Heat Recovery from Coal Gasifiers

This paper deals with heat recovery from pressurized entrained and fixed bed coal gasifiers for steam generation. High temperature waste heat, from slagging entrained flow coal gasifier, can be recovered effectively in a series of radiant and convection waste heat boilers. Medium level waste heat leaving fixed bed type gasifiers can be recovered more economically by convection type boilers or shell and tube heat exchangers. An economic analysis for the steam generation and process heat exchanger is presented. Steam generated from the waste heat boiler is used to drive steam turbines for power generation or air compressors for the oxygen plant. Low level heat recovered by process heat exchangers is used to heat product gas or support the energy requirement of the gasification plant. The mechanical design for pressure vessel shell and boiler tubes is discussed. The design considers metallurgical requirements associated with hydrogen rich, high temperature, and high pressure atmosphere