CN104801354B

CN104801354B - The purification process of hydrogen-oxygen type tertiary amine oxide anion exchange resin, its preparation method and the NMMO aqueous solution

Info

Publication number: CN104801354B
Application number: CN201510166663.5A
Authority: CN
Inventors: 蔡剑; 程鹏; 荀红利; 李婷; 田玲; 侯松欣
Original assignee: China Textile Academy
Current assignee: China Textile Academy
Priority date: 2015-04-09
Filing date: 2015-04-09
Publication date: 2017-10-03
Anticipated expiration: 2035-04-09
Also published as: CN104801354A

Abstract

The invention provides the purification process of a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, its preparation method and the NMMO aqueous solution.The preparation method comprises the following steps：S1, carries out oxidation reaction by tertiary amine-type anion exchange resin, obtains tertiary amine oxide anion exchange resin；S2, tertiary amine oxide anion exchange resin and aqueous alkali are reacted, hydrogen-oxygen type tertiary amine oxide anion exchange resin is obtained.When being purified using above-mentioned resin to NMMO solution, impurity is not ended up on hydrogen-oxygen type tertiary amine oxide resin anion exchange resin, so as to make it have higher reusable edible characteristic；The removal efficiency of transition metal anion in the exchange efficiency and the NMMO aqueous solution of ion exchange resin can be significantly improved simultaneously, and improves the economy and security of Lyocell fiber production process.

Description

Hydrogen-oxygen type tertiary amine oxide anion exchange resin, its preparation method and the NMMO aqueous solution Purification process

Technical field

Field is manufactured the present invention relates to cellulose fiber by solvent method, it is cloudy in particular to a kind of hydrogen-oxygen type tertiary amine oxide The purification process of ion exchange resin, its preparation method and the NMMO aqueous solution.

Background technology

NMMO (N-methylmorpholine-N- oxides) aqueous solution is the high-quality solvent of cellulose, is often applied to cellulose fiber In the manufacturing process of dimension.Using NMMO as solvent, it is named as Lyocell fibres by dissolving fiber made from the method for cellulose Dimension.Lyocell fiber has high intensity, high-modulus, have good compatibility to skin and can be mixed with most fibers The advantages of spinning, and its manufactured also have nontoxic and free of contamination feature.

Cellulose dissolution is formed into mixed liquor in the NMMO solvents of high concentration, then crystallized above-mentioned mixed liquor in spinning Bath neutralizes water contact, and by crystallizing precipitation process, Lyocell fiber can be made.In above process, the NMMO of high concentration is molten Agent is diluted into the 5~30%NMMO aqueous solution.Because NMMO is expensive, in order to improve Lyocell fiber production process Economy realizes cycling and reutilization, it is necessary to reclaimed to NMMO.

NMMO solvents have also dissolved impurity contained in raw materials used pulp when dissolving cellulose.In addition, in order to keep Need to add a certain amount of additive in good dissolubility energy and spinning properties, above-mentioned NMMO solvents.When NMMO solvents are dilute When being interpreted into crystallization bath, it is molten that these impurity and additive and each metal ion species of hardware used contamination are all dissolved in NMMO In agent.And NMMO is tertiary amine oxide class material, with certain thermal sensitivity and unstable characteristic, in organic free radical catalysis or mistake Crossing in the presence of metal ion to decompose, and can be exploded when serious.Therefore, in Lyocell fiber preparation process In, it is breakneck using not purified NMMO solvents, and this danger not only exists only in course of dissolution, but also deposit It is solvent concentration and spinning process.

In the purification process of the existing NMMO aqueous solution, using the anion in ion-exchange desolvation and sun from Son, but this method is the drawbacks of have very big.

First drawback is that the ion exchange bed volume fraction of ion exchange resin is low, and with the extension of use time, Exchange effect worse and worse.Anion in processed Lyocell fiber crystallization bath is contained based on cellulose decomposition product There is a small amount of cellulose colloid, the particle diameter distribution of above-mentioned colloid is at 0.05~2 μm, it is difficult to be removed with filtering or membrane separation process.And This part colloid is proved to carry negative electrical charge, either cellulose decomposition product or cellulose colloid, the negative electricity entrained by it Lotus quantity is all considerably beyond one.Above-mentioned reason causes at the two with being easily adsorbed to tree during contacts ionic exchange resin On fat.In addition, after ion exchange end cycle, because adsorption strength is high, these adsorb the cellulose anion on resin With cellulose colloid it is difficult to be replaced completely, it is in black completely to eventually cause color of resin change and be deep to, and resin surface is blocked Plug to expansion is crushed, and resin exchange capacity such as gradually reduces at the phenomenon.

Second drawback is that the transition metal ions removal efficiency of ion exchange resin is low.Under normal circumstances, metal ion is Removed using cationic ion-exchange resin.But in actual moving process, due to adding when dissolving cellulose using NMMO solvents Add gallate (PG) as stabilizer, it can be with transition metal formation complex.For example, PG gives birth to ferric ion Dissolving fine with univalent copper ion generation PG-Cu-PG complexs, i.e. transition metal into PG-Fe-PG complexs, and PG The plain process of dimension generates complex with PG, and the structure of above-mentioned complex is as follows.

It can be seen that transition metal is not to exist with simple metal ion form in crystallization bath, but with organic Complex form is present.It can be taken off in transition metal with what complex anionic form was present using anion exchange resin Remove, but the transition metal existed in complex n-propyl form can not then be removed.Therefore, using common ion exchange Method, it is impossible to remove transition metal completely.These elements are remained in recycling design, into concentration and dissolving spinning system Afterwards, risk can be caused to system, blast can be caused when serious.

Presence in view of the above problems, it is necessary to develop one kind during NMMO purifying aqueous solutions, anion exchange Efficiency high, resin cyclic utilization rate height and the high ion exchange resin of transition metal ions removal efficiency.

The content of the invention

It is a primary object of the present invention to provide a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, its preparation method and The purification process of the NMMO aqueous solution, to solve during NMMO purifying aqueous solutions, the anion of existing ion exchange resin is handed over The problem of changing low efficiency, low cyclic utilization rate and low transition metal removal efficiency.

To achieve these goals, according to an aspect of the invention, there is provided a kind of hydrogen-oxygen type tertiary amine oxide anion The preparation method of exchanger resin, comprises the following steps：S1, carries out oxidation reaction by tertiary amine-type anion exchange resin, obtains oxygen Change tertiary amine anion exchange；S2, tertiary amine oxide anion exchange resin and aqueous alkali are reacted, and obtain the oxidation of hydrogen-oxygen type Tertiary amine anion exchange.

Further, step S1 includes：S11, water and tertiary amine-type anion exchange resin are mixed, and adjust pH to 5~ 9, obtain question response liquid；S12, after question response liquid is mixed with oxidant, carries out oxidation reaction, obtains the friendship of tertiary amine oxide anion Change resin.

Further, oxidant is selected from the group of hydrogen peroxide, hypochlorite, chlorate, bichromate and perchlorate composition In one or more；Preferably, oxidant is selected from hydrogen peroxide and/or hypochlorite.

Further, the molal quantity of oxidant accounts for 1.1~2 times of the exchange capacity of tertiary amine-type anion exchange resin.

Further, in step S12, the reaction temperature of oxidation reaction is 60~105 DEG C, and the reaction time is 0.5~6h；It is excellent Selection of land, the reaction temperature of oxidation reaction is 70~90 DEG C, and the reaction time is 1.5~3h.

Further, one in the group that the alkali in aqueous alkali is constituted selected from lithium hydroxide, sodium hydroxide and potassium hydroxide Plant or a variety of；Preferably, the mass concentration of alkali is 2%~8% in aqueous alkali.

