Sustainable Ethanol Production from Cellulosic and Starchy Raw Materials. Energy- and Ecobalances 4. European Bioethanol Technology Meeting Association of Cereal Research, Detmold (Germany) 15. 16. April 2008 Sven Fleischer PD Dr. Thomas Senn
Sustainable ethanol production in regional plants Enzymes thin stillage Cereal Conversion Crop cultivation Plant in crop rotation fermented sludge Ethanol Distillation Steam Biogas plant stillage separation Process Electricity network Energy BHKW
Pretreatment of Biomass at a Maximum Temperature of 160 C Biomass mechanical treatment thermal treatment enzymatic hydrolysis Fermentation Distillation Temperature up to max. 160 C no acid or other adittives around 15% of dry matter after mechanical treatment dry matter after thermal treatment: - 7-8% after direkt heating - 15% after indirekt heating Content of furfural in all cases < 0,1mg/l Ethanol
Hydrolysis in Labscale Temperature: 55 C ph-value: 4,2-4,5 (ph-value is already reached in the substrate after pretreatment) Enzym dosage: 8,65 g Protein/kg DM of Biomass (1100kU/kg) Scale in lab: 250g of pretreated substrate
Degradation of glucans (%) Abbau Glucan [%] 100 90 Enzymatic Hydrolysis of mechanical treated versus not treated samples of corn silage after direct heating 80 70 60 50 40 30 20 10 0 160 C-30min, 6,5%TS, DM dispergiert 155 C-25min, 6,16%TS, DM dispergiert 155 C-20min, 5,98%TS, DM treated dispergiert 160 C-50min, 5,27%TS, DM dispergiert 160 C-50min, 7,5%TS, nicht dispergiert 7,5% DM not treated 0 20 40 48 h 60 80 100 120 140 160 Duration Hydrolysedauer of hydrolysis [h] (h)
Theoretical ethanol yield from corn silage 100kg DS 30-50% Glucans 30-50kg Glucans 100% Hydrolysis 33,3-55,6kg Glucose DS = Dry substance Total fermentation 19,54-32,3l Ethanol 100kg DS 14,8% Xylans 14,8kg Xylans 100% Hydrolysis 16,82kg Xylose Total fermentation 10,87l Ethanol
Theoretical ethanol content in mashes from corn silage 10-20%DS 30-50% Glucans 3,0-10% Glucans 100% Hydrolysis 3,3-11,1% Glucose total Fermentation 1,9-6,4%vol. Ethanol 10-20%DS 14,8% Xylans 1,48-2,96% Xylans 100% Hydrolysis 1,68-3,36% Xylose total Fermentation DS = dry substance 0,97-1,94%vol. Ethanol
Sustainable, regional ethanol production in regional plants including cellulosic materials Corn silage Conversion Fermentation Distillation Stillage separation thermal energy Thin stillage Triticale / Corn Conversion Ethanol Thick stillage Steam generation BHKW Co-substrate Crop production Biogas plant Liquid manure elektric energy Livestock Meat Fermented sludge Biogas Biogas
LCA of Szenario 1 Crop cultivation Triticale seed storage Straw storage Storage of Maize silage Triticale preparation Water Milling Methane 2 h starch hydrolysis 55 C, ph 3,5-4,0 25%TS Biogas fermentation Residue, Fertilizer Fermentation 96,8g EtOH/L mash EtOH Yield: 96 % Distillation Ethanol, 99,9%
Energy balance szenario 1 Input [GJ pro ha a] autark fossil Diff. Triticale cultivation 15,92 15,92 0 Maize cultivation 5,85 5,85 0 Distilleries energy consumption 13,69 18,68 4,99 Energie-Input 35,46 40,45 4,99 Output Electric power surplus 7,05 0-7,05 Ethanol 50,55 50,55 0 Methane 116,29 145,92 29,63 Energy f. Destillery by Biogas 13,69 0-13,69 Energie-Output 187,58 196,47 8,89 Energy gain (Output Input) 152,12 156,02 3,90 Energy gain : Energy-Input 4,29 3,86 Energy-Output : Energy-Input 5,29 4,86
