C4 light hydrocarbon pretreatment device

Abstract

The utility model relates to a C4 light hydrocarbon pretreatment device and belongs to the technical field of light hydrocarbon pretreatment. The technical problems that residual hydrogen in the hydrogenation process and light hydrocarbon in raw materials are not treated by a C4 light hydrocarbon pretreatment device in the prior art, only materials with specific purposes and sources are treated, the process is relatively complex, and the energy consumption is relatively high are solved. The C4 light hydrocarbon pretreatment device comprises a pre-fractionating tower, a coalescer, a first-section hydrogenation reactor, a dehydrogenation tower, a condenser and a reflux tank, the pre-fractionating tower is used for removing heavy components in the mixed C4; the coalescer is used for dehydrating the de-heavy C4; the first-stage hydrogenation reactor is used for selectively hydrogenating the dehydrated de-heavy C4; the dehydrogenation tower is used for precisely rectifying hydrogenated C4; the condenser condenses the mixed light hydrocarbon; the reflux tank is used for performing gas-liquid phase separation on the condensed mixed light hydrocarbon. The device disclosed by the utility model can be used for obtaining purified C4 with higher purity and fewer impurities, and is good in raw material applicability, simple in process and low in cost.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of processing device, specifically relates to a carbon four light hydrocarbon pretreatment device. BACKGROUND

[0002] Olefins in carbon four light hydrocarbon fraction are important chemical raw materials, which can produce various chemical products. For example, carbon four fraction mainly contains alkane-isobutane, olefin-isobutene, butene-1, trans-butene and cis-butene, which can be used to produce various chemical derivatives such as methyl tert-butyl ether, butyl rubber, polybutene, butadiene, methyl ethyl ketone, isooctane and the like. In addition, carbon four fraction also contains a small amount of diene and alkyne, and diene and alkyne not only can polymerize to form gum, but also can even affect the running period of the device in severe cases.

[0003] Therefore, before the light hydrocarbon raw material enters the subsequent processing unit, the diene and alkyne in the raw material must be removed. The catalytic carbon four of the oil refinery is affected by crude oil, and the carbon four contains a lot of sulfides. Although the material still contains a small amount of sulfides after being treated by the desulfurization and sweetening device, and the material residues of these treatment devices, these sulfides and residues are impurities of the hydrogenation catalyst, and the accumulation to a certain extent will cause the deactivation of the catalyst and affect the operation of the device. At the same time, the downstream process has certain requirements for the non-carbon four light hydrocarbon components in the material. For example, if the dissolved hydrogen content in the carbon four after hydrogenation is too high, it will cause the material in the etherification reactor to separate, causing the flow deviation phenomenon, and the material after reaction enters the catalytic distillation column, and too much non-condensable gas will cause the pressure of the catalytic distillation column to be too high, resulting in the influence on the operation; some carbon four formylation device process puts forward the process index requirements that the diene content is less than 5 ppm, the hydrogen content is less than 1 ppm, and the carbon three content in the carbon four fraction is less than 0.05%. However, in the conventional design, a flash tank is usually provided to remove excess hydrogen, but the flash process cannot completely remove the dissolved hydrogen in the carbon four material, and it cannot affect the content of carbon three and other light components. Excessive discharge will also cause the loss of carbon four to increase. Therefore, a new pretreatment device needs to be designed to solve these problems.

[0004] Patent CN 115253430A provides a pretreatment device in carbon four production process, which includes a water washing tower, a first coalescer, a dehydration dryer, an adsorber, a hydrogenation reactor, a raw material light removal tower, a comprehensive adsorber and a second coalescer, but its essence is the improvement of the coalescer, and it does not involve the separation of residual hydrogen and light hydrocarbon.