Further, the volume of aqueous alkali is 1.5~5 times of tertiary amine oxide anion exchange resin volume, preferably 2 ~3 times.

Another aspect of the present invention provides a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, the hydrogen-oxygen type tertiary amine oxide Anion exchange resin is prepared from by above-mentioned preparation method.

Another aspect of the present invention additionally provides a kind of purification process of the NMMO aqueous solution, and the purification process includes following step Suddenly：The NMMO aqueous solution is purified by above-mentioned hydrogen-oxygen type tertiary amine oxide anion exchange resin and cationic ion-exchange resin, Obtain purification solution.

Further, the flow velocity of the NMMO aqueous solution is 1.5~7.5 bed volumes/hour.

Further, cationic ion-exchange resin includes the first cationic ion-exchange resin and/or the second cationic ion-exchange resin； Wherein, before by the NMMO aqueous solution by hydrogen-oxygen type tertiary amine oxide anion exchange resin progress purge process, first by NMMO water Solution passes through the first cationic ion-exchange resin；And/or the NMMO aqueous solution is passed through into hydrogen-oxygen type tertiary amine oxide anion exchange resin After progress purge process, then by the second cationic ion-exchange resin, obtain purification solution；First cationic ion-exchange resin and Two cationic ion-exchange resins are identical or different.

Further, by the NMMO aqueous solution by hydrogen-oxygen type tertiary amine oxide anion exchange resin carry out purge process it Afterwards, or by the NMMO aqueous solution by optional second cationic ion-exchange resin after, further the NMMO aqueous solution is passed through strong Alkalescence anion-exchange resin.

The invention provides a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, its preparation method and the NMMO aqueous solution Purification process.Hydrogen-oxygen type oxygen made from the preparation method of the hydrogen-oxygen type tertiary amine oxide anion exchange resin provided by the present invention Change tertiary amine anion exchange is alkalescent, and its interaction between the material adsorbed is relatively weak, thus with compared with High cyclic utilization rate；Meanwhile, the oxygen atom in above-mentioned hydrogen-oxygen type tertiary amine oxide anion exchange resin is comprising three couples of orphans to electricity Son, can be with the organic matter of hydrogen bonds in adsorption aqueous solution.When being purified using this resin to NMMO solution, the resin can be with Cellulose anion and cellulose colloid of the absorption containing substantial amounts of hydrogen bond, simultaneously because n -Propyl gallate complex form Equally contain in hydrogen bond, thus above-mentioned purge process in the transition metal ions of presence, except can go divided by complex it is cloudy from The transition metal ions that sub- form is present, can also go divided by complex n-propyl the transition metal ions that exists of form, from And effectively increase the removal efficiency of transition metal.And then cause by made from above-mentioned preparation method hydrogen-oxygen type tertiary amine oxide the moon from Sub-exchange resin is when carrying out NMMO purifying aqueous solutions with higher anion exchange efficiency, preferable resin cyclic utilization rate And higher transition metal ions removal efficiency.

Brief description of the drawings

The Figure of description for constituting the part of the application is used for providing a further understanding of the present invention, and of the invention shows Meaning property embodiment and its illustrate be used for explain the present invention, do not constitute inappropriate limitation of the present invention.In the accompanying drawings：

Fig. 1 shows the process flow diagram of the purification process of the NMMO aqueous solution in one embodiment of the present invention；

Fig. 2 shows the process flow diagram of the purification process of the NMMO aqueous solution in another embodiment of the present invention；

Fig. 3 shows the process flow diagram of the purification process of the NMMO aqueous solution in another embodiment of the present invention.

Embodiment

It should be noted that in the case where not conflicting, the feature in embodiment and embodiment in the application can phase Mutually combination.Describe the present invention in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As described by background section, in existing process to the NMMO aqueous solution carry out purification process when, exist from The problem of sub-exchange resin ion-exchange effect is poor, cyclic utilization rate is low and transition metal removal efficiency is low.The invention provides A kind of preparation method of hydrogen-oxygen type tertiary amine oxide anion exchange resin, the preparation method comprises the following steps：S1, by tertiary amine-type Anion exchange resin carries out oxidation reaction, obtains tertiary amine oxide anion exchange resin；S2, by tertiary amine oxide anion exchange Resin reacted with aqueous alkali, obtains hydrogen-oxygen type tertiary amine oxide anion exchange resin.

The effect unit structure of the hydrogen-oxygen type tertiary amine oxide anion exchange resin is as follows：

When being purified using this resin to NMMO solution, itself and the cellulose anion and fibre in the NMMO aqueous solution The bond strength of the plain colloid of dimension is relatively weak.The NMMO aqueous solution is purified with it, after after ion exchange end cycle, exchange adsorption exists Cellulose anion, cellulose colloid and anionic impurity on resin are easier to be eluted.So that the tree after regeneration Fat is while higher anion exchange performance is kept, with higher reusable edible characteristic.Simultaneously as this hydrogen-oxygen Oxygen atom in type tertiary amine oxide anion exchange resin includes three pairs of lone pair electrons, can have with hydrogen bonds in adsorption aqueous solution Machine thing so that resin turns into excellent hydrogen bond receptor.Cellulose anion and cellulose colloid in the NMMO aqueous solution contain Substantial amounts of hydrogen bond, this is conducive to the adsorptivity between the effect enhancing three by hydrogen bond-lone pair electrons, and then can improve Ion-exchanging efficiency during NMMO purifying aqueous solutions, improves the purification effect of whole purifying process.Further, due to Equally contain hydrogen bond in the transition metal ions that n -Propyl gallate complex form is present so that the resin is except that can go Divided by complex anionic form exist transition metal ions outside, can also go divided by complex n-propyl form exist Transition metal ions, so as to effectively increase the removal efficiency of transition metal.Sum it up, causing to utilize the reason for above-mentioned several respects When hydrogen-oxygen type tertiary amine oxide anion exchange resin is purified to the NMMO aqueous solution made from the above method so that the purifying side Method has higher anion exchange efficiency, preferable resin cyclic utilization rate and higher transition metal ions removal efficiency. The hydrogen-oxygen type tertiary amine oxide anion exchange resin prepared using above-mentioned technique to NMMO solution when purifying, with yield It is high, the advantages of purity is high.

In the preparation method that the present invention is provided, those skilled in the art can select tertiary amine-type anion exchange resin Oxidation reaction technique.In a preferred embodiment, step S1 also includes：S11, by water and tertiary amine-type anion exchange tree Fat is mixed, and adjusts pH to 5~9, obtains question response liquid；S12, question response liquid is mixed with oxidant, is carried out oxidation reaction, is obtained To tertiary amine oxide anion exchange resin., can be by-the NR in tertiary amine-type anion exchange resin by above-mentioned oxidizing process₂ Radical oxidation is-NOR₂Group.And above-mentioned technique is used, be conducive to suppressing the generation of side reaction, improve above-mentioned oxidation reaction Reaction efficiency, obtains the tertiary amine oxide anion exchange resin for being suitable for purifying the NMMO aqueous solution.Preferably, adjusted in step S1 PH to 6~7.Solution is adjusted to above-mentioned pH scopes, is conducive to further suppressing the generation of side reaction.

In actual mechanical process, above-mentioned oxidation reaction one equipped with stirring reactor in carry out, this be conducive to by Water and tertiary amine-type anion exchange resin are uniformly mixed；Water is first added simultaneously and adds tertiary amine-type anion exchange resin, favorably In the security for improving oxidizing process；Further, since can be produced in gas, oxidizing process when oxidant selfdecomposition or oxidation impurities Persistently it is stirred, is conducive to avoiding occur security incident because of oxidant Local enrichment and non-uniform temperature.It is preferred to use and wards off Porcelain reactor as above-mentioned oxidation reaction reactor.

