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Breakthrough achieved in the world’s first industrial demonstration project for the indirect production of dimethyl carbonate from urea and methanol at a capacity of 50,000 tons per year. Author/Source: Official website of the Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences. Date: July 24, 2020. Clicks: 296. The core technology was provided by the Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences; the integrated design was carried out by Dalian Chemical Engineering Design Institute Co., Ltd.; and Shanxi Zhongke Hui’an Chemical Co., Ltd. invested in the construction of this project in Tunliu District, Changzhi City, Shanxi Province. The key process in this project – the reaction of urea with 1,2-propanediol to produce propylene carbonate – was officially put into operation on July 18. After 100 hours of continuous and stable operation, the established targets were achieved: a urea conversion rate of 100%, a one-pass yield of propylene carbonate greater than 90%, a purity of propylene carbonate of ≥99.95 wt%, and a purity of liquid ammonia of ≥99.9 wt%. This indicates that several key technical bottlenecks in the scale-up of the process for indirectly producing dimethyl carbonate from urea and methanol have been overcome, making large-scale application feasible. Industrial demonstration plant for the indirect production of dimethyl carbonate from 50,000 tons/year of urea and methanol. Currently, the transesterification method or methanol oxidation carbonylation method is primarily used in industry to produce dimethyl carbonate. Using propylene oxide or ethylene oxide as raw materials, propylene carbonate or ethylene carbonate is first produced; these compounds are then ester-exchanged with methanol to yield dimethyl carbonate ； The latter uses methanol, NO, CO, and O2 as raw materials to produce dimethyl carbonate via methyl nitrite. The method employed in this demonstration project uses urea and methanol as raw materials; urea is first reacted with 1,2-propanediol to produce propylene carbonate and liquid ammonia, which is then used together with methanol to manufacture dimethyl carbonate. The 1,2-propanediol produced as a by-product is recycled for the synthesis of propylene carbonate. This method offers advantages such as inexpensive and readily available raw materials, mild reaction conditions, environmental friendliness, and low costs; it has thus been one of the options for transformation and upgrading that the coal chemical industry in China, which is a major producer of urea and methanol, has been focusing on for many years.