摘要:
Methods are disclosed for the dehydrogenation of feed streams, such as in the manufacture of styrene from ethylbenzene, using a catalyst bed having catalyst with differing activities. In particular, the use of upstream and downstream catalyst beds of relatively low and high activities, respectively, can reduce the production of unwanted byproducts, especially in styrene production processes employing an oxidative reheat step (oxidation zone) prior to ethylbenzene dehydrogenation. The methods allow the maximum temperature in the oxidation zone to be decreased, thereby reducing the formation of unwanted oxygenated byproducts (e.g., phenol).