Pacific Rim Summit on Industrial Biotechnology and Bioenergy December 9, 2013@ San Diego An Integrated System of Ethanol Production from the Cellulosic Energy Crop Napier Grass M. Samejima, S. Morita Graduate School of Agricultural and Life Sciences, JAPAN E. Morita, S. Mihashi Research Association of Innovative Bioethanol Technology, JAPAN 1
Political background on biofuel in Japan Introduction "Sophisticated Methods of Energy Supply Structures" law in Japan mandates to introduce 850,000 kl/yr of ethanol equivalent to 500,000 kl/yr of crude oil in the trasnportation sector by 2017. The criteria of assessing biofuel is requested to be more than 50% reduction of greenhouse effect gases (GHG) versus the same action by gasoline. 2
Final target on bioethanol technology project Introduction To proceed biofuel project, establishment of technology to produce ethanol from cellulosic energy crops should be addressed as following conditions. Production cost of ethanol : 40 JPY/L (ca. 0.4 US$/L) Production scale of ethanol: 200,000kL/y Balance ratio by fossil energy used: over 2.0 Reduction of CO 2 emission: over 50%. 3
Framework of research group Introduction In 2009, to proceed this project, Research Association of Innovative Bioethanol Technology (RAIB) was established by six leading companies in Japan and our university cooperates with their activities. NEDO Technology Development Organization Contract Research Association of Innovative Bioethanol Technology (RAIB) Head Quarter/ Common laboratory (at Entrepreneur Plaza in UT) Member Companies: JX-Nippon Oil and Energy, Mitsubishi Heavy Industries, Toyota Motors, Kajima Corp., Sapporo Engineering, Toray Industries (UT), Graduate School of Agricultural & Life Sciences 4
Process flow of our project Introduction The aim of our project is to establish an integrated system of ethanol production from the cellulosic energy crop Napier grass with a size of bench-scale production (75 L of ethanol from 300 kg of feedstock for each run). Process Cultivation Harvest, Storage Transport Pre-treatment Saccharification Fermentation Concentration, Dehydration Cellulose Glucose Non-arable land Energy crops Lignin Hemicellulose Xylose Ethanol Dehydrated ethanol Toyota Kajima JX Energy Toray Sapporo Mitsubishi, RAIB Fundamental Idea and technologies University of Tokyo 5
Life cycle assessment of system Analysis Biomass Supply Fertilizer(NPK) Enegy Supply from Saccharification Residue Biomass Energy Supply Center Steam Steam Steam Electricity shredding Drying NH 3 treatment Post treatment Enzymatic Saccharification Fertilizer(Urea) Diesel Oil Nitrogen Gas Ammonia Sulfuric Acid Process Water Fermentation Enzyme Compressed Air Cooling Energy Ethanol Distillation Ethanol Dehydration LCA analysis with GaBi6 software Ethanol 6
Erianthus Napier Grass Setaria Sugar Cane Swicth Grass Corn Guinea Grass Crotalaria Ramie Sorghum Biomass productivity (t/ha) Cultivation and productivity of biomass Feedstock Cultivation sites Test Field of University of Tokyo (Tokyo) Cool-temperate climate Sapporo Temperate climate Tropical & subtropical climate Indonesia Australia Kumamoto Nasu Tokyo Ishigaki Island Erianthus 60 50 40 30 20 Example of biomass yield under tropical climate Test Field of Toyota Mortors (Indonesia) 10 0 Napier Grass Sugar Cane 7
Feedstock Year-round supply system of feedstock biomass Rainy season Dry season Field A Field B Field C Field D Field E Field F Annual Supply Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha 20t/ha Cultivation for adjustment of supply 20t/ha Cultivation for adjustment of supply 50t/ha year 20t/ha Case study of Nepier Grass in Indonesia (50 dried ton/year) 8
