Grantee Research Project Results

2008 Progress Report: Biomethane for Transportation

EPA Grant Number: SU833684
Title: Biomethane for Transportation
Investigators: Leonhardt, Eric , Cruse, Ryan , Jopin, Matt , Shaw, Todd , Blumhagen, Rachel , Swazo, Jamin , Welsh, Geoff , Freund, Alex , Castillo, Anthony , Sjodin, Jeremy , Stazel, Jordan , Wohlenhaus, Drew
Current Investigators: Leonhardt, Eric , Freund, Alex , Castillo, Anthony , Wohlenhaus, Drew , Welsh, Geoff , Swazo, Jamin , Sjodin, Jeremy , Stazel, Jordan , Jopin, Matt , Cruse, Ryan , Parent, Sean , Shaw, Todd
Institution: Western Washington University
EPA Project Officer: Page, Angela
Phase: II
Project Period: August 31, 2007 through July 31, 2008 (Extended to July 31, 2009)
Project Period Covered by this Report: August 31, 2007 through August 30,2008
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2007) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Awards , P3 Challenge Area - Air Quality , Sustainable and Healthy Communities

Objective:

To demonstrate the ability of dairy farm anaerobic digesters to produce biomethane for use in a vehicle.  To improve the economic value of the anaerobic digester in the Pacific Northwest and therefore increase the number of digesters operating in the region.  To improve regional air, water and soil quality and to reduce the effective greenhouse gas emissions from dairy farming.   

Progress Summary:

The original timeline for the project was to accomplish most of the tasks during the summer of 2007.  This work was delayed until the spring and summer of 2008.  The team created the original timeline based on the mistaken assumption that the Phase II award would be available during the summer of 2007.  This setback aside, the team has leveraged the EPA Phase II award for $75,000 into additional funding.  The Whatcom Public Utility District provided $20,000 for the installation costs associated with the compressors and refueling infrastructure.  A joint project with Washington State University has provided an additional $52,000 for faculty research salaries and for student research wages.  This funding has provided assistance to resolve challenges encountered with the original design approach.  The state legislature provided this funding to Washington State University, the fiscal manager, during July, 2007.  Our program was unable to access these funds until May 2008, so the hiring of researchers was impacted.  Although the timing of the project has been impacted significantly, the additional resources should ultimately create a better final product.

One goal for the project has changed. Based on studying past results including simulations of refinery efficiency and cost estimates, the design target of the refinery has been increased to provide 25 standard cubic feet per minute (scfm) of biomethane instead of 10 scfm.  This targets an annual production potential of 100,000 gasoline gallons of equivalent energy or one third the energy used to power the entire Whatcom County Transit Authority buses annually. The core refinery unit, based on using amine solutions to remove hydrogen sulfide and carbon dioxide from the biogas, is nearly complete.  The unit consists of two twenty foot towers with a 12” inside diameter.  The fiberglass tubes were fabricated locally and are connected with stainless steel piping.  A fractional factorial materials study was conducted to select the materials.  A steel framework to hold the towers has been constructed.  The tower and piping supports are being finalized.  A site has been selected at the farm. Placement of the towers should occur during October, 2008.

Three large, used, industrial compressed natural gas compressors have been purchased.  Each compressor is rated at 28 scfm.  Two were recently rebuilt.  Multiple refueling hoses and overhead support stands have been purchased as well.  More than twenty CNG high pressure tanks have been obtained.  Eight are certified but the remainder will still need to be recertified for storage. 

A prototype system for regenerating the amine was built.  A significant challenge of the current refinery design is that it depends upon amine to remove small amounts of hydrogen sulfide and large amounts of carbon dioxide.  The amine has a finite capacity to absorb hydrogen sulfide and carbon dioxide, so these compounds must be continually removed from the amine.  The prototype system consists of a heating unit to release the hydrogen sulfide and carbon dioxide from the amine.  Next a reverse flow tower sprays a solution of sodium hypochlorite (bleach) on the entering carbon dioxide and hydrogen sulfide.  The hydrogen sulfide reacts with the bleach solution, leaving the carbon dioxide to pass through.  A tower of iron filings removes hydrogen sulfide in the event that the sodium hypochlorite system fails.  A condenser unit removes water vapor from the gas before allowing the carbon dioxide to exit to the atmosphere. 

