RU2495910C1 - Reactor for hydraulic treatment of hydrocarbon stock - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to treatment of hydrocarbon stock. Proposed reactor consists of housing with cylindrical shell ring, upper and lower bottoms, axial stock feed pipe arranged at upper or lower bottom, separation zone at reactor upper part, housing lower zone with catalyst basket with stationary bed of pelletised catalyst, reaction product discharge pipe, level and pressure control system and gas discharge pipe atop reactor housing. Reactor accommodates at least one catalyst basket confined by two perforated walls shaped to truncated cone with taper angle of -45° to +45° and dead end walls. Note here that one perforated wall adjoins the shell ring in circle and at least one unit of heat exchange elements is arranged between said perforated walls. Pelletised catalyst is arranged between said heat exchange elements. Extra separation zone and at least one annular or cylindrical bypass to communicate extra and main separation zones are arranged at catalyst basket bottom. In case stock feed pipe is arranged upper bottom, it is provided with vertical pipe extending through catalyst baskets to reactor bottom.

EFFECT: reduced hydraulic resistance, catalyst load and metal input.

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Description

The invention relates to reaction apparatus for hydro-processing of hydrocarbon feedstocks, including processes with the removal of heteroatoms without changing the skeleton of the hydrocarbons being processed, including without cracking for low-boiling hydrocarbons (hydrotreatment), with cracking for low-boiling hydrocarbons (hydrocracking), processes with a change in the structural skeleton of some hydrocarbons present in the mixture, without cracking or with cracking of other hydrocarbons (hydrodewaxing) and similar processes, and may find application in food processing industry.

For hydroprocessing processes, in which the chemical transformations of the components of the raw materials are accompanied by the release of a significant amount of heat, it is important to ensure close to isothermal conditions for the process in the optimal temperature range. Local overheating of the catalyst and reaction mass leads to increased gas formation and a deterioration in the product balance of the processes, coking of the catalyst, a decrease in its activity, an increase in the hydraulic resistance of the catalyst layer and other negative consequences.

A number of reactor designs are known for isothermal carrying out liquid-phase catalytic processes [US Pat. RF №2371243, B01J 8/00, publ. 10/27/2009, Pat. RF №2435639, B01J 8/02, publ. December 10, 2011], including a cylindrical body with nozzles for supplying and discharging working media, lower and upper covers and with one or more blocks of heat transfer elements immersed in a layer of a stationary granular catalyst located in the inner space of the reactor bounded by perforated walls (in catalyst basket). The heat exchange units have a tubular, box-shaped or spiral-radial design. In addition, in known reactors there are at least two free spaces, one of which serves as a collector-distributor of raw materials, and the other as a collector-collector of the reacted reaction mass (product).

However, the known isothermal reactors cannot be used for hydro-processing of hydrocarbon feedstocks in connection with the two-phase state of the reaction mixture. In hydroprocessing options involving the circulation of a hydrogen-containing gas, the reaction mass is in a two-phase state when supplied to the reactor, inside the reactor, and when products are removed from it. In hydroprocessing options involving the circulation of a hydrogen solvent, the reaction mass is in a two-phase state inside the reactor and when the processed products are removed from the reactor. In this case, gaseous products (hydrogen sulfide, ammonia, water, light hydrocarbons) appear during hydroprocessing as a result of hydrogenolysis of the components of the reaction mixture.

The presence of a gas phase in the reaction mass impairs the hydrodynamics of the catalytic process occurring on the surface of the solid catalyst granules, leads to the accumulation of gas inside the reactor, isolation of a part of the catalyst, and, ultimately, to an unstable process, an increase in the volume of catalyst loading, and a decrease in the effective activity of the catalyst, increase the metal consumption of reactors.

Closest to the claimed invention in technical essence, a reactor for liquid-phase hydroprocessing, described in the patent "Control system, method and device for continuous liquid-phase hydroprocessing" [US Pat. RF №2411285, C10G 47/00, C10G 45/02, publ. 02/10/2011], which consists of a housing with a cylindrical shell, upper and lower bottoms, an axial inlet (pipe) for introducing the reaction mass (raw materials) located on the upper or lower bottom, the upper zone of the housing, designed for temporary placement gases (separation zone), the lower zone of the housing, designed for temporary placement of the reaction mass, in which there is a fixed layer of granular catalyst (catalyst basket), axial outlet (pipe) d I O the reaction products, located at the upper or lower bottom, level control and pressure in the reactor, the vent hole (nozzle) to remove gaseous products, located at the top of the housing.

