摘要:
A process for initiating a highly selective ethylene oxide catalyst is provided in which the highly selective ethylene oxide catalyst is operated first as a ‘standard’ Ag-based catalyst (e.g., a catalyst that contains only silver and alkali metal, especially cesium). Moreover, the inventive initiation procedure is more efficient when the concentration of carbon dioxide in the feed is higher than 6 vol. %, and even more efficient when the concentration of carbon dioxide in the feed is higher than 10 vol. %, of the feed mixture during the initiation period.
摘要:
A process for initiating a highly selective ethylene oxide catalyst is provided in which the highly selective ethylene oxide catalyst is operated first as a ‘standard’ Ag-based catalyst (e.g., a catalyst that contains only silver and alkali metal, especially cesium). Moreover, the inventive initiation procedure is more efficient when the concentration of carbon dioxide in the feed is higher than 6 vol. %, and even more efficient when the concentration of carbon dioxide in the feed is higher than 10 vol. %, of the feed mixture during the initiation period.
摘要:
A method to achieve a controlled start-up temperature of an expoxidation process which exceeds the maximum achievable temperature of the epoxidation reactor relative to using an external heat source. The method of the present invention employs an oxidation reaction within the reactor to bring the temperature of the reactor to a temperature that is suitable for conditioning a high selectivity catalyst. The method of the present invention includes first bringing a reactor including a high selectivity catalyst to a first temperature using the external heat source to the reactor, while staying within the reactor design limitations and maintaining a gas flow to the reactor that is within 25 to 100% of the design rates. Once the reactor has achieved the first temperature, at least an olefin, e.g., ethylene, and then oxygen are introduced to the reactor feed gas. The olefin and oxygen concentrations are adjusted to have a heat of reaction that will allow raising the reactor gas flow to 100% of design and then have sufficient heat of reaction to raise the reactor temperature to a second temperature which is greater than the first temperature and greater than the temperature of the reactor achievable by the external heat source.
摘要:
A method to achieve a controlled start-up temperature of an expoxidation process which exceeds the maximum achievable temperature of the epoxidation reactor relative to using an external heat source. The method of the present invention employs an oxidation reaction within the reactor to bring the temperature of the reactor to a temperature that is suitable for conditioning a high selectivity catalyst. The method of the present invention includes first bringing a reactor including a high selectivity catalyst to a first temperature using the external heat source to the reactor, while staying within the reactor design limitations and maintaining a gas flow to the reactor that is within 25 to 100% of the design rates. Once the reactor has achieved the first temperature, at least an olefin, e.g., ethylene, and then oxygen are introduced to the reactor feed gas. The olefin and oxygen concentrations are adjusted to have a heat of reaction that will allow raising the reactor gas flow to 100% of design and then have sufficient heat of reaction to raise the reactor temperature to a second temperature which is greater than the first temperature and greater than the temperature of the reactor achievable by the external heat source.
摘要:
A method for assuring safety of a particular chemical process plant includes measuring, for each of a plurality of sets of proposed process conditions for a particular chemical process within the particular chemical process plant, a pressure rise rate following a deliberate contained ignition of at least one material used within the particular chemical process. From the resulting plurality of pressure rise rates that corresponds with the plurality of sets of proposed process conditions a particular pressure rise rate that allows for a safe operation of the particular chemical reaction within the particular chemical process plant may be selected. The particular chemical process may be implemented within the particular chemical process plant while using a particular set of process conditions from the plurality of sets of process conditions that corresponds with the selected pressure rise rate. As an adjunct, the particular chemical reaction may also be subsequently and additionally optimized with respect to an ancillary parameter, such as product yield or feedstock utilization.