Reactor systems for oxidative dehydrogenation (odh) of ethane

A method of operating an oxidative dehydrogenation (ODH) reactor system, the method comprising:

• providing feed comprising ethane, oxygen, and diluent to a first ODH reactor comprising a tube side and a shell side to give a first reaction mixture flowing through the tube side;
• dehydrogenating, via ODH catalyst on the tube side, ethane to ethylene in the first reaction mixture flowing through the tube side, wherein the first ODH reactor comprises a first cooling section and a second cooling section operationally downstream of the first cooling section;
• flowing a first coolant through the shell side in the first cooling section, thereby maintaining the ODH catalyst in the first cooling section at a first temperature;
• flowing a second coolant through the shell side in the second cooling section, thereby maintaining the ODH catalyst in the second cooling section at a second temperature;
• and
• specifying the first temperature be less than the second temperature to favor ethylene selectivity in the first reaction mixture in the first cooling section.

An oxidative dehydrogenation (ODH) reactor system, comprising:

• a first ODH reactor comprising a first cooling section and a second cooling section separated by a flow barrier on a first shell side, the second cooling section operationally downstream of the first cooling section, wherein the first ODH reactor is a multi-tubular fixed bed reactor comprising:
• a first tube side having ODH catalyst to receive feed comprising ethane, oxygen, and steam to dehydrogenate ethane into ethylene in a first reaction mixture and discharge a first effluent comprising ethylene, acetic acid, water, carbon dioxide, carbon monoxide, and unreacted ethane through a first-effluent discharge conduit to a second ODH reactor;
• the first shell side to receive a first coolant into the first cooling section to maintain temperature of the ODH catalyst in the first cooling section at a first temperature and receive a second coolant into the second cooling section to maintain temperature of the ODH catalyst in the second cooling section at a second temperature, wherein the first temperature is lower than the second temperature;
• and
• the second ODH reactor comprising a third cooling section and a fourth cooling section separated by a flow barrier on a second shell side, the fourth cooling section operationally downstream of the third cooling section, wherein the second ODH reactor is a multi-tubular fixed bed reactor comprising:
• a second tube side having ODH catalyst to receive the first effluent to dehydrogenate ethane into ethylene in a second reaction mixture and discharge a second effluent through a second-effluent discharge conduit;
• and
• the second shell side to receive a third coolant into the third cooling section to maintain temperature of the ODH catalyst in the third cooling section at a third temperature and receive a fourth coolant into the fourth cooling section to maintain temperature of the ODH catalyst in the fourth cooling section at a fourth temperature, wherein the third temperature is lower than the fourth temperature.