In the preparation method that the present invention is provided, the addition manner of oxidant is preferred to be added dropwise or adds by several times.Above-mentioned dropwise addition is Refer to the uniform addition oxidant within the reaction time, addition by several times refers to add by several times on a time period within the reaction time and aoxidized Agent.In specific implementation process, oxidant can be consumed with reaction, be homogeneously added into oxidant, advantageously ensured that abundance Oxidant, be also beneficial to avoid oxidant transition from being enriched with to form potential safety hazard.

In the preparation method that the present invention is provided, tertiary amine-type anion exchange resin is oxidized to as long as oxidant disclosure satisfy that Tertiary amine oxide anion exchange resin.In a preferred embodiment, oxidant include but is not limited to hydrogen peroxide, it is secondary One or more in the group that chlorate, chlorate, bichromate and perchlorate are constituted.Above-mentioned oxidant has higher oxygen The property changed, at the same it is relatively inexpensive, it is more suitable for applying in industrialized handling process.Preferably, oxidant is hydrogen peroxide and/or secondary Chlorate.

In the preparation method that provides of the present invention, those skilled in the art can be with Selective Oxidation, oxidant and uncle The proportionate relationship of amine type anion exchange resin consumption.In a preferred embodiment, the molal quantity of oxidant accounts for tertiary amine 1.1~2 times of the volume-exchange capacity of type anion exchange resin.In above-mentioned oxidation reaction, as long as the oxidant energy added Enough by tertiary amine-type anion exchange resin complete oxidation.And be in above range, favorably by the molal quantity of above-mentioned oxidant In the conversion ratio for further improving tertiary amine-type anion exchange resin.

In the preparation method that provides of the present invention, those skilled in the art can be with the reaction temperature of Selective Oxidation and anti- Between seasonable.In a preferred embodiment, in step S12, the reaction temperature of oxidation reaction is 60~105 DEG C of reaction time For 0.5~6h.Be conducive to further improving the conversion ratio of the reaction rate of oxidation reaction using above-mentioned reaction condition.Preferably, The reaction temperature of oxidation reaction is 70~90 DEG C, and the reaction time is 1.5~3h.In the preparation method that the present invention is provided, oxidation is anti- The reaction temperature answered is that some scope refers to that the temperature of full response process is in above range, and is not that need will be whole The reaction temperature of individual process is some steady temperature；In reaction overall process, it can be carried out according to oxidation reaction, regulation reaction temperature Degree.PH scopes simultaneously involved in the present invention similarly refer to that the pH of full response process is interior for corresponding scope, rather than It is a steady state value to need the pH controls of whole process.The regulation of simultaneous reactions temperature and the pH no sequencing of regulation.

After oxidation reaction terminates, it is non-hydrogen-oxygen type to obtain tertiary amine oxide anion exchange resin, such as chlorine type or sulfuric acid Root type.During impurity in removing the NMMO aqueous solution, above-mentioned resin, can be by corresponding chlorion while impurity is absorbed Or sulfate ion is eluted, the DeGrain so purified.Therefore tertiary amine oxide anion exchange resin is converted For hydrogen-oxygen type tertiary amine oxide anion exchange resin.In the preparation method that the present invention is provided, side commonly used in the art can be used Method carries out above-mentioned conversion process.In the purification process that the present invention is provided, by the way that oxidized form tertiary amine resins and aqueous alkali are reacted When being converted into hydrogen-oxygen type tertiary amine oxide anion exchange resin, those skilled in the art can select the species of alkali.It is excellent in one kind In the embodiment of choosing, the alkali in alkaline aqueous solution includes but is not limited to lithium hydroxide, sodium hydroxide and potassium hydroxide composition One or more in group.Above-mentioned alkali has stronger alkalescence, and this is conducive to further improving hydrogen-oxygen type tertiary amine oxide anion The stability of exchanger resin.Preferably, the mass concentration of aqueous alkali is 2%~8%.

In practical operation, above-mentioned oxidized form tertiary amine resins are converted into the mistake of hydrogen-oxygen type tertiary amine oxide anion exchange resin Tertiary amine oxide anion exchange resin, is preferably filled into ion exchange bed and carries out by journey.Above-mentioned filling process can be that handle contains There are water and ion exchange resin after the completion of oxidation reaction to be filled into together in ion exchange bed, then by exchanging the tree in bed Fat carrier falls waste water filtering, so that ion exchange resin is filled into exchange bed；Filter plant handle can also first be used Wastewater treatment after the completion of oxidation reaction is fallen, then ion exchange resin is filled into exchange bed.

In the preparation method that the present invention is provided, as long as the aqueous alkali added can be by tertiary amine oxide anion exchange resin It is fully converted to hydrogen-oxygen type tertiary amine oxide anion exchange resin.Preferably, the volume of aqueous alkali is that tertiary amine oxide is cloudy 1.5~5 times of ion exchange resin volume.By the consumption of aqueous alkali be conducive to improving in above range tertiary amine oxide it is cloudy from The purification effect of sub-exchange resin.Preferably 2~3 times.It is to be conducive to further carrying in above range by the consumption of aqueous alkali The purification effect of high oxidation tertiary amine anion exchange.

Another aspect of the present invention provides a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, the hydrogen-oxygen type tertiary amine oxide Anion exchange resin is prepared from by above-mentioned preparation method.During being purified to the NMMO aqueous solution, the resin Have the advantages that anion exchange efficiency high, reusable edible and transition metal removal efficiency are high.

Another aspect of the present invention additionally provides a kind of purification process of the NMMO aqueous solution, and the purification process includes following step Suddenly：The NMMO aqueous solution is purified by hydrogen-oxygen type tertiary amine oxide anion exchange resin and cationic ion-exchange resin, obtained Purification solution.

Hydrogen-oxygen type tertiary amine oxide anion exchange resin and the cellulose anion and cellulose gum in the NMMO aqueous solution The bond strength of body is relatively weak.During with the above-mentioned purifying resin NMMO aqueous solution, after ion exchange end cycle, adsorb in resin On cellulose anion, cellulose colloid and anionic impurity be easier to be eluted, this make the resin after regeneration guarantor While holding higher anion exchange performance, with higher reusable edible characteristic.Simultaneously as cellulose anion and Contain substantial amounts of hydrogen bond in cellulose colloid, and hydrogen-oxygen type tertiary amine oxide anion exchange resin is excellent hydrogen bond receptor. For these reasons, it is also favourable when purifying the NMMO aqueous solution using hydrogen-oxygen type tertiary amine oxide anion exchange resin in the present invention Adsorptivity between the effect enhancing three by hydrogen bond-lone pair electrons, and then NMMO purifying aqueous solutions processes can be improved In ion-exchanging efficiency, improve the purification effect of whole purifying process.Simultaneously because with n -Propyl gallate complex shape Equally contain hydrogen bond in the transition metal ions that formula is present so that the resin is except that can go divided by complex anionic form is deposited Transition metal ions outside, can also go divided by complex n-propyl form exist transition metal ions so that effectively Improve the removal efficiency of transition metal.Sum it up, causing the NMMO aqueous solution of the invention provided the reason for above-mentioned several respects Purification process has higher anion exchange efficiency high, preferable resin cyclic utilization rate and higher transition metal ions concurrently Removal efficiency.In addition, the foreign ion in the NMMO aqueous solution is in addition to comprising anion, also comprising cation.Under normal circumstances, Also there is cation in the NMMO aqueous solution, the catabolite morpholine of such as alkali metal ion, alkaline-earth metal ions and NMMO or Ammonium ion of N-methylmorpholine formation etc..Cation is removed by cationic ion-exchange resin.

