Thermochemical Conversion of Biomass to Fuel.cenusa brown 5-25-12

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Dr. Robert Brown is a foremost expert and author on biomass conversion processes with the CenUSA project and the Bioeconomy Institute at Iowa State University. In this presentation he focuses on using thermochemical processes for production of liquid biofuels. Discussion of: feedstocks, renewable fuels tegnologies, gasification and pyrolysis, products and by-products, energy efficiency, opportunities and challenges, biochar.

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Thermochemical Conversion of Biomass to Fuel.cenusa brown 5-25-12

  1. 1. Center for Sustainable Environmental Technologies The  Thermochemical Option Robert C. Brown Robert C. Brown Center for Sustainable  Environmental Technologies Iowa State University Iowa State University CenUSA Webinar May 25, 2012
  2. 2. Center for Sustainable Environmental TechnologiesWhat is the Perfect Energy Carrier for Transportation Fuel?What is the Perfect Energy Carrier for Transportation Fuel? • Liquid at ambient conditions d b d • Immiscible in water • Low toxicity • High energy density • Cold weather operability • Stable during long‐term storage • Efficient production from a primary energy source
  3. 3. Center for Sustainable Environmental Technologies Drop‐In Fuels Drop‐In Fuels • Fully compatible with existing fuel infrastructure – Hydrocarbons (alkanes and aromatics) – Possibly butanol • Are drop in fuels  also the “perfect fuel?” – Close enough
  4. 4. Center for Sustainable Environmental Technologies Three Kinds of Biomass Three Kinds of Biomass • Lipid‐rich biomass Lipid‐rich biomass  • Lignocellulosic biomass • Waste biomass
  5. 5. Center for Sustainable Environmental Technologies Lignocellulosic Feedstock• Lignocellulose a three- three dimensional polymeric composites formed by plants as structural material• Constituents include: – Cellulose: main source of glucose (C6 sugar) – Lignin: source of xylose (C5 sugar) g ) Glycosidic• Simple sugars can be bonds liberated from carbohydrate either enzymatically or Cellulose is a polymer of monosaccharides thermally (glucose)
  6. 6. Center for Sustainable Environmental Technologies Lipid Feedstocks: Nearly hydrocarbons Lipid Feedstocks: Nearly hydrocarbons • Triglycerides:  Three fatty acids attached to glycerol  backbone found in oil seeds and microalgae b kb f d i il d d i l • Readily converted to pure hydrocarbons via  hydrogenation h d ti H2 H2 H2 H2 H2 H2 H2 H2 O H3C C C C C C C C C C O CH2 C C C C C C C C H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 O H3C C C C C C C C C C O CH C C C C C C C C H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 H2 O H3C C C C C C C C C C O CH2 C C C C C C C C H2 H2 H2 H2 H2 H2 H2 H2
  7. 7. Center for Sustainable Environmental Technologies Lipids vs Lipids vs Lignocellulose Which Kind of Plant Should Deoxygenate Carbohydrate? Glucose Unit Glycosidic Bonds OH CH2OH OH CH2OH OH CH2OH OH O O O O O O OH OH OH OH OH Plant No. 2 OH OH O O O O O O O CH2OH OH CH2OH OH CH2OH OH CH2OHPlant No. 1 CO2 H2O Lipid biosynthesis  Lipid involves biological  deoxygenation of  yg carbohydrates, too!  CO2 Cellulose to hydrocarbons  Cellulose to hydrocarbons involves deoxygenation of  CO2 Source: Nature Medicine  carbohydrate 11, 599 – 600, 2005.
