Maleic anhydride production device based on n-butane recovery

Abstract

The utility model discloses a maleic anhydride production device based on n-butane recovery, maleic anhydride production device is through setting up humidifier, condenser and gas -liquid separator on tail gas pipeline and completes deacidification after adsorbing CO through adsorption device, and the purity of tail gas n-butane is improved, and the recycling is used for circulating feed, solves the raw material waste and the defect of producing environmental protection pressure of prior art, guarantees the normal production of maleic anhydride, has realized the cost reduction and benefit increase.

Description

Technical Field

[0001] This utility model relates to the chemical industry, specifically to a maleic anhydride production device based on n-butane recovery. Background Technology

[0002] Existing maleic anhydride units using n-butane oxidation processes oxidize n-butane with air to produce maleic anhydride. The conversion rate of n-butane in the reactor is about 85%, leaving 15% of the n-butane unreacted. In most units, after the maleic anhydride is absorbed by the reaction gas in an absorption tower, the unreacted n-butane is directly discharged into the incinerator for combustion along with the tail gas. This not only results in a large waste of n-butane but also increases the unit's tail gas emissions.

[0003] Therefore, it is necessary to design a maleic anhydride production unit based on n-butane recovery to realize the recycling and utilization of n-butane and solve the shortcomings of existing technologies that waste raw materials and create environmental pressure. Utility Model Content

[0004] The purpose of this invention is to provide a maleic anhydride production device based on n-butane recovery, which solves the problems of raw material waste and environmental pressure caused by the recycling of n-butane in existing technologies.

[0005] To achieve the above objectives, the solution of this utility model is as follows:

[0006] A maleic anhydride production apparatus based on n-butane recovery includes a batching unit, an oxidation reactor, and a post-treatment unit connected in sequence. The post-treatment unit is used to separate products and tail gas. The tail gas output end of the post-treatment unit is connected in sequence to a humidifier, a condenser, and a gas-liquid separator. The gas output end of the gas-liquid separator is connected to the batching unit via an adsorption device. The adsorption device is used to adsorb CO.

[0007] Furthermore, the adsorption device is provided in several units and arranged in parallel.

[0008] Furthermore, the batching unit includes an air compressor, a steam generator, and a butane vaporizer, each connected to a mixer, which is connected to an oxidation reactor.

[0009] Furthermore, a detector is installed between the batching unit and the oxidation reactor.

[0010] Furthermore, the output end of the air compressor is connected to a heater; the output end of the steam generator is connected to a humidifier; the output end of the heater is connected to the humidifier, and the output end of the humidifier is connected to a mixer.

[0011] Furthermore, the output end of the adsorption device is equipped with a detector.

[0012] Furthermore, the post-processing unit includes an absorption tower, a stripping tower, and a distillation tower connected in series; the oxidation reactor is connected to the lower part of the absorption tower; the bottom of the absorption tower is connected to the upper part of the stripping tower, the lower part of the stripping tower is connected to the lower part of the distillation tower, and maleic anhydride is collected from the lower part of the distillation tower; the tops of the absorption tower and the stripping tower are respectively connected to a humidifier.

[0013] Preferably, a second condenser is provided between the oxidation reactor and the absorption tower.

[0014] Preferably, the tops of the absorption tower and the stripping tower are respectively connected to the incinerator.

[0015] Preferably, the desorption output of the adsorption device is connected to the incinerator.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] The production device described in this utility model improves the purity of n-butane in the tail gas by setting up a humidifier, condenser and gas-liquid separator on the tail gas pipeline to remove acid, and then adsorbing CO with an adsorption device and recycling it for use as feed. This solves the defects of existing technology that waste raw materials and create environmental pressure, ensures the normal production of maleic anhydride, and achieves cost reduction and efficiency improvement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an overall maleic anhydride production device based on n-butane recovery, which is provided for this utility model.

