Patrick Mathews, General Manager/CAO Salinas Valley Solid Waste Authority CALIFORNIA BIOMASS COLLABORATIVE 7 TH ANNUAL FORUM May 10 11, 2010
Salinas Valley Solid Waste Authority Joint Powers Authority made up of five Cities + eastern unincorporated Monterey County, CA 260,000 ton per year waste stream Goal 75% Diversion (by 2015) and 50 years of sustainable processing/ disposal capacity Enthusiasm for conversion technologies (CT) grew from opposition to new landfill studies in 2004 Study of CTs began in 2006 with formation of CT Committee CT decision will conclude this year
Who Are We? Publically owned utility Regional public service agency Manager/ operator of recycling, resource recovery and disposal facilities Educator/facilitator Independent voice for the unique nature of the Salinas Valley businesses and residents Economic engine for Salinas Valley jobs Advocate for sustainability movement "Change is the law of life and those who look only to the past or present are certain to miss the future. John F. Kennedy
Mission/Vision/Values Mission To manage Salinas Valley solid waste as a resource, promoting sustainable, environmentally sound and cost effective practices through an integrated system of waste reduction, reuse, recycling, innovative technology, customer service and education. Vision To reduce the amount of waste by promoting individual and corporate responsibility. To recover waste for its highest and best use while balancing rates and services. To eliminate the need for landfills. To transform our business from burying waste to utilizing waste as a resource. Values Innovation Integrity Public Education Efficiency Fiscally Prudent Resourcefulness Customer Service Community Partnerships
Where Do We Start? The Wastestream WASTESTREAMS 1.Residential Garbage Wet/Low Value 2.Commercial Garbage Wet/Low Value 3.Commercial Garbage Dry/High Recovery 4.C&D High Recovery 5.Mixed Curbside Recyclables 6.Source Separated Recyclables 7.Greenwaste/Woodwaste/Foodwaste
How To Keep It Out Of The Landfill? The Easy Ones Commercial Garbage, Dry Conventional MRF C&D Conventional MRF Mixed Curbside Recyclables Conventional MRF Source Separated Recyclables Facility Programs Greenwaste/Woodwaste/Foodwaste Composting/ Mulch Production
Where Do We Start? The Wastestream The Hard Ones 1.Residential Garbage Wet 2.Commercial Garbage Wet 3.Residue from the Easy Ones
What to Do With the Wet Stuff? Autoclave Technology for Cellulose Recovery, Developed by Comprehensive Resources Recovery and Reuse (CR3) 60% of Residential and Commercial Wet Wastestream is Cellulose: 200 300 TPD Many market opportunities for cellulostic material Simple Technology, extensively tested by USDA Relatively low cost: $20 $30/ton
Autoclave TesEng Program 2 year testing program Partenership with USDA, CR3 and SVSWA Environmental Impacts Air, wastewater, noise and residue Technological O&M requirements Downtime Energy usage Costs Marketability of products Ethanol Production (w/usda) Composting Digestion (w/usda) Implementation Decision at the End of the Testing program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave TesEng Program
Autoclave Conclusions Over 60% reduction in waste volume Cellulose recovery Ethanol production feedstock Compost feedstock Anaerobic digester feedstock for methane production Paper Pulp w/additional washing process Factual performance, emissions and cost information
Introduction Municipal solid waste (MSW) is comprised of residential and commercial refuse. 250 million tons are produced annually in the U.S. ~80 million tons of MSW are cellulosic wastes available for biofuel production. Figure 1. Photos of autoclave operation from top left, a) MSW being loaded into autoclave; b) MSW in autoclave prior to processing; c) MSW after processing; d) Trommel screen; e) Pulp fiber after Trommel screen; f) Hydrocyclone cleaned pulp. Autoclaving MSW Autoclaving uses only water and can be considered a green transformation process. Pulp can be isolated after autoclaving by a simple rotary screen. (Table 1) ~84 % of all organics in MSW are captured in the accepts bin. Hazardous hand sorting of raw garbage is eliminated. Hazardous leachates can be collected for disposal. Landfill volume can be reduced as much as 80-90 %. Incoming MSW 3/8 Screen Accepts 1 Screen Accepts Overs (> 1 ) % pulp/paper 31.7 93.0 15.8 3.4 % woody material 6.5 1.7 8.6 1.2 % fines 4.5 1.9 1.4 0 % plastic 15.5 1.3 21.9 36.0 % glass 4.0 1.0 18.1 0 % metal 3.6 0 3.6 14.0 % C&D Waste 5.9 0.8 16.3 7.7 % solid food waste 10.2 0 1.8 0.8 % rubber/leather/textiles 17.4 0.4 12.5 36.9 % total 99.3 100 100 100 Table 1. Component breakdown of incoming garbage and streams separated by the Trommel screen. Scheme 1. Simplified flow diagram for the MSW-based biorefinery. Model depicts the energy sources produced by segregation of the different components of MSW. Integrated Biorefinery An integrated biorefinery can divert virtually all organics from the landfill. ~50 % of the cellulose in the pulp fraction can be converted to ethanol without further pretreatment. ~ 14 MM gal/yr of ethanol can be produced directly from processing 3000 tpd