Generally when carrying out purge process, first ion exchange resin is filled into ion exchange bed, then will treat pure again The solution of change carries out ion exchange to complete purge process by ion exchange bed.In the purification process that the present invention is provided, ability Field technique personnel can select the flow velocity of the NMMO aqueous solution in purge process.In a preferred embodiment, NMMO is water-soluble The flow velocity of liquid is 1.5~7.5 bed volumes/hour.It in the flow control above range of the NMMO aqueous solution, will be conducive to controlling NMMO Residence time of the aqueous solution in ion exchange resin, so that providing time enough for purge process carries out ion exchange, enter And be conducive to improving purification effect.

In the purification process that the present invention is provided, as long as using tertiary amine-type anion exchange resin oxidation generation tertiary amine oxide Anion exchange resin, then it is translated into hydrogen-oxygen type tertiary amine oxide anion exchange resin, it is possible to reach that ion exchange is imitated Rate is high, cyclic utilization rate is high and the high effect of transition metal ions removal efficiency.In a preferred embodiment, tertiary amine-type One kind in the resins containing tertiary amine group such as D301 types resin, D370 types resin and 331 types of anion exchange resin or It is a variety of.Using above-mentioned anion exchange resin, be conducive to further improving the exchange efficiency and transition metal of ion exchange resin The removal efficiency of ion.Preferably D301 types resin or D370 type resins.

In the purification process that the present invention is provided, when being purified, cationic ion-exchange resin and tertiary amine oxide anion exchange Resin does not have sequencing.In a preferred embodiment, cationic ion-exchange resin includes the first cationic ion-exchange resin And/or second cationic ion-exchange resin；Wherein, the NMMO aqueous solution is carried out by hydrogen-oxygen type tertiary amine oxide anion exchange resin Before purge process, the NMMO aqueous solution is first passed through into the first cationic ion-exchange resin；And/or the NMMO aqueous solution is passed through into hydrogen-oxygen type Tertiary amine oxide anion exchange resin is carried out after purge process, then by the second cationic ion-exchange resin (as shown in Figure 1), is obtained To the process of purification solution.These ions can be adsorbed juxtaposition when contacting storng-acid cation exchange resin and change hydrogen ion, Hydroxide ion reaction generation water with being replaced on hydrogen-oxygen type tertiary amine oxide anion exchange resin, obtains pure NMMO water-soluble Liquid.

In above-mentioned purification process, those skilled in the art can also be by above-mentioned hydrogen-oxygen type tertiary amine oxide resin, cation Exchanger resin is used in series with strong-base anion-exchange resin.As shown in Fig. 2 in a preferred embodiment, will The NMMO aqueous solution is carried out after purge process by hydrogen-oxygen type tertiary amine oxide anion exchange resin, enters back into the second cation exchange After resin, the NMMO aqueous solution is finally passed through into strong-base anion-exchange resin.It will be conducive to more by above-mentioned purge process The anionic impurity in NMMO solvents is further removed, so as to further improve the purification effect of above-mentioned purification process.Need , it is noted that in actual applications, in order to avoid the absorption completely of the cellulose anion and cellulose colloid in NMMO solvents exists Can not be eluted on strong-base anion-exchange resin, should NMMO solvents by above-mentioned hydrogen-oxygen type tertiary amine oxide it is cloudy from After sub-exchange resin, then it is pure by above-mentioned strong-base anion-exchange resin and/or the progress of other weak-base ion-exchange resins Change process.First cationic ion-exchange resin can be with identical or different with the second cationic ion-exchange resin.

In addition, as shown in figure 3, in the preferred embodiment of the present invention, the NMMO aqueous solution is passed through into hydrogen-oxygen type oxygen Change tertiary amine anion exchange, then exchanged by the identical or different weakly-basic anion of tertiary amine oxide anion exchange resin Resin, purge process is carried out finally by cation ion exchange resin.By above-mentioned purge process, the impurity in NMMO solvents Can expeditiously it be removed, exchange capacity is moderate.

As long as using the present invention purification process and above-mentioned technological parameter that provide, it becomes possible to obtain combination property good NMMO solvents.In a preferred embodiment, after the ion exchange process in purge process terminates, all ions are handed over Change the step of resin carries out elution processing.Preferably, use quality concentration is 4% sodium hydrate aqueous solution to anion exchange tree Fat is eluted, and is that 4% aqueous hydrochloric acid solution is eluted to cationic ion exchanger resin with mass concentration.Take above-mentioned wash De- processing procedure, is conducive to improving the cyclic utilization rate of above-mentioned resin, reduces the cost of NMMO process for purifying aqueous solutions.

The present invention is described in further detail below in conjunction with specific embodiment, these embodiments are it is not intended that limit this Invent scope claimed.

Embodiment 1

The resins exchange bed of the series connection used in the present embodiment has carried out purification process, resins exchange bed to the NMMO aqueous solution A tertiary amine oxide type resin anion (R.A.) including priority series connection exchanges bed and a cation resin exchange bed.

The preparation technology of hydrogen-oxygen type tertiary amine oxide resin anion (R.A.) is as follows：

By 3m³Volume-exchange capacity is added to 5m for 1.4mol/L D301 resins³Enamel reactor in, then add 1m³Water, open stirring；Salt acid for adjusting pH value is added to 6.5,75 DEG C are warming up to；Then 54kg mass is added within every 20 minutes Concentration is 35% hydrogen peroxide, is added 10 times altogether, and adding up to 540kg hydrogen peroxide, (it is resin volume exchange capacity to add molal quantity 1.4 times), continue to react 30 minutes after all adding, be subsequently cooled to less than 40 DEG C.

It is 4m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net waste water；So Afterwards by 6m³The sodium hydroxide adverse current that mass concentration is 4% makes tertiary amine oxide anion exchange resin be converted into hydrogen by exchanging bed Oxygen type tertiary amine oxide anion exchange resin.Connected in series is that for a cation exchange bed, it is filled with 3m³Form ion Exchanger resin.Wherein, the form ion exchange resin is by 001 × 7 type cationic ion-exchange resin 6m³Mass concentration is 4% Regeneration of hydrochloric acid formed by.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentrations is 16% in the Lyocell fiber production crystallization bath used in the present embodiment, total iron content In 1.5ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 180, in brown color.By above-mentioned crystallization bath with 12m³The flow velocity of/hour (4 bed volumes/hour) send into above-mentioned tertiary amine oxide anion exchange bed and cation exchange bed.

Bed and above-mentioned cation resin exchange bed are exchanged by above-mentioned tertiary amine oxide resin anion (R.A.) after purification, and NMMO is molten Liquid total iron content is 0.02ppm, and chromium is not detected, the μ S/cm of electrical conductivity 9, in water white transparency, colourity≤20 degree.Passing through 220 bed bodies Product is 660m³After crystallization bath, electrical conductivity rises, and exchange terminates.Use 6m³Mass concentration regenerates hydrogen-oxygen type oxygen for 4% sodium hydroxide Change tertiary amine anion exchange, use 6m³Mass concentration is 4% regeneration of hydrochloric acid cationic ion-exchange resin, after regeneration ending, on Processing crystallization bath can be continued on for by stating ion exchange resin, and without any color on hydrogen-oxygen type tertiary amine oxide anion exchange resin Deposition.

