Liquid ammonia gasifying system and gasifying process thereof

Abstract

The invention relates to a liquid ammonia gasifying system and a gasifying process thereof, in particular to the liquid ammonia gasifying system applied to a selective catalytic reduction (SCR) denitration or ammonia desulphurization process and the gasifying process thereof. The liquid ammonia gasifying system comprises a liquid ammonia conveying device, a heat exchange device and a gas ammonia storage device which are connected with each other. The heat exchange device is a circulating water heat exchange device and comprises a casing, a heat exchange pipe arranged in the casing, a circulating water input port, a circulating water output port, a liquid ammonia input port and a gas ammonia output port, wherein the circulating water input port and the circulating water output port are arranged on the casing. In the process, circulating water is applied to gasify liquid ammonia. Compared with the prior art, the liquid ammonia gasifying system is optimized in design, simple in process flow, energy-saving and environment-friendly, the refrigeration performance of the liquid ammonia is fully utilized simultaneously when the required gas ammonia is obtained at low energy consumption and low investment, comprehensive utilization of energy is achieved, energy-saving effect is remarkable, utilized land is saved, economic cost is greatly reduced, and the liquid ammonia gasifying system is suitable for popularization and application in the fields of SCR denitration and the like where the gas ammonia needs applying.

Description

technical field [0001] The invention relates to a liquid ammonia gasification system and a gasification process thereof, in particular to a liquid ammonia gasification system and a gasification process applied in SCR denitrification or a desulfurization process using ammonia as a raw material. Background technique [0002] Sulfur and nitrogen oxides (SO 2 , NOx) pollutants, and the treatment technologies for these flue gas pollutants are relatively mature: limestone-gypsum method, ammonia method, double alkali method, selective catalytic reduction (SCR) method, selective non-catalytic reduction (SNCR) method, low-nitrogen combustion method, etc. Among them, the ammonia method is more respected because of its simple process flow and the efficient removal of sulfur and nitrogen pollutants in the flue gas without pollution. At the same time, the obtained ammonium salt product can also Make full use of it as a fertilizer source, correspondingly reduce investment costs and incre...

AI Technical Summary

Problems solved by technology

However, for applications requiring ammonia (NH 3 ) SCR denitrification and other processes generally consume a lot of energy, resulting in an increase in economic costs, which in turn leads to an increase in the cost of the entire ammonia purification process, thus limiting the promotion and application of the ammonia process

[0003] At present, there are two main methods to obtain gaseous ammonia: one is urea pyrolysis method, which uses electric heaters to provide heat through urea pyrolysis system to decompose urea into gaseous ammonia and carbon dioxide. This method starts from input of raw materials to pyrolysis reaction From generation to product separation, the process is complex and requires high system settings. At the same time, it also needs to consume a lot of materials and energy, and the economic cost is too high, which is not conducive to popularization and application; the other is to obtain gaseous ammonia through liquid ammonia gasification, mainly using The method of steam heating evaporates liquid ammonia into gaseous ammonia. Because the boiling point of liquid ammonia is -33.4°C, it is very easy to gasify. However, this method uses steam with high calorific value as a heat source, which inevitably causes a lot of waste of heat sources. Similarly, obtaining steam The heat source also requires energy consumption, thus causing an increase in economic costs and limiting the application of the ammonia method

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