Desulfurization of coking liquefied gas

The desulfurization process is relatively mature. Hydrogen sulfide is desulfurized using the amine method, with MDEA being commonly used. After absorbing hydrogen sulfide, MDEA is regenerated, and the acidic gas generated is sent to a sulfur recovery unit to recover sulfur. Thiols are desulfurized by alkaline washing. In recent years, desulfurization unit operations have utilized fiber membrane contact towers or liquid film towers, which offer high and stable desulfurization efficiency. Air oxidation is used for alkali solution regeneration, and a catalyst of cobalt sulfonophthalocyanine is required. During the regeneration process, sodium thiolate is converted into disulfides, which are then emitted along with the exhaust gases and alkaline slag. For coker liquefied gas, due to its high sulfur content – particularly with thiol levels as high as 3000–8000 mg/m3 – the conventional alkali regeneration process results in a regenerated alkali solution with poor ability to remove disulfides, which leads to frequent alkali replacement and unstable desulfurization and dewaxing performance. Since last year, Sinopec Maoming Petrochemical Company and Shandong Qiwanda Group have adopted an efficient alkali solution regeneration process that enables the recovery of liquid disulfides, and it is said to work well. Desulfurization alcohol remains stable, and the amount of alkaline slag discharged is **reduced**.

After desulfurization with MDEA, we directly use it in commercial hydrocarbons.