Method of testing：

1. concentration determination：High performance liquid chromatography (HPLC) is tested, chromatographic condition：Mobile phase is the second of mass concentration 8% The nitrile aqueous solution, 0.8mL/min, Detection wavelength 208nm, the μ L of sample size 10, quantified by external standard method.

2. metal ion is tested：Determinand is cleared up, the chromatography of ions (IC) test, chromatographic condition：Mobile phase 1.5mmol/L pyridinedicarboxylic acid, 1.0mL/min, 1.5mmol/L azo diethylaminos phenol is post-column derivation agent, 2.0mL/ Min, Detection wavelength 530nm, the μ L of sample size 25, quantified by external standard method.

3. electrical conductivity is tested：The electrical conductivity of NMMO solvents after purification is tested according to ISO 7888-1985 method.

4. colourity is tested：The colourity of NMMO solvents after purification is tested according to GB 11903-1989 method.

In the present embodiment, after tertiary amine-type anion exchange resin is oxidized, hydrogen-oxygen type tertiary amine oxide anion exchange tree Fat has reached 220 bed volumes to the treating capacity of the NMMO aqueous solution.Relative to use tertiary amine-type anion exchange resin D301 processing For the treating capacity (150 bed volume) of this kind of solution, 0.47 times of exchange capacity is improved；It is cloudy compared to tertiary amine-type is used alone For the process that ion exchange resin D301 type resins are purified, the equipment volume used in the present embodiment is original equipment volume 70%；In regenerative process, soda acid consumption is the 70% of former consumption.And due to fiber hydrolization product and cellulose gum after regeneration Body is reproduced, and the exchange capacity of ion exchange resin is not reduced with the extension of use time.NMMO through processing is molten Liquid Conductivity Results are preferable, and metal ion content is extremely low, and potential safety hazard is not constituted when concentrating and being redissolved cellulose.

Embodiment 2

Purification process, resins exchange bed bag have been carried out to the NMMO aqueous solution using the resins exchange bed of series connection in the present embodiment A hydrogen-oxygen type tertiary amine oxide resin anion (R.A.) for including successively series connection exchanges bed and cation resin exchange bed, a highly basic Property resin anion (R.A.) exchange bed.

By 0.5m³Volume-exchange capacity is added to 1m for 1.4mol/L D370 type resins³Enamel reactor in, then Add 0.2m³Water, open stirring；Salt acid for adjusting pH value is added to 5,62 DEG C are warming up to；Then at the uniform velocity it was added dropwise in 1 hour 825kg mass concentrations are 12% aqueous sodium hypochlorite solution (adding 1.9 times that molal quantity is resin volume exchange capacity), are added dropwise After the completion of, progressively it is warming up to 75 DEG C, is incubated 30 minutes, then it is warming up to 100 DEG C, 30 minutes are incubated, less than 40 DEG C are subsequently cooled to.

Resin and water in reactor is filled to 0.7m together³In the exchange bed of resin, net waste water is put；Then 1m is used³Matter Amount concentration makes tertiary amine oxide anion exchange resin be converted to hydrogen-oxygen type oxidation uncle for 4% sodium hydroxide adverse current by exchanging bed Amine anion exchange resin.It is connected in series to have：One cation exchange bed, it is filled with 1m³Form ion exchange resin, its In, the form ion exchange resin is by 001 × 7 type cationic ion-exchange resin 2m³Mass concentration is 4% regeneration of hydrochloric acid shape Into；And a strong-base anion-exchange resin connected with cation resin exchange bed, it is filled with 0.5m³201×7 Type hydrogen-oxygen type ion exchange resin, wherein, the hydrogen-oxygen type ion exchange resin is by 0.5m³201 × 7 type strong alkalinity anions are handed over Change resin 1m³Mass concentration regenerates what is formed for 4% sodium hydroxide solution.

The purification step of the NMMO aqueous solution is specific as follows：

MMMO mass concentrations is 23% in the Lyocell fiber production crystallization bath used in the present embodiment, total iron content In 4ppm, copper content 0.05ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 220, in dark brown yellow.By above-mentioned crystallization bath with 1m³The flow velocity (2 bed volumes/hour) of/hour sends into above-mentioned tertiary amine oxide type anion exchange bed, and is passed through in the way of just flowing Exchange bed.

By above-mentioned tertiary amine oxide resins exchange bed, above-mentioned cation resin exchange bed, above-mentioned strong alkalinity anion tree After purification, NMMO solution total iron content is 0.015ppm to Ester exchange bed, and copper, chromium are not detected, the μ S/cm of electrical conductivity 2, in colourless It is bright, colourity≤20 degree.It is being 60m by 120 bed volumes³After crystallization bath, electrical conductivity rises, and exchange terminates.Use 1m³Mass concentration Hydrogen-oxygen type tertiary amine oxide anion exchange resin is regenerated for 4% sodium hydroxide solution, 2m is used³Mass concentration is 4% hydrochloric acid Above-mentioned cationic ion-exchange resin is regenerated, 1m is used³Mass concentration regenerates above-mentioned strong alkalinity anion friendship for 4% sodium hydroxide solution Change after resin, regeneration ending, above-mentioned ion exchange resin can continue on for processing crystallization bath, and hydrogen-oxygen type tertiary amine oxide anion Without any color deposition on exchanger resin.

Method of testing：

1.NMMO concentration determinations：High performance liquid chromatography (HPLC) is tested, chromatographic condition：Mobile phase is mass concentration 8% Acetonitrile solution, 0.8mL/min, Detection wavelength 208nm, the μ L of sample size 10, quantified by external standard method.

In the present embodiment, because the bed volume of strong-base anion-exchange resin is relatively low, and the electricity of material crystal bath Conductance is high, after tertiary amine-type anion exchange resin is oxidized, and the treating capacity to the NMMO aqueous solution is 120 bed volumes.This relative to It is used alone for the treating capacity (100 bed volume) when above-mentioned strong-base anion-exchange resin handles this kind of solution, improves 0.2 times of exchange capacity；For the process that above-mentioned strong-base anion-exchange resin is purified is used alone, this reality The equipment volume used in example is applied for the 80% of original equipment；In regenerative process, soda acid consumption is the 80% of former consumption.And due to Fiber hydrolization product and cellulose colloid are reproduced after regeneration, and the exchange capacity of ion exchange resin is not with use time Extension and reduce.NMMO electrical conductivity of solution through processing is extremely low, only 2 μ S/cm, and metal ion content is also extremely low.

Embodiment 3

The resins exchange bed of the series connection used in the present embodiment has carried out purification process, resins exchange bed to the NMMO aqueous solution A tertiary amine oxide type resin anion (R.A.) including priority series connection exchanges bed, a weak anion resin and exchanges bed and one Cation resin exchange bed.

By 0.1m³Volume-exchange capacity is 2mol/L 331 type anion exchange resin, is added to 1m³Enamel reactor In, add 0.1m³Water, open stirring；Salt acid for adjusting pH value is added to 8,85 DEG C are warming up to；Then 12.25kg matter is added The chloric acid aqueous solutions of potassium that concentration is 20% is measured, controls every 20 minutes addition 12.25kg mass concentrations water-soluble for 20% potassium chlorate Liquid, is added 4 times altogether, and (molal quantity of addition is that resin volume is handed over to the chloric acid aqueous solutions of potassium that 49kg mass concentrations are 20% altogether Change capacity 1.2 times), continue to react 30 minutes after all adding, be warming up to 100 DEG C and be incubated 30 minutes, be subsequently cooled to 40 DEG C Below.

