CN215085153U

CN215085153U - Special filtering equipment for oxidation system of maleic anhydride device

Info

Publication number: CN215085153U
Application number: CN202120977656.4U
Authority: CN
Inventors: 蒲叶学; 徐彦秋
Original assignee: Zibo Hai Yi Fine Chemical Co ltd
Current assignee: Zibo Hai Yi Fine Chemical Co ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2021-12-10
Anticipated expiration: 2031-05-08

Abstract

The utility model belongs to the technical field of maleic anhydride apparatus for producing, concretely relates to special filtration equipment of maleic anhydride device oxidation system, including the fixed bed reactor, first gas cooler and the second gas cooler that connect gradually, the lower part of second gas cooler be equipped with filtration equipment, filtration equipment includes one-level filter equipment, second grade filter equipment and tertiary filter equipment from inside to outside in proper order. The utility model discloses increase filtration equipment in second gas cooler lower part space, can effectually filter the cubic organic matter that forms such as by-product acetic acid, acrylic acid and a small amount of cocatalyst and catalyst powder and block, effectually prevent that these organic matters from entering into solvent system and blockking up plate heat exchanger and pump filter, ensure the even running of device, can switch the synchronous clearance of cycle with the second gas cooler simultaneously, reduced the safe risk that the clearance switched and brought, ensured the safe long period even running of device.

Description

Special filtering equipment for oxidation system of maleic anhydride device

Technical Field

The utility model belongs to the technical field of maleic anhydride apparatus for producing, concretely relates to special filtration equipment of maleic anhydride device oxidation system.

Background

With the great increase of benzene price in the international market, the cost of producing maleic anhydride by the benzene process is much higher than that of the n-butane process, and europe, japan, korea and other countries close benzene process plants with low capacity. As the difference between benzene and n-butane is larger, the production cost of the maleic anhydride by the benzene method is 3000 yuan/t higher than that of the maleic anhydride by the n-butane method in 2005 in China. From the aspects of production cost and environmental protection, the conversion of benzene into n-butane as a raw material for producing maleic anhydride in China is a necessary trend. According to domestic market analysis, the apparent consumption of maleic anhydride in China is increasing continuously, in order to meet the increasing market demand of maleic anhydride as a basic organic raw material and processing production thereof, the synthesis of maleic anhydride industry is changed from benzene method synthesis to n-butane method synthesis, the production capacity of the n-butane method accounts for 80% of the total production capacity of the maleic anhydride, and the method is mainly used for a maleic anhydride device by the n-butane method.

A typical process for preparing maleic anhydride by using a normal butane fixed bed oxidation method is that normal butane and air are mixed and enter a fixed bed reactor, oxidation reaction is carried out on a catalyst bed layer to obtain gas containing maleic anhydride, liquid maleic anhydride is obtained through solvent absorption, desorption and refining, and flaky solid commodity maleic anhydride is obtained through sheeting.

The core of the maleic anhydride production process is a reaction process, and the main principle of the process is that raw materials of n-butane and air are fully mixed according to a certain proportion and then enter a reactor, and high-temperature heat release and gas-solid phase oxidation reaction are carried out in a tube nest filled with a certain amount of catalysts taking V-P-O as a main component to generate maleic anhydride. Approximately 83% of the n-butane participated in the reaction as it passed through the reactor. The impurity in the normal butane raw material is mainly isobutane, almost 100 percent of isobutane and other hydrocarbons participate in the side reaction to be converted into CO and CO₂And H₂And O. A small amount of acetic acid, acrylic acid, etc. is also produced in the reactor.

Air at normal temperature and normal pressure is filtered by an air filter, compressed by an electric blower unit and heated to 160 ℃ by an air heater. The raw material n-butane liquid is vaporized by an evaporator and then heated to 120 ℃ by a heater. Superheated n-butane gas and air are mixed into reaction gas with the concentration of 1.8-2.0 mol%, the reaction gas enters a vertical tube/shell type reactor, and a molten salt mixture is adopted to be circulated in a reciprocating manner through a molten salt pump in the shell pass of the reactor to serve as a cooling medium; the reaction gas enters the tube pass to carry out oxidation reaction under the action of the catalyst, and the cocatalyst is added in the reaction process. The heat of reaction is removed by the molten salt, and a portion of the molten salt passes through the shell side of the molten salt cooler to produce and cool steam by heat exchange with the boiler water of the molten salt cooler tubes. The reactor temperature is controlled by controlling the flow of molten salt through the molten salt cooler. The reacted hot reaction gas is cooled by the tube pass of the first gas cooler and the second gas cooler and then sent to the absorption process. Boiler water in the shell pass of the first gas cooler and the second gas cooler is heated and partially gasified, and steam generated in the molten salt cooler is separated from a steam packet to be superheated and then is sent to other devices to be used as a heat source.

The reaction product gas from the autoxidation step enters an absorption and desorption system. Absorbing maleic anhydride by solvent DBP, resolving maleic anhydride from DBP, and delivering waste gas of an absorption section to a tail gas treatment system. The crude maleic anhydride produced by the absorption and desorption system enters a maleic anhydride refining system for further refining, and the specification requirement of a finished product is met. The resolved DBP solvent needs to be continuously washed to remove impurities, when the concentration of the impurities is high, the system can be blocked, the DBP solvent resolved by the absorption and resolution system enters a solvent treatment system, and the treated solvent returns to the absorption system.

