(58f) Recent Developments in Modularized Air-Blown Coal Gasification Systems for Chemical and Industrial Applications

Coal gasification is receiving a significant amount of interest as the Energy Policy Act of 2005 takes effect. Most of the publicized attention is focused on relatively large-scale applications for either power generation or for the production of syngas for use as a feedstock in the production of either liquid fuels or other chemical products. These applications typically are oxygen-blown gasification with the attendant requirement to include an air separation system in the overall plant design. Recent developments in two-stage, fixed-bed, air-blown gasification systems make this approach very attractive for smaller, industrial-scale applications where the inclusion of an air separation plant would drive operating costs to uneconomic levels. The nature of the two-stage gasifier also allows easy segregation of the two gas streams exiting the gasifier, which may offer significant syngas and fuel gas benefit for chemical processes. These plants typically include modularized systems for removal and recovery of particles, tars and oils and for the removal of hydrogen sulfide (H2S). Additional equipment for removal of mercury (Hg) and for H2S polishing can be included. Projects using this technology are currently under development for a variety of industrial applications including chemical, mining and cement kilns, industrial steam boilers, various types of dryers, glass furnaces and IGCC plants.

This paper will discuss the design features of a modularized two-stage, air-blown gasification plant. The paper will also summarize the development status of various industrial applications mentioned above.