Highlights on biomass conversion technologies Conversion Biomass Ethanol Pretreatment Saccharification Fermentation Technical Highlights: Use of ammonia without addition of water. Technical Merits: All pretreated materials remain in solid without loss. No waste water is produced. Technical Targets: Reduction of ammonia used. Technical Highlights: Efficient production of enzymes. Optimization of enzyme cocktail. Recovery and reuse of enzymes. Technical Targets: Reduction of enzyme cost(less than 10 JPY/L of ethanol production) to obtain 500 g of sugar from 1 kg of biomass within 24 hrs incubation. Adaptation for Scale-up. Technical Highlights: Tandem C6/C5 fermentation. Use of Non-GM for C5 fermentation. Technical Targets: High performance and yield. 9
Effects of ammonia pretreatment Conversion The reactivity of enzymes for biomass is dramatically improved by following effects of ammonia pretreatment. 1) Breaking of ester linkages on xylan or between xylan and lignin 2) Swelling of cellulose structure Lignin Hemicellulose Cellulose Swelling of cellulose structure Cleavage of chemical bond Lignin-hemicellulose bond Ammonia pretreatment 10
Reduction of energy for pretreatment Conversion One-step process under higher pressure Two-steps process under lower pressure Dried Biomass Dried Biomass High Pressure Ammonia Treatment 3.7 MPa, 80 C Recovery of Ammonia Reduction of 88 % of Energy Low Pressure Ammonia Treatment Liquid Phase Ammonia Treatment Recovery of Ammonia 11
Sugar 糖収量 yield (g/kg (g/kg-dry 乾燥バイオマス biomass) ) Enzymatic saccharification of pretreated biomass -Most of sugar compounds retains in pretreated biomass as solid-state. -Dramatic improvement of sugar yield from biomass by enzymatic saccharification. Conversion 600 500 Sugar yield from biomass Napier grass Switchgrass Erianthus キシロース Xylose グルコース Glucose Salix 400 300 200 100 0 Before/After NH3-treat. Before/After NH3-treat. Before/After NH3-treat. Before/After NH3-treat. 未処理処理後未処理処理後未処理処理後未処理処理後 12
Strategy on reduction of enzyme cost Conversion (1) Production of Enzyme (2) Highly-efficient Saccharification Improvement of enzyme-producing fungi Optimization of culture condition Minimum enzyme components production Less than 1,000 JPY/kg of enzyme Enzyme cost 10 JPY/L (3) Enzyme Recovery & Reuse Optimization of enzyme components for ammoniapretreated biomass Less than 1/100 (Enzyme/Biomass) Optimization of enzyme recovery Optimization of enzyme components for reuse. More than 75 % 13
Analysis and improvement of enzyme cocktail Conversion Analysis of Base Enzymes Preparation Improvement of Enzyme Cocktail Feedstock: Ammonia treated Napier grass Enzyme/Biomass (1/100) 14
Tandem system for ethanol fermentation Conversion Ethanol 1 st Step: Glucose fermentation Yield: 93 % Ethanol separation 2 nd Step: Xylose fermentation Yield: 90 % 15
Storage Biomass Crusher & Dryer Reactor Saccharification vessel Solid-liquid separator Enzyme separation membrane Sugar concentrating membrane C6 Fermentation vessel Yeast separation facility Ethanol separator C5 Fermentation vessel Distiller Dehydrator Storage Pre-treated biomass Cellulosic Sugar Dehydrated ethanol Outline of bench-scale plant (1) Bench Plant Pre-treatment process Saccharification process Fermentation process Ammonia Enzyme solution Enzyme /Recycle Yeast /Recycle Ethanol solution Ammonia/ Effluent treatment Residue Discharged water Yeast Discharged water JX Energy Toray Industries Sapporo Engineering 16
Outline of bench-scale plant (2) Ammonia pretreatment (JX energy) Biomass feedstock (Napier grass) Bench Plant Enzymatic saccharification (Toray) Ethanol fermentation & purification (Sapporo) Ethanol 17
Summary of our achievement Production of feedstock (Napier grass): over 50 dried ton/ha Production cost of feedstock : less than 3 JPY/kg (ca 0.03 US$/kg) Enzyme cost : 10 JPY/L of ethanol production (ca 0.1 US$/L) Production cost of ethanol : less than 80 JPY/L (ca. 0.8 US$/L) Balance ratio by fossil energy used: over 2.0 Reduction of CO 2 emission: over 50%. 18