Desulfurization device and method for low temperature methanol washing circulating methanol partition extractive distillation tower

Abstract

The invention relates to a desulfurization device and method for a low temperature methanol washing circulating methanol partition extractive distillation tower. The device comprises a partition extractive distillation tower, an extracting agent regenerating tower, a condenser, a reboiler and a refluxing tank, and is characterized in that in the partition extractive distillation tower, a partitionis a rectangular steel plate, the steel plate is connected with the top and the inner wall of a rectification main tower, and the rectification tower is divided into a left rectification section, a right rectification section and a common stripping section; and the partition is positioned on the middle upper part of the rectification main tower, vapor phase extraction openings are separately formed in the top of the left rectification section and the top of the right rectification section, and an extracting agent inlet is formed in the middle of the right rectification section. A methanol / extracting agent mixture at the bottom of a divided-wall tower enters the extracting agent regenerating tower and is regenerated, methanol is evaporated out from the top of the tower, the total sulfur content of the methanol at the top of the tower is smaller than 10 mg / kg, and design requirements of low temperature methanol washing circulating methanol are met. By modification on a traditional low temperature methanol washing thermal regenerating tower, the problem that thiol compounds such as sulfur dioxide and methyl mercaptan are continuously accumulated in a low temperature methanol washng system is solved.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, and in particular relates to a device and method for desulfurization of a low-temperature methanol washing cycle methanol partition extraction distillation tower. Background technique [0002] Developing new coal chemical technology based on coal gasification to realize clean utilization of coal resources is an important research direction to solve my country's coal burning pollution and oil shortage, and to realize the overall optimization and sustainable development of resources, energy and environment. Sulfide is one of the main pollutants in gas, which can cause equipment corrosion, catalyst poisoning and environmental pollution. The type and content of sulfides in the gas are related to the area and type of coal mining, and generally contain sulfur dioxide, hydrogen sulfide, carbonyl sulfide, methyl mercaptan, ethanethiol, propanethiol and other mercaptan sulfides. [0003] L...

AI Technical Summary

Problems solved by technology

In order to prevent the loss of methanol, a secondary condenser (-30 degrees) is installed at the top of the methanol thermal regeneration tower, resulting in the continuous accumulation and circulation of mercaptan compounds such as sulfur dioxide and methyl mercaptan in the system, and the circulating methanol with high sulfur content In the main absorption tower, not only does it not absorb sulfide, but the sulfide in the circulating methanol will be desorbed into the purified gas instead, eventually resulting in the total sulfur content in the purified gas exceeding the standard

[0004] In my country, high-sulfur coal (S≥1.0%) accounts for a large proportion. With the development of coal chemical technology in China, the clean utilization of high-sulfur coal has become an urgent need. The traditional low-temperature methanol washing process cannot meet the desulfurization requirements. How to develop a high-efficiency desulfurization technology, improve the utilization rate of cheap and abundant high-sulfur coal, and reduce the loss of low-temperature methanol washing cycle methanol is of great significance to society and enterprises

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