Distributed recycling system and method for sulfur in coking industry

Abstract

The invention relates to a distributed recycling system and method for sulfur in coking industry. Based on coking flow system resource balance, the self-purification function of coking flows are brought into full play, the system considers coupling treatment of sulfur foams, sulfur-containing waste gas and sulfur-containing waste liquid, waste materials are recycled, and the resource process value is increased. According to the technical scheme, sulfur foams are purified, then, pure sulfur is obtained, incineration is performed to produce acid, and obtained concentrated sulfuric acid absorbs ammonia in coke oven gas to produce ammonium sulfate; the desulfurization waste liquid is subjected to decoloration and then subjected to sulfo-oxidation, sulfur is separated out for incineration to produce acid, after solution crystallization and separation, ammonium sulfate and ammonium thiocyanate mother liquor are obtained, the ammonium thiocyanate mother liquor is incinerated to produce SO2, ammonium hydroxide is used for absorbing the produced ammonium sulfite, the ammonium sulfite is oxidized to produce ammonium sulfate or ammonium sulfite to be adopted as a denitrification agent for flue gas denitrification; waste heat of coke oven flue gas is recycled, the coke oven flue gas is mixed with ozone, some or all NO in the flue gas is oxidized, then, the flue gas and the recycling process tail gas are subjected to desulfurization and denitrification, and finally ammonium sulfate and ammonium nitrate are produced.

Description

technical field [0001] The invention belongs to the technical field of waste resource utilization, and in particular relates to a distributed resource utilization system and method for sulfur in the coking industry. Background technique [0002] At present, the HPF method widely used in the coking industry uses wet oxidation to remove the H in the coke oven gas. 2 Most of S is converted into elemental sulfur, and a small part of it is a mixture of ammonium thiocyanate, ammonium thiosulfate and ammonium sulfate due to the side reaction of the wet oxidation process. [0003] In existing production, elemental sulfur is purified by molten sulfur or plate and frame pressure filtration, centrifugal defiltration, etc. to obtain sulfur paste, such as a process and equipment for separating molten sulfur by Ge Fangjin et al. (public number CN105502300A), Chai Xiandong et al. (public number CN204324873U), but because the sulfur paste contains more impurities, its color and purity are ...

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Problems solved by technology

[0006] The desulfurization methods of coke oven flue gas are mainly double-alkali method, calcium method and ammonia method, such as a kind of novel double-alkali method flue gas desulfurization method and flue gas desulfurization system (public number CN105498503A) of people such as Huang Wei, people such as Xu Jihong A method for rapid calcium flue gas desulfurization (publication number CN102485323A), the ammonia desulfurization device and process of Jiao Yanbin et al. The process occupies a large area and consumes a lot of energy. Although the calcium method and the traditional ammonia method have easy-to-obtain raw materials and simple processes, the products obtained by the calcium method are difficult to reuse and easily form new waste.

The traditional ammonia method is prone to ammonia escape, and cannot desulfurize and denitrify at the same time

[0007] The method of coke oven flue gas denitrification mainly contains SCR method and SNCR method, such as the SCR method flue gas denitrification device and flue gas denitrification method (public number CN104741001A) of people such as Hu Yongfeng, a kind of SNCR denitrification device and denitrification method of people such as Zhang Rui. method (publication number CN103349898A), the SNCR method requires a higher temperature, and the coke oven flue gas needs to be reheated outside the furnace for denitrification, and the energy consumption is high; Normal operation has great influence, not suitable for denitrification in coke oven

The SCR method requires denitrification under the condition of a catalyst. The investment of the catalyst is large, the cost of denitrification is high, and it is easily deactivated by pollution from other impurities in the flue gas.

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