Multi-Stage Oxidative Dehydrogenation Process with Inter-Stage Cooling

An apparatus for oxidatively dehydrogenating a dehydrogenation reactant comprising:

• (a) a first adiabatic reaction zone having a fixed bed of ferrite dehydrogenation catalyst adapted for receiving a gaseous feed stream comprising a dehydrogenation reactant, oxygen and superheated steam and providing an effluent stream enriched in dehydrogenated product at an effluent temperature higher than the temperature of the feed stream to the first adiabatic reaction zone;
• (b) a heat exchanger for receiving said effluent stream and cooling said effluent stream to a temperature lower than said effluent temperature to provide a second gaseous feed stream;
• (c) a second adiabatic reaction zone having a fixed bed of ferrite dehydrogenation catalyst adapted for receiving said second gaseous feed stream;
• and
• (d) an oxygen feed for supplying additional oxygen to said second reaction zone.

An apparatus for oxidatively dehydrogenating a dehydrogenation reactant comprising:

• (a) one or more upstream adiabatic reaction zone(s) having a fixed bed of ferrite dehydrogenation catalyst adapted for receiving gaseous feed comprising a dehydrogenation reactant, oxygen and superheated steam and providing an effluent stream enriched in dehydrogenated product at an effluent temperature higher than the temperature of the gaseous feed to the adiabatic reaction zone;
• (b) one or more heat exchanger(s) for receiving effluent stream(s) from said adiabatic reaction zone(s) and cooling said effluent stream(s) to a temperature lower than said effluent temperature to provide a gaseous feed stream(s) to other adiabatic reaction zone(s) at a lower temperature;
• (c) a downstream adiabatic reaction zone having a fixed bed of ferrite dehydrogenation catalyst atop a fixed bed of acetylene removal catalyst adapted for receiving a gaseous feed stream;
• and
• (d) oxygen feed for supplying oxygen to said reaction zone(s).

In a method of making butadiene by way of oxidative dehydrogenation, the improvement comprising:

• (a) dimerizing ethylene to n-butene in a homogeneous catalytic reaction medium to provide an n-butene rich stream;
• (b) mixing the n-butene rich stream with steam and an oxygen rich gas to provide a gaseous feed stream;
• (c) providing the gaseous feed stream to a plurality of adiabatic, catalytic reaction zones arranged in series, the feed stream including n-butene, oxygen and superheated steam, wherein the molar ratio of superheated steam to n-butene is from 0.5:1 to 16:1;
• (d) oxidatively dehydrogenating n-butene reactant in said plurality of adiabatic, catalytic reaction zones to provide a plurality of effluent streams enriched in butadiene as compared with the gaseous feed stream;
• (e) cooling the effluent stream(s) in one or more heat transfer zones to a temperature lower than its effluent temperature and injecting additional oxygen into the effluent stream(s) prior to feeding the effluent stream to a subsequent oxidative dehydrogenation reaction zone;
• and
• (f) recovering said butadiene.

In a method of co-producing butene-1 and butadiene from ethylene, the improvement comprising:

• (a) providing ethylene to a homogeneous reaction medium including a homogeneous titanium/aluminum catalyst housed in a dimerization reactor;
• (b) dimerizing ethylene predominantly to butene-1 in the homogeneous reaction medium to provide (i) a butene-1 rich feed and (ii) a butene-1 rich product stream;
• (c) withdrawing and purifying the butene-1 rich product stream and recovering butene-1 therefrom;
• (d) mixing said hydrocarbonaceous butene-1 rich feed stream with steam and oxygen to provide a gaseous feed stream;
• (e) providing the gaseous feed stream to a plurality of adiabatic, catalytic reaction zones arranged in series, the feed stream including n-butene, oxygen and superheated steam, wherein the molar ratio of superheated steam to n-butene is from 0.5:1 to 16:1;
• (f) oxidatively dehydrogenating n-butene reactant in said plurality of adiabatic, catalytic reaction zones to provide a plurality of effluent streams enriched in butadiene as compared with the gaseous feed stream;
• (g) cooling the effluent stream(s) in one or more heat transfer zones to a temperature lower than its effluent temperature and injecting additional oxygen into the effluent stream(s) prior to feeding the effluent stream to a subsequent oxidative dehydrogenation reaction zone;
• and
• (h) recovering said butadiene.