[0005] Patent CN 110256209A discloses an ether post carbon four raw material pretreatment method and device, comprising: dehydrating and deoxidizing the ether post carbon four raw material; and regenerating the dehydrating agent and the deoxidizing agent.The method can remove micro water, ethers, alcohols and other impurities in the ether post carbon four, and various indexes meet the limit requirements of n-butene isomerization unit and selective hydrogenation unit on the impurity content of the raw material.However, the process does not involve the separation of residual hydrogen and light hydrocarbons, and does not include hydrogenation reaction, and the process is long, the regeneration process is complicated, the energy consumption is high, and it is only suitable for the process of ether post carbon four as raw material. Practical new type content

[0006] Therefore, the carbon four light hydrocarbon pretreatment device is provided to solve the technical problems in the prior art, such as not treating the residual hydrogen and light hydrocarbons in the hydrogenation process, and only treating the source material for specific use, and the process is complicated and the energy consumption is high.

[0007] The technical solutions adopted by the carbon four light hydrocarbon pretreatment device to solve the above technical problems are as follows.

[0008] The carbon four light hydrocarbon pretreatment device comprises:

[0009] A prefractionation column is provided with a feed inlet for mixing carbon four into the prefractionation column, and is provided with a first discharge port and a second discharge port, the first discharge port is used for heavy component discharge, and the second discharge port is used for de-heavy carbon four discharge;

[0010] A coalescer is provided with a feed inlet connected to the second discharge port of the prefractionation column through a pipeline;

[0011] A first hydrogen inlet is arranged on the pipeline connecting the first hydrogenation reactor and the coalescer;

[0012] A dehydrogenation tower is provided with a first feed inlet connected to the discharge port of the first hydrogenation reactor through a pipeline, and is provided with a first discharge port and a second discharge port, the first discharge port is used for purifying carbon four discharge, and the second discharge port is used for mixed light hydrocarbon discharge;

[0013] A condenser is provided with a feed inlet connected to the second discharge port of the dehydrogenation tower through a pipeline;

[0014] A reflux tank is provided with a feed inlet connected to the discharge port of the condenser through a pipeline, and is provided with three discharge ports, one discharge port is used for settling water discharge, one discharge port is used for non-condensed steam discharge, and one discharge port is used for liquid phase carbon four discharge.

[0015] Further, the first-stage hydrogenation reactor comprises two catalyst beds arranged in sequence, and a second hydrogen inlet is arranged in the middle of the first-stage hydrogenation reactor.

[0016] Further, the first-stage hydrogenation reactor is filled with 1-butene isomerization catalyst.

[0017] Further, the device further comprises a second-stage hydrogenation reactor, a feed inlet of the second-stage hydrogenation reactor is connected to a discharge outlet of the first-stage hydrogenation reactor through a pipeline, and a discharge outlet of the second-stage hydrogenation reactor is connected to a first feed inlet of the dehydrogenation tower.

[0018] A third hydrogen inlet is arranged on the pipeline connecting the first-stage hydrogenation reactor and the second-stage hydrogenation reactor.

[0019] Further, the second-stage hydrogenation reactor comprises two catalyst beds arranged in sequence, and a fourth hydrogen inlet is arranged in the middle of the second-stage hydrogenation reactor.

[0020] Further, a water cooler is arranged between the first-stage hydrogenation reactor and the second-stage hydrogenation reactor.

[0021] Further, the second-stage hydrogenation reactor is filled with 1-butene isomerization catalyst.

[0022] Further, the device further comprises a sewage treatment device, the sewage treatment device is connected to a discharge outlet of the reflux tank for discharging the settlement water through a pipeline, and the settlement water is treated.

[0023] Further, the discharge outlet for discharging the non-condensed steam is connected to a flare or a gas pipeline network through a pipeline.

[0024] Further, the discharge outlet for discharging the liquid-phase C4 is connected to a second feed inlet of the dehydrogenation tower, a part of the liquid-phase C4 is returned to the top of the dehydrogenation tower as reflux, and the discharge outlet is also connected to a feed inlet of a product tank area, so that another part of the liquid-phase C4 is discharged to the product tank area.

