System and method for gasification-combustion process using post combustor

Abstract

Systems and methods for effectively combusting municipal wa ste are disclosed. Aspects of the present invention provide improved techniques for increasing efficiency of combusting municipal waste as well as decreasing emission of harmful gases. In one aspect of the present invention a system is provided which includes a post combustor for combusting gasified waste. In another aspect of the present invention, a method for using the post combustor to gasify the waste is provided.

1 . A system for gasifying and combusting waste comprising:
 a. a gasifier for mixing syngas with air or recirculated flue gas; said gasifier containing an entrance duct and a premixing nozzle designed to inject the air or recirculated flue gas into the gasifier; and   b. a post combustor comprising:
 i. an entrance duct for receiving syngas from the gasifier; 
 ii. a cyclone-shaped chamber positioned near the end of the entrance duct designed to collect fly ash or heavy weight particles; 
 iii. a top injection nozzle for directing air to flow through the post combustor into the cyclone shaped chamber; 
 iv. a tangential nozzle for directing air or recirculated flue gas into the post combustor; 
 v. a sensor for measuring temperature, moisture, or carbon dioxide; and 
 vi. a controller for positioning and controlling the tangential nozzle to make air flow and temperature more uniform in the post combustor. 
   
   
   
       2 . The system of  claim 1  wherein the top injection nozzle is positioned so that the air flowing through the nozzle forces the fly ash or heavy weight particles into the cyclone-shaped chamber. 
   
   
       3 . The system of  claim 1  wherein said tangential nozzle has a direction and a position; and said controller relies upon information from the sensor to determine the direction and position of the tangential nozzle. 
   
   
       4 . The system of  claim 1  comprising an exit duct for allowing gas to leave the post combustor. 
   
   
       5 . A method for gasifying and combusting waste comprising the following steps:
 a. mixing syngas with air or recirculated flue gas in a gasifier;   b. receiving the syngas from the gasifier at a post combustor;   c. collecting fly ash or heavy particles with a cyclone-shaped chamber;   d. directing air to flow through the post combustor into the cyclone shaped chamber;   e. directing air or recirculated flue gas into the post combustor;   f. using a sensor to gather measurements relating to temperature, moisture, and carbon dioxide of gas inside the post combustor;   g. analyzing these measurements for determining which direction and position a tangential nozzle connected to the post combustor should face;   h. adjusting the tangential nozzle so that it faces the determined direction and position.   
   
   
       6 . The method of  claim 5  comprising the step of allowing gas to leave the post combustor.