Emissions to air partially ( >99%) listet CML2001, GWP 100 years; kg CO2-Äqv./ha*a Inorganic Emissions autark fossil Diff. CO 2 1.290 2.350 1.060 N 2 O 1.370 1.380 8,85 SF 6 0,164 0,164 0,0 OrganicEmissionens Methane 227 286 59 VOC (inspecific) 0,489 0,490 0,01 Organic halogen compounds 0,642 1,27 0,626 Sum (kg CO2-Äqv./ha*a) 2.894,87 4.023,64 1.128,77
Triticale seed storage Crop cultivation Triticale preparation Milling Water LCA Szenario 2 Storage of Maize silage Mechanical treatment Hydrothermical treatment 160 C, 30 min Enzymatical hydrolysis 55 C, ph 4 2 h Starch hydrolysis 55 C, ph 3,5-4,0 25%TS Fermentation 144h 95,4 g EtOH/L mash EtOH Yield: 83,7 % Straw storage Methane Biogas fermentation Residue, Fertilizer Distillation Ethanol, 99,9%
Energybalance szenario 2 [GJ pro ha a] autark fossil Diff. Input Triticale cultivation 16,27 16,27 0 Maize cultivation 5,98 5,98 0 Distilleries energy consumption 42,51 81,47 38,96 Sum Energy-Input 64,76 103,72 38,96 Output Electric power surplus 4,42 0-4,42 Ethanol 65,14 65,14 0 Methane 88,49 159,30 70,82 Energy f. Destillery by Biogas 42,51 0-42,51 Energy-Ouput 200,56 224,45 23,89 Energy Gain 135,80 120,72-15,07 Energy gain : Energy-Input 2,10 1,16 Energy-Output : Energy-Input 3,10 2,16
Emissions to air partly ( >99%) listet Inorganic Emissions CML2001, GWP 100 years; kg CO2-Äqv./ha*a autark fossil Diff. CO 2 1.320 5.940 4.620 N 2 O 1.410 1.450 40 SF 6 0,168 0,168 0,00 Organic Emissions (VOC) Methane 233 451 218 VOC (inspecific) 0,051 0,051 0,00 Organic halogen compounds 0,658 6,01 5,35 Sum (kg CO2-Äqv./ha*a) 2963,82 7846,14 4882,32
CO 2 Reduction fossile CO2 emissions (kg CO2 / GJ) fuel Oil / Diesel 86,2 el. power-mix DE 174,0 natural gas 56,0 gasoline 85,0 CO 2 -output kgco 2 /ha*a CO 2 -fossile kgco 2 /ha*a el. power surplus 110 el. power-mix DE 1.228 Ethanol 782 Gasoline 4.297 Methane 1.795 Diesel / fuel Oil 10.024 Support Distillery 208 Diesel / fuel Oil 1.180 Sum 2.895 Sum 16.729 CO 2 avoided Kg CO 2 / ha*a 13.832,73
In Comparison: Biogas from Maize crop yield (t DM/ha) 20,0 Methane /t odm (m³/ha) 380 org. DM (t/ha) (86%) 17,2 Methane / ha (m³/ha) 6.536 crop product. (GJ/ha) 19,3 energy yield (35GJ/m³) 229 energy gain (GJ/ha) 210 CO2 - reduction kg CO 2 /ha Cogeneration efficiency 86% (GJ/ha) 181 CO2 in crop prod. 2310 electric power (GJ/ha) 72,4 el. Power-mix DE (174kg /GJ) 12.528 heating power (GJ/ha) 108,6 fuel oil (86,2kg/GJ) 9.360 CO2 reduction / ha 19.578 CO2 reduction without use of heating power 10.218
CO 2 -reduction / GJ energy provided Integrated Ethanol Production kg CO 2 / GJ related to energy provided 91,0 related to ethanol separately calc. 69,53 Biogas and Cogeneration kg CO 2 / GJ heating power used 108,2 heating power not used 141,1 GJ / ha related to energy provided 152 related to ethanol separately calc. 51 GJ / ha heating power used 181 heating power not used 72
Conclusions Ethanol production in regional plant leads to very good results in energy- and ecobalances It is possible to integrate ethanol production from cellulosic raw materials in regional plants This integrated processing enables fermented mashes with up to 10 12%vol Actually 60% of cellulose contained in maize silage can be converted to ethanol Residual cellulose in stillages is efficiently converted later to biogasas well as pentoses
Conclusions The combination of distillery and biogas production is an optimum choice This integrated practice leads to a reduction in greenhouse gas emissions of up to 13,8 t of CO 2equ, depending on the fossile source that is compared with
Many thanks for your attention and many thanks to Ministerium für Ländlichen Raum BaWü und Landesstiftung BaWü for supporting this projekt