Producing C5 olefins from steam cracker C5 feeds

Patent metadata

Field	Value
Publication number	US-10252240-B2
Application number	US-201815901261-A
Country	US
Kind code	B2
Filing date	Feb 21, 2018
Priority date	Jan 29, 2015
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

Producing C5 olefins from steam cracker C5 feeds may include reacting a mixed hydrocarbon stream comprising cyclopentadiene, C5 olefins, and C6+ hydrocarbons in a dimerization reactor where cyclopentadiene is dimerized to dicyclopentadiene. The dimerization reactor effluent may be separated into a fraction comprising the C6+ hydrocarbons and dicyclopentadiene and a second fraction comprising C5 olefins and C5 dienes. The second fraction, a saturated hydrocarbon diluent stream, and hydrogen may be fed to a catalytic distillation reactor system for concurrently separating linear C5 olefins from saturated hydrocarbon diluent, cyclic C5 olefins, and C5 dienes contained in the second fraction and selectively hydrogenating C5 dienes. An overhead distillate including the linear C5 olefins and a bottoms product including cyclic C5 olefins are recovered from the catalytic distillation reactor system. Other aspects of the C5 olefin systems and processes, including catalyst configurations and control schemes, are also described.

First claim

What is claimed:

1. A process for producing C5 olefins from a steam cracker C5 feed, the process comprising:
reacting a mixed hydrocarbon stream comprising cyclopentadiene, linear C5 olefins, cyclic C5 olefins, and C6+ hydrocarbons in a dimerization reactor wherein cyclopentadiene is dimerized to form dicyclopentadiene, producing a dimerization reactor effluent;
separating the dimerization reactor effluent in a fractionator to form a first fraction comprising the C6+ hydrocarbons and dicyclopentadiene and a second fraction comprising the linear and cyclic C5 olefins and linear C5 dienes;
feeding the second fraction, a saturated hydrocarbon diluent stream, and hydrogen to a catalytic distillation reactor system, wherein the second fraction is introduced below a first catalyst zone;
concurrently in the catalytic distillation reactor system:
separating the linear C5 olefins from the saturated hydrocarbon diluent, the cyclic C5 olefins, and linear C5 dienes contained in the second fraction; and
selectively hydrogenating at least a portion of the C5 dienes to form additional linear C5 olefins; and

recovering linear C5 olefins in an overhead distillate from the catalytic distillation reactor system;
recovering cyclic C5 olefins in a bottoms product from the catalytic distillation reactor system;
purging a portion of the bottoms product;
reacting a remaining portion of the bottoms product in a total hydrogenation unit to convert the cyclic C5 olefins to cyclopentane; and
recycling the cyclopentane to the catalytic distillation reactor system as the saturated hydrocarbon diluent.

2. The process of claim 1 , further comprising feeding the second fraction to a fixed bed selective hydrogenation unit to selectively hydrogenate C5 dienes prior to feeding the second fraction to the catalytic distillation reactor system.

3. The process of claim 1 , further comprising partially vaporizing the second fraction prior to introducing the second fraction to the catalytic distillation reactor system.

4. The process of claim 1 , further comprising separating the overhead distillate to recover a product fraction comprising linear C5 olefins and a recycle fraction comprising cyclopentene.

5. The process of claim 1 , wherein the steps of reacting the mixed hydrocarbon stream and separating the reacted mixture are performed concurrently in a low temperature/low pressure distillation column, reacting the cyclopentadiene to form a dimerized product comprising dicyclopentadiene, and fractionating the mixed hydrocarbon stream to form the first fraction comprising the C6+ hydrocarbons and dicyclopentadiene and the second fraction comprising the linear and cyclic C5 olefins and C5 dienes.

6. The process of claim 5 , further comprising operating the low temperature/low pressure distillation column at a pressure in the range from about 15 psia to about 85 psia, at an overhead condenser temperature in the range from about 90° F. to about 150° F. and at a reboiler temperature in the range from about 155° F. to 300° F.

7. The process of claim 1 , further comprising feeding the overhead distillate from the catalytic distillation reactor system to a metathesis unit and converting the linear C5 olefins to propylene.

8. The process of claim 1 , further comprising:
operating the dimerization reactor at a pressure in the range from about 130 psia to about 170 psia and a temperature in the range from about 210° F. to about 250° F.;
operating the fractionator at a pressure in the range from about 15 psia to about 85 psia and at a condenser temperature in the range from about 97° F. and 213° F.;
operating the catalytic distillation reactor system at a pressure in the range from about 60 psia to about 240 psia and a reboiler temperature in the range from 220° F. and 320° F., and a hydrogen partial pressure in the range from about 1 psi to about 25 psia; and
operating the total hydrogenation unit at a pressure in the range from about 220 psia to about 300 psia and at a temperature in the range from about 200° F. and 260° F.

Assignees

• Lummus Technology Inc

Inventors

• Xu Yongqiang
• Loezos Peter
• Groten Willibrord A
• Lemoine Romain

Classifications

• C10G50/00

  Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation · CPC title

• C10G45/32

  Selective hydrogenation of the diolefin or acetylene compounds · CPC title

• C07C7/177

  by selective oligomerisation or polymerisation of at least one compound of the mixture · CPC title

• C07C7/167

  for removal of compounds containing a triple carbon-to-carbon bond · CPC title

• C07C7/163

  by hydrogenation · CPC title