CN205953887U - Preparation of dense methylal gathers process units of methoxy dimethyl ether - Google Patents

Abstract

The utility model discloses a preparation of dense methylal gathers process units of methoxy dimethyl ether uses methylal and concentration to be 50%~88% formalin as the raw materials, to take place the reaction and contained the reaction liquid that gathers methoxy dimethyl ether and unreacted formalin and methylal, reaction liquid is followed tower upper portion and is sent into the extraction tower after the dehydrogenation to carry out the countercurrent contact reaction with the extractant that gets into from tower bottom, the methoxy dimethyl ether that gathers in the reaction liquid is dissolved in and obtains organic looks in the extractant, the formalin with the layering takes place organically mutually, and the extraction is sent into in the cut fraction fractionating tower organically mutually, send into mutually organically and carry out the air distillation separation in the cut fraction fractionating tower, retrieve the extractant that obtains the top of the tower and the extraction of tower cauldron the degree of polymerization 2~8 gather the methoxy dimethyl ether. The utility model discloses the cost is reduced to it is low to have improved synthesis conversion and yield, just the utility model discloses having and well moving hot effect, can promote the reaction to go on by the efficient, the conversion degree have realized the controllability.

Description

A kind of dense dimethoxym ethane prepares the process unit of polymethoxy dimethyl ether

Technical field

This utility model belongs to chemical production technology and equipment technical field, relates generally to formaldehyde and prepares polymethoxy diformazan The Technology of ether.

Background technology

The feature of China's energy resource structure is：Rich coal, oil-poor, few gas, economic maintaining sustained and rapid growth is more next to energy demand Bigger, the contradiction of society, expanding economy and oil supply.Since 2009, crude oil in China external dependence degree is even Continue and exceed warning line in 6 years（50%）, have a strong impact on the energy strategy safety of China.From China's energy strategy safety, in conjunction with me State's primary energy structure feature, development Coal-based Liquid Fuel synthetic technology undoubtedly has strategic significance.In addition, China's methanol produces Can be seriously superfluous, exploitation Downstream Products of Methanol, extension Chemical Industry chain, all there is realistic meaning.

With science and technology and economic progress, city incity automobile quantity showed increased, and motor vehicle exhaust emission thing becomes One of major reason of city haze.Compared to gasoline, diesel oil has higher boiling point, and H/C mass ratio is low, therefore diesel combustion During the waste gas CO of discharge, oxynitride, particulate matter etc. more, the damage ratio gasoline causing is more serious.Therefore, improve bavin Oil firing efficiency, reduces disposal of pollutants, improving urban air-quality is environmental protection task important at present.

Polymethoxy dimethyl ether is a kind of universally acknowledged cleaning diesel oil component, its Cetane number >=70, not sulfur-bearing, no Containing aromatic hydrocarbons.Being added in diesel oil in 5%-20% ratio, it is possible to increase diesel cetane-number, promoting burning it will be apparent that reducing automobile The discharge of the harmful gass such as PM2.5, PM10, NOx, CO in tail gas.Due to the excellent properties of polymethoxy dimethyl ether, it synthesizes work Skill has become the heat subject of domestic and international research.

At present, polymethoxy dimethyl ether is with one or more of methanol or dimethoxym ethane and formalin/tri- mostly Polyformaldehyde/paraformaldehyde reacts generation under the catalytic action of acidic catalyst.Using metaformaldehyde or paraformaldehyde, technique Long flow path and complexity, construction costs increases considerably, and production cost remains high.And adopt formalin relatively inexpensive, one Kind first refine as formaldehyde gases for formalin, with gas phase participation synthetic reaction；A kind of first concentrate as dense for formalin Formaldehyde, participates in synthetic reaction with concentrated formaldehyde.The preparation of gaseous formaldehyde need to be through extraction, dehydration, three technical processs of parsing, and formaldehyde is Become gas phase eventually, energy consumption is larger, and be related to another extractant, extractant has certain loss.The preparation of concentrated formaldehyde only needs The lower evaporation of decompression just can complete, and operation is relatively easy, and concentrated formaldehyde carries out synthetic reaction for raw material, for full liquid phase reactor, reacts bar Part is gentle, and yield is higher.By adjusting the charging proportioning of concentrated formaldehyde and dimethoxym ethane, product degree of polymerization distribution can be optimized, obtain More DMM3-5.Test proves that DMMn3-5 is the DMMn product being best suitable for doing diesel fuel additives.