  8. 8. Center for Sustainable Environmental Technologies Renewable Fuels Technologies Renewable Fuels Technologies FEEDSTOCKS TECHNOLOGY BIOFUELS OILSEED CROPS Transesterification FAME ALGAE Pyrolysis Gasification AG WASTES CELLULOSIC Catalysis BIOMASS FUEL HYDROCARBONS TREES Chemical GRASSES Catalysis GRAINS STARCH ALCOHOLS Biochemical SUGAR Conversion C i SUGARCANE
  9. 9. Center for Sustainable Environmental Technologies Thermochemical Biofuels Thermochemical Biofuels• The other cellulosic biofuels… • Syngas to biofuels  (via gasification) • Bi il t bi f l Bio‐oil to biofuels  (via fast pyrolysis)• Builds upon core competencies at Builds upon core competencies at  ½ tpd oxygen-blown gasifier at ISU’s BioCentury Research Farm ISU • Gasification and pyrolysis • Catalysis • Novel fermentations • Techno‐economic and life cycle  analysis l i 1/4 tpd fast pyrolyzer at ISU’s BioCentury Research Farm USDA REE E S it
  10. 10. Center for Sustainable Environmental Technologies Generalized Thermochemical Process Generalized Thermochemical Process Feedstock Depolymerization/ Decomposition Depolymerization/ Decomposition Thermolytic  Thermolytic Substrate Upgrading Biofuel
  11. 11. Center for Sustainable Environmental Technologies Gasification • Gasification is the thermal decomposition of organic matter  into flammable gases g Heating and Drying Pyrolysis Gas-Solid Reactions Gas-phase Reactions Volatile gases: CO, CO + H2O  CO2 + H2 CO2, H2, H2O light O, hydrocarbons, tar CO + 3H2  CH4 + H2O H 2O Heat CO 2 CO ½ O2 CO2 char 2H2 Porosity increases CO CH4 Thermal front H2O H2 penetrates particle Endothermic Exothermic reactions reactions 11
  12. 12. Center for Sustainable Environmental Technologies Two Major Gasification Options Two Major Gasification Options Low Temperature Gasification High Temperature Gasification (Bubbling Fluidized Bed) (Entrained Flow Gasifier) oxygen Syngas biomass Biomass 1300 °C Ash Fluidized Bed Water cooled radiation screen Steam/ Oxygen O raw syngas and molten slag
  13. 13. Center for Sustainable Environmental Technologies Syngas • Syngas consists mostly of CO, H2, CO2, CH4 Composition of syngas (volume percent) Hydrogen Carbon  Carbon  Methane Nitrogen HHV Monoxide Dioxide (MJ/m3) 32 488 15 2 3 10.4 0 • Syngas also contains small amounts of tar, alkali metals, sulfur,  nitrogen, and chlorine that must be removed before it can be  nitrogen and chlorine that m st be remo ed before it can be catalytically upgraded to transportation fuels  Raw Syngas Gasifier Particulate  Removal Biofuel Biomass Tar  Alkali  Sulfur  Nitrogen  Catalytic  Oxygen/Steam Removal Removal Removal Removal Synthesis
  14. 14. Center for Sustainable Environmental Technologies Gasification Efficiency • Thermal efficiency - conversion of chemical energy of solid fuel to chemical energy and sensible heat of gaseous product – High temperature, high-pressure gasifiers: >95% – Typical biomass gasifiers: 70 - 90% • Cold gas efficiency – conversion of chemical energy of solid fuel to chemical energy of gaseous product – T i l bi Typical biomass gasifiers: 50 75% ifi 50-75% 14
  15. 15. Center for Sustainable Environmental Technologies Gasification Opportunities and Challenges Gasification Opportunities and Challenges• Advantages  – Tolerates relatively dirty biomass  feedstock – Produces uniform intermediate  product (syngas) – Proven method for “cracking the  lignocellulosic nut”   – Allows energy integration in  biorefinery• Disadvantages  g – Gas cleaning technologies still  under development – Synfuel processing occurs at high processing occurs at high  ½ tpd gasification plant at ISU’s pressures BioCentury Research Farm
  16. 16. Center for Sustainable Environmental Technologies Syngas Upgrading to Fuels Syngas Upgrading to Fuels • Catalytic – performed at moderate  temperatures and high pressures  temperatures and high pressures using metal catalysts – Fischer‐Tropsch synthesis to  hydrocarbons suitable for fuels – Methanol synthesis followed by  upgrading to gasoline upgrading to gasoline – Ethanol synthesis • S Syngas fermentation – performed  f t ti f d at ambient temperature and  p pressure using biocatalysts g y
  17. 17. Center for Sustainable Environmental Technologies Pyrolysis Definition – thermal decomposition of  Definition thermal decomposition of carbonaceous material in the absence  of oxygen of oxygen
  18. 18. Center for Sustainable Environmental Technologies Py Products• Gas – non‐condensable gases like carbon dioxide,  carbon monoxide, hydrogen• Solid – mixture of inorganic compounds (ash) and  carbonaceous materials (charcoal) • Liquid – mixture of  water and organic  Bio- Bio-oil compounds known as  bio‐oil recovered from  bio oil recovered from pyrolysis vapors and  aerosols (smoke) aerosols (smoke)