[0019] The attached figures are labeled as follows:

[0020] AC1, Air compressor; AT1, Absorption tower; C1, Condenser 1; C2, Condenser 2; D1, Detector 1; D2, Detector 2; DT1, Distillation tower; E1, Heater 1; E2, Vaporizer; E3, Heater 2; H1, Humidifier 1; H2, Humidifier 2; LS1, Gas-liquid separator; M1, Mixer; GA1, Adsorption unit; RTO1, Incinerator; R1, Oxidation reactor; S1, Stripping tower; SG1, Steam generator. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0024] In one embodiment, such as Figure 1 As shown, a maleic anhydride production apparatus based on n-butane recovery is proposed, comprising a batching unit, an oxidation reactor R1, and a post-treatment unit connected in sequence. The post-treatment unit is used to separate products and tail gas. The tail gas output end of the post-treatment unit is equipped with a n-butane recovery unit, comprising a humidifier-H1, a condenser-C1, and a gas-liquid separator LS1 connected in sequence. The gas output end of the gas-liquid separator LS1 is connected to the batching unit via an adsorption device GA1. The adsorption device GA1 is used to adsorb CO.

[0025] In the above embodiments, by installing a humidifier H1 on the exhaust gas pipeline, the small amounts of acrylic acid, acetic acid, and maleic anhydride present in the exhaust gas can be dissolved in advance. Then, the components are condensed by a condenser C1 and separated by a gas-liquid separator LS1 to achieve effective separation of the above components and water. The CO in the exhaust gas is then adsorbed by an adsorption device to improve the purity of n-butane, which is then recovered for recycling and feed, reducing the impact on normal reactions. This also solves the defects of existing technologies that waste raw materials and create environmental pressure.

[0026] In the above embodiments, the n-butane recovery unit contains N2 while recovering n-butane. N2, as an explosion-proof gas, can effectively compress the explosion limit range of the mixed raw material gas through the high N2 concentration in the circulating tail gas, which is extremely advantageous for the fixed-bed n-butane oxidation to maleic anhydride process.

[0027] In a preferred embodiment, the adsorption device GA1 is provided in several units and connected in parallel, which can be switched for use; the adsorption device GA1 is a common isobaric adsorption device, filled with CO adsorbent, such as CuCl.

[0028] In a preferred embodiment, the batching unit includes an air compressor AC1, a steam generator SG1, and a butane vaporizer, all connected to a mixer M1, which is connected to an oxidation reactor R1. A detector D1 is installed between the mixer M1 and the oxidation reactor R1 to ensure that the feed ratio meets the requirements for high reaction conversion rate by detecting and analyzing the content of butane and water online.

[0029] In a preferred embodiment, the output of the air compressor AC1 is connected to a heater E1; the output of the steam generator SG1 is connected to a humidifier H2; the output of the heater E1 is connected to the humidifier H2, and the output of the humidifier H2 is connected to the mixer M1. The butane vaporizer includes a vaporizer E2 and a heater E3 connected to it. The vaporizer E2 is used to vaporize liquid n-butane, and the heater E3 preheats the n-butane before it enters the mixer M1 for mixing.

[0030] In a preferred embodiment, the output end of the adsorption device GA1 is equipped with a detector D2, which is used to analyze the content of butane and water in the treated tail gas online. This can be combined with controlling the new feed to meet the raw material ratio requirements of the catalytic oxidation reaction and improve the reaction conversion rate.

[0031] In the above embodiments, the oxidation reactor R1 is filled with a common catalyst, such as a common VPO catalyst. The detectors D1 and D2 are respectively equipped with probes for detecting n-butane and water content. The n-butane detection probe is a type of TD500S-C4H10 online butane detector probe. The feed ratio of water and n-butane can be controlled by interlocking the feed valves at the steam generator SG1 and the butane vaporizer end with the probes.

[0032] In a preferred embodiment, the post-processing unit includes an absorption tower AT1, a stripping tower S1, and a distillation tower DT1 connected in series; the oxidation reactor R1 is connected to the lower part of the absorption tower AT1; the bottom of the absorption tower AT1 is connected to the upper part of the stripping tower S1, the lower part of the stripping tower S1 is connected to the lower part of the distillation tower DT1, and maleic anhydride is collected from the upper part of the distillation tower DT1; the tops of the absorption tower AT1 and the stripping tower S1 are respectively connected to a humidifier H1. The absorption tower AT1 absorbs the product obtained from the oxidation reaction using a solvent method. The absorbed product enters the stripping tower S1 to remove light components, and then enters the distillation tower DT1 to remove the solvent and collect the target product, maleic anhydride.

