Process for improving SO2 desorption efficiency of desulfurization absorbent

Abstract

The invention discloses a process for improving SO2 desorption efficiency of a desulfurization absorbent. The process comprises the following steps: a, heating amine-rich liquid absorbing SO2 gas, andfeeding the heated amine-rich liquid into a low-pressure desorption tower for pre-desorption; b, feeding the pre-desorbed secondary lean amine solution into a high-pressure desorption tower for desorption; c, reducing SO2 contained in the lean amine output after desorption of the high-pressure desorption tower to be belower than 5g/L, or increasing the total desorption efficiency of SO2 in the amine-rich liquid input in the step a to be greater than 90%; pressurizing the high-pressure desorption steam output by the high-pressure desorption tower, and adopting as a heat source of steam required by steam stripping of SO2 in the desorption amine-rich liquid of the low-pressure desorption tower. According to the invention, a double-tower double-effect and low-pressurization two-time deep desorption process is adopted, the content of SO2 contained in the output lean amine liquid is less than 5g/L or the total desorption efficiency of SO2 in the amine-rich liquid is more than 90%, the operation is stable, the power consumption is low, the live steam consumption is saved by 30-50%, the desorption efficiency is improved by 4-12%, and the investment operation comprehensive cost is reducedby 20-40%; and ultra-low emission of desulfurization can be realized.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to various furnaces and reactors producing 2 The technical field of flue gas desulfurization, energy saving and ultra-low emission, specifically a method for improving the desorption of SO by desulfurization absorbents 2 Efficient craftsmanship. Background technique [0002] Flue gas discharged from various kilns or reactors contains SO 2 , direct discharge will pollute the environment or cause resource loss, organic amine desulfurization is due to SO 2 Resources are recycled and reused. Because of its environmental protection, high efficiency, energy saving, safety, high degree of automation, and almost no secondary pollution, it has been rapidly popularized and applied in the past ten years. With the organic amine method (also known as "ionic liquid method") desulfurization device treatment flue gas significantly increased (≥2.0×10 5 m 3 / h), the treated flue...

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Problems solved by technology

With the organic amine method (also known as "ionic liquid method") desulfurization device treatment flue gas significantly increased (≥2.0×10 5 m 3 / h), the treated flue gas contains SO 2 Increased concentration (≥6000mg / m 3 ), and require ultra-low emissions (≤35mg / m 3 ), the organic amine desulfurization unit uses a conventional single tower to desorb SO 2 Process configuration, the steam consumption has greatly increased or even exceeded the supply capacity of the factory; reducing the raw steam consumption of large-scale organic amine desulfurization devices has become the key. At present, the market generally adopts the process of single tower + mechanical vapor compression heat pump (MVR) + double reboiler In order to reduce the consumption of raw steam, the heat pump pressurizes about 200KPa, but because the desorption steam contains a certain amount of non-condensable gas (SO 2 etc.) and its wet state corrosion is strong, the MVR type selection is expensive, the failure rate is high, and it needs maintenance. When it is running, the power consumption per ton of steam is about 65KWh, and the operating cost is significantly increased. Especially, the MVR body is stable and reliable. Sexuality becomes a bottleneck, and even endangers the problem of stable and up-to-standard emission of flue gas. As a subject, a breakthrough is urgently needed

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