Chapter 1 Potential Biogas Supply from California Dairies .
19 California Dairy Industry.19 On-Farm Manure Management and Biogas Supply .21 On-Farm Manure Management Systems.21 Biogas Production Potential from California Dairies.22 Co-Digestion of Dairy and Other Wastes .24 Crop Residues .24 Food Processing Waste .25 Slaughterhouse Waste and Rendering Plant Wastewater .25 Green Waste from Municipal/Commercial Collection Programs .27 Conclusions Regarding Co-Digestion.27

Chapter 2: Production of Biogas by Anaerobic Digestion.
29 Elements of Anaerobic Digestion Systems.29 Anaerobic Digestion Technologies Suitable for Dairy Manure.31 Ambient-Temperature Covered Lagoon.32 Complete-Mix Digester.32 Plug-Flow Digester.32 Factors Influencing Anaerobic Digestion Efficiency .33 Environmental Impacts of Anaerobic Digestion .34 Reduced Greenhouse Gases Emissions.34 Reduced Volatile Organic Compound Emissions.35 Increased Nitrogen Oxide Emissions.36 Control of Unpleasant Odors.37 Control of Pathogens and Weed Seeds .37 Improved Water Quality .38 Motivation for Realizing Environmental Benefits on Dairy Farms.38 Increasing the Methane Content of Biogas.39 Pretreatment Techniques.39 Microbial Stimulants .40 Co-Digestion with Other Waste Sources .40 Effluent Absorption of Carbon Dioxide .42 Centralized Digestion of Dairy Wastes for Biogas Production.43 Centralized Digesters and Gas Production.43 Transport of Manure and Digested Effluent to Centralized Digesters.44

Chapter 3 Upgrading Dairy Biogas to Biomethane and Other Fuels.
47 Upgrading Biogas to Biomethane.47 Technologies for Removal of Hydrogen Sulfide from Biogas.47 Technologies for Removal of Water Vapor .51 iii Table of Contents Technologies for Removal of Carbon Dioxide.51 Environmental Effects of Gas Cleanup Technologies.59 Possible Design for Small Dairy Biomethane Plant.60 Blending Biogas with More Valuable Fuels.63 Compressing Biomethane.63 Converting Biomethane to Non-Cryogenic Liquid Fuels.63 Methane-Reforming and Catalytic Conversion Processes.64 Biomethane to Gasoline Using the Fischer-Tropsch Process.64 Biomethane to Methanol.65 Biogas or Biomethane to Hydrogen Fuel.66 Converting Biomethane to Liquefied Biomethane.67

Chapter 4 Storage and Transportation of Biogas and Biomethane.
71 Storage Systems and Costs.71 Biogas Storage.72 Biomethane Storage.73 Distribution of Biomethane.76 Distribution via Dedicated Biomethane Pipelines.77 Distribution via the Natural Gas Pipeline Network.77 Over-the-Road Transportation of Compressed Biomethane.78 Over-the-Road Transportation of Liquefied Biomethane.78

Chapter 5 Potential Uses of Biogas and Biomethane.
81 Potential On-Farm Uses of Biogas. 81 Biogas as a Fuel for Combined Heat and Power Applications.82 Alternative Uses of Biogas.88 Summary of On-Farm Demand for Biogas.93 Potential On-Farm and Off-Farm Uses of Biomethane.95 Non-Vehicular Uses of Biomethane.95 Vehicular Uses of Biomethane.96 Summary of On-Farm Demand for Biomethane.105

Chapter 6 Government Policies and Incentives.
107 Policy Responses to Environmental Issues.108 Environmental Regulation.108 Market-Based Incentives for Emission Control.110 Promotion of Environmentally Beneficial Technologies .112 Government Policies and Incentives for Renewable Energy.112 Federal Support for Biomass Energy Sources.112 California Renewable Energy Programs.116 Government Policies and Incentives for Alternative Fuels.118 Federal Policies and Incentives for Alternative Fuels .119 California Alternative Fuel Programs.121 Government Policies and Incentives for Alternative Fuel Vehicles.124 Federal Policies and Incentives for Alternative Fuel Vehicles.124 California Programs Alternative Fuel Vehicles.127 Summary and Conclusions.130 iv Biomethane from Dairy Waste: A Sourcebook for the Production and Use of Renewable Natural Gas in California

Chapter 7 Permits and Regulations for a Dairy Biomethane Plant.
133 Permits for a Biogas Upgrading Plant.133 Water Permits .134 Air Emission Permits .136 Hazardous Waste Regulations.137 California Environmental Quality Act Requirements.137 Local Land Use Regulations.137 Permits for a Centralized Upgrading Facility.138 Permitting and Regulation of Biomethane Storage and Transport.138 On-Vehicle Storage Systems.138 Transportation of Biomethane.141

Chapter 8 Financial Analysis of Biomethane Production .
147 Biogas and Biomethane as Commercial Products.147 Electricity Markets.147 Natural Gas Markets.150 Comparison of Natural Gas and Electricity Prices.152 Estimated Costs for a Dairy Anaerobic Digester Facility.153 Basic System Components.153 Cost Range for Dairy Anaerobic Digester and Electrical Generation Facility.153 Cost Range for Dairy Digester and Biogas Upgrading Facility.154 Summary of Financial Challenges to Building a Biomethane Plant.162

