Patent ID: 7657331

Claim:
A reaction system suitable for performing a process for the epoxidation of an olefin, which reaction system comprises a reactor which is configured to hold a highly selective silver-based catalyst and to receive a feed comprising the olefin, oxygen and a reaction modifier and has a temperature control system configured to control in the reactor a reaction temperature T, which reaction system further comprises a feed control system configured to control the reaction modifier being present in the feed in a relative quantity Q which is the ratio of an effective molar quantity of active species of the reaction modifier present in the feed to an effective molar quantity of hydrocarbons present in the feed, and which reaction system is configured to perform the process steps of: operating at a first operating phase wherein the value of T is T 1 and the value of Q is Q 1 , and subsequently operating at a second operating phase at a reaction temperature which is different from the reaction temperature employed in the first operating phase, such that the value of T is T 2 and the value of Q is substantially Q 2 , whereby Q 2 can be determined by calculation and Q 2 is defined by the formula Q 2 =Q 1 +B ( T 2 −T 1 ), wherein B denotes a constant factor which is in the range of from 0.01×10 −6 to 1×10 −6 (° C.) −1 , the relative quantity Q is in the range of from 1×10 −6 to 100×10 −6 , and the reaction temperature T is in the range of from 180 to 340° C.