The present disclosure provides a method for separating a feed stream in a distillation tower. The method includes operating a controlled freeze zone section in a distillation tower that separates a feed stream at a temperature and pressure at which the feed stream forms a solid in the controlled freeze zone section, wherein the feed stream includes a first contaminant; maintaining a melt tray assembly in the controlled freeze zone section; introducing the feed stream to the controlled freeze zone section; and accumulating a liquid in the melt tray assembly until the liquid is at a predetermined liquid level in the controlled freeze zone section, by: feeding a second contaminant to the controlled freeze zone section; and adding the second contaminant to the melt tray assembly, wherein the liquid comprises the second contaminant.

The present disclosure provides a method for separating a feed stream in a distillation tower. The method includes operating a controlled freeze zone section in a distillation tower that separates a feed stream at a temperature and pressure at which the feed stream forms a solid in the controlled freeze zone section, wherein the feed stream includes a first contaminant; maintaining a melt tray assembly in the controlled freeze zone section; introducing the feed stream to the controlled freeze zone section; and accumulating a liquid in the melt tray assembly until the liquid is at a predetermined liquid level in the controlled freeze zone section, by: feeding a second contaminant to the controlled freeze zone section; and adding the second contaminant to the melt tray assembly, wherein the liquid comprises the second contaminant.

A first method for refining dicyclopentadiene of the present invention is characterized in that the method separates and recovers dicyclopentadiene by distilling the crude dicyclopentadiene that contains dicyclopentadiene and is obtained by removing a C5 fraction and a BTX fraction from the reaction product obtained by dimerization reaction of the cracked gasoline by-produced in an ethylene plant that uses as feed stock a C2 fraction, a C3 fraction and a C4 fraction. A second method for refining dicyclopentadiene of the present invention is characterized in that the dicyclopentadiene-containing fraction refined by distillation is brought into contact with an inert gas or a hydrocarbon gas having 1 to 3 carbon atoms.

A first method for refining dicyclopentadiene of the present invention is characterized in that the method separates and recovers dicyclopentadiene by distilling the crude dicyclopentadiene that contains dicyclopentadiene and is obtained by removing a C5 fraction and a BTX fraction from the reaction product obtained by dimerization reaction of the cracked gasoline by-produced in an ethylene plant that uses as feed stock a C2 fraction, a C3 fraction and a C4 fraction. A second method for refining dicyclopentadiene of the present invention is characterized in that the dicyclopentadiene-containing fraction refined by distillation is brought into contact with an inert gas or a hydrocarbon gas having 1 to 3 carbon atoms.

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.

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.

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.

The presently disclosed subject matter relates to methods and systems for purifying 1,3-butadiene from a C.sub.4 hydrocarbon stream. An example method includes introducing a C.sub.4 hydrocarbon stream including 1,3-butadiene and acetylenes to an organic azide in the presence of a catalyst to generate a first stream including triazole, separating triazole from the first stream to produce a second stream including 1,3-butadiene, and distilling 1,3-butadiene from the second stream to produce a purified 1,3-butadiene product stream.

The presently disclosed subject matter relates to methods and systems for purifying 1,3-butadiene from a C.sub.4 hydrocarbon stream. An example method includes introducing a C.sub.4 hydrocarbon stream including 1,3-butadiene and acetylenes to an organic azide in the presence of a catalyst to generate a first stream including triazole, separating triazole from the first stream to produce a second stream including 1,3-butadiene, and distilling 1,3-butadiene from the second stream to produce a purified 1,3-butadiene product stream.

A composite adsorbent for separating ethylbenzene from C8 arene by an adsorption distillation contains 1-50 mass % of a xylene adsorbent and 50-99 mass % of a carrier liquid. The carrier liquid is selected from one or two of alkane, aryl-substituted alkane, decalin and alkyl-substituted decalin. The alkane is C10-C26 alkane, and the aryl-substituted alkane is C13-C16 aryl-substituted alkane. The composite adsorbent can increase the volatility of ethylbenzene relative to other C8 arenes and thus can separate a high-purity ethylbenzene from C8 arene by the adsorption distillation.