Chapter 9 Developing a Biomethane Industry.
165 Lessons from Sweden.165 Why Should the Public Support the Biomethane Industry?.166 Energy Independence and Renewable Fuel.166 Future Fuel Shortages and Increased Prices for Fossil Fuels.167 Environmental Benefits.168 Eight Steps to a Successful Biomethane Enterprise .169 Step 1: Find a Buyer for the Biomethane.169 Step 2: Obtain Feedstock for the Anaerobic Digester.170 Step 3: Determine Means of Transport.171 Step 4: Locate the Upgrading Plant.172 Step 5: Select a Technology and Prepare an Operating Plan.172 Step 6: Develop a Financial Model and Locate Potential Financing.173 Step 7: Identify Permitting Requirements and Develop a Permitting Plan.173 Step 8: Select a Designer and Contractor and Build the Facility.174 Five Possible Biomethane Plant Projects.174 Project 1: Support Community Vehicle Fleet that Uses Compressed Biomethane.174 Project 2: Sell Biomethane Directly to Large Industrial Customer.175 Project 3: Distribute Biomethane through Natural Gas Pipeline Grid.176 Project 4: Build Liquefied Biomethane Plant.176 Project 5: Use Compressed Biomethane to Generate Peak-Load Electricity.177 References.179 v Table of Contents

List of Figures
Figure 2-1 A dairy farm anaerobic digestion system.31 Figure 2-2 Simplified process of biogas production.31 Figure 3-1 Carbon dioxide absorption towers at the King County South Wastewater Treatment Plant.53 Figure 3-2 Schematic of a pressure swing absorption system with carbon molecular sieves for upgrading biogas.55 Figure 3-3 Cirmac amine carbon dioxide absorption process (LP Cooab™) for upgrading biogas.56 Figure 3-4 Schematic of Puente Hills landfills gas carbon dioxide-methane separation process.57 Figure 3-5 Carbon dioxide scrubbing process developed by Acrion Technologies.59 Figure 3-6 Water scrubbing process to remove carbon dioxide from biogas without regeneration.62 Figure 3-7 Skid-mounted 225-gpd landfill gas liquefaction Hartland Unit.69 Figure 4-1 Schematic of on-farm storage system for compressed biomethane.74 Figure 4-2 Schematic of storage system for liquefied biomethane.76 Figure 5-1 Principles of two-piston Stirling engine.87

List of Tables
Table 1-1 Recent Trends in the California Dairy Industry: More Cows, Fewer Dairies.20 Table 1-2 Number of Cows in California's Dairies, 2003.20 Table 1-3 Potential Daily Methane Production from California Dairies.23 Table 1-4 Potential Methane Generation from Biomass Sources, California.26 Table 2-1 Characteristics of Anaerobic Digesters Suitable for On-Farm Use.32 Table 2-2 Modeled Comparison of Biogas Generation Potential of Three Different Anaerobic Digestion Processes on Typical 1,000-Cow Dairy Merced, CA Dairy.33 Table 2-3 Theoretical Methane Content of Biogas.41 Table 2-4 Operational Parameters for Three Swedish Biogas Plants.42 Table 3-1 Components for Typical Small Biogas Upgrading Plant.61 Table 4-1 On-Farm Storage Options for Biogas and Biomethane.72

Table 5-1 Compressed Natural Gas Fuel Specifications vs. Typical Raw Biogas Composition.93 Table 5-2 Potential Annual Demand for Raw and Cleaned Biogas, Typical 1,000-Cow Dairy Farm.94 Table 5-3 California Market for Compressed-Natural-Gas-Fueled Vehicles.97 Table 5-4 California Market for Liquefied-Natural-Gas-Fueled Vehicles.98 Table 5-5 Summary of California Market for Natural-Gas-Fueled Vehicles.100 Table 5-6 Estimated Annual CNG and LNG Vehicle Consumption in California, 2004.101 Table 5-7 Potential Annual Vehicle Fuel Demand for Typical 1,000-Cow Dairy.102 Table 5-8 Companies Performing Vehicle Conversions to Compressed Natural Gas Fuel, Western USA.105 Table 5-9 Potential Annual Demand for Biomethane, Typical 1,000-Cow Dairy Farm.106 Table 6-1 Federal Policies and Programs that Encourage Alternative Fuels, Ranked According to Presumed Impact on Growth of Biomethane Industry.120 Table 6-2 California Policies and Programs that Encourage Alternative Fuels, Ranked According to Presumed Impact on Growth of Biomethane Industry.122 Table 6-3 Federal Policies and Programs that Encourage Use of Alternative Fuel Vehicles, Ranked According to Presumed Impact on Growth of Biomethane Industry.125 vi Biomethane from Dairy Waste: A Sourcebook for the Production and Use of Renewable Natural Gas in California Table 6-4 California Programs that Promote the Use of Alternative Fuel Vehicles.128

