Efficient fixed bed platform for production of ethylene oxide by partial oxidation of ethylene using catalyst of wide selectivity

A reaction vessel comprising:

• a shell having an inflow and an outflow;
• the shell with a length and width to define a reactor vessel interior volume;
• a catalyst bed shape defined by the reactor vessel interior volume, the catalyst bed having a length such that an out flow area and an in flow area over the 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;
• the catalyst bed defining a process side and having a length less than the shell length and a volume less than the shell volume;
• a fixed bed outlet zone-configured for a gaseous flow through the catalyst bed to a heat exchanger to quench the reactions;
• the catalyst bed forming a process side of the reaction vessel;
• and
• at least one coolant enclosure heat exchanger in the shell interior volume to define a coolant side of the reaction vessel, the coolant enclosure having an outside surface and an inside surface to define a heat transfer fluid flow path, the coolant enclosure outside surface in contact with the catalyst, the coolant enclosure having an inlet and an outlet for flow of heat transfer fluid through the coolant enclosure inner surface;
• the coolant enclosure further defining a cooling surface area with the coolant flow cross sectional area ratio to a cooling surface area being much less than 1.