CN1708472A - Process for producing terephthalic acid - Google Patents

Process for producing terephthalic acid Download PDF

Info

Publication number
CN1708472A
CN1708472A CN 200380102589 CN200380102589A CN1708472A CN 1708472 A CN1708472 A CN 1708472A CN 200380102589 CN200380102589 CN 200380102589 CN 200380102589 A CN200380102589 A CN 200380102589A CN 1708472 A CN1708472 A CN 1708472A
Authority
CN
China
Prior art keywords
terephthalic acid
filter cake
liquid
cake
slurries
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN 200380102589
Other languages
Chinese (zh)
Other versions
CN100383105C (en
Inventor
沼田元干
矶贝隆行
绪方知彦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Chemical Corp
Mitsubishi Rayon Co Ltd
Tomoe Engineering Co Ltd
Original Assignee
Mitsubishi Kasei Corp
Tomoe Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Kasei Corp, Tomoe Engineering Co Ltd filed Critical Mitsubishi Kasei Corp
Publication of CN1708472A publication Critical patent/CN1708472A/en
Application granted granted Critical
Publication of CN100383105C publication Critical patent/CN100383105C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

The invention is to provide a method for producing a high-purity aromatic dicarboxylic acid such as terephthalic acid with high energy efficiency using a simplified process, in the method for producing terephthalic acid according to the present invention, solid-liquid separation and cleaning steps are carried out using a single device, and in a step for removing any liquid adhered to terephthalic cakes by evaporation, internal energy stored in the terephthalic acid cakes and/or the liquid adhered thereto is used at least part of the energy for evaporating the liquid adhered to the cakes.

