Ethylene oxide process improvement

In a process for the production of ethylene oxide by catalytic oxidation of ethylene with oxygen using an alumina-supported silver catalyst wherein steam is generated from the heat conveyed by the coolant for cooling the reactor by the process comprising the steps of passing the coolant from the reactor to at least one first coolant condenser(s) wherein at least part of the coolant vapor is condensed by exchanging heat with boiler feed water to generate steam thereby producing a liquid-vapor coolant mixture, the improvement which comprises the steps of passing the vapor-liquid mixture coming out of said first coolant condenser(s) through a cyclone operated vapor-liquid separator whereby the liquid coolant is separated from the coolant vapor and flows via a "U" trap to at least one coolant surge drum(s) and the vapor passes through a second condenser(s) wherein it is condensed by exchanging heat with boiler feed water to generate steam at a lower pressure than that of the steam generated by said first coolant condenser;

• wherein said "U" trap has a sufficient height to insure that the coolant vapor flows upward to said second coolant condenser(s) while in the case of reactor runaway allows rapid relieving of the pressure in the reactor;
• said improvement enabling the plant to operate utilizing an improved silver-based catalyst with a lower optimum operating temperature than that of the alumina-supported silver catalyst for which the plant was designed by recovering residual heat from the coolant in the form of steam.