[0025] Compared with the prior art, the device has the following beneficial effects:

[0026] The device can remove butadiene and alkyne in mixed C4 from different sources such as catalytic cracking and ether post-treatment, separate and remove sulfides, oxides and light components and the like impurities to a certain extent, and control the content of residual hydrogen after hydrogenation, so that purified C4 with high purity and less impurities is obtained, thereby meeting the requirements of C4 in downstream utilization.

[0027] The device can economically and effectively remove impurities from carbon four and other light hydrocarbon fractions including oil refining catalytic cracking process, can remove diene and alkyne in carbon four and light hydrocarbon under mild conditions, has high adjustment capacity for diene and alkyne in raw materials, and maintains high carbon four light hydrocarbon yield. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to make the technical scheme in the specific embodiment of the utility model clearer, the drawings needed in the specific embodiment will be briefly introduced as follows, and obviously, the drawings in the following description are only some specific embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0029] Figure 1 It is a structure schematic view of the carbon four light hydrocarbon pretreatment device of the specific embodiment one of the utility model.

[0030] Figure 2 It is a structure schematic view of the carbon four light hydrocarbon pretreatment device of the specific embodiment two of the utility model.

[0031] In the drawing, 1 is mixed carbon four, 2 is heavy carbon four, 3 is a pre-fractionating column, 4 is a coalescer, 5 is hydrogen, 6 is heavy carbon four after dehydration, 7 is a first-stage hydrogenation reactor, 8 is first-stage hydrogenated carbon four, 9 is a second-stage hydrogenation reactor, 10 is carbon four after hydrogenation, 11 is a dehydrogenation tower, 12 is mixed light hydrocarbon, 13 is a condenser, 14 is a reflux tank, 15 is non-condensed steam, 16 is settling water, 17 is purified carbon four, and 18 is heavy component. DETAILED DESCRIPTION

[0032] In order to make those skilled in the art better understand the technical scheme of the utility model, the utility model will be further introduced in detail in combination with the drawings and specific embodiments. Specific embodiment one

[0034] As shown in the drawing, Figure 1 The carbon four light hydrocarbon pretreatment device of the utility model comprises a pre-fractionating column 3, a coalescer 4, a first-stage hydrogenation reactor 7, a dehydrogenation tower 11, a condenser 13 and a reflux tank 14.

[0035] The pre-fractionating tower 3 is used for removing heavy components in the mixed carbon four 1; the pre-fractionating tower 3 is provided with a feed inlet for the mixed carbon four 1 to enter the pre-fractionating tower 3, and is provided with a first discharge outlet and a second discharge outlet, the first discharge outlet is used for discharging the heavy components 18, and the second discharge outlet is used for discharging the heavy-removing carbon four 2;

[0036] The coalescer 4 is used for dehydrating the heavy-removing carbon four 2; a feed inlet of the coalescer 4 is connected with the second discharge outlet of the pre-fractionating tower 3 through a pipeline;

[0037] The one-stage hydrogenation reactor 7 is used for selectively hydrogenating the dehydrated heavy-removing carbon four 6; a feed inlet of the one-stage hydrogenation reactor 7 is connected with a discharge outlet of the coalescer 4 through a pipeline, and the pipeline connecting the one-stage hydrogenation reactor 7 and the coalescer 4 is provided with a first hydrogen inlet;

[0038] The dehydrogenation tower 11 is used for precisely rectifying the hydrogenated carbon four 10; a first feed inlet of the dehydrogenation tower 11 is connected with a discharge outlet of the one-stage hydrogenation reactor 7 through a pipeline, and the dehydrogenation tower 11 is provided with a first discharge outlet and a second discharge outlet, the first discharge outlet is used for discharging the purified carbon four 17, and the second discharge outlet is used for discharging the mixed light hydrocarbon 12;

[0039] The condenser 13 is used for condensing the mixed light hydrocarbon 12; a feed inlet of the condenser 13 is connected with a second discharge outlet of the dehydrogenation tower 11 through a pipeline;

[0040] The reflux tank 14 is used for separating the condensed mixed light hydrocarbon 12 into gas and liquid phases; a feed inlet of the reflux tank 14 is connected with a discharge outlet of the condenser 13 through a pipeline, and the reflux tank 14 is provided with three discharge outlets, one discharge outlet is used for discharging the settled water 16, one discharge outlet is used for discharging the non-condensed steam 15, and one discharge outlet is connected with a second feed inlet of the dehydrogenation tower 11 through a pipeline, so as to return part of the liquid-phase carbon four to the top of the dehydrogenation tower 11 as reflux, and is connected with a product tank area through a pipeline, so as to discharge another part of the liquid-phase carbon four to the product tank area.