Description

The preparation method of terephthalic acid
Technical field
The present invention relates to especially method of terephthalic acid of a kind of preparation aromatic dicarboxylic acid, in particular, the present invention relates to method by heating and a kind of compound of pressurization preparation, wherein, separate and washing step can carry out with single common equipment, and comprise and to remove the reaction medium that is attached on the gained filter cake and/or the step of washings in the utilization.
Background technology
Typically, the paste mixture of terephthalic acid and reaction mother liquor through separate and the exsiccant unit operation after, terephthalic acid can obtain with the form of solid granulates.
People repeatedly attempted improving whole flow process by improving described unit operation in the past.For example, have much about the solid isolating technology (disclosed) of selecting of a liquid as patent documentation 1.Especially, not only possess separation function, but also possess very high cleaning capacity as flat rubber belting formula strainer, rotary vacuum filter, screening centrifuge decanter equipment such as (screening separating centrifuges).By using these equipment, can reclaim the mother liquor that contains a large amount of impurity that obtains being separated from each other, the filtrate and the filter cake of the low washing of foreign matter content through washing.But these filter cakes still contain useful liquid.In order to reclaim such liquid, further need carry out drying or such liquid extraction is come out with solvent.May need special equipment with its separation (disclosed) as patent documentation 2.
The exsiccant example comprises with hot gas and carries out drying as the warm air of being carried by compressed air delivery type moisture eliminator (disclosed as patent documentation 3) by indirect heating.Also known (disclosed) by evaporation liquid in the slurries in heating tube with the method that obtains solid and gas as patent documentation 4 and 5 by the people.For these drying operationes all is isolating independently operation, must increase heat newly with dry cake.In order to reach this purpose, need extra energy and extra drying plant.
Before a solid liquid separated, common operation was to keep its suspended state with crystallization when reducing slurry temperature.For example, knownly come cool slurry so that terephthaldehyde's Acid precipitation (disclosed) as patent documentation 6 by evaporating solvent.But evaporation itself can only improve the concentration of slurries slightly, only plays the effect that reduces temperature during the course.
Obtain slurries once more and its flushing (disclosed as patent documentation 7) is also known by people by terephthalic acid and washings are mixed.Yet must after forming slurries, extract powder as everyone knows, extract powder under the pressure because be difficult in, a unfavorable factor of flushing, as, energy consumption is not taken into account.Therefore, disclosed as patent documentation 6 and 7, reduce the technology of slurry temperature and slurries reheat in drying step by consumed energy and can not say so energy-conservation.
People further know to be needed to separate filter cake under pressure.But this does not show heat energy residual before separated slurry yet effectively (seeing patent documentation 8 and 9) when dry cake.
(patent documentation 1: international monopoly PCT 93/24440; Patent documentation 2: Japanese patent gazette 60-506461; Patent documentation 3: Japanese patent gazette 52-59177; Patent documentation 4:58-11418; Patent documentation 5: Japanese patent gazette 55-164650; Patent documentation 6: English Patent 1152575; Patent documentation 7: Japanese patent gazette 11-33532; Patent documentation 8: Japanese patent gazette 1-299618; Patent documentation 9: United States Patent (USP) 5698734)
Summary of the invention
As mentioned above, multiple trial is used to improve separation independent of each other and drying operation.But do not operate the trial that comprehensively improves as a whole about separating with drying operation.
An object of the present invention is to provide a kind of with simple technology high energy efficiency ground preparation high purity aromatic dicarboxylic acid such as method of terephthalic acid.
The present inventor seeks the whole bag of tricks in the hope of reaching this purpose, and find: be not less than under the atmospheric pressure, use single general-purpose equipment that terephthalic acid cake is simply separated and wash, and after filter cake washing, reaction medium and/or the washings that is attached on the filter cake can be removed in continue using, lower filtrate of the high mother liquor of foreign matter content, foreign matter content and the crystal that contains liquid hardly can be reclaimed respectively.Thereby, can high yield make highly purified terephthalic acid.
Preparation method according to terephthalic acid of the present invention may further comprise the steps (A)~(D), (E)~(I) or (A)~(I).In these steps,, carry out with single general-purpose equipment Gu a liquid separates and washing step (B) and (C) and/or (G) and (I) being not less than under the atmospheric pressure.And in step (D) and/or (I), all remain on the terephthalic acid cake or interior liquid is all removed by evaporation.Terephthalic acid cake and/or be attached on the filter cake liquid had interior can be at least as a part that is attached to the energy of the liquid on the filter cake in order to evaporation.
(A) in based on the solvent that contains acetate, under the condition that catalyzer exists, with the step of molecular oxygen oxidation of p-xylene with the acquisition terephthalic acid.
(B) slurries that will contain terephthalic acid crystals are separated into the crude terephthalic acid filter cake and mainly contain the solid liquid separating step of the mother liquor of acetate.
(C) clean the step of crude terephthalic acid filter cake with washings.
(D) evaporation cleans that the back is any to be remained on the crude terephthalic acid filter cake/or the step of interior liquid.
(E) by under the condition that exists at catalyzer, crude terephthalic acid is contacted with hydrogen in main aqueous solvent, thus to the small part minimizing crude terephthalic acid the step of impurity.
(F) by reducing the pressure and temperature of reaction soln, the step of crystallization terephthalic acid in main aqueous solvent.
(G) slurries are separated into the solid liquid separating step of purified terephthalic filter cake and main aqueous mother liquor.
(H) clean the step of purified terephthalic filter cake with washings.
(I) evaporation cleans that the back is any to be remained on the purified terephthalic filter cake/or the step of interior liquid.
According to the present invention, through simple operationss such as separation and extraction, the filtrate and the highly purified terephthalic acid crystals that can obtain to have the high mother liquor of foreign matter content respectively, foreign matter content are lower.The present invention is owing to saving energy and simplifying technology thereby have industrial value.
The description of the drawings
Figure 1 shows that schema according to preferred production process of the present invention.
Embodiment
Describe the present invention now in detail.
According to the present invention, during the preparation terephthalic acid, Gu a liquid separates and washing step carries out continuously with individual equipment under certain pressure, this equipment can carry out obtaining a solid liquid separating step of terephthalic acid cake from reaction mixture, also can wash the step of terephthalic acid cake, as, with equipment such as screening separating centrifuge, rotary vacuum filter, flat rubber belting formula strainers.Then, after the washing terephthalic acid cake, filter cake washes in the low atmosphere of pressure ratio washing step pressure, thereby just can utilize terephthalic acid cake and/or the interior of liquid that be attached on the filter cake can evaporate the liquid that is attached on the filter cake.
