Catalytic Distillation Technologies

Montri Vichailak

Mario J Maraschino

Mitchell E Loescher

Martinus Johannes Almering

Bertrand R Klussman

Purvis K Ho

Lawrence A Smith, Jr

Gary G Podrebarac

Willibrord A Groten

Yongqiang Xu

Arvids Judzis, Jr

Nishit Sahay

Jianhua Wang

A process for reducing the concentration of benzene in a hydrocarbon stream, the process including: fractionating a reformate to form a benzene concentrate fraction comprising benzene and other Chydrocarbons, and a heavies fraction comprising Chydrocarbons; and hydrogenating the benzene concentrate fraction to form a hydrocarbon fraction having a reduced benzene concentration.

Process for ultra low benzene reformate using catalytic distillation

A process for recovering benzene, the process including: feeding hydrogen and a hydrocarbon fraction comprising benzene, components lighter than benzene, components heavier than benzene, and diolefins to a catalytic distillation reactor system comprising at least one reaction zone comprising a hydrogenation catalyst; concurrently in the catalytic distillation reactor system: contacting the diolefins and hydrogen in the presence of the hydrogenation catalyst to selectively hydrogenate at least a portion of the diolefins; and fractionating the hydrocarbon fraction to form a fraction comprising benzene and other Chydrocarbons, and a heavies fraction comprising Chydrocarbons; recovering the heavies fraction from the first catalytic distillation reactor system as a bottoms fraction; and withdrawing the fraction comprising benzene and other Chydrocarbons from the catalytic distillation reactor system as a benzene concentrate fraction.

Use of catalytic distillation for benzene separation and purification

A process for concurrently fractionating and hydrotreating a full range naphtha stream. The full boiling range naphtha stream is subjected to simultaneous hydrodesulfurization and splitting into a light boiling range naphtha and a heavy boiling range naphtha, which have been treated to convert mercaptans in the fractions to HS, which is separated with and separated from the light naphtha which is further hydrodesulfurized by contacting the light boiling range naphtha with hydrogen in countercurrent flow in a fixed bed of hydrodesulfurization catalyst to remove recombinant mercaptans which are formed by the reverse reaction of HS with olefins in the naphtha during the initial hydrodesulfurization wherein the improvement comprises fractionating said portion of light boiling range naphtha to remove a lighter fraction thereof from said countercurrent flow reactor before contact of said lighter fraction with said fixed bed catalyst, because the lighter fraction is substantially free of mercaptans and is not benefitted by further treatment.

HDS process using selected naphtha streams

A process for the separation of diisobutylene from tertiary butyl alcohol utilizing pressure swing azeotropic distillation to achieve the desired separation. The pressure swing azeotropic distillation takes advantage of the fact that different azeotropes are formed at different pressures. Isobutylene in Cstreams is oligomerized in the presence of tertiary butyl alcohol to produce the diisobutylene. Tertiary butyl alcohol is present in the dimerization because it improves the selectivity to the dimer (diisobutylene) by suppressing further reaction to the trimer or higher. The diisobutylene is separated from the tertiary butyl alcohol utilizing two distillation columns. The first distillation is operated at a higher pressure than the second such that the minimum boiling azeotropes of tertiary butyl alcohol and diisobutylene have different concentrations of tertiary butyl alcohol. Diisobutylene is removed as bottoms from the first distillation column and unreacted C4's are removed as overheads at 60-130 psig. A side draw containing the minimum boiling azeotrope is fed to the second distillation column, operated at 0-45 psig where a second minimum boiling azeotrope is formed having a lower tertiary butyl alcohol concentration. The tertiary butyl alcohol is recovered as bottoms and recycled to the reactor. The second minimum boiling azeotrope is removed as overheads and recycled to the first distillation column.

Separation of tertiary butyl alcohol from diisobutylene

A process for the desulfurization of a light boiling range (C -350&deg; F.) fluid catalytically cracked naphtha, which may be first subjected to a thioetherification to react the diolefins with mercaptans contained in it to form sulfides, is fed to a high pressure (>250 psig) catalytic distillation hydrodesulfurization step along with hydrogen under conditions to react most of the organic sulfur compounds, including sulfides from the thioetherification to form H S. The H S and a light product stream (C 's and C 's) are removed as overheads. The bottoms from the catalytic distillation hydrodesulfurization step is fractionated and the bottoms from the fractionation contacted with hydrogen in a straight pass hydrogenation step in the presence of a hydrodesulfurization catalyst at pressure of >250 and temperature >400&deg; F. to further reduce the sulfur content.

Process for the desulfurization of a light FCC naphtha

A process for concurrently fractionating and hydrotreating of a full range naphtha stream. The full boiling range naphtha stream is subjected to simultaneous hydrodesulfurization and splitting into a light boiling range naphtha and a heavy boiling range naphtha, which have been treated to covert mercaptans in the fractions to H S, which is separated with and separated from the light naphtha wherein the improvement is a further hydrodesulfurization by contacting the light boiling range naphtha with hydrogen in countercurrent flow in a fixed bed of hydrodesulfurization catalyst to remove recombinant mercaptans which are formed by the reverse reaction of H S with olefins in the naphtha during the initial hydrodesulfurization.

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Houston, TX, United States of America

Montri Vichailak