111

Evaporator Surfaces

Evaporator Surfaces

Steam + Oxygen

Syngas to Filtration

FIGURE 5-34. Schematic diagram of the Prenflo gasifier. (From Ratafia-Brown, J. et al., Major Environmental Aspects of Gasification-Based Power Generation Technologies, Office of Fossil Energy, U.S. Department of Energy, Washington, D.C., December 2002.)

Syngas to Filtration

Steam + Oxygen

Gasifier Slag Quench

FIGURE 5-34. Schematic diagram of the Prenflo gasifier. (From Ratafia-Brown, J. et al., Major Environmental Aspects of Gasification-Based Power Generation Technologies, Office of Fossil Energy, U.S. Department of Energy, Washington, D.C., December 2002.)

400 psig. Oxygen is combined with the slurry and injected into the first stage of the gasifier, where the highly exothermic gasification/oxidation reactions occur. Operation at the elevated temperatures eliminates the production of hydrocarbon gases and liquids in the product gas. The molten ash flows into a water bath, where it is quenched and removed. The raw gas from the first stage enters the second stage, where the remaining 25% coal slurry is injected. The endothermic gasification/devolatilization reactions occur in this stage at a temperature of ~1900°F, and some hydrocarbons are added to the product gas. Char is produced in the second stage and is recycled to the first stage, where it is gasified. The syngas exits the gasifier and undergoes further cooling and cleaning.

0 0

Post a comment