BioDigestion and Biogas Energy Ruihong Zhang, PhD, Professor Biological and Agricultural Engineering Department University of California, Davis Email: rhzhang@ucdavis.edu November 20, 2014
BioDigestion- Anaerobic Digestion Biogas Energy Electricity and heat Renewable natural gas Biogas Organic Waste Food Green Agricultural CH 4, CO 2 H 2, CO 2 Organic acids Sugars, Amino acids, Fatty acids Anaerobic Digester Digestate for Water and Fertilizer Fibers Nutrients Water
Organic Resource Recovery with Feedstock for Anaerobic Digesters: Advanced Anaerobic Digestion Food Processing and Agricultural Residues, Animal Manures, Municipal Solid Waste, 3
BioDigestion - Anaerobic Digestion Diverts organic waste food, green and agricultural from landfills; Produces bioelectricity, heat & renewable Natural Gas to power homes and vehicles; Converts byproducts to valuable organic soil amendments for farming; and Captures greenhouse gases & other harmful emissions.
High Solids Anaerobic Digestion (HSAD) Technology Developed at UC Davis Theromophilic digestion (three stage) Capable of treating a variety of organic solid waste Fast digestion rate and short retention time High biogas energy output Destruction of pathogens in waste, producing safe biofertilizers 5
High Solids Anaerobic Digester (HSAD) System Biogas Solid Waste Grinder 1 st Stage Wet Grind 2 nd Stage Solids Compost 3 rd Stage Liquid Effluent Hydrolysis Biogasification Biostablization Water Recycle
Concept to Commercialization for High Solids Anaerobic Digestion (HSAD) Technology Economic and Environmental Analyses Design commercial plants Pilot Design Pilot Construction Pilot Testing 2000 2004 2005 20072008 2010 2011 2012 Commercialization By CleanWorld Concept development laboratory testing 0.5-6 Gallons Process scale-up Pilot testing 50,000 Gallons Engineering design Equipment selection Construction, Operation,Monitoring, >300,000 Gallons
CleanWorld s Commercial Digester Projects American River Packaging 10 ton per day organic wastes (papers and food waste) City of Sacramento 100 ton per day organic waste (food, yard and paper waste) (25 ton per day in first phase and 75 ton per day in second phase) UC Davis Renewal Energy Anaerobic Digestion Project 50 ton per day mixed waste (food waste, animal waste, etc.)
UC Davis Renewable Energy Anaerobic Digester Treats 20,000 tons per year of mixed organic wastes Combines biogas and landfill gas to generate 5.6 GWh electricity per year Jointly developed by CleanWorld and UC Davis, with funding support from US Department of Energy, and the California Energy Commission and private investors Completed in January 2014
UC Davis Renewable Energy Anaerobic Digester
Digester Feedstock: Food Waste Food Processing Waste
UC Davis Renewable Energy Anaerobic Digestion (READ) Project Benefits Increase renewable energy supplies 5.6 million kwh per year Reduce greenhouse gas emissions Electricity 4,000 metric tons CO 2 e /year Feedstock emissions 6,000 metric tons CO 2 e/year Reduce waste sent to municipal landfills 50 tons/day from UC Davis campus and the region (20,000 tons/year)
Fertilizer and Soil Products from Digestate 6 Percent of Greenhouse Gases come from the production of fertilizers, more than cement production, aviation and iron and steel production A typical BioDigester will produce enough liquid and solid fertilizer product to provide nitrogen for 290 acres of California farmland, every day CleanWorld Organics specializes in creating high value fertilizer products from digester effluent Custom design soil products according to the feedstock characteristics and market needs
Digestate Processing and Biofertilizer Production Characterization and analysis of digestate Solids, fibers, nutrients and salt Particle size Digestate Processing for separation, concentration, and odor reduction Filtration Membrane Separation Aeration Solid and liquid fertilizer production Pelletized fertilizer Liquid Fertilizer
Fertilizer Production from Digestate
Testing Digestate As Organic Fertilizer Products Testing Variables Digestate dilution Application rate Application schedule Measurement Plant size Plant biomass Chlorophyl in leaves Nutrients uptake Soil properties
Determining optimum application method and rate of raw anaerobic digestate (RAD) RAD (50%) RAD (25%) RAD (12.5%) RAD (6.25%)
Field Testing of Digestate
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