CN100579643C - Combined axial flow gas-solid phase fixed-bed catalytic reactor with by-product steam - Google Patents

Abstract

A combined axial flow gas-solid-phase fixed-bed catalytic reactor for by-product steam, including a cylinder, an upper head, an adiabatic reaction section, a water cooling section in the tube and a lower head, and two adiabatic layers are arranged in the adiabatic reaction section , each insulation layer is equipped with a raw material gas shock composed of a cold shock distributor and a cold shock tube; a heat transfer medium collection pipe, a catalytic bed in the water cooling section of the tube, a heat transfer tube, and a heat transfer medium are arranged in the water cooling section in the tube. The distribution pipe, the lower support plate, and the cooling medium pass through the heat exchange tubes, and the catalyst is filled between the heat exchange tubes. The height of the loaded catalyst is 50-95% of the total height of the catalyst layer in the reactor. The advantages of the present invention are: it is specially designed for the characteristics of reversible exothermic reaction, the reactor structure is simple, the catalyst is convenient to load and unload, the catalyst is easy to heat up and reduce, the temperature of the catalytic bed is easy to control and adjust, and the high energy reaction heat can be recovered. Steam, suitable for large-scale chemical production.

Description

Combined axial flow gas-solid phase fixed-bed catalytic reactor with by-product steam

【Technical field】

The invention relates to the technical field of chemical reaction equipment, in particular to a combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam.

【Background technique】

In reversible exothermic reactions such as methanol synthesis, ammonia synthesis, carbon monoxide conversion, hydrogenation of organic compounds, dimethyl ether synthesis, liquid fuel synthesis, and ethylene oxide synthesis, solid particle catalysts are used, and heat affects the reaction results. And the problem of catalyst recycling; in the large-scale industrial production process, it is necessary to apply fixed bed catalytic reactor.

At present, the technologies relevant to the present invention mainly contain:

(1) Linde reactor

Compared with the shell-and-tube Lurgi reactor in Germany, when the catalyst is loaded in the Linde reactor, the catalyst is loaded between the tubes of the heat exchange tubes, and boiler water is used in the heat exchange tubes to remove the reaction heat to achieve isothermal operation. Since the heat exchange tube of the Linde reactor is in the form of a spiral coil, the processing and manufacturing are more complicated and the equipment cost is higher.

(2) Casale reactor

Casale has developed a catalytic reactor with plate heat exchange elements suitable for exothermic and endothermic heterogeneous reactions, and applied it to methanol production. The reactor is a water-cooled reactor, the catalyst is loaded in the shell side, and water flows in the heat exchange element; the heat exchange element is a plate heat exchanger; the reactor can use the original reactor shell to transform the original reaction The internal devices of the reactor reduce the investment in equipment; but its disadvantage is that the heat exchange elements of the reactor are more complicated.

【Content of invention】

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a combined axial flow gas-solid phase fixed bed that is suitable for the large-scale development of a single series in chemical production, uses energy reasonably, and is quick and convenient to operate by-product steam. catalytic reactor.

In order to achieve the above object, the technical scheme that the present invention takes is:

A combined axial flow gas-solid-phase fixed-bed catalytic reactor for by-product steam, comprising a cylinder body, an upper head, an adiabatic reaction section, a water cooling section in a tube and a lower head, and the upper head is provided with a gas inlet and a The manhole is equipped with a catalyst unloading port and a gas outlet on the lower head. It is characterized in that there are 1 to 2 insulation layers in the adiabatic reaction section, and each insulation layer is equipped with raw material gas cooling. The height of the adiabatic reaction section is It is 5% to 30% of the total height of the catalyst layer of the reactor; the water cooling section in the tube is equipped with a heat exchange medium collection pipe, a catalytic bed in the water cooling section in the tube, a heat exchange tube, a heat exchange medium distribution tube, and a lower support plate, and the heat exchange tube is connected to the Between the heat exchange medium collection pipe and the heat exchange medium distribution pipe, the heat exchange medium distribution pipe is connected to the upper end of the cooling medium inlet, and the lower end of the cooling medium inlet is fixed on the lower head; the heat exchange medium collection pipe is connected to the cooling medium The lower end of the outlet and the upper end of the cooling medium outlet are fixed on the upper head; the cooling medium is passed through the heat exchange tubes, and the catalyst is filled between the heat exchange tubes. The height of the loaded catalyst is 50-95% of the total height of the reactor catalyst layer %.