[0041] On the basis of the device in the specific embodiment one, for the raw material with high diene content (>0.8wt%), a one-stage hydrogenation reactor 7 containing upper and lower catalyst beds is adopted, and the one-stage hydrogenation reactor 7 is provided with a second hydrogen inlet in the middle part.

[0042] The use method of the above-mentioned carbon four light hydrocarbon pretreatment device is as follows: mixed carbon four 1 enters a pre-fractionating tower 3, and heavy components carbon five and impurities such as heavy sulfides are removed through rectification, heavy components 18 (mainly carbon five and heavy carbon four) are obtained at the tower bottom and discharged, and de-heavy carbon four 2 is obtained at the tower top and enters a deconglomerator 4, dehydrated de-heavy carbon four 6 is obtained, hydrogen 5 is divided into two routes, and after the flow is adjusted by a flowmeter, one route is combined with the dehydrated de-heavy carbon four 6 and enters a first-stage hydrogenation reactor 7, and the other route enters the middle part of the first-stage hydrogenation reactor 7, in the first-stage hydrogenation reactor 7, dienes and alkynes react with hydrogen to generate olefins, butadiene and alkyne are removed, and hydrogenated carbon four 10 is obtained; the hydrogen 5 in the middle part of the first-stage hydrogenation reactor 7 can be cold hydrogen, so that the temperatures of the two catalyst beds are kept in a reasonable range, and the temperature is preferably 40-80 ℃; the hydrogenated carbon four 10 enters a dehydrogenation tower 11 for precise rectification, the hydrogenated carbon four 10 brings heat into the dehydrogenation tower 11, heat recovery is performed, purified carbon four 17 is obtained at the tower bottom, and mixed light hydrocarbon 12 (residual hydrogen and carbon two and carbon three light hydrocarbons, and dimethyl ether, methanol, water and other oxygen-containing compounds in etherized carbon four) is obtained at the tower top, is condensed in a condenser 13, enters a reflux tank 14, is separated in the gas-liquid phase in the reflux tank 14, methanol, water and the like are separated out, the separated water 16 is discharged from the tank bottom, is sent to a sewage treatment device, the incondensable steam 15 is obtained from the tank top, part of the liquid-phase carbon four is returned to the top of the dehydrogenation tower 11 as reflux, and the other part is discharged as the output to a product tank area. The total hydrogenation amount of the first-stage hydrogenation reactor 7 is calculated according to the hydrogen ratio (1-2 mol / mol) required by the content of butadiene in the raw material, wherein the middle part feed (the second route) of the first-stage hydrogenation reactor 7 preferably accounts for 0%-50%, and is usually greater than 0% and less than or equal to 50%, and can also be adjusted according to requirements.

[0043] The device of the utility model, in the first-stage hydrogenation reactor 7, different types of hydrogenation catalysts are selected according to process targets, and the pretreatment process is matched, so that different process targets can be achieved.

[0044] (1) for the process with butene-1 as the target, dienes (butadiene and alkyne) react with H2 under mild conditions to generate butene, and the hydrogenation catalyst is prepared by the method in the patent CN104549247A;

[0045] (2) for the process with butene-2 as the target, such as alkylation, a 1-butene isomerization catalyst can also be selected, the selected catalyst can remove butadiene and isomerize a large amount of butene-1 into butene-2, and the hydrogenation catalyst is prepared by the method in the patent ZL98110280.8. Specific implementation method two

