Researchers from Lawrence Livermore National Laboratory (LLNL) and Florida-based Chemergy Inc plan to demonstrate a bioenergy technology that converts wastewater treatment plant byproducts into hydrogen gas to produce electricity.
The US$1.75 million project will be demonstrated on a limited industrial scale at the Delta Diablo Sanitation District (DDSD) facility in Antioch, California.
"We want to use this demonstration project as a model to encourage the widespread use of biosolids for energy production," said chemist Bob Glass, the LLNL project leader.
The demonstration project will be funded jointly by the California Energy Commission and Chemergy, and sponsored by the Bay Area Biosolids to Energy (BAB2E) Coalition. DDSD is spearheading this renewable energy effort for the coalition.
Chemergy uses a patent-pending technology that integrates two established chemical processes. First, thermochemistry is used to produce heat, non-greenhouse gas carbon dioxide and a hydrogen compound from wet biosolids. Secondly, the hydrogen compound is decomposed to produce renewable hydrogen gas. In this demonstration, the hydrogen gas will be used as a fuel and fed into fuel cells provided by CERL and the US Department of Energy (DOE) to generate electricity.
The demonstration project will start in mid-October and Glass anticipates that in about a year the Antioch wastewater treatment plant will be processing one ton per day of wet biosolids and will be producing up to 30 KW of electricity. The electricity, in turn, will be used to power select functions at the plant.
It is believed that the technology to be demonstrated by LLNL and Chemergy may convert wet biosolids into hydrogen at less than US$2 per kilogram (one kilogram of hydrogen is equivalent in energy content to one gallon of gasoline), making it useful both for stationary power as well as for transportation fuel.
As part of the demonstration studies, the scientists will examine the system's performance and efficiency, and the durability of the materials, among other aspects of the technology, Glass said.
"The Chemergy technology is of interest because of its innovative approach utilizing a chemical process for highmoisture feedstock at moderate temperatures and at smaller scale than traditional conversion technologies," said coalition spokesperson Caroline Quinn. "The coalition is specifically focused on combustion-free processes that can maximize the renewable energy potential of biosolids."
