Efficient fixed bed platform for production of ethylene oxide by partial oxidation of ethylene using catalyst of wide selectivity
AssigneeThe Dow Chemical Investments LLC
InventorsMax M. Tirtowidjojo, Subrata Sen, Christina Zarth, Pramod D. Patil
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Abstract
At least one method to efficiently produce alkylene oxide from partial oxidation of hydrocarbons using a high efficiency heterogeneous catalyst in a fixed bed enclosed within a reaction vessel, and a reaction vessel constructed to facilitate the same.
Claims17
A method for producing gaseous ethylene oxide product from partial oxidation of hydrocarbon using a heterogeneous catalyst in a fixed bed enclosed within a reaction vessel shell, comprising:
- introducing a sufficient amount of gaseous ethylene, oxygen, ballast gas, and catalyst promoter into a reaction vessel having an inflow and an outflow, said vessel having a shell with a length and a width to define a reactor vessel volume;
- said reactor vessel volume defining a catalyst bed shape;
- said catalyst bed having a length such that an out flow area and an in flow area over said catalyst bed length in between the reactor outflow and inflow has an absolute ratio difference less than or equal to about 1.3 meter anywhere in the reactor bed;
- said catalyst bed defining a process side and having a selectivity greater than about 80%, said catalyst bed length less than said shell length and having a volume less than said reactor shell volume;
- circulating a heat transfer fluid through at least one coolant enclosure heat exchanger in said shell interior to define a coolant side of the process;
- said coolant enclosure equipped with an outside surface and an inside surface;
- said coolant enclosure outside surface in contact with said catalyst bed and having an inlet and an outlet for the flow of coolant fluid therethrough;
- said coolant enclosure further defining a cooling surface area with a coolant flow cross sectional area ratio to cooling surface area less than about 1;
- said coolant side having a higher than said process side, and flowing said gaseous ethylene, oxygen, ballast gas and catalyst promoter over said catalyst bed and through a fixed catalyst bed outlet zone in said reactor vessel;
- said zone configured with average residence time less than or equal to 4 seconds of said gas ethylene, oxygen, ballast and catalyst promoter flow h the catalyst bed to the heat exchanger to quench said process to create gaseous ethylene oxide product and flowing said gaseous ethylene oxide product through said reactor vessel outlet.
The method of 1, wherein the coolant enclosure cross sectional area is at least equivalent to one tube having an inner diameter in the range of from up to about 0.2″ to about 1.8″.
A reaction vessel for production of gaseous alkylene oxide from partial oxidation of hydrocarbon, catalyst promoter and ballast gas using a high efficiency heterogeneous catalyst in a fixed bed enclosed within a reaction vessel shell, comprising:
- a shell having an inflow and an outflow;
- said shell with a length and width to define a reactor vessel interior volume;
- a catalyst bed shape defined by said reactor volume, said catalyst bed having a length such that an out flow area and an in flow area over said catalyst bed length in between the reactor outflow and inflow has an absolute ratio difference less than or equal to about 1.3 meter anywhere in the catalyst bed;
- said catalyst bed including a catalyst having a selectivity greater than about 80%, said catalyst bed defining a process side and having a length less than said shell length and a volume less than said shell volume;
- a fixed bed outlet zone configured with an average residence time less than or equal to 4 seconds of a gaseous flow through said catalyst bed to a heat exchanger to quench the reactions;
- said catalyst bed forming a process side of said reaction vessel;
- and
- at least one coolant enclosure heat exchanger in said shell interior volume to define a coolant side of the reaction vessel, said coolant enclosure having an outside surface and an inside surface to define a heat transfer fluid flow path, said coolant enclosure outside surface in contact with said catalyst, said coolant enclosure having an inlet and an outlet for flow of heat transfer fluid through said coolant enclosure inner surface;
- said coolant enclosure further defining a cooling surface area with the coolant flow cross sectional area ratio to a cooling surface area much less than 1;
- said coolant side having a pressure greater than or equal to said process side.
Dependencies are inferred from the claim text.