Polyhedral gasifier and relative method

Abstract

A gasifier is disclosed combining a fixed bed gasification section where coarse fuel is gasified and an entrained flow gasification section where fine fuel is gasified. The fixed bed section includes upper and lower sections. Coarse fuel is devolatilized in the upper fixed bed section and subjected to elevated temperatures sufficient to crack and destroy tars and oils in the effluent gases. The entrained flow gasification section is disposed in a lower plenum adjacent the lower fixed bed section. A plurality of injection ports are configured to introduce oxygen, steam, or air into different sections of the gasifier to control temperature and operating conditions. Activated carbon may be formed in the upper fixed bed section and in the entrained flow section. The activated carbon may be used as a sorbent to remove pollutants from the effluent gases. The gasifier may be used with various coarse and fine fuel feedstocks.

Description

technical field [0001] The present invention relates generally to the vaporization of carbonaceous fuels, and more particularly to a novel apparatus and method for vaporizing carbonaceous feedstocks that includes both fixed bed and entrained flow vaporization processes in one vessel. Alternatively, the principle of fluidization can be used in the vaporizer. Internally generated activated coke can be used as the primary sorbent for syngas that is purified to produce environmentally acceptable syngas. The present invention is capable of receiving and processing raw fuel in the fixed bed section, as well as pulverized or finely divided solids, liquid and gaseous feedstock in the entrained flow section. Background technique [0002] Broadly speaking, gasification is the process of producing a combustible gas called syngas from a carbonaceous fuel. Gasification is a well-known industrial process that uses reactants such as air, oxygen and steam to convert solid, liquid and gase...

AI Technical Summary

Problems solved by technology

A challenge in the fluidized bed gasification process involves fuel agglomeration in the fuel bed

In addition, the fluidized bed gasification process has some limitations similar to the fixed bed gasification process

[0013] In summary, the main limitations of existing gasification technologies include: limited ability to simultaneously process or gasify coarse solid fuels and fine solid fuels, or the ability to simultaneously process or gasify crude or liquid hydrocarbon feedstocks, resulting in Overall lack of fuel adaptability in either system

Although gasification plants are generally able to meet very high emission limits, their capital costs remain high

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