Use of pure carbon dioxide as an inerting and flow medium in powder injection systems for use in pulverized coal gasification under pressure

Abstract

A particulate feed arrangement used in pulverized coal gasification under pressure is provided. The arrangement includes a reservoir for stocking the pulverized coal, a plurality of powder injection tubes, and a metering unit. Pure carbon dioxide is fed to the components that are at operating pressure, namely the power injection tube and the metering unit, as the inerting and flow medium or fluidizing medium. The carbon dioxide-carrying components are heated in such a manner that the temperature is above the threshold of the diphase range. A method is also provided. The method allows elimination of any nitrogen in the product gas, which nitrogen is caused by the powder injection system, especially when used in pulverized coal gasification under pressure to produce a synthesis gas for the production of different hydrocarbons.

1 .- 5 . (canceled) 
   
   
       6 . A method for operating a particulate feed system for a pressurized gasification of pulverized coal, comprising:
 providing a bin for storing the pulverized coal which is subject to an ambient pressure;   providing a plurality of feed lock hoppers and a metering vessel both of which are subject to a high operating pressure;   heating the bin;   feeding heated nitrogen to the bin as an inerting and disaggregating medium;   supplying carbon dioxide to a feed lock hopper as an inerting and conveying medium; and   feeding carbon dioxide to the metering vessel as a fluidizing medium.   
   
   
       7 . The method as claimed in  claim 6 , wherein the supplied carbon dioxide is heated to a temperature above a threshold to a two-phase region at a high process pressure in a high pressure region of the system. 
   
   
       8 . The method as claimed in  claim 6 , wherein a feed lock hopper depressurization gas is expanded, heated and then filtered at the ambient pressure. 
   
   
       9 . The method as claimed in  claim 6 , wherein the high operating pressure is 40 bar. 
   
   
       10 . The method as claimed in  claim 6 , wherein carbon dioxide is used as an injection gas and is introduced into a plurality of pulverized coal conveying lines. 
   
   
       11 . A particulate feed arrangement for a pressurized gasification of pulverized coal, comprising:
 a bin for storing the pulverized coal which is subjected to an ambient pressure;   a plurality of feed lock hoppers which is subjected to a high operating pressure;   a metering vessel which is subjected to the high operating pressure,   wherein the bin is heated,   wherein heated nitrogen is fed to the bin as an inerting and disaggregating medium,   wherein carbon dioxide is supplied to the feed lock hopper as an inerting and conveying medium, and   wherein carbon dioxide is fed to the metering vessel as a fluidizing medium.   
   
   
       12 . The arrangement as claimed in  claim 11 , wherein a plurality of components to which carbon dioxide is applied may be heated to a particular temperature that is above a threshold of a two-phase region. 
   
   
       13 . The arrangement as claimed in  claim 11 , wherein the high operating pressure is 40 bar. 
   
   
       14 . The arrangement as claimed in  claim 11 , wherein carbon dioxide is used as an injection gas and is introduced into a plurality of pulverized coal conveying lines. 
   
   
       15 . The arrangement as claimed in  claim 11 , wherein a feed lock hopper depressurization gas is expanded, heated and then filtered at the ambient pressure.