CN207143157U - A kind of process unit of methanol and methyl acetate production methyl methacrylate - Google Patents

Abstract

The utility model discloses a kind of methanol and the process unit of methyl acetate production methyl methacrylate, by this process unit, directly using methanol as reaction raw materials, and by the parsing of aldol(s) obtain formaldehyde gas and form mixed gas stabilizing with methyl acetate simultaneously and deliver to fixed bed reactors progress catalytic reaction to obtain target product MMA.The process is phase mixed system, and at utmost reduce water brings the auto polymerization with formaldehyde into so as to improve target product MMA yield and product quality；Reaction raw materials wide material sources of the present utility model simultaneously, it is more cheap with respect to paraformaldehyde, formalin and dimethoxym ethane raw material, so as to reduce product cost.

Description

A kind of process unit of methanol and methyl acetate production methyl methacrylate

Technical field

The utility model belongs to field of energy and chemical technology, more particularly to methyl methacrylate MMA process units and Process.

Background technology

Methyl methacrylate (MMA) is mainly used in crowded glass, polyvinyl chloride auxiliary agent, clear and rich production intermediate, uses Way is extensively.The production method of methyl methacrylate mainly has acetone cyanohydrin hair (ACH methods), ethylene process (BASF methods), different at present Oxygenizement of butene, improve Acetone cyanohydrin method (MGC methods) and olefine aldehydr method (Alpha methods), wherein ACH methods in the presence of with acrylonitrile it is supporting, The shortcomings that raw material is limited, by-product ammonium hydrogen sulfate；Ethylene process (BASF methods) process route is longer, technical monopoly, plant investment expense It is high；The relative monopolization of isobutylene oxidation law technology, isobutene raw material are limited；It is complicated to improve Acetone cyanohydrin method (MGC methods) route, equipment It is it is required that high；Olefine aldehydr method (Alpha methods) technical monopoly, the country does not apply.

China Patent Publication No. CN104513163A discloses one kind by methyl acetate and Formaldehyde Production methyl methacrylate The method of ester, using three-step approach, and addition condensation obtains methyl methacrylate in the presence of catalyst.But the first of this method The source of aldehyde raw material does not refer to and spoken frankly, and the source of formaldehyde raw material is essentially all formalin or by more at present Point solution such as polyformaldehyde or dimethoxym ethane obtains formaldehyde.If reduced using formalin as formaldehyde source due to the presence of water MMA yield, while can also improve catalytic reaction observable index；And paraformaldehyde or dimethoxym ethane decompose and be used as formaldehyde source, first Depolymerization just needs additionally to consume the energy, and causes process complications, improves product cost.

The content of the invention

Goal of the invention：For above-mentioned existing problem and shortage, the purpose of this utility model is to provide a kind of methanol With the method and process unit of methyl acetate production methyl methacrylate, the process costs are lower, and disposal of pollutants is less.

Technical scheme：In order to solve the above-mentioned technical problem, the utility model uses following technical scheme：A kind of methanol and vinegar The process unit of sour methyl esters production methyl methacrylate, including oxidation of formaldehyde device, absorption synthetic tower and vent gas treatment tower are conciliate Tower is analysed, the oxidation of formaldehyde device is provided with four vigour entrances, the outlet of the oxidation of formaldehyde device and the bottom inlet of absorption synthetic tower Pipeline is connected, and the top for absorbing synthetic tower and top further respectively have isooctanol entrance and offgas outlet, and described absorb is closed Organic phase extracting mouth and dilute formaldehyde recovery port, the offgas outlet and tail gas absorbed at the top of synthetic tower are additionally provided with into the bottom of tower Treating column is connected, and the organic phase extracting mouth for absorbing synthesis tower bottom is connected with the entrance in the middle part of Analytic Tower, the Analytic Tower Bottom exports provided with isooctanol, and the top and top of Analytic Tower further respectively have methyl acetate entrance and the outlet of MMA unstripped gas, institute State the outlet of MMA unstripped gas and be also connected with methyl methacrylate reactor and rectifying column in turn.

