Energy Department to Help Sponsor Project Converting Wastewater to Biogas and Liquid Fuels

The US Department of Energy is awarding $1.2 million to Southern California Gas Co. to run a pilot project that converts wastewater solids to renewable natural gas or liquid fuels. SoCalGas is part of a consortium conducting the pilot, which will be required to equally share the cost.

The consortium is being led by the Water Environment & Reuse Foundation.

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, according to a release. SoCalGas will help oversee the project’s design and assist in obtaining state and federal regulatory approvals and incentives.

According to the Water Environment & Reuse Foundation, 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 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,” said Jeff Reed, SoCalGas’ director of business strategy and advanced technology, in a release.

“This new technology could have an enormous impact on energy and waste. Converting the wastewater solids produced by treatment plants in the U.S. with hydrothermal processing could produce about 128 billion cubic feet of natural gas per year and save treatment utilities $2.2 billion 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 $7 million per year in disposal costs, and power nearly 7,000 vehicles per day.”

The Pacific Northwest National Laboratory has been working on this technology for 40 years — one that takes waste solids and converts it to biocrude and methane gas using water, heat and pressure, reports Green Car Congress. The national lab says, the publication adds, that the technology is highly efficient and that it is able to capture 85% of feedstock energy.

The biocrude oil, will be refined in an existing refinery, while the methane gas will be sold for transport in the gas pipeline system or used at the pilot plant to offset power needs elsewhere in the plant, Green Car Congress reports.

“If fully implemented in wastewater treatment operations across the US, the technology will produce more than two billion gallons of gasoline equivalent per year,” the publication says. “The system also produces fertilizer byproducts.”