RU2188069C1 - Reactor for catalytic dehydrogenation of hydrocarbons - Google Patents

Abstract

FIELD: units for catalytic dehydrogenation of hydrocarbon, radial reactors, in particular; chemical and petrochemical industries. SUBSTANCE: proposed reactor has cylindrical housing and basket with catalyst which is mounted coaxially; this basket consists of inner and outer perforated cylinder; reactor is also provided with fairing made in form of cone-shaped body of revolution located in inner perforated cylinder; said body of revolution consists of three parts: cylindrical part at base whose height is equal to 0.02-0.25 L; hemispherical part at vertex whose height is equal to 0.005-0.05 L and middle part at

, where R_т is radius of present section of middle part of body of revolution; R_in is radius of inner perforated cylinder; h is distance between vertex of body of revolution and its present section; L is height of body of revolution. Cross-section area of catalyst basket is equal to 0.5 to 6 cross-section areas of inner perforated cylinder. Cross- section area of space between housing and outer perforated cylinder is equal to 1 to 5 cross-section areas of inner perforated cylinder. Free section area of perforation of inner cylinder is equal to 1-20 cross-section areas. Free section area of perforation of outer cylinder is equal to 0.5-6 free section areas of perforation of inner cylinder. EFFECT: enhanced efficiency of press due to smooth distribution of flow of reaction mixture; improved quality of final product. 5 cl, 1 dwg

Description

 The invention relates to devices for catalytic dehydrogenation of hydrocarbons, in particular to radial type reactors, and can be used in the chemical and petrochemical industry for the dehydrogenation of ethylbenzene to styrene, isoamylenes to isoprene, butylenes to butadiene, etc.

 A known axial type reactor for producing styrene, consisting of a cylindrical body filled with a layer of a fixed coarse-grained catalyst. (NN Lebedev "Chemistry and technology of basic organic and petrochemical synthesis". Chemistry, 1975, p. 575). The known reactor has a large height of the catalyst layer and, accordingly, a large pressure drop across the layer (hydraulic resistance), which leads to low dehydrogenation rates. In addition, the creation of large-scale production facilities based on axial-type reactors encounters considerable difficulties because of their relatively low productivity.

 Closest to the proposed reactor and devoid of these drawbacks is a radial type reactor for catalytic dehydrogenation of hydrocarbons, comprising a cylindrical body, a coaxially mounted annular basket with a catalyst made of internal and external perforated cylinders, inside of which a cowl is arranged coaxially in the form of a body of revolution (RU 2154523 Cl , 08/20/2000). However, the disadvantage of this reactor lies in the fact that its design does not provide a uniform distribution of the flow of the reaction mixture throughout the volume of the catalyst, which reduces the efficiency of the process and affects the quality of the final products.

 The objective of the invention is to increase the efficiency of the reactor due to the uniform distribution of the flow of the reaction mixture.

где R_т - радиус текущего сечения средней части тела вращения;
R_вн - радиус внутреннего перфорированного цилиндра;
h - расстояние от вершины тела вращения до его текущего сечения;
L - высота тела вращения.A reactor for the catalytic dehydrogenation of hydrocarbons is proposed, comprising a cylindrical body, a coaxially mounted annular basket with a catalyst made of internal and external perforated cylinders, and a cowling in the form of a cone-shaped body of revolution located in the internal perforated cylinder. The rotational body used consists of three parts in height: cylindrical at the base, the height of which is 0.02-0.25 L, at the top - hemispherical, the height of which is 0.005-0.05 L, and the middle, for which

where R _t is the radius of the current section of the middle part of the body of rotation;
R _vn is the radius of the inner perforated cylinder;
h is the distance from the top of the body of revolution to its current section;
L is the height of the body of revolution.

In the proposed reactor:
- the cross-sectional area of the basket with the catalyst is 0.5-6 square cross-sectional areas of the inner perforated cylinder;
- the cross-sectional area of the space between the housing and the outer perforated cylinder is 1-5 square cross-sections of the inner perforated cylinder;
- the free cross-sectional area of the perforation of the inner cylinder is 1-20 squares of its cross section;
- the free cross-sectional area of the perforation of the outer cylinder is 0.5-6 the free cross-sectional area of the perforation of the inner cylinder.

 The drawing shows a diagram of the proposed reactor for the catalytic dehydrogenation of hydrocarbons. The reactor contains a cylindrical body 1, inside of which the outer 2 and inner 3 perforated cylinders are arranged coaxially, forming a basket in which the catalyst layer 4 is enclosed. A cowl 5 in the form of a body of revolution is located in the inner perforated cylinder 3. The cowl contains a cylindrical part “a”, a hemisphere “in” and between them the middle part “c” with the geometry of the outer surface varying in height. The middle part "c" can be made, for example, in the form of a set of truncated cones (see drawing).

 The reaction mixture through the nozzle 6 enters the inner cylinder 3, flows around the fairing 5, passes sequentially the holes of the perforated cylinder 3, the catalyst layer 4, the holes of the perforated cylinder 2 and leaves the reactor through the nozzle 7.

 The proposed shape of the fairing provides in the reactors of catalytic dehydrogenation of hydrocarbons a uniform distribution of the flow of the reaction mixture throughout the volume of the catalyst loaded into the annular basket.

 Using the proposed reactor for catalytic dehydrogenation can improve the efficiency of the process of catalytic dehydrogenation of ethylbenzene to styrene and improve the quality of the final product.

Claims (5)

1. A reactor for catalytic dehydrogenation of hydrocarbons, comprising a cylindrical body, a coaxially mounted annular basket with a catalyst made of internal and external perforated cylinders, and a cowling in the form of a cone-shaped body of revolution located in the internal perforated cylinder, characterized in that the body of revolution used consists of the height of three parts: at the base - cylindrical, the height of which is 0.02-0.25 L, at the top - hemispherical, the height of which is 0.005-0.05 L, and cf one for which

where R _t is the radius of the current section of the middle part of the body of rotation;
R _vn is the radius of the inner perforated cylinder;
h is the distance from the top of the body of revolution to its current section;
L is the height of the body of revolution.  2. The reactor according to claim 1, characterized in that the cross-sectional area of the basket with the catalyst is 0.5-6 square cross-sections of the inner perforated cylinder.  3. The reactor according to claims 1 and 2, characterized in that the cross-sectional area of the space between the housing and the outer perforated cylinder is 1-5 square cross-sections of the inner perforated cylinder.  4. The reactor according to claims 1 to 3, characterized in that the free cross-sectional area of the perforation of the inner cylinder is 1-20 square cross-sections.  5. The reactor according to claims 1 to 4, characterized in that the free cross-sectional area of the perforation of the outer cylinder is 0.5-6 square free cross-sectional area of the perforation of the inner cylinder.