  19. 19. Center for Sustainable Environmental Technologies The many faces of pyrolysis The many faces of pyrolysis Technology Residence Heating Rate Temperature Predominate  Time (C) Productscarbonization days very low 400 charcoalconventional 5‐30 min low 600 oil, gas, chargasification 0.5‐5 min moderate >700 gasFast pyrolysis 0.5‐5 s very high 650 oilflash‐liquid <1 s high <650 oilflash‐gas <1 s high <650 chemicals, gasultra <0.5 s very high 1000 chemicals, gasvacuum 2‐30s 2 30s high <500 oilhydro‐pyrolysis <10s high <500 oilmethano‐pyrolysis <10s high <700 chemicalsMohan D., Pittman C. U. Jr., and Steele P. H. “Pyrolysis of Wood/Biomass for Bio‐oil: A Critical Review” Energy & Fuels, 20, 848‐889 (2006)
  20. 20. Center for Sustainable Environmental Technologies Carbonization (slow pyrolysis) Carbonization (slow pyrolysis)• Charcoal is the carbonaceous  residue obtained from heating  biomass under oxygen‐starved  bi d d conditions.• Charcoal word origin ‐ “the making  of coal. of coal ”• Geological processes that make coal  are quite different from those that  produce charcoal and properties are  Charcoal yields (dry weight basis)  y ( y g ) quite different. for different kinds of batch kilns• Charcoal contains 65% to 90%  Kiln Type Charcoal Yield carbon with the balance being  Pit  12.5‐30 volatile matter and mineral matter  l til tt d i l tt Mound   Mound 2‐42 2 42 (ash). Brick  12.5‐33• Antal, Jr., M. J. and Gronli, M. (2003)  Portable Steel (TPI) 18.9‐31.4 The Art, Science, and Technology of  The Art, Science, and Technology of Concrete (Missouri) 33 Kammen, D. M., and Lew, D. J. (2005) Review of technologies for the production and use  Charcoal Production, Ind. Eng.  of charcoal, Renewable and Appropriate Energy Laboratory, Berkeley University, March  1, http://rael.berkeley.edu/files/2005/Kammen‐Lew‐Charcoal‐2005.pdf, accessed  Chem. Res. 42, 1619‐1640 November 17, 2007.
  21. 21. Center for Sustainable Environmental Technologies The many faces of pyrolysis The many faces of pyrolysis Technology Residence Heating Rate Temperature Predominate  Time (C) Productscarbonization days very low 400 charcoalconventional 5‐30 min low 600 oil, gas, chargasification 0.5‐5 min moderate >700 gasfast pyrolysis 0.5‐5 s very high 650 oilflash‐liquid <1 s high <650 oilflash‐gas <1 s high <650 chemicals, gasultra <0.5 s very high 1000 chemicals, gasvacuum 2‐30s 2 30s high <500 oilhydro‐pyrolysis <10s high <500 oilmethano‐pyrolysis <10s high <700 chemicalsMohan D., Pittman C. U. Jr., and Steele P. H. “Pyrolysis of Wood/Biomass for Bio‐oil: A Critical Review” Energy & Fuels, 20, 848‐889 (2006)
  22. 22. Center for Sustainable Environmental Technologies Fast Pyrolysis y y Fast pyrolysis - rapid thermal decomposition of organic compounds in the absence of oxygen to produce predominately liquid product Biochar
  23. 23. Center for Sustainable Environmental Technologies Fast Pyrolysis Fast Pyrolysis • Dry feedstock: <10% • Small particles: <3 mm • Moderate temperatures (400‐500 oC) • Short residence times: 0.5 ‐ 2 s • Rapid quenching at the end of the process • Typical yields Oil:     60 ‐ 70% Char:  12 ‐15% Gas:   13 ‐ 25%
  24. 24. Center for Sustainable Environmental Technologies Bio‐Oil Bio Oil Source: Piskorz, J., et al. (1988) White  PoplarPyrolysis liquid (bio‐oil)  Sprucefrom flash pyrolysis is a from flash pyrolysis is a Moisture content, wt% 7.0 3.3low viscosity, dark‐ Particle size, m (max) 1000 590brown fluid with up to  Temperature 500 49715 to 20% ater15 to 20% water Apparent residence time Apparent residence time 0 65 0.65 0 48 0.48 Bio‐oil composition, wt %, m.f. Saccharides 3.3 2.4 Anhydrosugars 6.5 6.8 Aldehydes 10.1 14.0 Furans 0.35 ‐‐ Ketones 1.24 1.4 Alcohols 2.0 1.2 Carboxylic acids 11.0 8.5 Water‐Soluble – Total Above 34.5 34.3 Pyrolytic Lignin 20.6 16.2 Unaccounted fraction 11.4 15.2
  25. 25. Center for Sustainable Environmental Technologies Energy Efficiency Energy Efficiency • Conversion to 75 wt‐% bio‐oil translates to energy  efficiency of 70% ffi i f 70% • If carbon used for energy source (process heat or  slurried with liquid) then efficiency approaches 94% slurried with liquid) then efficiency approaches 94% Source: http://www.ensyn.com/info/23102000.htm
