The US Department of Energy (US DOE) has selected Southern California Gas' (SoCalGas) pilot hydrothermal wastewater processing project for a federal funding of $1.2m

SoCalGas is part of a consortium conducting the pilot, which will be required to share the cost at a minimum of 50% in order to receive federal funds. The consortium is being led by the Water Environment & Reuse Foundation.

The project will use hydrothermal processing technology to convert wastewater solids into renewable natural gas as well as liquid fuels.

DOE funding is expected to pay for about half of the design and planning of a pilot plant to produce these renewable fuels at a municipal wastewater treatment facility near Oakland, California. SoCalGas will help oversee the project's design and assist in obtaining state and federal regulatory approvals and incentives.   

The new technology converts waste solids from a wastewater treatment plant into biocrude and methane gas using water, heat and pressure.

The biocrude oil replaces fossil oil, providing green fuels with nearly zero net new carbon emissions. The methane gas can be used in the same ways as fossil natural gas.

SoCalGas' business strategy and advanced technology director Jeff Reed said: "SoCalGas and its partners have demonstrated that this process can very effectively convert wastewater solids into renewable natural gas, using existing infrastructure, to help replace fossil fuels and reduce greenhouse gas emissions.

"This new technology could have an enormous impact on energy and waste. Converting the wastewater solids produced by treatment plants in the US with hydrothermal processing could produce about 128 billion cubic feet of natural gas per year and save treatment utilities $2.2bn in solids disposal costs.

"A city of one million people could produce more than 600 million cubic feet of natural gas per year, save more than $7m per year in disposal costs, and power nearly 7,000 vehicles per day." 

The Central Contra Costa Sanitary District, near Oakland, California, will host the pilot system. The consortium includes the Water Environment & Reuse Foundation, which represents many of the 16,000 wastewater systems in the US.

The consortium also includes Genifuel Corp. with technology from DOE's Pacific Northwest National Laboratory, Merrick & Co., Tesoro Corp., Metro Vancouver, MicroBio Engineering, Brown and Caldwell, and over a dozen utility partners.