Process for producing diphenyl carbonate
AssigneeShell Oil Company
InventorJ. Yong Ryu
Life of this patent
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Abstract
Processes for producing diaryl carbonates are disclosed, where such processes may provide for the production of diaryl carbonates from green house gases, such as carbon dioxide. The processes disclosed advantageously integrate diethyl carbonate and diaryl carbonate production, eliminating the need for solvent-based extractive distillation, as is commonly required when producing diaryl carbonates from dimethyl carbonate, providing for the integration of separation equipment and raw material usage, and reducing the operating and capital requirements for such processes. In some embodiments, processes disclosed herein may be operated essentially closed-loop with respect to ethanol usage, for example.
Claims10
A process for producing diaryl carbonate, comprising:
- a. reacting ammonia and carbon dioxide in a first reaction zone to form first reaction product comprising a urea;
- b. transesterifying the urea with ethanol in the presence of a first transesterification catalyst in a second reaction zone to form a second reaction product comprising diethyl carbonate and ammonia;
- c. separating the second reaction product to recover a first diethyl carbonate fraction and a first ammonia fraction;
- d. transesterifying at least a portion of the first diethyl carbonate fraction with an aryl hydroxy compound in the presence of a second transesterification catalyst in a third reaction zone to form a third reaction product comprising ethyl aryl carbonate and ethanol;
- e. separating the third reaction product to recover an ethyl aryl carbonate fraction and an ethanol fraction;
- f. disproportionating at least a portion of the ethyl aryl carbonate fraction in the presence of a disproportionation catalyst in a fourth reaction zone to form a fourth reaction product comprising diaryl carbonate and diethyl carbonate;
- g. separating the fourth reaction product to recover a diaryl carbonate fraction and a second diethyl carbonate fraction;
- h. recycling at least a portion of the ethanol fraction to the second reaction zone;
- and
- i. recycling at least a portion of the second diethyl carbonate fraction to the third reaction zone.
Dependencies are inferred from the claim text.