Preferably, the absorption synthetic tower includes extracting section, column plate section and packing section, the column plate successively from bottom to up Section is staggered for multiple bubble cap plates and formed, and the packing section is multistage packing section, and every grade of packing section is wrapped successively from bottom to up Column plate space, packing layer, distributor and spray equipment are included, the column plate is provided with vapor riser, the side in the column plate space Pipeline pump is connected with wall and is circulated with spray equipment and is connected.

Preferably, also it is sequentially provided with evaporator, blender and filtering before four vigour entrances of the oxidation of formaldehyde device Device, the offgas outlet being connected with blender circulating line is additionally provided with the top of the vent gas treatment tower.

Beneficial effect：Compared with prior art, the utility model directly uses methanol as reaction raw materials, and passes through alcohol aldehyde The parsing of condensation product obtains formaldehyde gas and forms mixed gas stabilizing with methyl acetate simultaneously delivering to fixed bed reactors and urged Change reaction and obtain target product MMA.The process is phase mixed system, at utmost reduces the autohemagglutination brought into formaldehyde of water Close so as to improve target product MMA yield and product quality；Reaction raw materials wide material sources of the present utility model simultaneously are relatively more Polyformaldehyde, formalin and dimethoxym ethane raw material are more cheap, so as to reduce product cost.

Brief description of the drawings

Fig. 1 is that the flow for the method that methanol described in the utility model and methyl acetate produce methyl methacrylate is illustrated Figure.

Fig. 2 is the connection diagram of absorption synthetic tower and Analytic Tower described in the utility model；

Fig. 3 is the structural representation of packing section in absorption synthetic tower described in the utility model.

Wherein, evaporator 1, blender 2, filter 3, oxidation of formaldehyde device 4, absorption synthetic tower 5, vent gas treatment tower 6, heat exchange Device 7, circulating pump 8, Analytic Tower 9, packing section 51, filler 52, gas distributor 53, spray 54, tedge 55.

Embodiment

Below in conjunction with the accompanying drawings and specific embodiment, the utility model is furtherd elucidate, it should be understood that these embodiments are only used for Illustrate the utility model rather than limitation the scope of the utility model, after the utility model has been read, art technology Modification of the personnel to the various equivalent form of values of the present utility model falls within the application appended claims limited range.

Shown in Fig. 1, the method for alcohol and methyl acetate production methyl methacrylate of the present utility model, concrete technology step It is as follows：

(1) aoxidized using methanol as raw material in oxidator and formaldehyde raw material gas is prepared, during being somebody's turn to do, methanol liquid passes through The mode such as heating evaporation or gas sparging evaporation gasifies and with air and steam and tail gas after filtering, pre- in premixed device Heat is to 110 DEG C of formation quaternary gaseous mixtures, and oxidation obtains formaldehyde gas and adopted from oxidation of formaldehyde device bottom in oxidation of formaldehyde device Go out 5KPa, 150 DEG C or so of formaldehyde gas, and be sent into the bottom of follow-up absorption synthetic tower；The top of absorption synthetic tower has more Level packing section, bottom is then made up of multistage bubble cap plate.

(2) isooctanol material liquid is sent at the top at the same time absorbing synthetic tower, and control absorbs synthesis column bottom temperature and existed 70 ± 2 DEG C, tower top temperature is at 40 ± 2 DEG C.Formaldehyde gas rises upwards after bottom of towe entrance initially enters column plate section, in column plate section Mixing flow quantity containing isooctanol and formaldehyde and aldol(s) is advantageous to greatly the absorbing reaction of formaldehyde gas；Do not absorbed completely Formaldehyde gas continue to rise and fully contact absorption condensation reaction in packing section with the isooctanol material liquid having just enter into, it is simultaneously logical Cross external hanging type pipeline pump will in each layer filler mix hydrops be recycled in spray equipment from top to bottom spray after, pass through distributor Distribution is recycled into absorption formaldehyde gas again, so that it is guaranteed that formaldehyde gas fully absorbs；And the mixed liquor after absorbing reaction Further absorbed from upper strata packing section into lower floor's packing section.Because the aldol(s) of adsorption reaction is not soluble in water and density All it is that the organic phase of aldol(s) preferentially enters lower floor in each layer packing section less than the organic phase of water, and finally in bottom of towe Static layering, and produce by interface liquid level gauge the organic phase on upper strata in real time.In the step, column plate section using higher temperature and Larger fluid flow can effectively avoid the auto polymerization of formaldehyde gas, and when rising to packing section, contact surface is increased using filler Product finally on the premise of formaldehyde gas autohemagglutination is avoided, improves the absorption of formaldehyde isooctanol so as to heighten adsorption efficiency Efficiency.Packing section in synthetic tower is absorbed forms for multistage filler, as shown in figure 3, one-level filler includes what is set on column plate Tedge, tedge top is loads filler, and the upper surface for loading filler is liquid distribution trough, and the top of liquid distribution trough is then set Shower nozzle is equipped with, and the shower nozzle is by pipeline with the hydrops position UNICOM on column plate so that the hydrops on column plate is followed by circulating pump Ring delivers to shower nozzle ejection, so as to maximumlly improve absorption efficiency and Synthesis conversion.

