Mitsubishi Heavy, Southern Company begin underground injection of captured CO2 from coal-fired plant; 500 metric tons per day

15 September 2012

A carbon capture and sequestration (CCS) demonstration project jointly under way by Mitsubishi Heavy Industries, Ltd. (MHI) and Southern Company, a major US electric utility, has begun underground injection of CO₂ recovered from emissions from a coal-fired power generation plant. The event marks a milestone in the first integrated CCS project for flue gas from a coal-fired power plant—which contains significant quantities of impurity—on a scale of 500 metric tons per day (mtpd).

The demonstration project calls for the capture and compression of CO₂ from the flue gas of a coal-fired plant by a CO₂ capture facility built at Southern Company’s Plant Barry in Alabama, and its sequestration in a saline formation at a depth of 3,000-3,400 meters in the Citronelle Dome geologic structure, approximately 12 miles west from the plant.

The sequestration aspect of the project is being conducted as Phase III of the Regional Carbon Sequestration Partnerships program, a program sponsored by the US Department of Energy (DOE) aimed at reducing greenhouse gas emissions.

The volume of CO₂ injection, which began following approval by the Alabama state government, has been progressively expanded and now reached the full-scale target of 500 mtpd. In the project MHI is responsible for basic planning, engineering, core equipment supply, and provision of technology support during the demonstration operation in CO₂ recovery and compression.

At Plant Barry, CO₂ capture demonstration test has been successfully being conducted since June last year. The CO₂ capture facility, which was built jointly by MHI and Southern Company, is currently the largest deployed: 500 mtpd, with CO₂ recovery efficiency above 90%. The facility consists primarily of a flue-gas scrubber, flue-gas CO₂ capture/re-generation system, CO₂ compression machinery, and electrical components.

For CO₂ recovery the facility adopts the KM CDR Process, which uses a proprietary KS-1 high-performance solvent for CO₂ absorption and desorption that was jointly developed by MHI and the Kansai Electric Power Co., Inc. Compared with other CO₂ capture technologies, the KM CDR Process uses significantly less energy, according to MHI.

Southern Company is one of the largest energy companies in the US, with a generating capacity of more than 42,000 megawatts serving 4.4 million customers in the country’s southeast.

MHI has installed 10 natural gas-fired CO₂ capture facilities currently in operation, plus one under construction, for chemical plant applications. In the area of CO₂ recovery from coal-fired plant flue gas, the company, working in cooperation with the Research Institute of Innovative Technology for the Earth (RITE) and Electric Power Development Co., Ltd. (J-POWER), has already completed small-scale demonstration testing at 10 mtpd and confirmed uninterrupted stable operation.