[0033] In a preferred embodiment, since the oxidation reaction process is at a high temperature, the product needs to be cooled down. Therefore, a condenser C2 is provided between the oxidation reactor R1 and the absorption tower AT1.

[0034] In a preferred embodiment, the tops of the absorption tower AT1 and the stripping tower S1 are also connected to the incinerator RTO1. The incinerator RTO1 can be set up synchronously with the n-butane recovery unit. For example, when multiple adsorption devices GA1 are regenerated at the same time, it is necessary to ensure the timely treatment of the tail gas. On the other hand, the incinerator RTO1 can appropriately discharge N2 to avoid excessive accumulation that would affect the reaction conversion rate.

[0035] In a preferred embodiment, the desorption output end of the adsorption device GA1 is connected to the incinerator RTO1 to incinerate the CO generated by heating and desorption of the packing material.

[0036] It is understood that the production equipment also includes other instruments, meters or valves installed in each unit or pipeline. Instruments and meters are used to monitor the status parameters of materials or unit devices, valves are used to control the start and stop or flow of materials, and power pumps are used to provide power for material transfer. All of these are within the design scope of this solution and will not be elaborated here.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A maleic anhydride production apparatus based on n-butane recovery, characterized in that, The device includes a batching unit, an oxidation reactor (R1), and a post-treatment unit connected in sequence. The post-treatment unit is used to separate the product and the tail gas. The tail gas output end of the post-treatment unit is connected in sequence to a humidifier (H1), a condenser (C1), and a gas-liquid separator (LS1). The gas output end of the gas-liquid separator (LS1) is connected to the batching unit via an adsorption device (GA1). The adsorption device (GA1) is used to adsorb CO.

2. The maleic anhydride production apparatus according to claim 1, characterized in that, The adsorption device (GA1) is provided in several units and is arranged in parallel.

3. The maleic anhydride production apparatus according to claim 1, characterized in that, The batching unit includes an air compressor (AC1), a steam generator (SG1), and a butane vaporizer, which are connected to a mixer (M1), and the mixer (M1) is connected to an oxidation reactor (R1).

4. The maleic anhydride production apparatus according to claim 3, characterized in that, A detector (D1) is installed between the batching unit and the oxidation reactor (R1).

5. The maleic anhydride production apparatus according to claim 3, characterized in that, The output of the air compressor (AC1) is connected to heater one (E1); the output of the steam generator (SG1) is connected to humidifier two (H2); the output of heater one (E1) is connected to humidifier two (H2), and the output of humidifier two (H2) is connected to mixer (M1).

6. The maleic anhydride production apparatus according to claim 1, characterized in that, The adsorption device (GA1) is equipped with a detector (D2) at its output end.

7. The maleic anhydride production apparatus according to claim 1, characterized in that, The post-processing unit includes an absorption tower (AT1), a stripping tower (S1), and a distillation tower (DT1) connected in series; the oxidation reactor (R1) is connected to the lower part of the absorption tower (AT1); the bottom of the absorption tower (AT1) is connected to the upper part of the stripping tower (S1), the lower part of the stripping tower (S1) is connected to the lower part of the distillation tower (DT1), and maleic anhydride is collected from the lower part of the distillation tower (DT1); the tops of the absorption tower (AT1) and the stripping tower (S1) are respectively connected to a humidifier (H1).

8. The maleic anhydride production apparatus according to claim 7, characterized in that, A second condenser (C2) is provided between the oxidation reactor (R1) and the absorption tower (AT1).

9. The maleic anhydride production apparatus according to claim 7, characterized in that, The tops of the absorption tower (AT1) and stripping tower (S1) are respectively connected to the incinerator (RTO1).

10. The maleic anhydride production apparatus according to claim 9, characterized in that, The adsorption device (GA1) is connected to the desorption output terminal of the incinerator (RTO1).

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