CCS and Power Systems
Advanced Energy Systems - Gasification Systems
Long-Term Refractory Durability Tests (Transport Gasifier)
Performer: Southern Company Services, Inc.
Project No: NT0000749
The Power Systems Development Facility (PSDF) gasification process features the transport gasifier, which is a dry-feed, non-slagging, fluidized bed gasifier. The gasifier has operated successfully on a wide range of fuels, including sub-bituminous, bituminous, and lignite coals as well as biomass fuel. It consists of an assembly of dual-layered refractory-lined pipe and is ideally suited to process low-rank coals, which are more than half of the worldwide reserve. The outermost refractory is for insulation as it is necessary to withstand the variations in temperature (ambient up to 1,800 degrees Fahrenheit). The inner most refractory provides erosion resistance as it must also tolerate corrosive gases, rapidly flowing fuel, and ash particles. Failure of the refractory requires unit shut-down and the loss of valuable power production.
In the gasifier, solids from the separation and collection unit enter the lower portion of the mixing zone and combust to provide the heat necessary for the gasification reactions. Coal and sorbent are fed to the gasifier in the upper mixing zone, where hot circulating solids traveling upward from the lower mixing zone provide the heat necessary to devolatilize and gasify the coal in the riser, producing syngas and gasification ash.
Operational reliability depends upon the ability of the materials, especially the refractory, to tolerate these harsh environments for extended periods of time. This work examines the refractory materials and operational environment with the goal of increasing service life.