It is 0.15m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net useless Water；Then by 0.45m³Mass concentration be 2.5% sodium hydroxide adverse current by exchanging bed, obtain hydrogen-oxygen type tertiary amine oxide anion Exchanger resin.It is connected in series to have：One resin anion (R.A.) exchanges bed, and it is filled with 0.1m³001 × 7 hydrogen-oxygen type anion exchange Resin, wherein, the hydrogen-oxygen type anion exchange resin is by 0.1m³331 type ion exchange resin, use 0.45m³Mass concentration is 2.5% sodium hydroxide is regenerated to the formation of hydrogen-oxygen type；One exchanges the resin cation that bed is connected with above-mentioned resin anion (R.A.) Bed is exchanged, it is filled with 0.1m³Form ion exchange resin, wherein, the form ion exchange resin be by 001 × 7 type sun from Sub-exchange resin is used, 0.8m³Mass concentration for 4% regeneration of hydrochloric acid to form ion exchange resin.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentration is 11% in the Lyocell fiber production crystallization bath used in the present embodiment, and total iron contains Amount is in 1.1ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 120, in brown color.Crystallization is bathed with 0.6m by above-mentioned³/ hour Flow velocity (6 bed volumes/hour) sends into above-mentioned tertiary amine oxide type anion exchange bed, and by exchanging bed in the way of just flowing.

By above-mentioned tertiary amine oxide resin anion (R.A.) exchange bed, above-mentioned weak anion resin exchange bed and it is above-mentioned sun from After purification, NMMO solution total iron content is 0.03ppm to subtree Ester exchange bed, and chromium is not detected, the μ S/cm of electrical conductivity 6, in colourless It is bright, colourity≤20 degree.It is being 60m by 260 bed volumes³After crystallization bath, electrical conductivity rises, and exchange terminates.Use 0.45m³Quality is dense Spend and regenerate hydrogen-oxygen type tertiary amine oxide anion exchange resin for 2.5% sodium hydroxide, use 0.45m³Mass concentration is 2.5% Sodium hydroxide regenerates above-mentioned anion exchange resin, uses 0.8m³Mass concentration is the 4% above-mentioned cation exchange tree of regeneration of hydrochloric acid Fat, above-mentioned ion exchange resin can continue on for processing crystallization bath, and nothing is appointed on hydrogen-oxygen type tertiary amine oxide anion exchange resin What color deposition.

Method of testing：

NMMO concentration determinations：High performance liquid chromatography (HPLC) is tested, chromatographic condition：Mobile phase is mass concentration 8% Acetonitrile solution, 0.8mL/min, Detection wavelength 208nm, the μ L of sample size 10, quantified by external standard method.

Metal ion is tested：Determinand is cleared up, the chromatography of ions (IC) test, chromatographic condition：Mobile phase 1.5mmol/L Pyridinedicarboxylic acid, 1.0mL/min, 1.5mmol/L azo diethylaminos phenol be post-column derivation agent, 2.0mL/min, Detection wavelength 530nm, the μ L of sample size 25, quantified by external standard method.

In the present embodiment, it is jointly processed by after tertiary amine-type anion exchange resin is oxidized with above-mentioned anion exchange resin Afterwards, the treating capacity to the NMMO aqueous solution has reached 260 bed volumes, relative to the above-mentioned weak-base anion-exchange resin of exclusive use For treating capacity (200 bed volume) when handling this kind of solution, 0.3 times of exchange capacity is improved；Relative in exclusive use State for the process that anion exchange resin is purified, the equipment volume used in the present embodiment is only the 75% of original equipment； In regenerative process, soda acid consumption is the 75% of former consumption.And due to fiber hydrolization product and cellulose colloid quilt after regeneration It is born again, the exchange capacity of resin is not reduced with the extension of use time.NMMO electrical conductivity of solution result reason through processing Think, metal ion content is extremely low, potential safety hazard is not constituted when concentrating and being redissolved cellulose.

Embodiment 4

By 3m³Volume-exchange capacity is added to 5m for 1.4mol/L D301 resins³Enamel reactor in, then add 1m³Water, open stirring；A small amount of salt acid for adjusting pH value is added to 5,75 DEG C are warming up to；Then adding 283kg mass concentrations is 20% chloric acid aqueous solutions of potassium, then adds the chloric acid aqueous solutions of potassium that 283kg mass concentrations are 20% for every 20 minutes, 10 is added altogether It is secondary, total 2830kg (adding 1.1 times that molal quantity is resin volume exchange capacity), after all adding, temperature is 62 during reaction ~105 DEG C, continue to react 30 minutes, be subsequently cooled to less than 40 DEG C.

It is 4m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net waste water；So Afterwards by 9.45m³Mass concentration is entered for 2% potassium hydroxide adverse current by exchanging bed, turns tertiary amine oxide anion exchange resin Turn to hydrogen-oxygen type tertiary amine oxide anion exchange resin.Connected in series is for a cation exchange bed, to be filled with 3m³Hydrogen Ion exchange resin.Wherein, the form ion exchange resin is by 001 × 7 type cationic ion-exchange resin 6m³Mass concentration is Formed by 4% regeneration of hydrochloric acid.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentrations is 16% in the Lyocell fiber production crystallization bath used in the present embodiment, total iron content In 1.5ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 200, in brown color.By above-mentioned crystallization bath with 4.5m³The flow velocity of/hour (1.5 bed volumes/hour) send into above-mentioned tertiary amine oxide type anion exchange bed, and by exchanging bed in the way of just flowing.

Bed and above-mentioned cation resin exchange bed are exchanged by tertiary amine oxide resin anion (R.A.) after purification, and NMMO solution is total Iron content is 0.02ppm, and chromium is not detected, the μ S/cm of electrical conductivity 10, in water white transparency, colourity≤20 degree.Passing through 200 bed volumes Afterwards, electrical conductivity rises, and exchange terminates.Use 6m³Mass concentration is handed over for 4% sodium hydroxide regeneration hydrogen-oxygen type tertiary amine oxide anion Resin is changed, 6m is used³Mass concentration is 4% regeneration of hydrochloric acid cationic ion-exchange resin, after regeneration ending, above-mentioned ion exchange resin Processing crystallization bath can be continued on for, and without any color deposition on hydrogen-oxygen type tertiary amine oxide anion exchange resin.

Method of testing：

In the present embodiment, after tertiary amine-type anion exchange resin is oxidized, the treating capacity to the NMMO aqueous solution reaches 155 bed volumes, for D301 is used alone and handles the treating capacity (handling this bed volume of solution 130) of this kind of solution, are carried High 0.19 times of exchange capacity；For the process that D301 type resins are purified is used alone, adopted in the present embodiment Equipment volume is the 70% of original equipment volume；Soda acid consumption is the 70% of former consumption in regenerative process.And due to regeneration Fiber hydrolization product and cellulose colloid are reproduced afterwards, and the exchange capacity of resin does not drop with the extension of use time It is low.NMMO electrical conductivity of solution result through processing is preferable, and metal ion content is extremely low, when concentrating and being redissolved cellulose not Constitute potential safety hazard.

Embodiment 5

By 3m³Volume-exchange capacity is added to 5m for 1.4mol/L D301 resins³Enamel reactor in, then add 1m³Water, open stirring；Salt acid for adjusting pH value is added to 9,75 DEG C are warming up to；Then it is 50% to add 494kg mass concentrations Potassium dichromate aqueous solution, then add within every 20 minutes the hydrogen peroxide that 494kg mass concentrations are 50%, add 10 times altogether, add up to 4940kg hydrogen peroxide (adds 5 times that molal quantity is resin volume exchange capacity), after all adding, and reaction temperature is 60~105 DEG C, continue to react 6 hours, be subsequently cooled to less than 40 DEG C.

