Oxidative dehydrogenation (ODH) of ethane
Processes and associated reaction systems for the oxidative dehydrogenation of ethane are provided. In particular, a process is provided that comprises supplying a feed gas comprising ethane and oxygen to a multitubular fixed-bed reactor and allowing the ethane and oxygen to react in the presence of an oxidative dehydrogenation catalyst to yield a reactor effluent comprising ethylene; and supplying a coolant to an interior shell space of the multitubular fixed-bed reactor in a flow pattern that is co-current with the flow of the feed gas through reactor.
1. A process for the oxidative dehydrogenation of ethane to ethylene comprising:
providing a multitubular fixed-bed reactor comprising a reactor inlet, an interior shell space, and a plurality of reactor tubes, wherein the plurality of reactor tubes comprise a catalyst bed that comprises an oxidative dehydrogenation catalyst;
supplying a feed gas comprising ethane and oxygen to the reactor inlet and allowing the ethane and oxygen to react in the presence of the oxidative dehydrogenation catalyst to yield a reactor effluent comprising ethylene; and
supplying a coolant to the interior shell space of the multitubular fixed-bed reactor in a flow pattern that is co-current with the flow of the feed gas through the plurality of reactor tubes,
wherein the coolant is supplied to the interior shell space via an upstream coolant inlet at an upstream inlet coolant temperature and is withdrawn from the interior shell space via a downstream coolant outlet at a downstream outlet coolant temperature, and wherein the downstream outlet coolant temperature exceeds the upstream inlet coolant temperature by 5° C. to 30° C.
2. The process of claim 1 , wherein the coolant is supplied to the interior shell space via an upstream coolant inlet at an upstream inlet coolant temperature of from 250° C. to 500° C.
3. The process of claim 1 , wherein the coolant is supplied to the interior shell space via an upstream coolant inlet at an upstream inlet coolant temperature of from 250° C. to 400° C.
4. The process of claim 1 , wherein the coolant is supplied to the interior shell space via an upstream coolant inlet at an upstream inlet coolant temperature of from 300° C. to 400° C.
5. The process of claim 1 , wherein the coolant is supplied to the interior shell space via an upstream coolant inlet at an upstream inlet coolant temperature and is withdrawn from the interior shell space via a downstream coolant outlet at a downstream outlet coolant temperature, and wherein the downstream outlet coolant temperature exceeds the upstream inlet coolant temperature by 5° C. to 20° C.
6. The process of claim 1 , wherein the multitubular fixed-bed reactor further comprises a perforated partition that divides the interior shell space into an upstream region and a downstream region.
7. The process of claim 6 , wherein the upstream region is from 10% to 20% of the length of the reactor tubes.
8. The process of claim 6 , wherein the coolant is supplied to the upstream region via the upstream coolant inlet, is withdrawn from the upstream region via an upstream coolant outlet, is supplied to the downstream region via a downstream coolant inlet that is in fluid communication with the upstream coolant outlet, and is withdrawn from the downstream region via the downstream coolant outlet.
9. The process of claim 1 , wherein the oxidative dehydrogenation catalyst in the catalyst bed has the following formula:
Mo 1 V a Te b Nb c O n
wherein:
a, b, c and n represent the ratio of the molar amount of the element in question to the molar amount of molybdenum;
a is from 0.01 to 1;
b is 0 or from >0 to 1;
c is from >0 to 1; and
n is a number which is determined by the valency and frequency of elements other than oxygen.