Plasma Feedwater and/or Make Up Water Energy Transfer System

Abstract

A method and system for converting a feedstock using thermal plasma or other gassifier, into a feedwater or make up water energy transfer system. Feedstock is any organic material or fossil fuel. The energy transferred in the feedwater or make N up water is used in any Rankine or other steam process, or any process that requires heat. Heat is extracted from a gas product issued by a gassifier and is delivered to a power plant via its feedwater system or make up water system. Preferably, the gassifier is a plasma gassifier and the gas product is syngas that is combusted in an afterburner. A heated air flow and/or EGR flow is provided the afterburner at a variable flow rate that is responsive an operating characteristic of the afterburner.

What is claimed is: 
     
         1 . A method of extracting heat energy from a gassifier and delivering the heat energy to a power plant, the method comprising the steps of:
 extracting heat energy from a gas product issued by the gassifier; and   delivering the extracted heat energy to a selectable combination of a feedwater system and a make up water system of a power plant.   
     
     
         2 . The method of  claim 1 , wherein the gassifier is a plasma gassifier. 
     
     
         3 . The method of  claim 1 , wherein the gas product is syngas. 
     
     
         4 . The method of  claim 3 , wherein prior to performing said step of extracting heat energy there is provided the further step of combusting the syngas in an afterburner. 
     
     
         5 . The method of  claim 4 , wherein there is further provided the step of supplying an air flow to the afterburner. 
     
     
         6 . The method of  claim 5 , wherein said step of supplying an air flow to the afterburner is performed in excess of stoichiometric to cool the outlet charge of the afterburner. 
     
     
         7 . The method of  claim 5 , wherein said step of supplying air flow to the afterburner is performed at a selectable one of an approximately stoichiometric level and a sub-stoichiometric level. 
     
     
         8 . The method of  claim 4 , wherein there is further provided the step of injecting recirculated exhaust gas into the afterburner. 
     
     
         9 . The method of  claim 8 , wherein said step of injecting recirculated exhaust gas into the afterburner is performed at a flow rate that is varied in response to an afterburner temperature characteristic. 
     
     
         10 . The method of  claim 5 , wherein said step of supplying an air flow to the afterburner is performed at a variable flow rate. 
     
     
         11 . The method of  claim 10 , wherein the flow rate is varied in response to an A/F ratio. 
     
     
         12 . The method of  claim 10 , wherein the flow rate is varied in response to an afterburner temperature characteristic. 
     
     
         13 . The method of  claim 5 , wherein there is further provided the step of preheating the air flow to the afterburner to reclaim energy from the system. 
     
     
         14 . The method of  claim 1 , wherein the gassifier is a plasma gassifier, and there is further provided the step of cooling a plasma torch by using a selectable combination of an incoming feedwater and a make up water from the power plant. 
     
     
         15 . The method of  claim 1 , wherein there is provided the further step of supplementing the extracted heat energy with a selectable one of natural gas and propane. 
     
     
         16 . The method of  claim 1 , wherein there is provided the further step of reducing emissions by subjecting the gas product to a ceramic media filter. 
     
     
         17 . A method of providing heat energy from a gassifier to a power plant, the method comprising the steps of:
 issuing a gas product from the gassifier;   delivering the gas product to a heat exchanger arrangement;   delivering a selectable combination of feedwater and make up water from the power plant to the heat exchanger arrangement;   extracting heat energy from the gas product in the heat exchanger arrangement;   delivering the extracted heat energy to the selectable combination of feedwater and make up water from the power plant in the heat exchanger arrangement; and   returning the selectable combination of feedwater and make up water with the extracted heat energy to the power plant.   
     
     
         18 . The method of  claim 17 , wherein the gassifier is a plasma gassifier, and the gas product is a syngas product. 
     
     
         19 . The method of  claim 18 , wherein the plasma gassifier is provided with a plasma torch, and there is provided the further step of cooling the plasma torch with the selectable combination of feedwater and make up water of the power plant. 
     
     
         20 . The method of  claim 18 , wherein prior to performing said step of delivering the gas product to the heat exchanger arrangement, there is provided the further step of combusting the syngas in an afterburner. 
     
     
         21 . The method of  claim 20 , wherein there is further provided the step of supplying an air flow to the afterburner. 
     
     
         22 . The method of  claim 21 , wherein said step of supplying an air flow to the afterburner is performed at a variable flow rate responsive to an operating condition of the afterburner. 
     
     
         23 . The method of  claim 17 , wherein there is provided the further step of supplementing the extracted heat energy with a selectable one of natural gas and propane. 
     
     
         24 . The method of  claim 17 , wherein there is provided the further step of injecting recirculated exhaust gas (EGR) into the afterburner. 
     
     
         25 . The method of  claim 24 , wherein said step of injecting recirculated exhaust gas (EGR) into the afterburner is performed at a variable flow rate responsive to an operating condition of the afterburner.