The raw material gas cooling is composed of a cooling gas distributor and a cooling tube, the cooling gas distributor is a ring structure, and a small hole is arranged in the lower part of the ring structure; the lower end of the cooling tube is connected to the cooling gas distribution On the reactor, the upper end of the cold shock tube is fixed on the upper head of the reactor.

The heat insulation layer is a heat insulation layer provided with a feed gas chiller.

The raw material gas cooling is composed of a cooling gas distributor and a cooling tube.

The raw material gas cooling is composed of multiple cooling gas distributors and multiple cooling tubes.

The heat exchange medium collection pipe is an annular pipe, and the upper end of the heat exchange pipe and the lower end of the cooling medium outlet are connected to the pipe.

The heat exchange medium distribution pipe is an annular pipe, and the lower end of the heat exchange pipe and the upper end of the cooling medium inlet are connected to the pipe.

The diameter of the small holes in the lower part of the cold-stimulated gas distributor of the ring structure is 1-5 mm.

When the reaction gas of reversible exothermic reactions such as synthetic gas to methanol, synthetic ammonia reaction, synthetic gas to dimethylformamide, synthetic liquid fuel, etc. enters the reactor axially, it first passes through the above-mentioned thermal insulation layer composed of industrial particle size catalysts, and after the adiabatic reaction The gas is then cooled by the raw material gas, and exchanges heat with the cold raw material gas, so that the temperature of the reaction gas is reduced to the reaction temperature of the next reaction; an insulating layer is installed on the upper part of the reactor, which can absorb the harmful and poisonous catalyst in the reaction gas. To ensure that the catalyst in the lower part of the reactor is not affected by harmful and toxic gases, and prolong the service life of the catalyst.

When the reaction gas axially flows through the catalyst layer in the water-cooling section in the tube, the heat of reaction generated is cooled and removed by the medium in the heat exchange tube. The medium can be water or other heat medium; if it is water, it should be from the lower part of the reactor. The inlet of the cooling medium enters, and after absorbing heat, it forms medium-pressure steam and is discharged from the outlet of the cooling medium on the upper part of the reactor; After changing, it is discharged from the cooling medium outlet on the upper part of the reactor. In some cases, it can also enter from the outlet of the cooling medium in the upper part of the reactor and discharge from the inlet of the cooling medium in the lower part of the reactor.

The effect of the combined axial flow gas-solid phase fixed-bed catalytic reactor of by-product steam of the present invention is:

(1) It is a fixed-bed catalytic reactor proposed for the characteristics of reversible exothermic reactions, such as synthesis gas to methanol, synthesis ammonia, synthesis gas to dimethyl ether, and liquid fuel synthesis. It fully considers the reversible exothermic reaction The thermal effect of the catalyst should be arranged reasonably, and the heat insulation layer and the raw material gas cooling shock should be installed on the upper part of the reactor, which not only increases the loading amount of the catalyst, increases the production capacity, but also can absorb harmful and toxic substances to the catalyst; in the lower part of the reactor Heat exchange tubes are installed, the catalyst is installed between the heat exchange tubes, and the cooling medium—boiling water is passed through the heat exchange tubes. The heat released during the reaction is removed by the boiling water, and medium-pressure steam is produced as a by-product, which fully and reasonably utilizes the high-level energy. heat.

(2) The catalyst is integrated in the reactor, and the cold-stimulated gas distributor, heat-exchange medium collection pipe, heat-exchange medium distribution pipe and heat-exchange pipe are arranged in the catalyst bed.

(3) The structure of the reactor is simple, the loading and unloading of the catalyst is convenient, the temperature of the catalyst is easy to reduce, the temperature of the catalytic bed is easy to control and adjust, the high energy reaction heat can be recovered, and the by-product steam is suitable for large-scale chemical production.