MSW. Remainder of organic fraction can be gasified to produce process steam/electricity and sell electricity back to the grid. Food waste and other soluble organics are anaerobically fermented to methane. Anaerobic digestion polishes process water for reuse. Recyclables are readily collected and combustible wastes are gasified to produce energy. Aqueous pretreatment of MSW Liquid hot water pretreatment and steam explosion are green technique and can improve hydrolysis yields to 80-90 % of theoretical. (Figure 2) Since no chemicals are used, these techniques are compatible with the rest of the integrated biorefinery. Pretreatment can increase the yield of ethanol to ~30 MM gal/yr on a 3000 tpd basis. Aqueous pretreatment can also improve the degree of hydrolysis of wastes such as rice straw. Figure 2. Optimal residence times at given temperatures provide maximum % conversion of available glucose for the unfractionated MSW. Economics MSW provides economic justification for building a biorefinery due to its good ROI and relatively small payback period. MSW is produced year round and provides a realistic substrate the biorefinery. Transportation costs are low because it is already collected. MSW is produced near population centers and brought to a central facility for processing. Revenue Electricity, $/yr $ 2,404,012 Ethanol, $/yr $ 32,850,410 Tipping fees for diversion, $/yr $ 34,783,636 Recyclables, $/yr $ 313,727 Total revenue, $/yr $ 70,351,786 PROFITS, $/yr $ 49,717,624 Economic Indicators NPV @ 10 % discount rate, $ $ 104,815,859 IRR, % 16.2 Annualized ROI, % 16.8 Payback Period, yrs 5.8 Table 2. Revenue flow and economic indicators for the 3000 tpd biorefinery. Incorporation of ag-waste Ag-waste can be incorporated seasonally into an MSW-based biorefinery, alleviating the tight operating margins for a traditional biorefinery. Cellulosics such as rice straw can be converted to ethanol at a 50-60 % efficiency. Other ag-wastes such as spinach are largely solubilized in the autoclave and readily fermentable to methane. Autoclaving serves as a perfect alternative for tainted or expired food crops.
Partnership: SVSWA, USDA-ARSAlbany, CR3, & HDR/ Brown-Vance Integrated, Flexible Biorefineries for Handling Municipal Solid Waste and Agricultural Residues Articulated vessel allows rapid loading & unloading and improves mixing VOCs to treatment/ Untreated MSW disposal Recyclables FW Large waste to landfill Trommel screen Autoclave MSW pulp 1 accepts Heavy rejects Pulp Cleaning Glucose Enzymatic Hydrolysis/ Fermentation Polished process water Distillation Ash to landfill Gasification Process energy and steam/ Electricity to grid Solids Separation Unreacted solids Polished process water Aqueous phase Anaerobic Digestion/ Polishing Biogas (CH4) ADDING VALUE TO ALL STREAMS: Producing Ethanol, Electricity, Methane, Recycled Paper, Recycled Plastic UC Davis Digester Fermentation to Ethanol Gasification Energy Digestion Methane Ethanol Bottoms Excess to sewer
Autoclave Technology What s Next? Design/financing/procurement CEQA Permitting Construction Start up 2012?
What s LeL: Residues? The Hardest of the Hard Ones 1.Residue from the Hard Ones 2.Residue from the Easy Ones Metal, plastics, synthetics, some heavy fibers (unrecovered cardboard), lignens (unrecovered wood), inerts (soil, rocks)
What to Do With the Residue, Except Landfilling? Incineration Rocket to the Sun Conversion Technologies?
What is a Conversion Technology? A change in nature or form Gasification Gasification with introduction of Plasma Field Pyrolysis Hydrolysis Anaerobic Digestion Many other options in various states of study
And the Winner is? GasificaEon Use of heat, pressure and steam Conversion to syngas that can produce electricity Various processes: conventional, plasma, and pyrolysis
How to get Rid of a Landfill: THE PROCESS! RFP Goals Maximum diversion Materials separation/recovery Reduce environmental impact Financially self sustaining Comparable gate fees Public private partnership Education center
What Do They Do? Vendor Responsibilities Public outreach + education Stakeholder meetings Project development CEQA and permitting Financing Construction Operations
What Do We Do? Authority Responsibilities Public outreach & education Provide land Dedicate tonnage Establish rates Ensure compliance Construction oversight Operations oversight Utilize Education Center
What s Next? Conversion Technology Term Sheet negotiations with final two vendors Final vendor selection Summer 2010 Contract development end of 2010 CEQA Permitting Construction Start up 2014?
A FUTURE WITHOUT LANDFILLS Wet Garbage Recyclables Green/ Wood/Food Autoclave MRF/ Program Residue Composting Residue Biorefinery Digestion Composting Pulp Washing Residue Markets Gasification Ag Markets Gasification Biomass Fuels Ethanol Methane/ Fuels Electricity Ag Markets Paper Mill Gasification Electricity Const. Products Electricity Const. Products Electricity Fuel Electricity Const. Products
For Further InformaEon Contact: Patrick Mathews, General Manager/CAO Salinas Valley Solid Waste Authority 128 Sun Street, Suite 101 Salinas, CA 95060 (831) 775 3000