UC Davis Research Reports Title Renewable Natural Gas Research Center Project Permalink https://escholarship.org/uc/item/0055g3kb Authors Raju, Arun Roy, Partho S Publication Date 2019-10-01 eScholarship.org Powered by the California Digital Library University of California Renewable Natural Gas Research Center Project A Research Report from the National Center October 2019 for Sustainable Transportation Arun Raju, University of California, Riverside Partho Sarothi Roy, University of California, Riverside TECHNICAL REPORT DOCUMENTATION PAGE 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. NCST-UCR-RR-19-02 N/A N/A 4. Title and Subtitle 5. Report Date Renewable Natural Gas Research Center Project October 2019 6. Performing Organization Code N/A 7. Author(s) 8. Performing Organization Report No. Arun Raju, PhD https://orcid.org/0000-0001-8599-1664 N/A Partho Sarothi Roy, PhD 9. Performing Organization Name and Address 10. Work Unit No. University of California, Riverside N/A Bourns College of Engineering – Center for Environmental Research & Technology 11. Contract or Grant No. 1084 Columbia Avenue USDOT Grant 69A3551747114 Riverside, CA 92507 SCAQMD Contract 17349 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered U.S. Department of Transportation Final Report (June 2016 – October 2017) Office of the Assistant Secretary for Research and Technology 14. Sponsoring Agency Code 1200 New Jersey Avenue, SE, Washington, DC 20590 USDOT OST-R South Coast Air Quality Management District 21865 Copley Drive Diamond Bar, CA 91765-4178 15. Supplementary Notes DOI: https://doi.org/10.7922/G2J101CZ 16. Abstract Renewable Natural Gas (RNG) is an important alternative fuel that can help the State of California meet several greenhouse gas (GHG) reduction and renewable energy targets. Despite considerable potential, current RNG use on national and state levels are not significant. RNG production potential in California through thermochemical conversion was evaluated as part of this project by assessing technical biomass availability in the state. Biomass feedstocks are defined broadly and include most carbonaceous matter including waste. The types of waste biomass available in the state are classified into three categories: municipal solid waste (MSW), agricultural residue and forest residue. A total of 32.1 million metric tonnes per year (MMT/year) of biomass is estimated to be technically available in the state. The energy content of this biomass is equivalent to approximately 602.4 million mmbtu/year. A survey of current renewable electricity generation and curtailment trends in California was conducted. Real-time data show significant curtailment throughout the year totaling more than 1,300 GWh from 2016 to early 2019. Power to gas and other forms of long-term storage integrated into the electric grid can mitigate these losses and enable smooth integration of additional renewables into the grid. Oxygen/air blown gasification, hydrogasification and pyrolysis are the three major technology options available for thermochemical biomass conversion to a gaseous fuel, including RNG. Although there are no commercial thermochemical biomass to RNG conversion facilities in operation, a number of gasification and pyrolysis technologies are undergoing pilot scale demonstration and development. Design basis for two thermochemical and power to gas conversion projects were developed as part of this project. Life cycle and economic analysis were conducted for the recommended processes. 17. Key Words 18. Distribution Statement Biomass fuels; Electric power transmission; Energy storage No restrictions. systems; Natural gas; Natural gas distribution systems; Renewable energy sources; Thermal power generation 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 58 N/A Form DOT F 1700.7 (8-72) Reproduction of completed page authorized About the National Center for Sustainable Transportation The National Center for Sustainable Transportation is a consortium of leading universities committed to advancing an environmentally sustainable transportation system through cutting- edge research, direct policy engagement, and education of our future leaders. Consortium members include: University of California, Davis; University of California, Riverside; University of Southern California; California State University, Long Beach; Georgia Institute of Technology; and University of Vermont. More information can be found at: ncst.ucdavis.edu. U.S. Department of Transportation (USDOT) Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the information presented herein. This document is disseminated in the interest of information exchange. The report is funded, partially or entirely, by a grant from the U.S. Department of Transportation’s University Transportation Centers Program. However, the U.S. Government assumes no liability for the contents or use thereof. South Coast Air Quality Management District (SCAQMD) Disclaimer This report was prepared as the result of work sponsored by the South Coast Air Quality Management District. It does not necessarily represent the views of the SCAQMD nor those of its employees. The SCAQMD, its employees, contractors, and subcontractors make no warrant, expressed or implied, and assume no legal liability for the information in this report; nor does any party represent that the use of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the South Coast Air Quality Management District nor has the SCAQMD passed upon the accuracy or adequacy of the information in this report. Acknowledgments This study was funded, partially or entirely, by a grant from the National Center for Sustainable Transportation (NCST), supported by USDOT through the University Transportation Centers program. The authors would like to thank the NCST and USDOT for their support of university- based research in transportation, and especially for the funding provided in support of this project. This study was supported by the South Coast Air Quality Management District (SCAQMD) with cost share support from the Southern California Gas Company (SoCalGas), and the National Center for Sustainable Transportation (NCST), a USDOT University Transportation Center. The authors would like to thank the NCST, USDOT, SCAQMD and SoCalGas for their support of university-based research in transportation, and especially for the funding provided in support of this project. Renewable Natural Gas Research Center Project A National Center for Sustainable Transportation Research report October 2019 Arun Raju and Partho Sarothi Roy College of Engineering – Center for Environmental Research & Technology, University of California, Riverside [page intentionally left blank] TABLE OF CONTENTS EXECUTIVE SUMMARY .................................................................................................................... iv Introduction .................................................................................................................................... 1 Background ................................................................................................................................. 1 Renewable Natural Gas Potential Evaluation ................................................................................. 1 Biomass Resources...................................................................................................................... 1 Methodology............................................................................................................................... 2 Biomass Availability .................................................................................................................... 4 Biomass Availability Summary .................................................................................................. 13 Power-to-Gas Resources ........................................................................................................... 13 Generation and Curtailment ..................................................................................................... 16 Thermochemical Conversion Technologies .................................................................................. 20 Oxygen/Air Blown Processes .................................................................................................... 21 Hydrogasification ...................................................................................................................... 21 Pyrolysis Based Processes ......................................................................................................... 22 Design Basis Calculations .............................................................................................................. 27 Pipeline Quality RNG Production via Gasification .................................................................... 27 Power to Gas-Based Hydrogen Production .............................................................................. 31 Life Cycle and Techno-Economic Analysis ................................................................................ 32 Outreach ....................................................................................................................................... 42 Summary and Discussion .............................................................................................................