MixAlco: Biofuels from Biomass Professor Mark Holtzapple Department of Chemical Engineering Texas A&M University

Transcription

1 MixAlco: Biofuels from Biomass Professor Mark Holtzapple Department of Chemical Engineering Texas A&M University Presentation by Scott L. Wellington, PhD Research Advisor Shell International E&P

2 Biofuels CO 2

3 Examples of Biomass Fuels and Chemicals forest residues & trees grass clippings agricultural residues energy crops municipal solid waste sewage sludge animal manure most of these are lignocellulose. lignocellulose.

4 Nature Converts Cellulose into Organic Acids, i.e., animal rumen - cattle - sheep - deer - elephants anaerobic sewage digestors swamps termite guts

5 Why are Organic Acids Favored? C 6 H 12 O 6 2 C 2 H 5 OH + 2 CO 2 G G = kcal/mol glucose ethanol C 6 H 12 O 6 3 C 2 H 3 OOH G G = kcal/mol glucose acetic acid The actual stoichiometry is complex: Briefly 5 C 6 H 12 O 6 6 acetate + 2 propionate + butyrate + 5 CO CH H 2 O (67 mol%) (22 mol%) (11 mol%)

6 Conversion of City Yard, Crop and Forrest Waste

7 Research Statistics Year started = early 1991 Time spent = 13 years Labor = ~110 person years Funding, over $2.3 mill

8 Researchers Faculty Mark Holtzapple Richard Davison Post Docs Praveen Vadlani Vincent Chang Xu Li Cesar Granda Masters Murlidahar Nagwani Chang Ming Lee Champion Lee Seth Adleson Robert Rapier William Kaar David Gaskin Hiroshi Shirage Wilbelto Adorno-Gomez Shelly Williamson Maria Almendarez Ramasubramania Narayan Patricia O'Dowd Hung-Wen Yeh Manohar Vishwanathappa PhD Nan Sheng Chang Shushien Chang Mitch Loescher Kyle Ross Susan Domke Salvador Aldrett-Lee Cateryna Aiello-Mazzarri Wenning Chan Piyarat Thanakoses Xu Li Guillermo Coward-Kelly Li Zhu Se Hoon Kim Frank Agbogbo Zihong Fu Jonathan O'Dwyer

9 Aerobic Compost Pretreatment then Anaerobic Fermentation Tarp Cover Air Biomass Pretreat - ph Control (Lime, Calcium Carbonate), air Then Anaerobic Fermentation Gravel

10 Vapor-Compression Dewatering Compressor Work Fermentor Broth Solution of Organic Acids Distilled Water Carboxylate Salt Crystals Filter

11 Thermal Conversion Stoichiometry (One Option) O O O H 3 CCOCaOCCH 3 Η 3 CCCH 3 Calcium Acetate Acetone + CaCO 3 O O O H 3 CCH 2 COCaOCCH 2 CH 3 Calcium Propionate Η 3 CCH 2 CCH 2 CH 3 + CaCO 3 Diethyl Ketone O O O H 3 CCH 2 CH 2 COCaOCCH 2 CH 2 CH 3 Η 3 CCH 2 CH 2 CCH 2 CH 2 CH 3 + CaCO 3 Calcium Butyrate Dipropyl Ketone

12 Ketone Hydrogenation Option Liquid Ketones Catalyst = 200 g/l Raney nickel Temperature = 130 o C Time = 35 min (@ P = 15 atm) H 2

13 Ketone Hydrogenation Stoichiometry O OH H 3 CCCH 3 + H 2 H 3 CCCH 3 Acetone H Isopropanol O OH H 3 CCCH 2 CH 3 + H 2 H 3 CCCH 2 CH 3 H Methyl Ethyl Ketone 2-Butanol O OH H 3 CCH 2 CCH 2 CH 3 + H 2 H 3 CCH 2 CCH 2 CH 3 Diethyl Ketone H 3-Pentanol

14 MixAlco Process: 1) Compost Pretreatment & Fermentation 2) Dewater & Collect Carboxylate Salts 3) Heat to Form Ketones: Many Process Options and Products 4) Hydrotreat to Alcohols Mixed Alcohol Fuels Biomass Pretreat Ferment Dewater Thermal Conversion Mixed Ketones Hydrogenate Lime Lime Kiln Water Calcium Carbonate Hydrogen