[0047] For example Figure 2The utility model discloses a carbon four light hydrocarbon pretreatment device, including: prefractionating column 3, coalescer 4, one stage hydrogenation reactor 7, second hydrogenation reactor 9, dehydrogenation tower 11, condenser 13 and reflux tank 14,

[0048] The prefractionating column 3 is used for removing heavy components in the mixed carbon four 1, and the prefractionating column 3 is provided with a feed inlet for the mixed carbon four 1 to enter the prefractionating column 3, and the prefractionating column 3 is provided with a first discharge port and a second discharge port, the first discharge port is used for discharging heavy components 18, and the second discharge port is used for discharging heavy carbon four 2,

[0049] The coalescer 4 is used for dehydrating the heavy carbon four 2, and the feed inlet of the coalescer 4 is connected with the second discharge port of the prefractionating column 3 through a pipeline,

[0050] The one stage hydrogenation reactor 7 is used for selectively hydrogenating the heavy carbon four 6 after dehydration, the feed inlet of the one stage hydrogenation reactor 7 is connected with the discharge port of the coalescer 4 through a pipeline, and the pipeline connected with the one stage hydrogenation reactor 7 and the coalescer 4 is provided with a first hydrogen inlet,

[0051] The second hydrogenation reactor 9 is used for selectively hydrogenating the one stage hydrogenation carbon four 8 obtained from the one stage hydrogenation reactor 7, the feed inlet of the second hydrogenation reactor 9 is connected with the discharge port of the one stage hydrogenation reactor 7 through a pipeline, the discharge port of the second hydrogenation reactor 9 is connected with the first feed inlet of the dehydrogenation tower 11, and the pipeline connected with the one stage hydrogenation reactor 7 and the second hydrogenation reactor 9 is provided with a third hydrogen inlet,

[0052] The dehydrogenation tower 11 is used for precisely rectifying the carbon four 10 after hydrogenation, the first feed inlet of the dehydrogenation tower 11 is connected with the discharge port of the one stage hydrogenation reactor 7 through a pipeline, the dehydrogenation tower 11 is provided with a first discharge port and a second discharge port, the first discharge port is used for discharging purified carbon four 17, and the second discharge port is used for discharging mixed light hydrocarbon 12,

[0053] The condenser 13 is used for condensing the mixed light hydrocarbon 12, and the feed inlet of the condenser 13 is connected with the second discharge port of the dehydrogenation tower 11 through a pipeline,

[0054] The reflux tank 14 is used for separating the mixed light hydrocarbon 12 after condensation into gas and liquid phases, the feed inlet of the reflux tank 14 is connected with the discharge port of the condenser 13 through a pipeline, the reflux tank 14 is provided with three discharge ports, one discharge port is used for discharging settling water 16, one discharge port is used for discharging non-condensable steam 15, and one discharge port is connected with the second feed inlet of the dehydrogenation tower 11 through a pipeline and connected with a product tank area through a pipeline, so that part of the liquid phase carbon four is returned to the dehydrogenation tower 11 as reflux, and the other part of the liquid phase carbon four is discharged to the product tank area.

[0055] On the basis of the device of the second embodiment, a water cooler is preferably arranged between the first hydrogenation reactor 7 and the second hydrogenation reactor 9. The temperature of the material entering the second hydrogenation reactor 9 is ensured to be within a suitable range, preferably 40-80°C.

[0056] On the basis of the device of the second embodiment, one or both of the first hydrogenation reactor 7 and the second hydrogenation reactor 9 contain two catalyst beds arranged in an up-down manner. When the first hydrogenation reactor 7 contains two catalyst beds arranged in an up-down manner, a second hydrogen inlet is arranged in the middle of the first hydrogenation reactor 7. When the second hydrogenation reactor 9 contains two catalyst beds arranged in an up-down manner, a fourth hydrogen inlet is arranged in the middle of the second hydrogenation reactor 9. The hydrogen 5 in the middle of the first hydrogenation reactor 7 and the second hydrogenation reactor 9 can be cold hydrogen, so as to ensure that the temperature of the two catalyst beds is maintained within a reasonable range, preferably 40-80°C.

