Process for improving washing and removing efficiency of benzene in coal gas from coal

Abstract

The invention discloses a process for improving the washing and removing efficiency of benzene in coal gas from coal. The process comprises the following steps: cooling coal gas from an ammonium sulfate workshop section in a final cooling tower, then allowing the cooled coal gas to enter a benzene washing tower from the top of the benzene washing tower, to pass through packing layers in the benzene washing tower from bottom to top and to realize countercurrent contact with circulating washing oil sprayed from the top of the benzene washing tower, and after benzene in the coal gas is absorbed by the circulating washing oil, subjecting the coal gas to removal of droplets via a mist capturing section of the benzene washing tower and then allowing the coal gas to leave the benzene washing tower; subjecting the circulating washing oil to heat exchanging via an oil gas heat exchanger and a lean oil-rich oil heat exchanger, then heating the washing oil with a tubular furnace, allowing the heated washing oil to enter a benzene removing tower, carrying out steam stripping and distillation in the benzene removing tower in virtue of superheated steam from a regenerator, allowing crude benzenesteam to escape from the top of the benzene removing tower, subjecting the washing oil having undergone benzene removal to heat exchanging and cooling with the lean oil-rich oil heat exchanger, and then conveying the washing oil to the benzene washing tower for cyclic usage; and allowing oil gas to enter the oil gas heat exchanger and crude benzene to enter a condensation cooler, separating waterfrom obtained crude benzene by using an oil-water separator, then allowing the crude benzene to enter a reflux tank and conveying the crude benzene to the top of the benzene removing tower in virtueof a reflux pump. When the process is used for treating benzene included in coal gas, the content of benzene is allowed to reach a set safety value, little pollution is posed to environment, and humanhealth is guaranteed.

Description

technical field [0001] The invention relates to a process, in particular to a process based on improving the efficiency of eluting benzene from coal gas. Background technique [0002] Coal gas is a gas containing combustible components produced by processing coal as raw material. According to the processing method, gas properties and uses, it is divided into: water gas, semi-water gas, air gas (or producer gas) obtained from coal gasification, these gases have low calorific value, so they are collectively called low calorific value gas; coal dry distillation method The gas obtained from medium coking is called coke oven gas and blast furnace gas. It belongs to medium calorific value gas, which can be used as civil fuel in cities. Carbon monoxide and hydrogen in gas are important chemical raw materials. Coke oven gas refers to the combustible gas obtained by coking coal made of several kinds of bituminous coal, after high-temperature dry distillation in the coke oven, whil...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the problem that the above-mentioned existing process does not completely treat these benzene, which causes impurities when the gas is used, produces a lot of harmful substances, seriously pollutes the environment, and causes harm to people's bodies. The gas is used to elute the benzene efficiency process. This process treats the contained benzene to reduce its content to a set safe value. It is safer for people to use, has less pollution to the environment, and ensures the health of the body. It solves the problem of these benzene If the treatment is not complete, there will be impurities when the gas is used, and a lot of harmful substances will be produced, which will seriously pollute the environment and cause harm to people's bodies.