15 Typical Product Spectrum at Different Fermentation Temperatures 40 o C 55 o C C2 Acetic 41 wt % 80 wt % C3 Propionic 15 wt % 4 wt % C4 Butyric 21 wt % 15 wt % C5 Valeric 8 wt % <1 wt % C6 Caproic 12 wt % <1 wt % C7 Heptanoic 3 wt % <1 wt % 100 wt % 100 wt %

16 Energy Content Energy (MJ/L) (Btu/gal) Gasoline Mixed Alcohols Ethanol , , ,300

17 Properties of Fuel Oxygenates Blending Reid Blending Vapor Pressure o C (kpa) (R + M)/2 Alcohols 214 Methanol (MeOH) Ethanol (EtOH) Isopropanol (IPA) tert-butanol (TBA) Isobutanol (IBA) 102 Klass, Biomass for Renewable Energy, Fuels, and Chemicals, Academic Press (1998).

18 Key Numbers tonne digested Conversion = 0.75 tonne fed Selectivit y = tonne acids 0.65 tonne fed tonne digested tonne acids Yield = = tonne fed tonne digested tonne acids 0.49 tonne fed Solid residue will be burned for process heat, sold as compost, or landfilled.

19 U.S. Biodegradable Wastes Wastes Only Municipal Solid Waste Sewage Sludge Industrial Biosludge Recycled Paper Fines Agricultural Residues Forestry Residues Manure Amount Alcohol Potential (million tonne/year) (billion gal/year) Total 1, U.S. Gasoline Consumption = 130 billion gal/year U.S. Diesel Consumption = 40 billion gal/year

20 Fuels and Sugar from Energy Cane

21 Energy Cane Processing Energy Cane Sugar Extract Sugar Mill Residue (Boiler Fuel) Sugar Biomass Fiber MixAlco Process Alcohol Fuel

22 Sweet Sorghum Grows in ~35 US states Yield = dry ton/(acre yr) 100% planted 345 mi William Rooney, Soil and Crop Sciences, Texas A&M University

23 Land Area in United States 1 2 3

24 Effect of Automotive Efficiency 1 (Current) 2 better 302 mi 213 mi 3 better 174 mi

25 Land Area in United States 1 2 3

26 U.S. Biodegradable Wastes Wastes Only Municipal Solid Waste Sewage Sludge Industrial Biosludge Recycled Paper Fines Agricultural Residues Forestry Residues Manure Amount Alcohol Potential (million tonne/year) (billion gal/year) Total 1, U.S. Gasoline Consumption = 130 billion gal/year U.S. Diesel Consumption = 40 billion gal/year

27 Advantages of MixAlco Approach robust efficient nonsterile fermentation natural occurring microorganisms culture passed from one compost pile to another no spoiled batches since natural process inexpensive compost like pretreat & fermentation no enzyme addition required conventional plant operation and fuel distribution flexible using organic residue wastes and/or crops high performance bio-fuel or fuel additive products

28 green - simple - robust - widely applicable and - timely The MixAlco Process is: - green Professor Holtapple is the Recipient of the Presidential Green Chemistry Award

29 MixAlco Process Next Steps Convert Pilot Plant for Other Studies 3 Quarter 2005 Complete Design of Demonstration Plant Year End 2004 Organize a Demonstration Project Early 2004 Commercialize the Process ASAP

30 Patents 5,865,898 5,693,296 5,962,307 5,874,263 5,986,133 5,969,189 6,262,313 Mixed Alcohol Fuels Biomass Pretreat Ferment Dewater Thermal Conversion Mixed Ketones Hydrogenate Lime Lime Kiln Calcium Carbonate 6,043,392 6,395,926 Hydrogen

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32 Chemical Flowchart Calcium Magnesium Acetate Isobutylene Isopropyl Tertiary Butyl Ether B I O M A S S Calcium Acetate Calcium Propionate Acetic Acid H 2 Ethanol Propionic Acid H 2 n-propanol Acetone Ethyl Acetate Propyl Propionate H 2 Diethyl Ketone Isopropanol H 2 3-Pentanol Diisopropyl Ether Calcium Butyrate Butyric Acid Dipropyl Ketone H 2 4-Heptanol H 2 n-butanol Butyl Butyrate

33 Centralized Processing 15.3 mi 50% of area planted

34 MixAlco Process Version 2 Mixed Alcohol Fuels Biomass Pretreat Ferment Carboxylate Salts Dewater Acid Springing Mixed Acids Hydrogenate Lime Lime Kiln Calcium Carbonate Hydrogen