  26. 26. Center for Sustainable Environmental Technologies Fast Pyrolysis Opportunities and Challenges Fast Pyrolysis Opportunities and Challenges • Advantages of bio oil: Advantages of bio‐oil: – Can be upgraded to drop‐in  ( y (hydrocarbon) fuels ) – Opportunities for distributed  processing ¼ ton per day fast pyrolysis pilot plant at  • Disadvantages of bio‐oil ISU BioCentury Research Farm – High oxygen and water content makes bio‐oil inferior to High oxygen and water content makes bio oil inferior to  petroleum‐derived fuels  – Phase‐separation and polymerization and corrosiveness  make long‐term storage difficult
  27. 27. Center for Sustainable Environmental Technologies Applications of Bio‐Oil Applications of Bio‐Oil • Stationary Power Stationary Power • Commodity Chemicals • Transportation Fuels i l
  28. 28. Center for Sustainable Environmental Technologies And Sugar and Bioasphalt! And Sugar and Bioasphalt! Heavy EndsSugar solution (>20 wt%) Water Wash Raffinate (mostly phenolic oligomers derived from lignin)
  29. 29. Center for Sustainable Environmental Technologies Biochar • Carbonaceous residue from  pyrolysis of biomass pyrolysis of biomass • Yields range from 5‐40% of  biomass depending upon process  biomass depending upon process conditions • Fine, porous structure ,p • Several potential applications,  the most intriguing being dual  g g g use as soil amendment and  carbon sequestration agent
  30. 30. Center for Sustainable Environmental Technologies Terra Preta: Anthropogenic Soils from Biochar Terra Preta: Anthropogenic Soils from Biochar• Created hundreds of years  y Terra Preta Oxisol ago by pre‐Colombian  inhabitants  of Amazon  Basin• Result of slash and char  agriculture• Much higher levels of soil  organic carbon• F Far more productive than  d i h Applied to the land, biochar serves as undisturbed  both soil amendment and carbon oxisol soils sequestration agent Glaser et al. 2001. Naturwissenschaften (2001) 88:37–41
  31. 31. Center for Sustainable Environmental Technologies Biochar s Biochar’s Impact• Biochar increases soil cation exchange  Increases: capacity (CEC), holding ammonium ions  capacity (CEC), holding ammonium ions g Cation Exchange  (NH4+) and other cations in the soil Capacity Soil Organic Matter• Biochar adsorbs soil organic matter which  g Drainage contains plant‐available organic nitrogen1 Aeration• Biochar’s low bulk density increases soil  aeration and water drainage, lessening the  g , g Decreases: D likelihood of denitrification (NO3‐  N2O  N2) and associated N2O emissions2 Soil Bulk Density Denitrification• Addition of biochar has been shown to  Addition of biochar has been shown to N2O Emissions decrease nutrient leaching (nitrate,  phosphate, cations) from manure  Nutrient Leaching amendments3 1. Laird, D. A., Agron J 2008, 100, (1), 178-181. 2. Rogovska, et al. North American Biochar Conference, Boulder, CO, Aug 2009. 3. Laird, et al. 2008 GSA-SSSA-ASA-CSA Joint Meeting, Houston, TX, Oct 2008.
  32. 32. Center for Sustainable Environmental Technologies GHG Impacts of Soil Application of Biochar GHG Impacts of Soil Application of Biochar Increased CO2 Competition emissions due between food to enhanced and biomass soil microbial crops may respiration increase land under cultivation. + 0 _ Increase C Increased Reduce CO2 Reduce N2O Increase C Reduce CO2 input to soil yields may emissions emissions sequestration emissions due due to decrease the due to bio-oil from soils in soils to decreased enhanced amount of displacing due to better (Biochar C is use of lime plant growth land needed fossil fuel soil aeration very stable) and fertilizer to grow food.
  33. 33. Center for Sustainable Environmental Technologies Proof‐of‐Concept:  Terra Preta in Brazil Proof‐of‐Concept: Terra Preta in Brazil Terra Preta Oxisol
  34. 34. Center for Sustainable Environmental Technologies Lovelock on Biochar Lovelock on Biochar “There is one way we could  save ourselves and that is  through the massive burial of  through the massive burial of charcoal. It would mean  farmers turning all their  farmers turning all their agricultural waste…into non‐ James Lovelock in an  biodegradable charcoal, and  otherwise pessimistic  burying it in the soil.” interview with New  Scientist Magazine  (January 2009) on our  prospects for halting global  t f h lti l b l climate change
  35. 35. Center for Sustainable Environmental Technologies ISU Facilities to Support Thermochemical Research Lab-scale pyrolyzers Micropyrolyzers & Batch and fixed bed and gasifiers bio-oil analysis catalytic upgrading reactorsISU Biorenewables Laboratory Quarter-ton/day pilot plant fast pyrolyzer Half-ton/day p y pilot p plant oxygen-blown gasifier ISU BioCentury Research Farm

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