The prototype system requires a continual supply of bleach solution to operate and a system to remove precipitate waste.  This solution is not an ideal match to the goals of the P3 award.  The team sought a biological solution that may ultimately replace the current, amine-based refining technology.  Dr. Craig Moyer, biologist, joined the team to help locate bacteria that could convert the hydrogen sulfide into sulfur.  The current goal is to build a bioreactor system that uses the carbon dioxide and hydrogen sulfide gas from the amine regeneration unit to produce sulfur.  A factorial test run at the farm for several weeks helped determine what conditions could promote the growth of the bacteria.  A second test is being set up to help determine the processing rate of the microbes.  Once it is determined how much unit area of microbes is required to process an amount of hydrogen sulfide, the final bioreactor will be built.  This complexity has taken additional time.  However, the outcome should match P3 goals more effectively and provide a commercially viable solution.

The team has not located a cost effective, real time measurement system for hydrogen sulfide.   We have received quotes for several systems that range from $4,000 to more than $20,000, but the low cost systems will not survive prolonged exposure to the raw biogas.  The industrial rated units cost more than the value of the materials in our refinery towers.  At this point we will take measurements as a batch process. 

Our test vehicle, Viking 32, suffered a failure of its electric motor and controller while driving to an event.  We have a quote for repairing the parts for nearly $18,000.  We are investigating a lower cost solution to return the vehicle to operation as a plug-in hybrid. 

Future Activities:

The team will strive to complete the unit so that full scale testing can occur during the spring of 2009, prior to the EPA P3 event.  If the testing is successful, we believe that this approach will provide a relatively low-cost means of dramatically reducing the global warming potential of Whatcom County while improving dairy farm economics and reducing the environmental impacts from dairy waste.  The Whatcom County goal for reducing annual carbon dioxide emissions is 1.1 million tons (lbs.) by 2020 [7].  If this project were implemented across the county, more than 10% of this goal could be achieved.  The opportunity for exporting this technology is also significant with a pilot test potential for the Philippines and interest from Costa Rica as well. 

References:

1. Hart, H., “An overview of the agriculture, fishing, and forestry industrial sectors”, Center for Economic and Business Research, Western Washington University, p.11.
2. Frear, C., Zhao, B., Fu, G., Richardson, M. and Chen, S., 2005, “Biomass Inventory and Bioenergy Assessment”, Washington State University, p. 30.
3. Frear, C., Zhao, B., Fu, G., Richardson, M. and Chen, S., 2005, “Biomass Inventory and Bioenergy Assessment”, Washington State University, p. 71.
4. U.S. EPA. 1999, “EIIP Volume VIII: Estimating Greenhouse Gas Emissions. Emission Inventory Improvement Program (EIIP) and U.S. EPA”, U.S. EPA, 1999.  (Latest version is currently under review)
5. Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. Betts, D.W. Fahey, J. Haywood, J. Lean, D.C. Lowe, G. Myhre, J. Nganga, R. Prinn, G. Raga, M. Schulz and R. Van Dorland, 2007: Changes in Atmospheric Constituents and in Radiative Forcing. In: Climate Change 2007:The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on ClimateChange [Solomon, S., D. Qin, M Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, p. 214.
6. Reeves, C. and Kremen, P., 2006, “Climate Protection and Energy Conservation Action Plan”, Local Governments for the Sustainability for the Northwest Clean Air Agency and Whatcom County, p. 17.
7. Reeves, C. and Kremen, P., 2006, “Climate Protection and Energy Conservation Action Plan”, Local Governments for the Sustainability for the Northwest Clean Air Agency and Whatcom County, p. 22

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

Biofuel, biodiesel ethanol, CHP, natural gas vehicle, hybrid vehicles, NGV, CNG, RFA, Scientific Discipline, Sustainable Industry/Business, Pollution prevention, Sustainable Environment, Energy, Environmental Chemistry, Technology for Sustainable Environment, Environmental Engineering, sustainable development, environmental sustainability, alternative materials, biomass, alternative fuel, biodiesel fuel, energy efficiency, energy technology, alternative energy source, Sustainable Industry/Business, RFA, Scientific Discipline, POLLUTION PREVENTION, Technology for Sustainable Environment, Sustainable Environment, Environmental Chemistry, Environmental Engineering, Energy, energy technology, alternative energy source, environmental sustainability, sustainable development, bio-based energy, alternative materials, energy efficiency, biomass, biodiesel fuel

Progress and Final Reports:

Original Abstract

Final Report

P3 Phase I:

Biomethane for Transportation  | Final Report