Low temperature methanol washing integrated Claus sulfur recovery system and process

Abstract

The invention relates to a reclaiming system and a process for low-temperature methanol washing integrated Claus sulfur of coal gas and natural gas. The system is additionally provided with a Claus tail gas washing tower and uses sulfur-free methanol saturated by CO2 from a CO2 product tower as a washing agent, and the washed liquid returns to an H2S concentrating tower; through combination of heating, gas stripping and pressure adjustment, concentration of H2S in acid gas washed by methanol is adjusted flexibly; at the same time, the system is additionally provided with a tail gas pre-heater before hydrogenation reaction to compensate heat loss of a hydrogenation reaction system. The process mainly comprises the following steps: removing H2S-CO2 gas, condensing H2S, reclaiming Claus sulfur, hydrogenising and reducing the gas, selectively absorbing and desulfurizing saturated cold methanol. The process has the advantages that the process can efficiently, flexibly, safely and energy-conservatively treat carbonyl gas with different pressures, temperatures, water content and sulfur concentration; and total sulfur reclamation ratio can reach more than 99.9 percent. The concentration of the H2S in emptied tail gas is below 25 mg / Nm3, so the H2S gas can meet the requirement of environmental protection, and can be exhausted directly without being burnt.

Description

technical field [0001] The invention relates to a system and process for purification, treatment and recovery of coal-based gas, natural gas and other carbonyl gases, in particular to a low-temperature methanol washing integrated Claus sulfur recovery system and process. Background technique [0002] The low-temperature methanol washing process is a purification process developed in the 1950s and put into industrial production. It is the most economical and high-purification purification method recognized at home and abroad. Especially for the purification of coal, coal water slurry, or slag, and heavy oil as raw materials to produce synthesis gas, the effect of this method is better. At present, low-temperature methanol washing has been widely used in the gas purification process for the production of synthetic ammonia, synthetic methanol, city gas, and industrial hydrogen production. The process is to use cold methanol as a solvent to remove acid gases, usually CO 2 and H...

AI Technical Summary

Problems solved by technology

And this will cause H 2 Insufficient cold supply of ammonia cooler (24) at the top of the S concentration tower (10), increased methanol circulation, or insufficient nitrogen supply for stripping

As a result, in the actual production process, there are problems such as high failure rate of sulfur recovery and tail gas treatment devices, low operating rate, low sulfur recovery rate, and the exhaust tail gas is far from meeting the national environmental protection standards.

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