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公开(公告)号:US09926251B2
公开(公告)日:2018-03-27
申请号:US15521033
申请日:2015-11-26
发明人: Tao Zhang , Shuo Al , Mingyuan Zheng , Aiqin Wang , Weizhen Li , Xiaodong Wang
CPC分类号: C07C29/80 , B01D1/26 , B01D3/009 , B01D3/065 , B01D3/10 , B01D3/146 , B01D15/08 , B01J29/40 , C07C1/24 , C07C29/88 , C07C31/18 , C07C31/202
摘要: This invention discloses an approach for the separation of the close-boiling mixture of polyols. The raw material is ethylene glycol containing miscellaneous polyols (such as 1,2-propylene glycol and 1,2-butanediol). Over an acid catalyst, these miscellaneous polyols, through (1) a dehydration reaction, (2) pinacol rearrangement, and (3) acetalization or ketalization reaction, are converted into aldehydes (small amounts), acetals, and ketals (trace amount), which are simultaneously and readily separated via distillation. Meanwhile, after the reaction, the mixture is further separated to obtain an ethylene glycol product at a high purity. The invention provides a technique to remove the miscellaneous polyols from ethylene glycol via liquid-phase dehydration reactions under mild conditions, with low energy consumption. In particular, this approach is markedly effective for the removal of 1,2-butanediol that is difficult to be removed via conventional techniques. The purity of the resulting ethylene glycol product is high, and value-added acetals or ketals are co-produced.
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2.
公开(公告)号:US10654781B2
公开(公告)日:2020-05-19
申请号:US15735190
申请日:2015-11-26
发明人: Ruiyan Sun , Mingyuan Zheng , Tao Zhang , Jifeng Pang , Yu Jiang , Aiqin Wang , Xiaodong Wang
IPC分类号: B01J23/89 , B01J35/00 , B01J37/02 , B01J23/62 , B01J33/00 , B01J25/02 , B01J37/18 , B01J23/835 , C07C29/132
摘要: This invention provides a method for catalytic conversion of carbohydrates to low-carbon diols using alloy catalysts. In the process, carbohydrates as the feedstock are subjected to one-step catalytic conversion to realize the highly efficient and selective production of ethylene glycol etc. under hydrothermal conditions, with an alloy catalyst composed of tin, and a transition metal such as iron, cobalt, nickel, rhodium, ruthenium, palladium, iridium, platinum and copper, or a mixture thereof. The reaction is carried out in water at a temperature range of 120-300° C., with a hydrogen pressure range of 1-13 MPa. Compared with the present petroleum based synthesis technology of ethylene glycol, the method in this invention possesses advantages of using renewable feedstock, high atom economy and environmental friendly. Besides, compared with other technologies using biomass as feedstock to produce ethylene glycol, the alloy catalyst in this invention possesses the advantages of few leaching amount, good hydrothermal stability and easy to recycle.
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