An innovative project that uses algae to mitigate carbon emissions from a coal-fired power plant owned by Arizona Public Service (APS) has received a $70.5 million grant from the Department of Energy (DOE).

The funds, awarded from the American Recovery and Reinvestment Act (ARRA), will be used to expand the project. This includes testing it with a new coal-based gasification system at the 995-MW Cholla Power Plant in Holbrook, Ariz.

APS will scale up—by one order of magnitude—a process for coproduction of electricity by which natural gas is produced from coal without releasing carbon dioxide. The process, called hydrogasification, works by causing the coal to react with hydrogen in a high-temperature and high-pressure reaction process, producing methane.

At the same time, the utility will scale up the technology with which it reuses power plant carbon dioxide emissions to grow carbon-hungry algae. The algae are then processed into liquid transportation fuels.

Researchers expect that the algae farm will reuse CO2 at a rate of 70 metric tons per acre per year. APS will focus on the engineering aspects of continuous cultivation, harvesting, and processing of algae grown from power plant emissions. After the construction period, the Energy Department expects the project to run for a minimum of two years to prove operability.

Funding for the project expansion falls under the ARRA’s $1.52 billion solicitation for carbon capture and storage from industrial sources. The industrial sources include cement plants, chemical plants, refineries, steel and aluminum plants, manufacturing facilities, and pet coke–fired and other power plants. Part of the solicitation includes innovative concepts for beneficial CO2 reuse (CO2 mineralization, algae production, etc.) and CO2 capture from the atmosphere.

The APS project is one of two already-existing projects in the industrial carbon capture program administered by the DOE’s Office of Fossil Energy. The other, previously announced, is a Ramgen Power Systems project to scale-up a device that uses supersonic shockwaves to compress CO2 for capture and storage.

Source: DOE