System for the Conversion of Coal to a Gas of Specified Composition

Abstract

The present invention provides a coal gasification system with an integrated control subsystem. The system generally comprises, in various combinations, a gasification reactor vessel (or converter) having one or more processing zones and one or more plasma heat sources, a solid residue handling subsystem, a gas quality conditioning subsystem, as well as an integrated control subsystem for managing the overall energetics of the conversion of coal to energy and maintaining all aspects of the gasification processes at an optimal set point The gasification system may also optionally comprise a heat recovery subsystem and/or a product gas regulating subsystem.

1 . A system for the conversion of coal to a gas of a specified composition, comprising:
 a gasification reaction vessel comprising one or more processing zones, one or more plasma heat sources; one or more coal input means for adding the coal to the gasification reaction vessel at an adjustable coal feed rate, one or more process additive input means for adding process additives to the gasification reaction vessel at an adjustable process additive feed rate, and one or more outlets for the output gas,   a solid residue handling subsystem;   a gas quality conditioning subsystem;   an integrated control system comprising:
 system monitoring means for measuring one or more system parameters to generate data, 
 computing means for collecting and analyzing the data generated by the system monitoring means, and 
 output means to send appropriate signals to effect change in one or more system regulators located throughout the system, 
   
       wherein the control system monitors the one or more system parameters and sends signals to the appropriate system regulators to effect change in the one or more system regulators and thereby produce a product gas of a specified composition. 
     
     
         2 . The system according to  claim 1 , further comprising a heat recovery subsystem, wherein the heat recovery subsystem comprises one or more gas-to-air heat exchangers, and means to transfer the product gases to the one or more gas-to-air heat exchangers, wherein the transfer means is in fluid communication with the one or more output gas outlets. 
     
     
         3 . The system according to  claim 2 , wherein the heat recovery subsystem further comprises one or more heat recovery steam generators, and means to transfer the product gases to the one or more heat recovery steam generators. 
     
     
         4 . The system according to  claim 1 , wherein the gas quality conditioning subsystem comprises one or more of a particulate matter removal means, an acid gas removal means, a heavy metals removal means, and a means for adjusting the humidity and temperature of the gas as it passes through the gas quality conditioning subsystem. 
     
     
         5 . The system according to  claim 1 , further comprising a product gas regulating subsystem. 
     
     
         6 . The system according to  claim 5 , wherein the product gas regulating subsystem is a homogenization tank. 
     
     
         7 . The system according to  claim 1 , wherein the process additive input means is one or more steam inlets, one or more oxidant inlets or both. 
     
     
         8 . The system according to  claim 7 , wherein the oxidant is air, oxygen or oxygen-enriched air. 
     
     
         9 . The system according to  claim 1 , wherein the solid residue handling subsystem comprises a solid residue conditioning chamber, a plasma heating means, and a stag output means. 
     
     
         10 . A process for converting coal to a product gas having a specified composition, said process comprising the steps of:
 passing coal into a gasification zone at a coal input rate;   passing a process additive into said gasification zone at an process additive input rate;   subjecting said coal to heating to provide an offgas and by-product ash;   passing the offgas to a reforming zone;   heating the offgas with a plasma heat source;   adding steam to said offgas at a steam input rate to convert the offgas to a synthesis gas.   
     
     
         11 . The process according to  claim 10 , further comprising the steps of:
 passing said by-product ash into a melting zone;   subjecting said by-product ash to heating by a slag conditioning plasma heat source to convert the by-product ash to slag and maintain the slag in a molten condition;   exhausting the molten slag from the melting zone, and   allowing said molten slag to cool to provide said vitreous slag.   
     
     
         12 . The process according to  claim 10 , further comprising a corrective feedback procedure that comprises one or more of a step of monitoring the composition of the product gas, a step of monitoring the product gas flow and a step of monitoring the product gas temperature. 
     
     
         13 . The process according to  claim 12 , wherein said corrective feedback procedure further comprises the step of adjusting one or more of the coal input rate, the oxygen input rate and the steam input rate to provide a specified product gas composition. 
     
     
         14 . The process according to  claim 12 , wherein said corrective feedback procedure further comprises the step of adjusting one or more of the coal input rate, the oxygen input rate and the steam input rate to account for a measured change in the synthesis gas composition.