reduction), pretreatment, enzymatic hydrolysis and ethanologenic fermentation. Developments in all aspect will all contributed to reduce the cost of bioethanol. Hot water pretreatment cost-effective maximize the solubilization of the hemicellulose fraction1,2 minimize the formation of sugar monomers1,2 Liquid hot water pretreatment has several advantages: 1) only water no other chemicals. 2) An optimized hot water pretreatment would maximize the solubilization of the hemicellulose fraction as liquid soluble oligosaccharides while the formation of sugar monomers is minimized. It prevents the degradation of the monomeric sugars to harmful degradation products. Corn stover as a promising lignocellulose food stock for ethanol production has continued to receive a great deal of attention because it is available in bulk quantities at relatively low cost. Ethanol-from biomass production is seen as a high-potential technology that offers great benefits to the market and the environment. By replacing gasoline with ethanol as transportation fuel, urban air pollution and global warming may be ameliorated, the US economy will then become less dependent on foreign oil, and jobs will be created in the agriculture sector. Lignocellulosic biomass feedstocks typically contain 55%--75% by dry weight carbohydrates that are polymers of five- and six-carbon sugar units which can be converted to ethanol by SSF. Corn stover is one of the cereal lignocellulose, which makes up a large portion of the agricultural residues. 2.SSF refers to simultaneous saccharification and fermentation of the biomass. It combines the enzymatic hydrolysis of polymeric cellulose to monosaccharides with the fermentative conversion of these monomers to ethanol in the same environment. 3. Although rich in carbohydrates, biomass is an insoluble substrate with complex structure: cellulose fibers are embedded in a sheath of hemicellulose and lignin, and held together by hydrogen and van der waals bonds. The structure makes lignocellulose recalcitrant to enzymatic break down. 4. So a pretreatment step is required to increase the digestibility of cellulose before it is exposed to enzymes. Basically, as shown, in the pretreatment, the compact relations between different components will be destroyed, makes it relax and amenable to enzymatic conversion. There are several ways for pretreatment : mechanical, physical or chemical pretreatment. Hot water pretreatment was firstly introduced by our lab and was approved to be comparable to other chemical methods in efficiency and more economical. Hydrolysis of Solids Ethanol Fermentation

Pretreatment gives enzyme accessible substrate Cellulose Lignin Pretreatment Hemicellulose Amorphous Region Crystalline Region Pretreatment changes the physical structure of the cellulose portion (black lines) as well as disrupting the lignin (a glue like material) that protects the cellulose from hydrolysis (pink line). The structure – once disrupted by pretreatment is opened up and is amenable to hydrolysis since the catalysts that cause hydrolysis to occur can get into the cellulose structure.

Components of plant cell walls Cellulose Cellulose Fermentable sugars obtained from cellulose in 1819 Lignin Lignin Hemicellulose (need special yeast to convert to ethanol) Extractives Extractives Ash Ash Chapple, 2006; Ladisch, 1979

Yeast Metabolism: pentose fermentation Xylose Glucose NAD(P)H NAD(P)+ Xylitol Glucose-6-P NAD+ NADH Fructose-6-P Xylulose Glyceraldehyde-3-P Xylulose-5-P NAD+ NADH 3-Phosphoglycerate PPP Ethanol NADH NAD+ Phosphoenolpyruvate Ho et al TCA Cycle Pyruvate Acetaldehyde

Yields of Ethanol from Corn Stover (Cellulose Ethanol) From Cellulose: 50 to 55 gal / ton From Xylan: 30 to 35 gal / ton Total: 80 to 85 gal / ton. Corresponds to about 250,000 tons /yr for 20 million gal per year plant Requires engineered yeast, pretreatment cellulase enzymes

Other molecules from biomass sugars Fermentable sugars are the feedstock Products in addition to ethanol Butanol, Acetone 2,3 Butanediol Acetic, Lactic acid Microbial polysaccahrides (for enhanced oil recovery) Ladisch et al, 1979; 1991

*Supported by the NSF Plant Genome Research and REU Programs Plant Cell Wall Genomics at Purdue Identified over 1100 genes involved in cell wall construction Generated over 900 mutants in Arabidopsis and 200 in maize; maize mutants represent a resource of genetic diversity for feedstock testing Characterized cell walls of these materials using spectroscopic, chemical, and imaging assays Identified novel cell-wall genes that can contribute to feedstock diversity Used genetics and molecular biology to analyze the functions of cell-wall gene products This slide summarizes the scope of work accomplished by our cell wall genomics team. This multi-institutional team received a grant from the National Science Foundation’s Plant Genome Research Program ($6M) to characterize cell-wall mutants of maize and Arabidopsis using high-throughput screening by infrared spectroscopy. Maize and Arabidopsis are representative of the two distinct kinds of growing walls made by flowering plants. http://cellwall.genomics.purdue.edu *Supported by the NSF Plant Genome Research and REU Programs

Trees: 5 to 10 tons /acre Chapple and Meilan, 2006 http://www.gvrd.bc.ca/

Switchgrass: 5 to 10 tons /acre, less inputs Elbersen, Wageningen, 2004

Using Hay 1 Bale = 970 lbs = 2000 miles Assuming 50 gal x 40 mpg Engel, 2006

Vision Learning and engagement to illustrate science and engineering as agents of change Transfer discovery from laboratory to the field or plant in a contiguous high tech / biotech / agriculture corridor Combine engineering, science and agriculture to catalyze of sustainable growth of a US bioenergy sector Work is not complete until it proven valuable to industry.

Challenges: What will it take? Utilize biomass materials from a wide range of sources: Cellulosics Fiber Corn Apply biotechnology and nanotechnology to develop bio-catalytic conversion routes Yeasts Fixed bed catalysts Enzymes

Opportunities Designer crops for bio-energy production Bioprocess Engineering built around advanced biocatalysts (yeasts, enzymes, fixed bed catalysts) that process designer crops High energy corn that maximizes polysaccharides rather than oil or protein Understand role of forages (switchgrass) and wood poplar grown for energy crops Seeds for the same

Research Plant genomics Microbial genomics Bioprocess Engineering Agriculture Economics Industrial Test Beds

Bioprocess Discovery Activities advanced pretreatments integrated with plant science to enhance the digestibility/reactivity of the fiber component (cellulose and hemicellulose) of DG, enzymatic hydrolysis of pretreated celluloses to produce fermentable sugars, remove part or all of the cellulose and hemicellulose, increase feed value of residual solids, ferment hexose and pentoses using genetically engineered yeasts to ethanol and their transformation to other biobased products, Bio-catalysts to make diesel from soybeans, sugars from biomass convert alcohol and soybean oil to diesel Separations technology energy efficient recovery form water of different bio-products 6. comprehensive economic analysis of the processes, technologies, and markets, incorporating uncertainty in key technological and market parameters.

Concluding Thoughts “Increasing energy consumption, coupled with decreased petroleum supplies, has made development of alternate energy sources a pressing national problem. “Changes in technology and philosophy will be required in order to establish a renewable resource base for the …industry. “Utilizing cellulosics as this basis, we are tapping the earth’s most abundant and readily renewable resource, while providing our industry with relatively inexpensive, and reliable, raw materials. Quote from 1979.