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Biogas production from sugar beet silage. Jin Mi Triolo University of Southern Denmark. Why sugar beet silage ? . Dedicate energy crop for biogas production : prohibited until 2011
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Biogas production from sugar beet silage Jin Mi Triolo University of Southern Denmark
Whysugarbeetsilage? • Dedicateenergycrop for biogas production: prohibiteduntil 2011 • New regulationsince 2012: up to 25% of dedicateenergycropallowed as co-feedstock (at least 75% must beanimalmanure) • Sugarbeet : Highest dry matter yield per. ha : Easilydegradable, high methane potential : Ensilagingproducealcohols and organicacids (quick biogas production)
FurtherStudy 1 • Grøngas A/S (Hjørring) • Long term monitering of beet ensilage (Harvested in Nov. 2013- Ensilaginguntil December 2014) (6 silos with different scenarios) • GHG emission • Biogas potentials • Optimisinghigh rate biogas production • Organiccomposition
Furtherstudy 2 • 1 Spring barleystraw • 2 Spring barleystraw in the swath, 21/10 • 3 Spring barleystraw + aftermath, fresh • 4 Spring barleystraw + aftermath, ensiled • 5 Grass seed straw, fresh • 6 Grass seed straw, silage • 7 Grass seed straw, silagegrass juice • 8 Grass seed aftermath, fresh • 9 Grass seed afterforageensiled • 10 Maise silage
Furtherstudy 3 Grøngas A/S (Hjørring)
Examples of concept model work Biogas production of sugar beet in Energy production and Greenhouse Gas Reduction • Harvest in October • Beet top for animalfeed • Beet root for bigasproduction • Dry Cleaning in the field • Removingsoil, sand, stones, etc. • Ensilage for 8 months • Whole beet root, fermentation • Covered Cattle manure • Co-digestion with cattle manure • 1200m3, 6ton/day, 37°C, HRT 20days • PVC roof (avoiddilution), • untilfieldapplication • Applied in October or April
Flow chartof Reference Scenario 7 process units and sub-systems with a total of 15 process streams x6 CO2 g Top harvested m2g x2 H2O g Emission m6g Soil m4g x6 CH4 g x2 DM g Root harvested m3g Sugarbeet in field Washed root m5g Unit 3. Storage Unit 2. Cleaning m1g Unit 1. Harvest x1top g x3root g x5H2O g x1root g x3soil g x5DM g x1soil g x5ash g x5VS g x11 CH4 g Biogas (emitted) m11g x11 CO2 g x10 CH4 g x7 H2O g x11NH3 g x13 CH4 g Silage m7g x7 DM g x10 CO2 g Gas m13g x10 H2O g Biogas (obtained) m10g x13 CO2 g x7VS g x10 NH3 g x13 NH3 g x7 ash g x10 H2O g Mixed substrate m9g Cattle slurry m8g Digestate m12 g Unit 4. Mixing Unit 5. Anaerobic digestion Unit 6. After-storage x12 H2O g x8 H2O g x9 H2O g x12 DM g x9 DM g x8 DM g x12 ash g x9 ash g x8 VS g x12VS g Gas m15g x9VS g x8 ash g x14 H2O g Fertilizer m14 g x14 DM g x14 ash g m15 N2O g x14VS g m15 CO2 g m15 NH3 g Model 1 (Basis unit :1000g beet) Model 2 (Basis unit : ton/ha) Unit 7 Field
Process unit 1. Harvest Top Removed 2 221.4 H2O g 255.6g 34.2 DM g Sugarbeet in field • Top for animalfeed • Root for biogas production • Soil : 22% of beet’s dry matter Root harvested Unit 1. Harvest 744.4g 1000g 1 706.9root g 706.9root g 3 37.5soil g 37.5soil g Composition of root +soil (stream 3)
Process unit 2. Cleaning Soil Removed 5 4.5 H2O g 35.3g 30.8 DM g Cleanedroot • Soilresidue • 3.4% (dry cleaning) • 2.1% (wetwashing) Root harvested Root cleaned Unit 2. Cleaning 709.1g 744.4g 4 706.9root g 547.9 g H2O 6 37.5soil g 161.2 g DM AgroTech (Jørgen Pedersen) 8.5 g ash 151.7 g ash VS Composition of cleaned root (Stream 6)
Process unit 3. Ensilage GHG • CO2 emission through ensilage : 12.7 L /kg beet • CH4 emission duringfirstperiod ( 2-3 weeks) : 1.24 L/kg beet 2.5% (Agrotech) VS and BMP lossduring ensilage • German study (Weißbach et al., 2011) • Ourstudy • High BMP ofalcohol
Process unit 3. Ensilage Gas emission 8 0.9 CH4 g • VS lossuntil the end of March • under carefulstorage • 16% 23.5g 22.6 CO2g Silage Root cleaned Unit 3. Ensilage 694.1.g 709.1g 7 Root silage 538.9 g H2O 9 547.9 g H2O 136.8 g DM 161.2 g DM 8.5 g ash 8.5 g ash 128.3 g VS 151.7 g VS AgroTech (Jørgen Pedersen) Changes of Carbohydrateduring ensilage Fraction : Weißbach et al., 2009
Process unit 5. Biogas production 3% of total biogas VS destruction • Methane production rate and cumulativeyield 92% of BMP removed Beet 85% of BMP removed Cattle manure
Overview of model 1( 1000 g of beet + cattlemanure) Process unit (g)
Model for beetproduction per ha(139 ton/ha) (+381 ton cattlemanure)
Energy production Model 1 (1000g) Model 2(ton /ha)