35 Acid Springing R 3 N HAc Ca(Ac) 2 R 3 NHAc H 2 O CO 2 CaCO 3 R = - CH 2 CH 3 R= - CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3 R 3 NHAc R 3 N

36 Carboxylic Acid Production CO 2 Biomass Pretreat CaO Lime Kiln Ferment CaCO 3 Dewater CO 2 Carboxylate Salt Springing Carboxylic Acid acetic acid propionic acid butyric acid

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40 Required Area Scale = 800 tonne/h Feedstock yield = 30 ton/(acre yr) 800 tonne 8000h 1.1 ton acre yr Area = = h yr tonne ,000acre = 366 mi 2

41 Feedstock Yard Clippings 1000wet ton d 0.5 dry ton wet ton Sewage Sludge 650 wet ton d 0.3 dry ton wet ton tonne 1.1ton tonne 1.1 ton 280d yr 365 d yr yr 8000h yr 8000 h = = dry tonne 16 h dry tonne 8 h Total = 24 tonne h

42 Key Assumptions tonne digested Conversion = 0.83 tonne fed Selectivit y = tonne acids 0.65 tonne fed (High because of sugar) tonne digested tonne acids Yield = = tonne fed tonne digested tonne acids 0.54 tonne fed 0.54tonne acids 0.54tonne alcohol Product = = tonne fed tonne acids 0.29 tonne alcohols tonne fed

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44 Production Rate 800 tonne fed 0.29 tonne alcohols Production Rate = = h tonne fed = 297,000 L/h = 78,600 gal/h = 44,900 bbl/d = 629 mill gal/yr tonne alcohols 233 h

45 Plant Capacity Plant Capacity (tonne/h) (mill gal/yr) City Population Base Case , , , ,200, ,000,000

46 What is lignocellulose? Cellulose Hemicellulose Lignin - glucose polymer - xylose polymer - aromatic polymer

47 Hydrogenation Water Mixed Alcohols Carboxylic Acids Esters Alcohols H 2 Heavy Alcohols

48 In-Situ Digestion 48-h h Digestion (g digested/g fed) Sugar- cane bagasse African millet straw Sorghum straw Tobacco stalks Untreated Lime-treated

49 Land required in Brazil 1 2 3

50 Supply US Gasoline Consumption gal gas 1.2 gal alc plant yr Plants = 6 yr gal gas gal alc = 248 plants 366 mi Area = 248plants = plant 2 90,900 mi 2 100% planted 302 mi

51 Expected Product Yields (mesophilic 40 o C) tonne biomass 8000 h 0.49 tonne acid 2200 lb Total Acid = 24 = 207 h yr tonne biomass tonne Plant Production mill lb yr US Production mill lb totalacid 0.41lb C2 C2 = 207 = yr lb totalacid mill lb totalacid 0.15 lb C3 C3 = 207 = yr lb total acid mill lb total acid 0.44 lb C4 + C4 + = 207 = yr lb total acid mill lb 85 yr mill lb 31 yr mill lb 91 yr mill lb 3700 yr mill lb 250 yr (2.3%) (12.4%)

52 Expected Product Yields (thermophilic 55 o C) tonne biomass 8000 h 0.49 tonne acid 2200 lb Total Acid = 24 = 207 h yr tonne biomass tonne Plant Production mill lb yr US Production mill lb total acid 0.80 lb C2 C2 = 207 = yr lb total acid mill lb total acid 0.04 lb C3 C3 = 207 = yr lb total acid mill lb total acid 0.16 lb C4 + C4 + = 207 = yr lb total acid mill lb 166 yr mill lb 8.3 yr mill lb 33 yr mill lb 3700 yr mill lb 250 yr (4.5%) (3.3%)

53 Lime Treatment T = 100 o C t = 1 h Lime loading = 0.1 g Ca(OH) 2 /g biomass Water loading = 5 to 15 g H 2 O/g biomass

54 Affordable Fermentors Above-ground stainless steel Above-ground carbon steel Above-ground concrete In-ground plastic $380/m 3 $125/m 3 $ 69/m 3 $ 12/m 3

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56 Heat Requirements Btu lb water removed Single-effect effect evaporator 1000 Triple-effect effect evaporator 333 Amine dewatering 60