[0057] The above-mentioned carbon four light hydrocarbon pretreatment device is mainly used for a higher diene content (>0.8wt%). The method is as follows: the mixed carbon four 1 enters the prefractionation column 3, and the heavy components carbon five and impurities such as heavy sulfides are removed by rectification. The heavy components 18 (mainly carbon five and heavy carbon four) are obtained at the bottom of the column and discharged. The de-heavy carbon four 2 is obtained at the top of the column and enters the coalescer 4. The dehydrated de-heavy carbon four 6 is obtained. The hydrogen 5 is divided into three paths and the flow rate is controlled by the flow meter. One path is combined with the dehydrated de-heavy carbon four 6 and enters the first hydrogenation reactor 7. Another path enters the middle of the first hydrogenation reactor 7. The first hydrogenation carbon four 8 obtained by the first hydrogenation reactor 7 is combined with the third path hydrogen 5 and enters the second hydrogenation reactor 9, and the hydrogenated carbon four 10 is obtained. The hydrogenated carbon four 10 enters the dehydrogenation column 11 for precise rectification. The hydrogenated carbon four 10 brings heat into the dehydrogenation column 11 for heat recovery. The purified carbon four 17 is obtained at the bottom of the column. The mixed light hydrocarbon 12 (remaining hydrogen, carbon two, carbon three light hydrocarbon, and oxygen-containing compounds such as dimethyl ether, methanol, and water in the ether carbon four) is obtained at the top of the column, sent to the condenser 13 for condensation, and then enters the reflux tank 14. The gas-liquid phase is separated in the reflux tank 14. The methanol, water, and the like are separated and discharged. The non-condensable steam 15 is obtained at the top of the tank. Part of the liquid phase carbon four is returned to the top of the dehydrogenation column 11 as reflux. Another part of the liquid phase carbon four is discharged as product to the product tank area. The total hydrogenation amount of the first hydrogenation reactor 7 is calculated according to the hydrogen ratio (1-2mol / mol) required by the content of butadiene in the raw material. The middle part of the first hydrogenation reactor 7 (second path) preferably accounts for 0%-50%, usually greater than 0% and less than or equal to 50%. The feed (third path) of the second hydrogenation reactor 9 is 20%-100% of the feed of the first hydrogenation reactor 7.

[0058] Alternatively, the hydrogen is divided into four paths, and each path is controlled by a flow meter, one path is combined with the dehydrated de-heavy carbon four 6 to enter the first hydrogenation reactor 7, another path enters the middle part of the first hydrogenation reactor 7, the first hydrogenation carbon four 8 obtained from the first hydrogenation reactor 7 is combined with the third path hydrogen 5 to enter the second hydrogenation reactor 9, and the other path of hydrogen 5 enters the middle part of the second hydrogenation reactor 9, and the others are the same as above. The total amount of hydrogen in the first hydrogenation reactor 7 is calculated according to the hydrogen ratio (1-2 mol / mol) required by the content of butadiene in the raw material, and the middle part of the first hydrogenation reactor 7 (the second path) is preferably 0%-50%, usually greater than 0% and less than or equal to 50%, and the feed (the third path) of the second hydrogenation reactor 9 is 20%-100% of the feed of the first hydrogenation reactor 7; the middle part of the second hydrogenation reactor 9 (the fourth path) is preferably 0%-50% of the hydrogen feed of the second hydrogenation reactor 9, usually greater than 0% and less than or equal to 50%.

[0059] The device of the utility model, in the first hydrogenation reactor 7 and the second hydrogenation reactor 9, different types of hydrogenation catalysts are selected according to process targets, and the pretreatment process is matched, so that different process targets can be achieved.

[0060] (1) for the process with butene-1 as the target, under mild conditions, diene (butadiene and alkyne) reacts with H2 to generate butene, and the hydrogenation catalyst is prepared by the method of patent CN104549247A;

[0061] (2) for the process with butene-2 as the target, such as alkylation, 1-butene isomerization catalyst can also be selected, and the selected catalyst can remove butadiene while isomerizing a large amount of butene-1 into butene-2, and the hydrogenation catalyst is prepared by the method of patent ZL98110280.8.