Content of the invention

Goal of the invention：For above-mentioned problem and defect, this utility model provides a kind of concentrated formaldehyde and prepares poly- first The process of epoxide dimethyl ether and device, solve at present with bring in paraformaldehyde/trimerization production process high cost, conjunction Become conversion ratio and the low problem of yield, and this utility model have good move thermal effect, reaction can be efficiently promoting and carry out, conversion Degree achieves controllability.

Technical scheme：For achieving the above object, this utility model employs the following technical solutions：One kind is based on above-mentioned work The dense dimethoxym ethane of process prepares the process unit of polymethoxy dimethyl ether, including the reactor being sequentially connected, lightness-removing column, extraction Tower, extractant recovery tower, one-level treating column and two grades for the treatment of columns, the top of described reactor is provided with mixed material charging aperture, institute State mixed material charging aperture and be connected with mixing liquid distributor, the stage casing of described reactor is filled with solid acid resin catalyst, institute State reactor bottom to be provided with reactant liquor outlet and be connected with lightness-removing column.

Preferably, described reactor is fluid bed.

Preferably, described extraction tower is packed tower.

Beneficial effect：Compared with prior art, this utility model has advantages below：Solve at present with paraformaldehyde/ The low problem of the high cost, Synthesis conversion and the yield that bring in trimerization production process, and this utility model has and good moves heat Effect, can be efficiently promoting reaction and carry out, transforming degree achieves controllability.

The reaction of the fluidized-bed reactor in this utility model have more more preferable heat transfer property than fixed bed reactors, no matter It is radially or axial temperature Temperature Distribution is all visibly homogeneous, due to the strenuous exercise of bed, eliminate the layer near heat-transfer area Laminar boundary layer is far above the other types reactor such as fixed bed and blank pipe so that it moves the thermal efficiency.

This utility model adopts the formalin of higher concentration to replace with the solid such as paraformaldehyde or formaldehyde of living scattered simultaneously Raw material, combined coefficient and high income；Balanced using the forward reaction that the formalin of high concentration can promote polyreaction simultaneously.

Brief description

Fig. 1 is the structural representation of the process unit that dense dimethoxym ethane described in the utility model prepares polymethoxy dimethyl ether.

Wherein, reactor 1, lightness-removing column 2, extraction tower 3, extractant recovery tower 4,5, two grades for the treatment of columns 6 of one-level treating column.

Specific embodiment

Below in conjunction with the accompanying drawings and specific embodiment, it is further elucidated with this utility model it should be understood that these embodiments are only used for This utility model is described rather than limits scope of the present utility model, after having read this utility model, art technology Personnel all fall within the application claims limited range to the modification of the various equivalent form of values of the present utility model.

As shown in figure 1, the synthesis of this utility model polymethoxy dimethyl ether and separating-purifying device, including reactor, take off gently Tower, extraction tower, extractant recovery tower, DMM2 product tower, DMM3 ~ 5 product tower.Wherein：

Its version of described reactor is not limited to fluid bed or fixed bed, for full liquid phase reactor, with respect to solid-liquid reaction, Reactant contact surface is bigger, and reaction efficiency is high, high income.Reactor head arranges concentrated formaldehyde-dimethoxym ethane mixed solution charging aperture, And carry out feeding mixed liquor distribution by liquid distribution trough；Reactor stage casing loads solid acid resin catalyst, reactor bottom It is provided with reactant liquor outlet, and be connected with lightness-removing column.

Described reactor feedstocks adopt concentrated formaldehyde and liquid dimethoxym ethane.Concentrated formaldehyde and liquid dimethoxym ethane are in static mixer Add from reactor head after uniformly mixing in proportion, through solid acid resin catalyst, reach reactor bottom reactant liquor and go out Mouthful.Shifting hot facility can be set in reactor reaction section as cooled down using outer circulation or increasing cooling tube, but this is not required, excellent Choosing is not provided with moving hot facility.

Described lightness-removing column charging aperture coupled reaction device bottom reactant liquor discharging opening, reactant liquor removes first contracting in lightness-removing column Aldehyde.This tower top atmospheric operation, tower top setting condenser and return tank, reflux ratio preferably 1 ~ 2.Tower top obtains pure component dimethoxym ethane. Tower reactor obtains the reactant liquor without dimethoxym ethane.

