This process can be operated on all types of coal without pretreatment. Dried, pulverized coal and oxygen are converted in a horizontal, entrained-flow gas­ifier at about 1820°C and near-atmospheric pressure. The raw gas is quenched with water to solidify entrained molten ash, scrubbed to remove entrained solids, and purified to remove hydrogen sulfide and a controlled quantity of carbon dioxide. The resulting product is used as synthesis gas.

Shell Oil Co. Process

This process is a dry feed, entrained-flow, high temperature-high pressure, slagging gasifier that converts a wide variety of coals from lignite to bituminous to a medium-energy gas for combined cycle power generation. The unit oper­ates with pressurized, predried coal, oxygen, and steam at 1500°C and attains carbon conversions above 99%.

Texaco, Inc. Process

This process is a single-stage, pressurized, entrained-flow slagging process that uses a water slurry of ground coal which is pumped along with oxygen to the gasifier. The operating temperature in the gasifier is 1200 to 1500°C. Careful control of the oxygen feed to maintain a reducing atmosphere results in a synthesis gas that is predominantly carbon monoxide and hydrogen.