(3) organic phase removes moisture in dehydrating tower, and control water content is to try to control below 1% and enters MMA Water content in catalytic tower reaction system, the presence of water is avoided to reduce MMA yield.Specifically having hemiacetal Mutually 110~110 DEG C of the control tower bottom temperature in column plate type dehydrating tower, tower top are less than the progress isolated tower of rectifying at 100 DEG C to machine Dilute formaldehyde of less than 20% concentration on top, and bottom of towe obtains anhydrous hemiacetal, and it is sent into follow-up Analytic Tower；

(4) organic phase by dehydration is then sent into the middle part of Analytic Tower, and analytically methyl acetate is sent at the top of tower Material liquid, organic phase in Analytic Tower hypomere and 160~200 DEG C occur parsings obtain formaldehyde gas and isooctanol liquid.With Methyl acetate material liquid progressively gasifies after tower top entrance simultaneously for this, and the feeding amount of methyl acetate makes the molar equivalent of parsing formaldehyde 1.2~2 times (more preferably 1.35 times), the formaldehyde gas of itself and rising is formed mixed gas stabilizing and depart from from isooctanol, The temperature control of tower top is at 70~100 DEG C, it is ensured that analytically tower bottom separation Posterior circle is sent into absorption synthetic tower to isooctanol liquid

(5) parsing column overhead obtains methyl acetate and the mixed gas stabilizing of formaldehyde is sent into MMA fixed bed reactors, is urging The lower hydrogenation of agent effect is condensed to yield methyl methacrylate.

Claims (3)

1. A kind of 1. process unit of methanol and methyl acetate production methyl methacrylate, it is characterised in that：Including oxidation of formaldehyde Device, absorption synthetic tower and vent gas treatment tower and Analytic Tower, the oxidation of formaldehyde device are provided with four vigour entrances, the oxidation of formaldehyde device Outlet with absorb synthetic tower bottom inlet pipeline be connected, it is described absorption synthetic tower top and top further respectively have it is different pungent Alcohol inlet and offgas outlet, the bottom for absorbing synthetic tower are additionally provided with organic phase extracting mouth and dilute formaldehyde recovery port, the suction The offgas outlet for folding into top of tower is connected with vent gas treatment tower, the organic phase extracting mouth for absorbing synthesis tower bottom and parsing Entrance connection in the middle part of tower, the parsing tower bottom export provided with isooctanol, and the top and top of Analytic Tower further respectively have vinegar The outlet of sour methyl esters entrance and MMA unstripped gas, the MMA unstripped gas outlet be also connected with turn methyl methacrylate reactor and Rectifying column.
2. 2. the process unit of methanol and methyl acetate production methyl methacrylate according to claim 1, it is characterised in that： It is multiple bubble cap plates that the absorption synthetic tower includes extracting section, column plate section and packing section, the column plate section successively from bottom to up It is staggered and forms, the packing section is multistage packing section, and every grade of packing section includes column plate space, filler successively from bottom to up Layer, distributor and spray equipment, the column plate are provided with vapor riser, pipeline pump are connected with the side wall in the column plate space And circulate and connect with spray equipment.
3. 3. the process unit of methanol and methyl acetate production methyl methacrylate according to claim 1, it is characterised in that： Evaporator, blender and filter, the vent gas treatment tower are also sequentially provided with before four vigour entrances of the oxidation of formaldehyde device Top be additionally provided with the offgas outlet being connected with blender circulating line.