It is 4m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net waste water；So Afterwards by 10.5m³The lithium hydroxide adverse current that mass concentration is 8% converts tertiary amine oxide anion exchange resin by exchanging bed For hydrogen-oxygen type tertiary amine oxide anion exchange resin.Connected in series is for a cation exchange bed, to be filled with 3m³001×7 Type cationic ion-exchange resin, and used 6m³Mass concentration for 4% regeneration of hydrochloric acid to form ion exchange resin.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentration is 14% in the Lyocell fiber production crystallization bath used in the present embodiment, and total iron contains Amount is in 1.5ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 140, in brown color.By above-mentioned crystallization bath with 22.5m³/ hour Flow velocity (7.5 bed volumes/hour) sends into tertiary amine oxide type anion exchange bed, and by exchanging bed in the way of just flowing.

Bed and above-mentioned cation resin exchange bed are exchanged by above-mentioned tertiary amine oxide type resin anion (R.A.) after purification, NMMO Solution total iron content is 0.015ppm, and chromium is not detected, the μ S/cm of electrical conductivity 8, in water white transparency, colourity≤20 degree.Passing through 280 After bed volume, electrical conductivity rises, and exchange terminates.Use 6m³Mass concentration is cloudy for 4% sodium hydroxide regeneration hydrogen-oxygen type tertiary amine oxide Ion exchange resin, uses 6m³Mass concentration is 4% regeneration of hydrochloric acid cationic ion-exchange resin, after regeneration ending, and above-mentioned ion is handed over Processing crystallization bath can be continued on for by changing resin, and without any color deposition on hydrogen-oxygen type tertiary amine oxide anion exchange resin.

Method of testing：

In the present embodiment, after tertiary amine-type anion exchange resin is oxidized, the treating capacity to the NMMO aqueous solution reaches 250 bed volumes, when D301 is used alone and handles this kind of solution for treating capacity (handling this bed volume of solution 190), are carried High 0.32 times of exchange capacity；For the process that D301 type resins are purified is used alone, adopted in the present embodiment Equipment volume is the 70% of original equipment volume；Soda acid consumption is the 70% of former consumption in regenerative process.And due to regeneration Fiber hydrolization product and cellulose colloid are reproduced afterwards, and the exchange capacity of resin does not drop with the extension of use time It is low.NMMO electrical conductivity of solution result through processing is preferable, and metal ion content is extremely low, when concentrating and being redissolved cellulose not Constitute potential safety hazard.

Embodiment 6

By 3m³Volume-exchange capacity is added to 5m for 1.4mol/L D301 resins³Enamel reactor in, then add 1m³Water, open stirring；Salt acid for adjusting pH value is added to 6.0,75 DEG C are warming up to；Then adding 54kg mass concentrations is 35% hydrogen peroxide, then adds the hydrogen peroxide that 54kg mass concentrations are 35% for every 20 minutes, adds 10 times altogether, add up to 540kg Hydrogen peroxide (adds 1.4 times that molal quantity is resin volume exchange capacity), after all adding, and reaction temperature is 70~90 DEG C, after Continuous reaction 1.5 hours, is subsequently cooled to less than 40 DEG C.

It is 4m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net waste water；So Afterwards by 6m³The sodium hydroxide adverse current that mass concentration is 4% makes tertiary amine oxide anion exchange resin be converted into hydrogen by exchanging bed Oxygen type tertiary amine oxide ion exchange resin.Connected in series is that for a cation exchange bed, it is filled with 3m³Hydrogen form cation Exchanger resin.Wherein, the form ion exchange resin is by 001 × 7 type cationic ion-exchange resin 6m³Mass concentration is 4% Regeneration of hydrochloric acid formed by.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentration 15%, total iron content in the Lyocell fiber production crystallization bath used in the present embodiment In 1.5ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 100, in brown color.By above-mentioned crystallization bath with 12m³The flow velocity of/hour (4 bed volumes/hour) send into tertiary amine oxide type anion exchange bed, and by exchanging bed in the way of just flowing.

Bed and above-mentioned cation resin exchange bed are exchanged by above-mentioned tertiary amine oxide resin anion (R.A.) after purification, and NMMO is molten Liquid total iron content is 0.012ppm, and chromium is not detected, the μ S/cm of electrical conductivity 6, in water white transparency, colourity≤20 degree.Passing through 350 After volume, electrical conductivity rises, and exchange terminates.Use 6m³Mass concentration for 4% sodium hydroxide regeneration hydrogen-oxygen type tertiary amine oxide it is cloudy from Sub-exchange resin, uses 6m³Mass concentration is 4% regeneration of hydrochloric acid cationic ion-exchange resin, after regeneration ending, above-mentioned ion exchange Resin can continue on for processing crystallization bath, and without any color deposition on hydrogen-oxygen type tertiary amine oxide anion exchange resin.

Method of testing：

In the present embodiment, after tertiary amine-type anion exchange resin is oxidized, the treating capacity to the NMMO aqueous solution reaches 270 bed volumes, when D301 is used alone and handles this kind of solution for treating capacity (handling 180 volumes of this solvent bed), are carried High 0.5 times of exchange capacity；For the process that D301 type resins are purified is used alone, used in the present embodiment Equipment volume be original equipment volume 70%；Soda acid consumption is the 70% of former consumption in regenerative process.And after regeneration Fiber hydrolization product and cellulose colloid are reproduced, and the exchange capacity of resin is not reduced with the extension of use time. NMMO electrical conductivity of solution result through processing is preferable, and metal ion content is extremely low, not structure when concentrating and being redissolved cellulose Into potential safety hazard.

Embodiment 7

The resins exchange bed of the series connection used in the present embodiment has carried out purification process, resins exchange bed to the NMMO aqueous solution A cation resin exchange bed and a tertiary amine oxide type resin anion (R.A.) including priority series connection exchange bed.

The preparation technology that hydrogen-oxygen type tertiary amine oxide resin anion (R.A.) exchanges bed is as follows：

By 3m³Volume-exchange capacity is added to 5m for 1.4mol/L D301 resins³Enamel reactor in, then add 1m³Water, open stirring；Salt acid for adjusting pH value is added to 7.0,75 DEG C are warming up to；Then adding 280kg mass concentrations is 30% sodium hypochlorite, then adds the hydrogen peroxide that 280kg mass concentrations are 30% for every 20 minutes, adds 10 times altogether, add up to 2800kg hydrogen peroxide (adds 1.4 times that molal quantity is resin volume exchange capacity), continues reaction 3 hours after all adding, so After be cooled to less than 40 DEG C.

It is 4m that resin and water in reactor is filled to resin fill volume together³Exchange bed in, put net waste water；So Afterwards by 10m³The sodium hydroxide adverse current that mass concentration is 5% is converted into tertiary amine oxide anion exchange resin by exchanging bed Hydrogen-oxygen type ion exchange resin.Connected in series is that for a cation exchange bed, it is filled with 3m³Form ion exchanges tree Fat.Wherein, the form ion exchange resin is by 001 × 7 type cationic ion-exchange resin 6m³Mass concentration is 4% hydrochloric acid Formed by regeneration.

The purification step of the NMMO aqueous solution is specific as follows：

NMMO mass concentration is 18% in the Lyocell fiber production crystallization bath used in the present embodiment, and total iron contains Amount is in 1.5ppm, chromium content 0.03ppm, the μ S/cm of electrical conductivity 260, in brown color.By above-mentioned crystallization bath with 12m³The stream of/hour Fast (4 bed volumes/hour) feeding tertiary amine oxide type anion exchange bed, and by exchanging bed in the way of just flowing.

