Methanol washing process for direct supplied liquidized nitrogen in ammonia synthesis

Abstract

A liquid nitrogen-methanol washing process in synthesizing ammonia includes methanol washing step, air separation step and / or liquid nitrogen washing step. The CO2 desorption tower, hydrogen sulfide concentrating tower and methanol regeneration tower are used in said methanol washing step. When initial gas introduction, the liquid nitrogen in air separation step and / or nitrogen washing step is filled in the hydrogen sulfide concentrating tower. Its advantage is hort initial gas introduction time reduced from 5 hr to 2 hr.

Description

technical field [0001] The invention relates to a methanol washing process in synthetic ammonia, which is a methanol washing process for direct replenishment of liquid nitrogen in synthetic ammonia, and is particularly suitable for the transformation of the existing methanol washing process in synthetic ammonia. Background technique [0002] At present, the synthetic ammonia process generally includes methanol washing section, air separation section, and liquid nitrogen washing section. The methanol washing process in synthetic ammonia generally adopts the technology of Linde, Germany, and utilizes the good physical absorption performance of methanol at low temperature and high pressure. Absorption and removal of CO from shift gas 2 、H 2 S, COS and other acid gases. Methanol is a good polar organic solvent at low temperature, and there are great differences in the dissolution of various components in the shift process gas. Therefore, low-temperatur...

AI Technical Summary

Problems solved by technology

The methanol liquid in the upper, middle, and lower parts of the carbon dioxide desorption tower enters the upper and middle parts of the hydrogen sulfide concentration tower through three regulating valves, and continues to throttle and expand to make the CO in the methanol 2 Further desorption, while passing nitrogen at the bottom of the hydrogen sulfide concentration tower, using nitrogen to reduce CO 2 、H 2 S gas is stripped under partial pressure to completely desorb the gas dissolved in methanol, so as to achieve the purpose of producing refrigeration and concentrating H2S. The gas at the top of the hydrogen sulfide concentration tower is discharged to the atmosphere after recovering the refrigeration, but the nitrogen is discharged to the atmosphere. will consume a certain amount of cooling

When driving the gas, the carbon dioxide only increases slowly with the entry of the process gas, and the process of obtaining cooling capacity is also slow; at the beginning of driving, due to the lack of carbon dioxide, the cooling capacity is insufficient, so that the driving needs to accumulate cooling capacity instead of Prolong the time, causing energy to be burned in vain (no product) and a lot of waste