[0062] Obviously, the above specific embodiments are only examples for clearly illustrating, and not limited to the specific embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the specific embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. A C4 light hydrocarbon pretreatment device, characterized in that, include: A pre-fractionation tower (3) is provided with a feed inlet for mixing C4 (1) into the pre-fractionation tower (3). The pre-fractionation tower (3) is provided with a first outlet and a second outlet. The first outlet is used for discharging heavy components (18), and the second outlet is used for discharging de-heavy C4 (2). The coalescer (4) has its inlet connected to the second outlet of the pre-fractionation tower (3) via a pipe. A hydrogenation reactor (7) is provided, the inlet of which is connected to the outlet of the coalescer (4) via a pipe, and a first hydrogen inlet is provided on the pipe connecting the hydrogenation reactor (7) and the coalescer (4). The dehydrogenation tower (11) has a first feed port connected to the outlet of the first-stage hydrogenation reactor (7) via a pipeline. The dehydrogenation tower (11) is provided with a first outlet and a second outlet. The first outlet is used for purifying C4 (17) for discharge, and the second outlet is used for mixing light hydrocarbons (12) for discharge. The condenser (13) has its inlet connected to the second outlet of the dehydrogenation tower (11) via a pipe. The reflux tank (14) has its inlet connected to the outlet of the condenser (13) via a pipe. The reflux tank (14) has three outlets: one outlet for discharging sediment (16), one outlet for discharging non-condensable steam (15), and one outlet for discharging liquid-phase C4.

2. The C4 light hydrocarbon pretreatment apparatus according to claim 1, characterized in that, The hydrogenation reactor (7) contains two catalyst beds, upper and lower, and a second hydrogen inlet is provided in the middle of the hydrogenation reactor (7).

3. The C4 light hydrocarbon pretreatment device according to claim 1, characterized in that, The hydrogenation reactor (7) is filled with a 1-butene isomer catalyst.

4. The C4 light hydrocarbon pretreatment apparatus according to claim 1, characterized in that, It also includes a two-stage hydrogenation reactor (9), the inlet of which is connected to the outlet of the first-stage hydrogenation reactor (7) via a pipeline, and the outlet of the two-stage hydrogenation reactor (9) is connected to the first inlet of the dehydrogenation tower (11). Furthermore, a third hydrogen inlet is provided on the pipeline connecting the first-stage hydrogenation reactor (7) and the second-stage hydrogenation reactor (9).

5. The C4 light hydrocarbon pretreatment apparatus according to claim 4, characterized in that, The two-stage hydrogenation reactor (9) contains two catalyst beds, upper and lower, and a fourth hydrogen inlet is provided in the middle of the two-stage hydrogenation reactor (9).

6. The C4 light hydrocarbon pretreatment apparatus according to claim 4, characterized in that, A water cooler is installed between the first-stage hydrogenation reactor (7) and the second-stage hydrogenation reactor (9).

7. The C4 light hydrocarbon pretreatment apparatus according to claim 4, characterized in that, The two-stage hydrogenation reactor (9) is filled with a catalyst that is 1-butene isomer.

8. The C4 light hydrocarbon pretreatment apparatus according to claim 1, characterized in that, It also includes a wastewater treatment device, which is connected to the discharge port of the return tank (14) for discharging sediment (16) via a pipeline to treat the sediment (16).

9. The C4 light hydrocarbon pretreatment apparatus according to claim 1, characterized in that, The discharge port for non-condensable steam (15) is connected to the flare or gas pipeline via a pipe.

10. The C4 light hydrocarbon pretreatment apparatus according to claim 1, characterized in that, The discharge port for liquid C4 is connected to the second inlet of the dehydrogenation tower (11), and a portion of the liquid C4 is returned to the top of the dehydrogenation tower (11) as reflux. It is also connected to the inlet of the product tank area, and another portion of the liquid C4 is discharged to the product tank area.

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