Two Years After Completion: Biogas Project a Great Success

IMG_4042Back in 2006, the City of Grand Junction began researching a biogas project that would allow methane gas produced at the Persigo Wastewater Treatment Facility to be used as vehicle fuel. Currently, the facility produces approximately 120,000 cubic feet of gas in the anaerobic digestion process per day. Since plant startup back in 1984, only a small amount of the methane was used to fuel the boilers that heat the digestion process, with the vast majority of the gas being flared off.

Fast forward eleven years: The Persigo Methane to Compressed Natural Gas project was completed in April 2015. Through May 2017, the equivalent of 179,000 gallon of gas has been piped to the City fueling site and utilized as a vehicle fuel.  The City of Grand Junction, Grand Valley Transit and Monument Clean Fuels have been the beneficiaries of this alternative fueling source and the $1.50 per gallon price paid back to Persigo has generated approximately $268,500 in revenue for the Wastewater Plant.

In addition to fuel sales, Persigo generates revenue from the sale of renewable identification numbers (RINs) based on the amount of gas produced and ultimately used as a vehicle fuel. These RINs are marketed and sold to companies obligated to comply with the Renewable Fuel Standard which requires an increasing amount of renewable fuel use ultimately stepping up to 36 billion gallons by 2022. As of the first quarter of 2017, Persigo has marketed and sold almost $211,000 worth of RINs.

Scrubbing the methane gas and the process of converting it to a bio-fuel requires approximately $85,000 in expenditure annually. Since completion of this project in April 2015, approximately $174,000 in expenses has been netted out against the $447,500 of revenue for a net profit to the system of $273,500.

Potential: Since startup, Persigo has been optimizing the operation. It is now at a point where it is anticipated that 400 gallons of gas equivalent will soon make it into the pipeline on a daily basis. Once this happens we will be generating gross revenue of approximately $700,000 per year for the Persigo system, with $219,000 coming from fuel revenues and $489,000 from RINs.

History: In 2011, the City began implementing a plan for the future by beginning to purchase Compressed Natural Gas (CNG) fleet vehicles and planning for construction of a fueling station for them. The first CNG solid waste trucks were delivered within days of the CNG fueling station being completed.

In 2014, the City contracted with BioCNG, LLC to design a system to capture, collect and purify the digester biogas at the wastewater plant to a natural gas quality vehicle fuel. The project included a 5.7-mile pipeline which delivers the fuel to the existing CNG fueling site and is used as the primary source of fuel. The fueling station includes slow-fill stations for fueling City and County vehicles, as well as a public fast-fill station that is operated by a private contractor.

Currently the equivalent of 400 gallons of gasoline is produced onsite daily and has offset the same volume use of diesel fuel. This has resulted in a carbon emission reduction of approximately 3 million pounds per year.

Since the first purchase of CNG vehicles in 2011, the City (and in partnership with the County) have continued to add to the CNG fleet each year as vehicles come up for replacement. There are currently 62 CNG vehicles between the City and the County ranging from street sweepers to transit busses.

The City of Grand Junction has received international attention for the biogas project, which is believed to be the only one of its kind in the United States.

Contact:  Sam Rainguet, Communications Manager       970-244-1507 or samr@gjcity.org

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