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600,000-ton polyolefin project canceled! Sinopec to Build a New 500,000-ton Coal-Based PGA Plant in Guizhou Author/Source: CCUS and Bioenergy Materials Compiled and edited Date: February 25, 2021 Clicks: 42 On February 18, the draft environmental impact assessment for Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd.’s 500,000-ton per year polyglycolic acid (PGA) production plant was made public. The original \"600,000-ton polyolefin project\" will not be constructed any longer; instead, a new \"500,000-ton/year polylactic acid (PGA) project\" by Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd. is planned to be built at the original site. Excerpts from the \"Draft Opinion\" regarding CCUS and bioenergy materials are as follows: Origin of the project: On November 25, 2020, the People’s Government of Guizhou Province and Sinopec Group Co., Ltd. signed another strategic cooperation framework agreement in Guiyang to promote high-quality development; this agreement outlined further plans for the development of the \"coal-electricity-chemical integration\" industrial projects at the Zhijin New Energy Chemical Industry Base (Guizhou Zhijin Economic Development Zone). To promote the high-quality development of the coal chemical industry, it is necessary to facilitate the implementation of the regulations issued by the General Office of the State Council aimed at restricting and reducing the use of plastic bags in order to curb \"white pollution\". This is also part of the effort to better align with Sinopec’s industrial strategy of \"one foundation, two wings, and three innovations\" (including the development of high-end materials as part of those \"two wings\"). The original \"600,000-ton polyolefin project\" will not be carried out any longer. Instead, a new \"500,000-ton per year polylactic acid (PGA) project\" by Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd. is planned to be built at the original site (hereinafter referred to as the \"500,000-ton PGA project\"). The original \"combined heat and power plant project\" will have its construction adjusted to become part of the infrastructure developments associated with the \"500,000-ton PGA project\". Total project investment: 2,376,767 million yuan, of which the total investment for Phase I is 1,233,160 million yuan, and the total investment for Phase II is 1,143,607 million yuan. Construction timeline: The project will be built in two phases; the first phase will involve the construction of a 200,000 tons per year PGA facility, with completion expected in 2024 ； The second phase involves the construction of a 300,000 tons per year PGA plant, to be completed in 2026. This project consists of the main plant (production units), storage and transportation facilities, utility systems, auxiliary production facilities, as well as off-site facilities. The main production units include a gasification unit, a coupled hydrogenation unit, a polyglycolic acid unit, and cryogenic separation. Image: Overview of the overall process flow in the plant. Raw coal is processed through pulverization, gasification, shift reaction, purification, and cryogenic separation to produce purified gases of CO and H2, which serve as feedstocks for the coupling and hydrogenation units downstream; the acidic gases generated by the gasification unit are used to produce sulfur. Methyl nitrite produced from methanol, nitric acid, and sodium nitrite is coupled with CO to yield dimethyl oxalate and the by-product dimethyl carbonate (which is sold). Dimethyl oxalate is partially hydrogenated to produce methyl glycolate, methanol, and crude ethylene glycol (all of which are sold); methanol is separated and reused, while methyl glycolate enters a polyglycolic acid production facility where it undergoes polymerization and depolymerization to yield lactide. Lactide then undergoes ring-opening polymerization to produce high-molecular-weight polyglycolic acid (the main product). PGA process flow: The capacity of the first phase of the PGA unit is 200,000 tons per year, with 4 production lines of 50,000 tons per year each; in the second phase, 3 additional production lines of 100,000 tons per year are added. The total capacity for both phases combined is 500,000 tons per year. The PGA plant produces PGA products using methyl glycolate, and it is primarily composed of the following units: a prepolymerization unit, a cyclization unit, a purification unit, and a final polymerization unit. ①Prepolymerization unit: In this unit, methyl glycolate (MG) is prepolymerized to produce oligomers and methanol. Methanol is recovered after separation, while the oligomers go to the cyclization unit. ②Cyclization unit (depolymerization of oligomers to produce lactide): The oligomers enter the cyclization reactor where lactide is produced. ③Purification unit (lactide purification): After lactide is purified, refined lactide is obtained through centrifugation and drying. ④The terminal polymerization unit, lactide, enters the terminal polymerization reactor to produce PGA product. The coupling device for this project utilizes Sinopec’s own coupling technology. The polyglycolic acid device utilizes technology from Shanghai Pujing Chemical Technology Co., Ltd./Sinopec Shanghai Engineering Co., Ltd.