According to the summary of the actual production and operation of the device, the hot reaction gas after reaction is cooled by the tube pass of the first gas cooler and the second gas cooler, the temperature of the hot reaction gas is reduced to 150-160 ℃, the hot reaction gas is sent to an absorption process to be the optimal temperature, but the hot reaction gas is converted into CO and CO through side reaction in the reactor₂And H₂O and byproducts such as acetic acid, acrylic acid and a small amount of cocatalyst, catalyst powder and the like in the second gas cooler tube pass at the temperature rangeThe wall and the inner wall of the pipeline from the subsequent reaction gas to the absorption tower form blocky organic matters. Along with the continuous formation and adhesion of the blocky organic matters, the heat exchange effect of the second gas cooler is poor, and the switching cleaning period of the second gas cooler is 35-45 days generally. However, these organic lumps adhering to the inner wall of the pipeline are carried to the solvent system for subsequent absorption and desorption by the continuous impact of the reaction gas, and especially, these organic lumps adhering to the inner wall of the pipeline are largely dropped off and carried to the solvent system with the change of temperature and wind during each switching of the second gas cooler and the device start-up, resulting in a solvent system for the absorption and desorption section (the solvent circulation is very large, and can reach 850m at maximum)³H,) clogging of multiple plate heat exchangers and pump filters, which seriously affects the smooth operation of the plant and even can lead to plant downtime.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: the defects of the prior art are overcome, the special filtering equipment for the oxidation system of the maleic anhydride device is provided, blocky organic matters formed by-products of acetic acid, acrylic acid, a small amount of cocatalyst, catalyst powder and the like can be effectively filtered and blocked, the organic matters are effectively prevented from entering a solvent system to block a plate heat exchanger and a pump filter, and the stable operation of the device is ensured.

The utility model discloses an adopt following technical scheme to realize:

the special filtering equipment for the oxidation system of the maleic anhydride device comprises a fixed bed reactor, a first gas cooler and a second gas cooler which are sequentially connected, wherein the lower part of the second gas cooler is provided with the filtering equipment, and the filtering equipment sequentially comprises a primary filtering device, a secondary filtering device and a tertiary filtering device from inside to outside.

Preferably, the primary filtration device comprises pall ring packing and a 5 mesh filter element.

Preferably, the secondary filtration device is a 10 mesh filter cartridge.

Preferably, the three-stage filtering device is a 20-mesh filter element.

Compared with the prior art, the beneficial effects of the utility model are as follows:

1. the utility model discloses according to the actual conditions and the characteristics make full use of existing equipment and the space of present device, equipment, increase filtration equipment in second gas cooler lower part space, can effectually filter the cubic organic matter that forms such as by-product acetic acid, acrylic acid and a small amount of cocatalyst and catalyst powder and block, effectually prevent that these organic matters from entering into solvent system and blockking up plate heat exchanger and pump filter, ensure the even running of device.

2. The utility model discloses filtration equipment can switch the synchronous clearance of cycle with the second gas cooler, has reduced the safe risk that the clearance switch brought, has ensured the safe long period even running of device.

Drawings

Fig. 1 is a schematic structural view of the present invention;

in the figure: 1. a fixed bed reactor; 2. a first gas cooler; 3. a second gas cooler; 4. a filtration device; 5. a primary filtration device; 6. a secondary filtration device; 7. and a third-stage filtering device.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the special filtering equipment for the oxidation system of the maleic anhydride device comprises a fixed bed reactor 1, a first gas cooler 2 and a second gas cooler 3 which are sequentially connected, wherein a filtering equipment 4 is arranged at the lower part of the second gas cooler 3, and the filtering equipment 4 sequentially comprises a primary filtering device 5, a secondary filtering device 6 and a tertiary filtering device 7 from inside to outside.

Wherein: the first-stage filtering device 5 is a pall ring filler and a 5-mesh filter element, the second-stage filtering device 6 is a 10-mesh filter element, and the third-stage filtering device 7 is a 20-mesh filter element.

Of course, the above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and the technical field of the present invention is equivalent to the changes and improvements made in the actual range of the present invention, which should be attributed to the patent coverage of the present invention.

Claims

1. The utility model provides a special filtration equipment of maleic anhydride device oxidation system, includes fixed bed reactor (1), first gas cooler (2) and second gas cooler (3) that connect gradually, its characterized in that: the lower part of the second gas cooler (3) is provided with a filtering device (4), and the filtering device (4) sequentially comprises a primary filtering device (5), a secondary filtering device (6) and a tertiary filtering device (7) from inside to outside.

2. The filtering apparatus special for the oxidation system of the maleic anhydride unit as set forth in claim 1, wherein: the primary filtering device (5) comprises pall ring packing and a 5-mesh filter element.

3. The filtering apparatus special for the oxidation system of the maleic anhydride unit as set forth in claim 1, wherein: the secondary filtering device (6) is a 10-mesh filter element.

4. The filtering apparatus special for the oxidation system of the maleic anhydride unit as set forth in claim 1, wherein: the third-stage filtering device (7) is a 20-mesh filter element.