The feed is introduced axially into the reactor, the reaction mass moves vertically from top to bottom or from bottom to top through the catalyst bed. In the reactor, several layers of a stationary granular catalyst can be placed with an axial input of raw materials into each of the layers.

The disadvantage of the reactor is the large hydraulic resistance of the catalyst layer inherent in axial feed reactors, which leads to the necessity of using large catalyst granules, which reduces the active surface of the catalyst, increases diffusion resistance, reduces the effective activity of the catalyst, the reaction rate, and also leads to an increase in volume catalyst loading and increase the metal consumption of the reactor. In addition, the design of the reactor does not provide isothermal conditions for the flow of hydroprocessing, since when the reaction mass moves along the catalyst bed, the temperature rises due to the heat generated by chemical transformations.

The objective of the invention is the provision of isothermal conditions in the reactor, reducing hydraulic resistance, reducing the amount of catalyst load and metal consumption of the reactor.

The technical result that can be obtained by implementing the method:

- providing isothermal conditions in the reactor by placing heat exchange elements in the catalyst bed for heat removal,

- reduction of hydraulic resistance of the reactor due to the radial input of raw materials,

- reducing the amount of catalyst load and metal consumption of the reactor by reducing the size of the granules of the catalyst and increase its activity.

The specified technical result is achieved by the fact that in the reactor for hydro-processing of hydrocarbon raw materials, consisting of a body with a cylindrical shell, an upper and lower bottom, an axial pipe for introducing raw materials located on the upper or lower bottom, a separation zone located in the upper part of the reactor, the lower zone housings with a catalyst basket with a fixed bed of granular catalyst, a pipe for outputting reaction products, a system for regulating the level and pressure in the reactor, a pipe for removing gas shaped products located in the upper part of the housing, the feature of which is that the reactor has at least one catalyst basket, which is the space inside the reactor bounded by two perforated walls having the shape of a truncated cone with a taper angle from -45 ° to + 45 ° and blind end walls, while one of the perforated walls is made adjacent to the shell around the circumference, so as to ensure radial movement of raw materials from the wall of the vessel into the reactor and and from the axis of the reactor to its wall, and in the space between the perforated walls, at least one block of heat exchange elements, for example, of a spiral-radial type, with nozzles for entering and leaving the refrigerant, is placed, in addition, a granular catalyst is placed between the heat exchange elements, and in the upper part of the catalyst basket there is an additional separation zone, and at least one overflow of a ring or cylindrical shape connecting the additional separation zone and the separation zone is located in the upper part of the reactor.

When the raw material input pipe is located on the upper bottom, it is additionally equipped with a vertical pipe passing through the catalyst basket to supply raw materials to the bottom of the reactor. When several catalyst baskets are placed in the reactor, a vertical pipe passes through all the catalyst baskets to the bottom of the reactor.

The implementation of the catalyst basket in the form of a space inside the reactor, limited by two perforated walls having the shape of a truncated cone with a taper angle from -45 ° to + 45 ° and blind end walls, can significantly increase the filtration area of the raw material through the catalyst layer and, accordingly, reduce the layer thickness and its hydraulic resistance. In addition, this allows to reduce the size of the granules of the catalyst, to increase the turbulence of the flow of raw materials and the activity of the catalyst, which ultimately leads to a decrease in the load of the catalyst and the metal consumption of the reactor. An increase in the taper angle of more than 45 ° in absolute value is impractical, since it leads to an increase in the diameter of the reactor and an increase in its metal consumption.

The implementation of one of the perforated walls adjacent to the circumference of the shell provides a radial movement of raw materials from the wall of the vessel into the reactor or from the axis of the reactor to its wall.

Placing in the space between the perforated walls of the catalyst basket of the block (s) of heat exchange elements provides isothermal conditions for hydroprocessing, without increasing temperature when the reaction mass moves through the catalyst bed.

Placing in the reactor an additional separation zone and at least one annular or cylindrical overflow in the upper part of the catalyst basket connecting the additional separation zone and the separation zone located in the upper part of the reactor provides a bypass bypass of the gas or gas-liquid part of the feed directly to the separation zone, bypassing catalyst layer, which prevents the gas phase from entering the catalyst layer and creates favorable hydrodynamic conditions for and processing.

