Method for disposing household refuse in cooperation with cement kiln with partial waste heat recovery function and system

Abstract

The invention discloses a method for disposing household refuse in cooperation with a cement kiln with a partial waste heat recovery function and a system for implementing the method, and relates to the field of energy conservation and environment protection. The method includes the steps that household refuse is sent into a sealed negative-pressure refuse room to be stored and fermented for five days to seven days, air in the refuse room is extracted and sent into a mechanical fire grate refuse combustion furnace to be used as primary air and secondary air, hot smoke enters a waste heat furnace for heat exchange after drying, thermal decomposition, combustion and after-combustion are conducted on the refuse in the combustion furnace, produced low-pressure steam is sent to a cement kiln waste heat power generation system, the smoke is sent to a decomposition furnace after heat exchange is conducted on the smoke in the waste heat furnace, dioxin and other harmful gas produced by the refuse are absorbed and disposed through the high-temperature alkaline negative-pressure condition in a decomposition furnace, and combustion slag serves as a cement raw material. According to the method and the system, through combination with the existing waste heat power generation system of the cement kiln, dioxin exhaust and heavy metal solidification during refuse combustion can be effectively controlled, waste heat power generation capacity of the cement kiln can be improved, waste heat power generation investment and tail gas clean-up investment are saved, and good environment protection characteristics and economical efficiency are achieved.

Description

technical field [0001] The invention relates to the field of energy saving and environmental protection, in particular to a method and a system for co-processing domestic garbage in a cement kiln with partial waste heat recovery. Background technique [0002] The incineration treatment of municipal solid waste has the advantages of the most obvious reduction effect, the most complete harmlessness, and the effective use of incineration heat. Therefore, it is widely used in developed countries and has developed rapidly in my country. Its disadvantages are large investment and high operating costs, and waste-to-energy projects with a scale below 500 tons / day are not economical; due to the increasing awareness of environmental protection among ordinary people, it is also very difficult to select sites for waste-to-energy projects. [0003] Cement kiln co-processing domestic waste technology has been demonstrated and applied in cement plants as a treatment technology with low inv...

AI Technical Summary

Problems solved by technology

Its shortcomings are large investment and high operating costs, and waste-to-energy projects with a scale of less than 500 tons / day are not economical; due to the increasing awareness of environmental protection among ordinary people, it is also very difficult to select sites for waste-to-energy projects

[0003] Cement kiln co-processing domestic waste technology has been demonstrated and applied in cement plants as a treatment technology with low investment, small footprint, good environmental protection, and zero emission of dioxins, but its proportion in waste treatment is very small. Co-processing domestic waste technology is a new type of solid waste treatment technology. It has just started in China, and national policies have not yet been implemented. Compared with waste power generation, the economic benefits are poor, and cement companies are not very enthusiastic.

[0004] Chinese Patent No. 200610076668.X adopts "Cement Rotary Kiln and Incinerator Combined Treatment System for Municipal Solid Waste", and Patent No. 201010567035.5 utilizes cement rotary kiln to process domestic waste. The flue gas is introduced into the cement kiln pre-decomposition system to provide heat for the decomposition of cement raw meal. This technology can make full use of the existing cement plant facilities and sites, save land and investment, and also solve the problem of secondary pollution from incineration, with a good environment benefits, but its economic benefits have not been reflected, and it can only rely on high waste subsidies to maintain the production and operation of enterprises

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