In order to remove excess impurity gases such as argon and nitrogen accumulated in the system during the production of the ethylene glycol unit of the Chemical Industry Department, a certain amount of circulating gas must be discharged into the waste heat boiler for incineration. This also discharges 25% of high-concentration ethylene in the circulating gas at the same time. How to reduce ethylene emissions and how to recycle the discharged ethylene is a matter that has been considered by the Chemical Industry Department in recent years. Last year, after detailed inspections, they decided to introduce membrane separation technology developed by foreign companies. In January of this year, they applied membrane separation technology in the incremental transformation of the ethylene glycol plant to transform the original cycle gas discharge system process. After the reformed ethylene glycol unit was put into operation, the ethylene recovery rate in the exhaust gas was kept above 85%, and the removal rate of argon and nitrogen components in the recycle gas system was ensured. It is understood that the introduction of membrane separation technology will be able to recover investment within one year, and from the current situation, it will benefit at least within 10 years.
The ethylene glycol plant of the Chemical Industry Division of Shanghai Petrochemical Co., Ltd. is expected to recycle 300 tons of ethylene and reduce expenses by 1.24 million yuan this year due to the use of membrane separation technology.