Radial flow reactor for an ethanol dehydration process
A process for dehydration of an ethanol feed stream comprising sending said ethanol feed stream and steam to a radial flow reactor to contact a catalyst under reaction conditions and produce an effluent comprising ethylene. The use of a radial flow reactor eliminates concerns about pressure drops that may occur with conventional fixed bed downflow reactors.
1 . A process for dehydration of an ethanol feed stream comprising:
mixing said ethanol feed stream with steam and feeding the ethanol feed stream and steam mixture to a charge heater to produce a heated charge stream; and
sending said heated charge stream to a radial flow reactor to contact a catalyst under reaction conditions and produce an effluent comprising ethylene, wherein a pressure drop through a catalyst bed in the radial flow reactor is about 3 to about 5 psi.
2 . The process of claim 1 wherein said radial flow reactor comprises a first reactor and a second reactor.
3 . The process of claim 2 wherein a water stream is recycled and mixed with said ethanol feed stream.
4 . The process of claim 2 wherein said reactor is about 30-40% less in volume than in a dehydration process wherein said ethanol feed stream remains a single stream.
5 . The process of claim 2 wherein said reactor further comprises a third reactor.
6 . The process of claim 2 wherein an oxygenate feedstock is pretreated to remove contaminants and then a pretreated oxygenate stream is sent to said reactor.
7 . The process of claim 6 wherein said pretreated oxygenate stream is fractionated to separate ethanol from heavier oxygenates and then said ethanol is said ethanol feedstream.
8 . The process of claim 2 wherein said ethanol feed stream sent to said first reactor is heated to about 400° C. to about 550° C. and converted to ethylene over a dehydration catalyst at about 455 kPa to about 630 kPa.
9 . The process of claim 2 wherein an effluent from the first reactor is heated to about 400° C. to about 550° C. and converted to ethylene over a dehydration catalyst at about 420 kPa to about 700 kPa.
10 . The process of claim 2 wherein an effluent from said second reactor is sent to an interheater and then a heated product effluent is sent to a third reactor.
11 . The process of claim 10 wherein said product effluent of said third reactor contains no measurable diethyl ether.
12 . The process of claim 2 wherein said first reactor and said second reactor contain less steam than when all of said ethanol feed stream is sent to a single reactor with said first and second reactors operating at an increased endotherm level.