基于电渗析法MDEA胺液净化技术研究

Study on the Purification Technology of MDEA Amine Solution Based on Electrodialysis

甲基二乙醇胺(MDEA)溶剂对硫化氢气体吸收具有高选择性和稳定性,普遍应用于炼厂脱硫装置,但长周期运行中会产生溶剂变质以及设备腐蚀等问题。该文研究了导致胺液系统对设备设施产生腐蚀的影响因素,从工艺、设备两个方面有针对性的提出预防性措施。阐述胺液系统中热稳定盐的形成原因以及对胺液系统产生的后果。以某企业14万吨/年硫磺回收装置为例,通过增设临时电渗析撬装设施,使用电渗析法的MDEA胺液净化技术的实际应用,有效去除胺液系统中颗粒物,改善溶剂外观,将该装置胺液系统中热稳盐含量由5%降低至1%以下,硫化氢含量由5000 mg/L降低至500 mg/L以下。电渗析法胺液净化技术能够在不影响主装置正常运行的前提下,有效降低热稳态盐含量、改善胺液品质、减少系统性腐蚀。从而保证脱硫系统及设备设施安全、长周期稳定运行。

Methyldiethanolamine(MDEA)solvent has high selectivity and stability in the absorption of hydrogen sulfide gas,and is widely used in desulfurization unit in refineries.However,the amine liquid system may encounter problems such as solvent deterioration and equipment corrosion due to various factors during long-term operation.This article analyses the factors that cause corrosion of equipment and facilities in amine liquid systems,and proposes preventive measures from both process and equipment aspects.Explain the reasons for the formation and consequences of thermally stable salts in amine liquid systems.Taking a 140000 t/a sulfur recovery unit of an enterprise as an example,by using the MDEA amine purification technology of electrodialysis method,the particles in the amine system were effectively removed,the solvent appearance was improved,and the thermal stable salt content in the amine system of the unit was reduced from 5%to below 1%,and the hydrogen sulfide content was reduced from 5000 mg/L to below 500 mg/L.The amine purification technology of electrodialysis can effectively reduce the salt content in thermal stability,improve the quality of amine solution and reduce systematic corrosion without affecting the normal operation of the main unit,and to ensure the safe and long-term stable operation of the desulfurization system and equipment and facilities.