Low temperature methanol washing gas stripping regeneration methyl alcohol equipment and utilization method thereof

Abstract

The invention discloses low temperature methanol washing gas stripping regeneration methyl alcohol equipment and a utilization method thereof. The equipment is arranged between a methyl alcohol washing tower and a gas stripping regeneration tower; a purified gas outlet drain is arranged on a purified gas outlet pipeline at the top of the methyl alcohol washing tower; a downstream end of the purified gas outlet drain is communicated with the bottom of the gas stripping regeneration tower and the other end is connected with a nitrogen source. When the nitrogen source cannot provide nitrogen, the equipment enables purified gas at the top of the methyl alcohol washing tower to pass through the opening purified gas outlet drain and be reduced pressure through a reducing valve and lead to the gas lifting regeneration tower to serve as gas stripping gas to regenerate the methyl alcohol. Accordingly, under the nitrogen source fault condition, ceaseless operation of the gas lifting regeneration tower is guaranteed, continuous operation of a low temperature methanol washing step is guaranteed, an air separation device is not required to be introduced, and economic losses are reduced.

Description

technical field [0001] The invention relates to a production process for methanol regeneration after shift gas is washed with low-temperature methanol in the synthetic ammonia process, in particular to a device for stripping and regenerating methanol after low-temperature methanol washing and its use method. Background technique [0002] In the production of synthetic ammonia, the low-temperature methanol washing process is used for the purification of shift gas, that is, the use of methanol at low temperature to absorb carbon dioxide (CO 2 ), hydrogen sulfide (H 2 S) and organic sulfur impurities such as carbon oxysulfide (COS), etc.; at the same time, the saturated water brought in by the changing gas is also removed, and the qualified purified gas is sent to the methanol synthesis station or liquid nitrogen washing station. After the low-temperature methanol is eluted, it must be regenerated by air stripping before it can be recycled again. Usually, the eluted methanol ...

AI Technical Summary

Problems solved by technology

The nitrogen production capacity of the commonly used air separation unit is 6000m 3 / h, the actual nitrogen production is 4500~8500m 3 / h, far greater than the amount of nitrogen required for methanol washing, the excess nitrogen must be disposed of during use, resulting in a certain waste

If the air separation unit breaks down and cannot continuously provide the required nitrogen, it will also cause the shutdown of the low-temperature methanol washing step, and the entire synthetic ammonia production process will be interrupted

[0021] How to effectively and economically ensure that the low-temperature methanol washing step can continue to work when a continuous sufficient amount of nitrogen cannot be provided has always been a difficult problem recognized by those skilled in the art and a direction to explore hard, but so far there is no satisfactory solution Technical solutions come out

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