Table 7-1 Permitting Information for Biogas Upgrading Plant.134 Table 7-2 Summary of Major Safety Standards for Compressed and Liquefied Natural Gas Vehicles.140 Table 7-3 Basic Pipeline Quality Standards for Major California Distributors.143 Table 8-1 Average Price of Natural Gas for PG&E Small Commercial Users, 2000 – 2005 .150 Table 8-2 Natural Gas Wellhead, City-Gate, and Distribution Prices (Current Price and Historical Highs and Lows from 2000 through 2005).151 Table 8-3 Natural Gas to Electricity Conversion at Various Efficiency Rates.152 Table 8-4 Estimated Costs of Generating Electricity from Biogas Produced on a Typical 1,000-Cow Dairy.154 Table 8-5 Operating Parameters and Associated Costs for Four Swedish Biogas to Biomethane Plants.157 Table 8-6 Estimated Costs for Three Hypothetical Dairy Biogas to Biomethane Plants.157 Table 8-7 Estimated Costs for Three Hypothetical Dairy Anaerobic Digester and Biogas to Biomethane Plant.158 Table 8-8 Estimated Inputs, Outputs and Associated Costs for Large Dairy Digester, Generator, and Liquefied Biomethane Facility.159 Table 8-9 Estimated Range of Costs for Dairy Digester and Biogas to Biomethane Plant.161 Table 8-10 Estimated Biomethane Production and Distribution Costs Compared to Current Natural Gas Prices.162

Appendices
Appendix A Stoichiometry of the Anaerobic Digestion Process.A-1 Two-Phase Anaerobic Digestion.A-2 Removal of Carbon Dioxide During the Digestion Process.A-4 Conclusions .A-6 Appendix B Detailed Description of the Three Main Dairy Digester Technologies.B-1 Description of Covered Lagoon Digester.B-1 Components of Covered-Lagoon Digester.B-3 Covered-Lagoon Design Variables.B-3 Operation and Maintenance of Covered-Lagoon Digester.B-7 Description of Plug-Flow Digester .B-7 Components of Plug-Flow Digester.B-8 Design Criteria and Sizing the Plug-Flow Digester.B-8 Description of Complete-Mix Digester.B-9 Components of Complete-Mix Digester.B-10 Complete-Mix Digester Design Criteria.B-11 Operation and Maintenance of Complete-Mix and Plug-Flow Digesters.B-12

Appendix C Conversion of Biogas to Biomethanol.C-1 Past Unrealized Projects.C-1 The Smithfield Foods Utah Project: From Hog Manure to Biodiesel.C-1 vii Table of Contents Appendix D Compressed Natural Gas and Liquefied Natural Gas Vehicles Available in California.D-1 CNG Vehicles.D-1 Light-Duty CNG Vehicles.D-1 Medium- and Heavy-Duty CNG Vehicles.D-2 LNG Vehicle Types.D-5 Appendix E Energy Contents / Equivalences for Natural Gas Fuels versus Electricity.E-1 Appendix F Cost of Building Dairy Anaerobic Digesters per Kilowatt.F-1 Appendix G Linking Potential Biomethane Production with Possible Off-Farm Markets in California’s Central Valley: Geographic Case Studies.G-1 Selection Criteria for Regional Focus.G-1 Concentration of Dairies.G-1 Regional Demand for Compressed Natural Gas as a Transportation Fuel.G-3 Summary of Reasons for Selecting San Joaquin Valley as Geographic Focus.G-4 Data Sources.G-4 Dairies.G-4 Demand for Compressed Natural Gas.

G-5 Landfills and Wastewater Treatment Facilities.G-6 Local Businesses with High Demand for Compressed Natural Gas.G-6 Analysis of the Accuracy of Data Collected.G-6 Determination of Viable Project Locations.G-7 Initial Criteria: Nearby Fueling Stations.G-7 Initial Site Rankings: Proximity to Dairies.G-7 GIS Analysis: More In-depth Rankings.G-8 Additional Data.G-11 Description of Sites .G-13 Site #1: City of Tulare, FleetStar.G-13 Site #2: Visalia SoCal Gas, FleetStar.G-16 Site #3: Kings County Yard/PFC.G-19 Site #4.G-20 Conclusion and Further Study .G-23 Appendix G References.G-25 Annex G1: Characteristics of Dairy Industry in the San Joaquin Valley.G-26 Annex G2: Data Accuracy.G-27 Annex G3: CNG Filling Stations.G-31 Annex G4: Analysis of Sites 5 through 8.G-32 Annex G5: Southern California Edison Service Territory.G-37 Annex G6: Wastewater Treatment Plants.G-38 Annex G7: Landfills and Disposal Sites.G-41 viii Biomethane from Dairy Waste: A Sourcebook for the Production and Use of Renewable Natural Gas in California Acknowledgements Program Manager Michael Marsh, Chief Executive Officer, Western United Dairymen Research Manager Ken Krich, Sustainable Conservation Authors Ken Krich, Sustainable Conservation Don Augenstein, Institute for Environmental