Then the reactant liquor without dimethoxym ethane is sent in extraction tower and carry out extractive reaction.Described extraction tower adopt filler or Person's plank frame, preferred filler tower.Reactant liquor is added by extraction tower top, and extractant diisopropyl ether adds from extraction tower bottom, Reactant liquor and diisopropyl ether counter current contacting, the density due to diisopropyl ether is gently gradually turned with density contrast from top to down upwards by bottom The reactant liquor moving carries out uninterrupted counter current contacting, and during being somebody's turn to do, DMMn constantly extracts and is transferred to organic faciess, and formalin Aqueous phase then constantly sinks, and realizes expiring the uninterrupted separation of the extraction of continuous extraction and upper layer of extraction liquid under liquid status, effect in tower Rate is higher.Should during diisopropyl ether be light materials, can DMMn effectively in extractive reaction liquid, and there is not chemistry instead with DMMn Answer, and follow-up dehydrogenation separates and is easier.

The Organic substance based on DMMn in reactant liquor is dissolved in extractant, and the water in reactant liquor and formaldehyde cannot be dissolved in In extractant, due to there is obvious density contrast between them, therefore produce noted phase separation phenomena in tower, highly controlled by boundary System extraction upper liquid and subnatant.Subnatant is the aqueous solution mainly containing formaldehyde；Upper liquid is mainly to contain DMM2 ~ 8 component and extraction Take the organic faciess of agent component, upper liquid discharging opening is connected with extractant recovery tower charging aperture.

Described extractant recovery tower charging connects extraction tower upper liquid discharging.It should be noted that the separation time that extractant reclaims Sequence is not fixing, and it is relevant with the extractant species adopting, and can reclaim extractant for high boiling extractant and put After product tower.Preferably extractant recovery tower is after extraction tower.Extractant recovery tower adopts filler or plate column, normal pressure Operation, tower top adopts condenser and return tank, preferably reflux ratio 1 ~ 4. overhead extraction extractant material, and kettle liquid obtains product material DMM2~8.

According to described, kettle liquid product feeding DMM2 product.This tower adopts filler or plate column, atmospheric operation, and tower top is adopted With condenser and return tank, by controlling reflux ratio 0.5 ~ 2, produce the DMM2 product conforming to quality requirements.For not meeting matter The product that amount requires will be fed into the charging of this tower and again refines it is also possible to increase reflux ratio improve product quality.

According to described, DMM2 product tower bottoms is DMM3 ~ 8 product.This kettle liquid sends into DMM3 ~ 5 product tower.This tower is using filling out Material or plate column, decompression operation, preferred operations pressure 2 ~ 20kPa（Absolute pressure）, tower top adopts condenser and return tank, excellent Reflux ratio is selected to be that 0.5 ~ 2. tower top obtains DMM3 ~ 5 product.It should be noted that overhead product is not necessarily, different regions The different product of extraction quality can be controlled, such as, in the area that southern winter temperature is higher, the lowest temperature is also far above DMM6 Condensation point, suitably can produce part DMM6, more preferable blended diesel component.For northern area, then on the contrary, need to control and produce As far as possible few DMM6 is contained, it is to avoid wherein contain high condensation point blend component in product.

Preferably, extractant can also adopt and normal hexane.Most preferably adopt normal hexane, due to relative density The counter current contacting of minimum, extractant and reactant liquor is more violent, and the DMMn therefrom extracting is more thorough, has more preferably separating effect.

Claims (3)

1. a kind of dense dimethoxym ethane prepare polymethoxy dimethyl ether process unit it is characterised in that：Including the reaction being sequentially connected Device, lightness-removing column, extraction tower, extractant recovery tower, one-level treating column and two grades for the treatment of columns, the top of described reactor is provided with mixing Material inlet, described mixed material charging aperture is connected with mixing liquid distributor, and the stage casing of described reactor is filled with solid acid Resin catalyst, described reactor bottom is provided with reactant liquor outlet and is connected with lightness-removing column.

2. according to claim 1 dense dimethoxym ethane prepare polymethoxy dimethyl ether process unit it is characterised in that：Described anti- Device is answered to be fluid bed.

3. according to claim 1 dense dimethoxym ethane prepare polymethoxy dimethyl ether process unit it is characterised in that：Described extraction Tower is taken to be packed tower.