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According to news from April 4, 2025, **information from the Intellectual Property Office shows that Sinopec Guangzhou Engineering Co., Ltd. has filed a patent application for a process titled “A Process for Separating Liquefied Gas to Produce Polymer-grade Propylene,” with the publication number CN 119751193 A; the application was submitted in November 2024.** The patent abstract indicates that this invention discloses a process for producing polymeric-grade propylene through the separation of liquefied gas. In this process, the feed liquefied gas is separated in a depropanization tower; the bottom product of this tower is a mixture of C4 compounds, while the C3 compounds and ethane at the top of the tower are sent to a primary hydrolysis unit to remove COS and CS2. The primary hydrolysis unit is typically a container or tower equipped with a hydrolyzing agent ； The carbon tertiary and ethane gases free of COS and CS2 are sent to the deethanizer tower, where the ethane gas is removed. This ethane gas contains not only the hydrocarbons such as carbon monoxide, carbon dioxide, and carbon tertiary compounds that are produced by the normal gas distillation unit, but also most of the H2S generated during the hydrolysis process in step 1); the carbon tertiary compounds at the bottom of the tower are then sent to the propylene tower ； The bottom liquid from the deethanization tower is fed into the propylene tower for separation; the bottom product of this tower is propane, while the top product is propylene ； The propylene at the top of the tower is sent to the primary H2S removal unit for H2S removal ； The propylene liquid is further sent to the secondary hydrolysis unit and the secondary H2S removal unit to remove COS, CS2, and H2S. This invention significantly reduces the number of zinc oxide beds or the frequency of switching between zinc oxide desulfurization beds, thereby cutting down on investment costs.