SHELL CLOSES HOUSTON COAL GASIFICATION PLANT

April 22, 1991
Shell Oil Co. has shut down its SCGP-1 coal gasification demonstration plant near Houston after meeting all its objectives. The program at the plant was jointly conducted by Shell Oil and Shell International Research, both Royal Dutch/Shell Group companies. The Electric Power Research Institute supported the project. "We set out to demonstrate the versatility, reliability, efficiency, and environmental cleanliness of the Shell process, and our 4 year program exceeded all expectations," said

Shell Oil Co. has shut down its SCGP-1 coal gasification demonstration plant near Houston after meeting all its objectives.

The program at the plant was jointly conducted by Shell Oil and Shell International Research, both Royal Dutch/Shell Group companies. The Electric Power Research Institute supported the project.

"We set out to demonstrate the versatility, reliability, efficiency, and environmental cleanliness of the Shell process, and our 4 year program exceeded all expectations," said James L. McCormick, manager of Shell Oil synfuels business development.

In 1989, after 2 years of SCGP-1 operation, the technologically proven Shell process was licensed by Shell Internationale Petroleum Mij. BV to Demkolec BV, a subsidiary of the Dutch Electricity Generating Board, for a 253,000 kw integrated coal gasification combined cycle plant at Buggenum, Netherlands.

Plant design, environmental permit applications, and process guarantees were based on performance data provided by SCGP-1. The Demkolec plant received all permits and is under construction, with start-up scheduled for 1993.

PLANT ACCOMPLISHMENTS

Since 1989 Shell has tested additional feedstocks and further optimized the process.

Overall, SCGP-1 gasified 18 feedstocks, including bituminous and sub-bituminous coals, lignite, and petroleum coke.

Shell said there is extensive process data for design, environmental permitting, construction, and operation of commercial coal gasification plants fed by U.S. coal, non-U.S. coal, or petroleum cokes.

Since start-up in 1987, SCGP-1 logged nearly 15,000 hr of safe, reliable operation, McCormick said.

The plant set production records for bituminous coal-145% of design capacity and for lignite-104% of design. SCGP-1 routinely switched on line from one coal to another, achieving coal to gas efficiencies as high as 83% and carbon conversion rates of more than 99%.

Although feedstock sulphur content ranged from 0.3% to 5.2%, more than 99% sulfur removal efficiencies were obtained regardless of feedstock. All sulfur recovered from SCGP-1 operations was sold as commercial product.

With gasifier temperatures as high as 3,000 F., SCGP-1 product gas contained such low levels of air pollutants, as defined in the 1990 Clean Air Act amendments, that McCormick believes coal gasification combined cycle could be recognized as maximum achievable control technology for coal based power generation.

The coal ash in SCGP-1 was removed as a granular slag, classified as nonhazardous under the Resource Conservation and Recovery Act. The slag was used on site as concrete aggregate. Trace metals in the feed coal were captured in the slag.

SCGP-1 liquid effluent was biotreated within National Pollutant Discharge Elimination System water quality standards.

SCGP-1 achieved an 82% on stream factor during a 5 month run and operated for more than 2 months without a shutdown. Key equipment consistently proved to be durable and reliable, McCormick said.

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