【Description of drawings】

The accompanying drawing is a schematic structural view of a combined axial-flow gas-solid phase fixed-bed catalytic reactor for by-product steam of the present invention.

The labels in the figure are:

1. Gas inlet, 2. The first heat insulation layer, 3. The first cold shock gas distributor, 4. The second heat insulation layer, 5. The second cold shock gas distributor, 6. Heat exchange medium collection pipe, 7. Inside the pipe Catalytic bed in water cooling section, 8. Heat exchange tube, 9. Heat exchange medium distribution pipe, 10. Lower support plate, 11. Catalyst discharge port, 12. Gas outlet, 13. Cooling medium inlet, 14. Lower head, 15, Cylinder body, 16, upper head, 17, manhole, 18, second cooling tube, 19, cooling medium outlet, 20, first cooling tube.

【Detailed ways】

Hereinafter, specific embodiments of the present invention will be given with reference to the drawings, but the present invention is not limited to the following embodiments.

A combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam, comprising a cylinder body 15, an upper head 16, an adiabatic reaction section, a water cooling section in a tube and a lower head 14, and the upper head 16 is provided with A gas inlet 1 and a manhole 17 are provided, and a catalyst unloading port 11 and a gas outlet 12 are provided on the lower head 14 .

The inner diameter of the cylinder 15 is 3.8 meters, and the upper part is an adiabatic reaction section, which is provided with two adiabatic layers: a first adiabatic layer 2 and a second adiabatic layer 4, the first adiabatic layer 2 is arranged above the second adiabatic layer 4; After the first heat insulation layer 2, there is a raw material gas cooling system composed of the first cooling gas distributor 3 and the first cooling tube 20. The first cooling gas distributor 3 is a ring structure, and the lower part of the ring structure is arranged There are small holes, the diameter of which is 1 to 5 mm, the lower end of the first cold shock gas distributor 3 is connected to the first cold shock tube 20, and the upper end of the first cold shock tube 20 is fixedly connected to the upper head of the reactor 16, at the same time, it plays the role of fixing the first cold excitation gas distributor 3 behind the first heat insulation layer 2; behind the second heat insulation layer 4, there is a raw material gas cold shock, which is controlled by the second cold excitation gas distributor 5 (the structure is the same as the first cold shock distributor 3) and the second cold shock pipe 18 (the structure is the same as the first cold shock pipe 20), and the lower end of the second cold shock gas distributor 5 is connected with the second cold shock pipe 18, The upper end of the second cold shock tube 18 is fixedly connected to the reactor upper head 16, and plays the role of fixing the second cold shock gas distributor 5 behind the second heat insulation layer 4; the height of each heat insulation layer is 1.25 meters , the height of the adiabatic reaction section is 5-30% of the total height of the catalyst layer of the reactor, and 28 cubic meters of catalyst can be filled.

The raw material gas chilling of the present invention can be composed of a chilling gas distributor and a chilling tube, and can also be composed of multiple chilling gas distributors and multiple chilling tubes.

The lower part of the cylinder body 15 is the water-cooling section in the tube, and its inner diameter is also 3.8 meters. It is equipped with a heat exchange medium collection tube 6, a catalytic bed 7 in the tube water-cooling section, a heat exchange tube 8, a heat exchange medium distribution tube 9, and a lower support plate 10. A group of heat exchange tubes 8 with a diameter of 25 mm and a tube wall thickness of 2 mm are connected between the annular tubular heat exchange medium collection pipe 6 and the annular tubular heat exchange medium distribution pipe 9; the heat exchange medium distribution pipe 9 is connected to The upper end of the cooling medium inlet 13 and the lower end of the cooling medium inlet 13 are fixedly arranged on the lower head 14; the heat exchange medium manifold 6 is connected to the lower end of the cooling medium outlet 19, and the upper end of the cooling medium outlet 19 is fixedly arranged on the upper head 16; the cooling medium is passed through the heat exchange tubes 8, and the catalyst is packed between the heat exchange tubes 8. The height of the loaded catalyst is 50% to 95% of the total height of the catalyst layer of the reactor, and 57 cubic meters of catalyst can be filled. The whole reaction A total of 85 cubic meters of catalyst can be loaded in the container.

