Processes for Producing an Oxalate by Coupling of CO
AssigneesChina Petroleum & Chemical Corporation, Shanghai Research Institute of Petrochemical Technology, Sinopec
InventorsJuntao LIU, Zhiyan Zhu, Wanmin Wang, Lei Li
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Abstract
Provided are processes for producing an oxalate by coupling of CO in the presence of a nitrite, wherein two or more reaction zones in series are used, and at least a portion of the oxalate as reaction product is separated between the reaction zones, and/or the nitrite is fed stagewise. The processes described herein can effectively enhance the selectivity to the oxalate and the single-pass conversion of the feedstock.
Claims20
A process for producing an oxalate by coupling of CO, comprising
- a) feeding a nitrite and CO as feedstock to a first reaction zone to contact them with a first palladium-containing catalyst, to form a first reaction effluent containing unreacted nitrite, CO and oxalate product;
- b) passing the first reaction effluent into a gas-liquid separator to conduct gas-liquid separation, to obtain a liquid product stream and a gas mixture stream;
- c) feeding the liquid product stream obtained from b) to a separation unit, to obtain a first portion of the oxalate product;
- d) feeding the gas mixture stream obtained from b) to a second reaction zone to contact it with a second palladium-containing catalyst, to form a second reaction effluent containing the oxalate;
- and
- e) feeding the second reaction effluent to the separation unit, to obtain a second portion of the oxalate product,
- wherein the molar ratio of the CO to the nitrite in the feedstock fed to the first reaction zone is from 1:1 to 5:1.
A process for producing an oxalate by the coupling of CO, comprising
- a) feeding a first nitrite stream and CO feedstock to a first reaction zone to contact them with a first palladium-containing catalyst, to form a first reaction effluent containing the oxalate;
- b) optionally, passing the first reaction effluent into a gas-liquid separator to conduct gas-liquid separation, to obtain a gas stream and a liquid product stream, with the liquid product stream being passed into a separation unit to separate the oxalate product;
- c) feeding the first reaction effluent or the gas stream obtained from b) together with a second nitrite stream to a second reaction zone to contact them with a second palladium-containing catalyst, to form a second reaction effluent containing the oxalate;
- and
- d) passing the second reaction effluent into a separation unit to separate the oxalate product,
- wherein the molar ratio of the nitrite in the first nitrite stream to the nitrite in the second nitrite stream ranges from 0.1:1 to 10:1, and wherein the molar ratio of the CO to the total nitrite in the first nitrite stream and the second nitrite stream ranges from 1:1 to 5:1.
Dependencies are inferred from the claim text.