The cross-sectional area of the bypass is selected so that there is no noticeable decrease in the degree of conversion of the raw material, or the level of phase separation in the additional separation zone is regulated. If necessary, the additional separation zone may not be equipped with a level controller and completely filled with liquid.

The reactor 1 consists of a shell 2, upper 3 and lower 4 bottoms, and is equipped with a raw material inlet pipe 5, a product outlet pipe 6 and a gas outlet pipe 7. Inside the reactor there are: a separation space 8, an additional separation space 9 with an overflow 10, a catalyst basket 11 (one basket is shown) formed by perforated walls 12 and 13 and blind ends 14 and 15, inside of which there is a layer of granular catalyst 16, as well as at least one block 17 of heat exchange elements, for example, spiral-radially of the second type (one unit is conventionally shown), with the inlet and outlet pipes of the refrigerant 18. When the raw material inlet pipe 5 is placed on top, it is additionally equipped with a vertical pipe 19 passing to the bottom of the reactor. To reduce hydraulic resistance in the direction of the reaction mass, chippers 20 can be placed in the reactor.

The drawings show: a reactor with a bottom feedstock and a positive taper angle of the perforated walls of the catalyst basket (Fig. 1), a reactor with a lower feedstock and a negative taper angle of the perforated walls of the catalyst basket (Fig. 2), a reactor with a top feedstock and a positive angle the taper of the perforated walls of the catalyst basket (figure 3), the reactor with the upper input of raw materials and the negative angle of the taper of the perforated walls of the catalyst basket (figure 4).

When carrying out hydroprocessing, the feed mixture (I) containing raw materials, diluent and hydrogen heated to the temperature of the hydroprocessing is fed to the reactor 1 through the feed inlet 5. The raw material mixture enters the bottom of the reactor (in FIGS. 3 and 4 through the pipe 19) and is distributed in the space between the shell and the perforated wall 13 (Fig.2 and 4) or in the space bounded by the inner perforated wall 12 (Fig.1 and 3). The gas phase present in the feed mixture is separated in the additional separation space 9 and through the hole 10 enters the separation zone 8 located in the upper part of the reactor 1, and the degassed feed mixture passes through the catalyst 16 located between the heat exchange surfaces of the blocks of heat exchange elements 17, where a reaction occurs between hydrogen dissolved in the feed mixture and the components of the feed. The reaction products (II) containing, including gaseous components, are separated to obtain a blow (III) containing gaseous components, which is discharged through pipe 7 and a liquid product (IV), which is removed from pipe 6. The temperature in the catalyst layer is maintained at a predetermined level by supplying a coolant (not shown in the diagram) to the tube space of the blocks of the heat exchange elements 17 through the nozzles 18. The pressure and level of the liquid phase in the reactor are also regulated.

Thus, the proposed reactor design allows for isothermal conditions in the reactor, to reduce its hydraulic resistance, to reduce the amount of catalyst load and metal consumption of the reactor.

Claims (1)

Hydrocarbon processing reactor for hydrocarbons, consisting of a housing with a cylindrical shell, upper and lower bottoms, an axial nozzle for introducing raw materials located on the upper or lower bottoms, a separation zone located in the upper part of the reactor, the lower zone of the housing with a catalyst basket with a fixed granular layer catalyst, a pipe for outputting reaction products, a system for regulating the level and pressure in the reactor, a pipe for removing gaseous products located on top of the housing, from characterized in that at least one catalyst basket is placed in the reactor, which is the space inside the reactor bounded by two perforated walls having the shape of a truncated cone with a taper angle of from -45 ° to + 45 ° and blind end walls, with one made of perforated walls adjacent to the shell around the circumference in such a way as to ensure radial movement of raw materials from the wall of the vessel into the reactor or from the axis of the reactor to its wall, and in the space between the perforated walls at least one block of heat-exchange elements, for example, of a spiral-radial type, with nozzles for introducing and discharging refrigerant is placed, in addition, a granular catalyst is placed between the heat exchange elements, and an additional separation zone is placed in the upper part of the catalyst basket, and at least one annular or cylindrical overflow connecting the additional separation zone and the separation zone located in the upper part of the reactor, and with the location of the pipe for introducing raw materials into the upper bottom, it is additionally equipped with a vertical pipe passing through the catalyst baskets to the bottom of the reactor.

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