US 2006/0135831 A1 · Dehydrogenation process

Abstract

A process for the dehydrogenation of a C2 or C3 alkyl aromatic compound to a corresponding vinyl aromatic compound in a tubular reactor incorporating a spiral flow path. Preferred embodiments of the invention provide processes for the production of styrene or divinylbenzene by the catalytic dehydrogenation of ethylbenzene or diethylbenzene, respectively. A feedstock containing a C2 or C3 alkyl aromatic and steam is supplied into the inlet of a tubular reactor containing a dehydrogenation catalyst and comprising a hydrogen permeable outer wall. The alkyl aromatic compound is dehydrogenated to a corresponding vinyl aromatic compound with the attendant production of hydrogen. The feedstock and products of the dehydrogenation reactor are flowed along a longitudinal spiral flow path providing for an outward radial flow of hydrogen to provide a pressure gradient through the hydrogen permeable outer wall of the reactor with the flow of hydrogen therethrough. Hydrogen is removed from the outer wall of the reactor. The resulting vinyl aromatic product is recovered from the tubular reactor.

Claims22

Dependent claims

A process for the production of a vinyl aromatic compound by the catalytic dehydrogenation of C2 or C3 alkyl aromatic compound comprising:

(a) supplying a feedstock containing a C2 or C3 alkyl aromatic compound and steam into an elongated tubular reactor containing a dehydrogenation catalyst and comprising a hydrogen permeable outer wall extending longitudinally of said reactor;
(b) operating said tubular reactor under temperature conditions effective to cause the dehydrogenation of said alkyl aromatic compound to a corresponding vinyl aromatic compound with the attendant production of hydrogen in the presence of said dehydrogenation catalyst;
(c) flowing said feedstock within at least a portion of said reactor along a spiral flow path extending longitudinally of said reactor and providing for an outwardly radial flow of hydrogen to provide a pressure gradient through said hydrogen permeable outer wall with the attendant flow of hydrogen through said permeable outer wall;
(d) removing hydrogen from the vicinity of the outer wall of said tubular reactor to enhance the flow of hydrogen through said hydrogen permeable outer wall from the interior to the exterior of said reactor;
and
(e) recovering said vinyl aromatic product from a down stream section of said tubular reactor.

3 more elements

A process for the production of a vinyl aromatic compound by the catalytic dehydrogenation of a C2 or C3 alkyl aromatic compound comprising:

(a) supplying a feedstock containing a C2 or C3 alkyl aromatic compound and steam into a plurality of elongated tubular reactors, each characterized by a hydrogen permeable outer wall, located within the interior of a dehydrogenation reactor vessel and arranged in a parallel relationship with respect to one another in which at least some of the tubular reactors are spaced from one another and spaced from the interior wall of the reaction vessel;
(b) heating the interior of said reaction vessel to provide heat externally of said tubular reactor to provide an amount of heat which varies along the lengths of the tubular reactors;
(c) within said tubular reactors, supplying said mixed steam and said alkyl aromatic compound into contact with a particulate dehydrogenation catalyst in said tubular reactors under temperature conditions effective to cause the dehydrogenation of said alkyl aromatic compound to a corresponding vinyl aromatic compound with the attendant production of hydrogen in the presence of said dehydrogenation catalyst;
(d) flowing said feedstock within at least a portion of said reactors along spiral flow paths extending longitudinally of said reactors and providing for an outwardly radial flow of hydrogen to provide a pressure gradient through said hydrogen permeable outer walls with the attendant flow of hydrogen through said permeable outer walls;
(e) removing hydrogen from the vicinity of the outer walls of said tubular reactors to enhance the flow of hydrogen through said hydrogen permeable outer wall from the interior to the exterior of said reactor;
and
(f) recovering said vinyl aromatic product from said tubular reactors through outlets of said tubular reactors.

4 more elements

In a reaction system for the catalytic reaction of a plurality of reactants in a feed stream to produce reaction products including hydrogen, the combination comprising:

(a) a plurality of parallel-arranged, elongated tubular reactors each having a hydrogen permeable wall and having inlet side and outlet sides;
(b) an inlet manifold connected to said tubular reactors for supplying a mixture of reactants to the inlet sides of said reactors;
(c) a mixing section in each of said reactors adjacent to the inlet side thereof and comprising a baffle in an elongated helical configuration providing a spiral flow path;
(d) a reaction and products section in each of said reactors located downstream of said mixing section and comprising a bed of catalyst particles and having a baffle in an elongated helical configuration providing a spiral flow path for the outwardly radial flow of reaction products;
(e) an outlet manifold connected to the outlet sides of said tubular reactors;
and
(f) a recovery system for recovering a reaction product from said tubular reactor.

4 more elements

Dependencies are inferred from the claim text.

Dehydrogenation process

Life of this patent

Dehydrogenation process

Life of this patent

Abstract

Claims22