Bed sum is exchanged by 001 × 7 type cation resin exchange bed and tertiary amine oxide resin anion (R.A.) after purification, NMMO Solution total iron content is 0.03ppm, and copper is not detected, and chromium is not detected, the μ S/cm of electrical conductivity 12, in water white transparency, colourity≤20 degree. After by 180 bed volumes, electrical conductivity rises, and exchange terminates.Use 6m³Mass concentration regenerates hydrogen-oxygen type for 4% sodium hydroxide Tertiary amine oxide anion exchange resin, uses 6m³Mass concentration is 4% regeneration of hydrochloric acid cationic ion-exchange resin, after regeneration ending, Above-mentioned ion exchange resin can continue on for processing crystallization bath, and without any face on hydrogen-oxygen type tertiary amine oxide anion exchange resin Color is deposited.

Method of testing：

In the present embodiment, after tertiary amine-type anion exchange resin is oxidized, the treating capacity to the NMMO aqueous solution reaches 310 bed volumes, when D301 is used alone and handles this kind of solution for treating capacity (handling this bed volume of solvent 180), are carried High 0.72 times of exchange capacity；For the process that D301 type resins are purified is used alone, adopted in the present embodiment Equipment volume is the 70% of original equipment volume；Soda acid consumption is the 70% of former consumption in regenerative process.And due to regeneration Fiber hydrolization product and cellulose colloid are reproduced afterwards, and the exchange capacity of resin does not drop with the extension of use time It is low.NMMO electrical conductivity of solution result through processing is preferable, and metal ion content is extremely low, when concentrating and being redissolved cellulose not Constitute potential safety hazard.

As can be seen from the above description, the above embodiments of the present invention realize following technique effect：The present invention is carried In the purification process of the NMMO aqueous solution of confession, anion exchange resin has reusable edible, simultaneously because itself is distinctive Property can significantly improve the removal efficiency of transition metal anion in ion-exchanging efficiency and the NMMO aqueous solution, simplify simultaneously The equipment that purge process is used, and reduce the amount of the soda acid used during ion exchange resin regeneration.It can thus be appreciated that this Inventing the purifying of the NMMO aqueous solution provided has safe and environment-friendly, simple to operate, the low feature of cost.

When being purified using this resin to NMMO solution, itself and the cellulose anion and fibre in the NMMO aqueous solution The bond strength of the plain colloid of dimension is relatively weak, and this makes the resin after regeneration while higher anion exchange performance is kept, With higher reusable edible characteristic.Simultaneously as the oxygen atom in this hydrogen-oxygen type tertiary amine oxide anion exchange resin , can be with the organic matter of hydrogen bonds in adsorption aqueous solution comprising three pairs of lone pair electrons so that resin turns into excellent hydrogen bond receptor. Cellulose anion and cellulose colloid in the NMMO aqueous solution contain substantial amounts of hydrogen bond, and this is conducive to right by hydrogen bond-orphan Adsorptivity between the effect enhancing three of electronics, and then the ion exchange effect during NMMO purifying aqueous solutions can be improved Rate, improves the purification effect of whole purifying process.Further, due to the mistake existed with n -Propyl gallate complex form Cross and equally contain hydrogen bond in metal ion so that the resin is except the transition gold that can be gone divided by complex anionic form is present Belong to ion outside, can also go divided by complex n-propyl form exist transition metal ions, so as to effectively increase transition The removal efficiency of metal.Sum it up, causing to utilize hydrogen-oxygen type tertiary amine oxide made from the above method cloudy the reason for above-mentioned several respects When ion exchange resin is purified to the NMMO aqueous solution so that the purification process have higher anion exchange efficiency, compared with Good resin cyclic utilization rate and higher transition metal ions removal efficiency.In addition, the cation in the NMMO aqueous solution passes through Cationic ion-exchange resin removes cation.

The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.Within the spirit and principles of the invention, that is made any repaiies Change, equivalent substitution, improvement etc., should be included in the scope of the protection.

Claims

1. a kind of preparation method of hydrogen-oxygen type tertiary amine oxide anion exchange resin, it is characterised in that comprise the following steps：

S1, carries out oxidation reaction by tertiary amine-type anion exchange resin, obtains tertiary amine oxide anion exchange resin；

S2, the tertiary amine oxide anion exchange resin and aqueous alkali are reacted, obtain the hydrogen-oxygen type tertiary amine oxide it is cloudy from Sub-exchange resin；One kind in the group that alkali in the aqueous alkali is constituted selected from lithium hydroxide, sodium hydroxide and potassium hydroxide Or it is a variety of, the mass concentration of alkali described in the aqueous alkali is 2%~8%, and the volume of the aqueous alkali is the oxidation 1.5~5 times of tertiary amine anion exchange volume.

2. preparation method according to claim 1, it is characterised in that the step S1 includes：

S11, water and the tertiary amine-type anion exchange resin are mixed, and adjust pH to 5~9, obtain question response liquid；

S12, after the question response liquid is mixed with oxidant, carries out the oxidation reaction, obtains the tertiary amine oxide anion Exchanger resin.

3. preparation method according to claim 2, it is characterised in that the oxidant is selected from hydrogen peroxide, hypochlorite, chlorine One or more in the group of hydrochlorate, bichromate and perchlorate composition.

4. preparation method according to claim 3, it is characterised in that the oxidant is selected from hydrogen peroxide and/or hypochlorous acid Salt.

5. the preparation method according to claim 3 or 4, it is characterised in that the molal quantity of the oxidant accounts for the tertiary amine 1.1~2 times of the exchange capacity of type anion exchange resin.

6. preparation method according to claim 2, it is characterised in that in the step S12, the reaction of the oxidation reaction Temperature is 60~105 DEG C, and the reaction time is 0.5~6h.

7. preparation method according to claim 6, it is characterised in that the reaction temperature of the oxidation reaction is 70~90 DEG C, the reaction time is 1.5~3h.

8. preparation method according to claim 1, it is characterised in that the volume of the aqueous alkali is the tertiary amine oxide 2~3 times of anion exchange resin volume.

9. a kind of hydrogen-oxygen type tertiary amine oxide anion exchange resin, it is characterised in that the hydrogen-oxygen type tertiary amine oxide anion is handed over Resin is changed to be prepared from by the preparation method any one of claim 1 to 8.

10. a kind of purification process of the NMMO aqueous solution, it is characterised in that the purification process comprises the following steps：Will be described The NMMO aqueous solution is carried out by the hydrogen-oxygen type tertiary amine oxide anion exchange resin described in claim 9 and cationic ion-exchange resin Purifying, obtains purification solution.

11. purification process according to claim 10, it is characterised in that the flow velocity of the NMMO aqueous solution is 1.5~7.5 Bed volume/hour.

12. the purification process according to claim 10 or 11, it is characterised in that the cationic ion-exchange resin includes first Cationic ion-exchange resin and/or the second cationic ion-exchange resin；

Wherein, the NMMO aqueous solution is subjected to the purge process by the hydrogen-oxygen type tertiary amine oxide anion exchange resin Before, the NMMO aqueous solution is first passed through into first cationic ion-exchange resin；And/or

After the NMMO aqueous solution carried out into the purge process by the hydrogen-oxygen type tertiary amine oxide anion exchange resin, Again by second cationic ion-exchange resin, the purification solution is obtained；First cationic ion-exchange resin and described Two cationic ion-exchange resins are identical or different.

13. purification process according to claim 12, it is characterised in that the NMMO aqueous solution is passed through into the hydrogen-oxygen type Tertiary amine oxide anion exchange resin is carried out after the purge process, or the NMMO aqueous solution is passed through optional described After second cationic ion-exchange resin, the NMMO aqueous solution is further passed through into strong-base anion-exchange resin.