One stage coal gasification process

Abstract

An improved one stage, upflow process for coal gasification whereby a dry particulate carbonaceous material and an oxygen-containing gas are combusted in a vertical gasifier thereby converting the carbonaceous material (coal) into a hot gas. The hot, entrained flyslag gas is then contacted with a cooled, recycled gas in a quench zone, thus cooling the gaseous product stream and causing the molten slag particles to convert to nonsticky flyslag particles. The high level thermal energy from the flyslag-laden gaseous product stream is recovered in a fire tube heat exchanger and the flyslag particles from the gaseous product stream are separated by conventional means and recycled back to the gasifier. The product raw gas is further treated for use in a gas turbine to produce electricity.

What is claimed is: 
     
       1. A non-catalytic, one stage, upflow process for gasification of a carbonaceous material, wherein the process consisting essentially of the steps of: a) partially combusting in a fired, vertical slagging gasifier a stream comprising an oxygen-containing gas and a dry particulate carbonaceous material at high temperatures and forming a molten slag stream and a gaseous product stream having entrained therein sticky, molten slag particles;   b) separating said molten slag stream from the gaseous stream;   c) quenching the gaseous product stream in a quench zone with an inert gas thereby cooling the gaseous product stream and the entrained molten slag particles in the gaseous product stream to flyslag particles;   d) passing said gaseous product stream and entrained flyslag particles directly from the quenching step (c) to the thermal energy recovery step (e), without further processing and without flyslag particle removal;   e) recovering high level thermal energy from a flyslag-laden gaseous product stream in a fire tube heat exchanger; and   f) separating the flyslag particles from the gaseous product stream of step (e).   
     
     
       2. The process of claim 1 wherein the carbonaceous material is coal. 
     
     
       3. The process of claim 1 wherein the oxygen-containing gas is air or oxygen-enriched air. 
     
     
       4. The process of claim 1 wherein the inert gas is a recycled gaseous product from the process. 
     
     
       5. The process of claim 4 wherein part of the quenched, raw gas from step (e) is recycled to the gasifier exit by a compressor. 
     
     
       6. The process of claim 4, wherein the flyslag particles are separated from the gaseous product stream using ceramic candle filters. 
     
     
       7. The process of claim 6 wherein most of the flyslag particles from step (e) are recycled back to the gasifier. 
     
     
       8. The process of claim 1 wherein step (a) is performed at a temperature of from about 1371° C. (about 2500° F.) to about 1926° C. (about 3500° F.) pressure of from about 300 psia (about 20.7 bara) to about 500 psia (about 34.5 bara). 
     
     
       9. The process of claim 8 wherein the gaseous product mixture is quenched in step (b) to a temperature of from about 899° C. (about 1650° F.) to about 1038° C. (about 1900° F.). 
     
     
       10. The process of claim 9 wherein the gaseous product stream is cooled to a temperature of from about 899° C. (about 1650° F.) to about 232° C. (about 450° F.) in the fire tube heat exchanger.