Method for separating CO2 through chemical looping combustion in coal pressure high-density circulating fluidized bed

Abstract

The invention provides a method for separating CO2 through chemical looping combustion in a coal pressure high-density circulating fluidized bed, which comprises the following steps: coal particles and a gasifying agent are subjected to gasification reaction in a fuel reactor 1 of the coal pressure high-density circulating fluidized bed, and gasified products and oxygen carriers which return to the fuel reactor are subjected to combustion reaction to produce CO2 and H2O; smoke which is produced during the reaction and carries oxygen-lost oxygen carriers and carbon-containing coal ash enters a primary cyclone separator 2 for separation, and separated oxygen-lost oxygen carriers are in contact with transversely passing air for reaction in an air reactor 5 of a cross flow moving bed to be regenerated and are turned to the combustion reactor through a primary material returning device 8 to continuously participate in the combustion reaction; and separated smoke in the primary cyclone separator 2 further enters a secondary cyclone separator 10 for separation, solid particles secondarily separated are returned to the fuel reactor 1 through a secondary material returning device 13 to continuously participate in the combustion reaction, and H2O is removed from the separated gases through condensation to obtain high-purity CO2.

Description

Technical field [0001] The invention belongs to the field of clean combustion and efficient utilization of coal, and relates to a coal pressurized high-density circulating fluidized bed chemical chain combustion to separate CO 2 method. technical background [0002] Among the many greenhouse gases, the burning of fossil fuels produces the largest carbon dioxide emissions and has the most serious impact on the global climate. How to reduce carbon dioxide emissions has become one of the main problems to be solved for human sustainable development. Chemical Looping Combustion (CLC) is a new type of flameless combustion technology. Its basic principle is the cyclic and alternate reaction of oxygen carriers between two fluidized bed reactors, replacing the fuel directly with air. Realize the combustion process: On the one hand, the oxygen carrier is used to separate the oxygen in the air in the air reactor; on the other hand, the oxygen carrier in the fuel reactor is used to transfer...

AI Technical Summary

Problems solved by technology

But so far, the research on CLC technology and oxygen carrier using gaseous fuel or liquid fuel is relatively mature, while the research on CLC technology using solid fuel is still in its infancy, and there are many problems

One of the main problems is that due to the difference between the combustion reaction rate of fuel / oxygen carrier and the oxygen carrier reaction rate of oxygen carrier by 2 to 3 orders of magnitude, it is difficult for conventional CLC technology to achieve a good match between the combustion reaction and the oxygen carrier reaction. Low efficiency, so there is no internationally recognized technical route so far

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