Synthetic gas consisting of 74.64% hydrogen, 10.89% carbon monoxide, 1.36% carbon dioxide and a small amount of methane (CH ₄ ), nitrogen (N ₂ ) and argon (Ar) enters the reactor at a temperature of 190°C , the pressure is 8.0Mpa, the reaction temperature after cooling through the first cooling gas distributor 3 is 202°C, and the reaction temperature after cooling through the second cooling gas distributor 5 is 209°C, and enters the catalyst bed in the water-cooling section of the pipe The hot spot temperature after the layer is 236°C, the temperature of the gas outlet 12 of the reactor is 231°C, and the flow rate of gas entering the reactor is 765141Nm ³ /h. The invention can produce 600,000 tons of methanol per year (calculated on the basis of 300 days), and produce medium-pressure steam of 1.2 tons per ton of methanol.

In specific implementation, the combined axial flow gas-solid phase fixed-bed catalytic reactor with by-product steam can have multiple combinations, such as: adiabatic-cold shock-adiabatic-cold shock-in-tube water cooling by-product steam combination; or , a combination of adiabatic-cold shock-in-pipe water-cooled by-product steam; when the height of the insulation layer is low, it can also be a combination of adiabatic-in-pipe water-cooled by-product steam without a cold-shock structure.

Claims (8)

1. A combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam, comprising a cylinder body, an upper head, an adiabatic reaction section, a water-cooled section in a tube, and a lower head, and the upper head is provided with a gas Inlet and manhole, catalyst unloading port and gas outlet are provided on the lower head. It is characterized in that there are 1 to 2 insulation layers in the adiabatic reaction section, and there is a raw material gas cooling and adiabatic reaction section behind each insulation layer. The height of the reactor catalyst layer is 5-30% of the total height of the catalyst layer; the water cooling section in the tube is equipped with a heat exchange medium collection pipe, a catalytic bed in the water cooling section in the tube, a heat exchange tube, a heat exchange medium distribution tube, a lower support plate, and a heat exchange tube Connected between the heat exchange medium collection pipe and the heat exchange medium distribution pipe, the heat exchange medium distribution pipe is connected to the upper end of the cooling medium inlet, and the lower end of the cooling medium inlet is fixed on the lower head; the heat exchange medium collection pipe is connected to The lower end of the cooling medium outlet, and the upper end of the cooling medium outlet are fixed on the upper head; the cooling medium is passed through the heat exchange tubes, and the catalyst is filled between the heat exchange tubes. The height of the loaded catalyst is 50% of the total height of the reactor catalyst layer. ~95%. 2. The combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1, characterized in that the raw material gas quenching is composed of a quenching gas distributor and a quenching tube, The cold shock gas distributor is a ring structure, and a small hole is provided in the lower part of the ring structure; the lower end of the cold shock tube is connected to the cold shock gas distributor, and the upper end of the cold shock tube is fixed on the upper head of the reactor. 3. The combined axial-flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1, characterized in that, each heat-insulating layer is provided with a feed gas chiller. 4. The combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1 or 2, characterized in that the raw material gas is cooled by a cooled gas distributor and a The root cold shock tube is formed. 5. The combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1 or 2, characterized in that, the cooling of the raw gas is composed of a plurality of cooling gas distributors and It is composed of multiple cold shock tubes. 6. The combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1, characterized in that, the heat exchange medium collection pipe is an annular pipe, and a heat exchange pipe is connected to the pipe The upper end and the lower end of the cooling medium outlet. 7. The combined axial flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 1, characterized in that, the heat exchange medium distribution pipe is an annular pipe, and a heat exchange pipe is connected to the pipe The lower end and the upper end of the cooling medium inlet. 8. The combined axial-flow gas-solid phase fixed-bed catalytic reactor for by-product steam according to claim 2, characterized in that the diameter of the small hole in the lower part of the ring-shaped cold-stimulated gas distributor is 1 to 5 mm.

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