Prepare method of terephthalic acid according to the present invention and comprise two reactions steps, i.e. oxidation step (A) and reduction reaction step (E), each step all link to each other with a solid liquid separating step and washing step.Carry out with single equipment commonly used with at least one links to each other in step (A) and the step (E) a solid liquid separating step and washing step, terephthalic acid cake prepared in these steps is washed to remove liquid attached to it.
Preferably, the solid liquid separating step and the washing step that link to each other with oxidation step or reduction reaction step carry out with single equipment commonly used, and terephthalic acid cake prepared in these steps is washed the liquid that is attached on the filter cake to remove.In this manual, step (A)~(D) refers to crude terephthalic acid (CTA) preparation process sometimes, and step (E)~(H) refers to purified terephthalic (PTA) preparation process sometimes.
[step (A)]
In step (A), in based on the solvent that contains acetate, under the condition that catalyzer exists, p-Xylol is by the oxidation of molecular oxygen institute.
Terephthalic acid is an aromatic dicarboxylic acid, and according to the present invention, terephthalic acid can make with common processes.Typically, terephthalic acid can react under the condition that catalyzer exists by p-Xylol and molecular oxygen and make, and described catalyzer contains heavy metal, as cobalt, iron and manganese, preferably contains the salt and the bromine of these heavy metals.
Used reaction medium preferably mainly contains acetate.As the consumption of acetic acid solvent 2~6 times of p-Xylol consumption.Except that acetate, acetic acid solvent also can contain other component, as water.The consumption of other component should not influence reaction, for example, account for gross weight 10% or lower.
Typically, the temperature that oxidizing reaction is carried out is 130~250 degrees centigrade, and preferred 150~230 degrees centigrade, pressure is 0.2~12Mpa, preferred 0.3~7Mpa, further preferred 1~3Mpa, most preferably 1~1.5Mpa.
The reactor that is used for oxidizing reaction has no particular limits, and the form of typical reactor is the complete tempering tank of belt stirrer.Reaction is preferably carried out continuously.Reaction times (mean residence time) is 30~300min.Oxidizing reaction can be carried out in a step.But in order to increase the transformation efficiency of p-Xylol, also can increase additional reactor to carry out oxidizing reaction in additional reactor in subordinate phase, temperature of reaction is lower slightly than the temperature in the main reactor, preferred 140~190 degrees centigrade.The form of the additional reactor in the subordinate phase except form is the reactor of complete mixing grooved, can be a plug flow reactor.
Oxidizing reaction can be converted into terephthalic acid with the p-Xylol of 95wt% or more (preferred 99wt% or more), thereby makes slurries, and wherein, the xln that contains terephthalic acid is separated.The impurity of trace also may produce, and impurity typically has 4-carboxyl benzaldehyde (being also sometimes referred to as " 4-CBA ").Usually, in the prepared mixture of oxidizing reaction, the content of 4-CBA is 500~500ppm of terephthalic acid.
[step (B)]
Step (B) is a solid liquid separating step, wherein, is separated into crude terephthalic acid filter cake and reaction mother liquor by the prepared slurries that contain terephthalic acid crystals of step (A).
Step (B) and subsequent step (C) preferably carry out with single general-purpose equipment.
And used here crude terephthalic acid refers to and does not also carry out reduction reaction to remove the filter cake of 4-CBA.Typical crude terephthalic acid contains the above 4-CBA of 500ppm that accounts for terephthalic acid.
Except acetate, also contain water, heavy metal catalyst, byproduct of reaction by the reaction mother liquor of consolidating a liquid resulting separation, as paratolunitrile, 4-CBA and methyl acetate as solvent.
Separate if the screening centrifuge decanter is used to a solid liquid, it is operated under the centrifugal force of 500~2000G usually.
Gu a liquid/gas separator is operated being not less than under the atmospheric pressure usually, preferably is not less than 0.2Mpa, further preferably is not less than 0.3Mpa; And be not higher than 22Mpa, preferably be not higher than 12Mpa, further preferably be not higher than 7Mpa, especially preferably be not higher than 1.5Mpa, most preferably be not higher than 1.2Mpa.And,, carry out Gu a liquid separates preferably under the situation of the pressure of the oxidation reaction process that has kept at least a portion step (A) for more energy-efficient.
When step (A) finished, if the pressure that requires to increase in the solid liquid/gas separator makes it carry out step (B) under the pressure that is higher than step (A), the pressure of separator can increase with for example pump when transmitting slurries.
[step (C)]
In step (C), the crude terephthalic acid filter cake that is obtained by step (B) is not less than under the atmospheric condition at pressure, cleans with washings.As described below, step (C) and step before (B) are preferably carried out in single general-purpose equipment.
Washings has no particular limits, and can be aqueous solvent, also can be oil-based solvent.But preferably contain with as the acetate of the major constituent of oxidation solvent identical contain acetic acid solution.The acetate component preferably is not less than 90%, except acetate, and the acetate esters that vaporization heat is relatively low, all available as methyl acetate, ethyl acetate, propyl acetate or butylacetate.
Pressure in the washing step is not less than normal atmosphere usually, preferably is not less than 0.2Mpa, further preferably is not less than 0.3Mpa; And be not higher than 22Mpa, preferably be not higher than 12Mpa, further preferably be not higher than 7Mpa, especially preferably be not higher than 1.5Mpa, most preferably be not higher than 1.2Mpa.
[single general-purpose equipment]
In order to reduce according to the used number of devices of method of the present invention, step (B) and step (C) are preferably carried out in single general-purpose equipment.And, by using single general-purpose equipment, Gu a liquid separating step (B) can carry out under identical pressure with washing step (C).
Step (B) and the used single general-purpose equipment of step (C) can be flat rubber belting formula strainer, rotary vacuum filter or screening centrifuge decanter (screening separating centrifuge).Wherein, the screening centrifuge decanter is only.The screening centrifuge decanter is for carrying out the integration apparatus that solid-liquid separates and washs simultaneously.When reacted crude terephthalic acid filter cake passed the washing position of band strainer, washings was sprayed on the filter cake, with this washing leaching cake.After passing through strainer, washings can be separated from filter cake and be recovered.
The screening centrifuge decanter can be disclosed the sort of of WO98/18750 or WO93/24440.It is separated into solid and liquid with slurries under action of centrifugal force.Solid is placed in the washing position that is sent to the band strainer on the spiral plate.
The material and the shape of strainer have no particular limits.Such as, it can be porcelain filter, wire screen or metal diagrid.Considered erosion resistance and stop up the tendency back and select suitable a kind of.If use the metal diagrid, that will select then that a part of filter cake can pass the sort ofly stops up avoiding.When screening drew off the centrifuge decanter, all mother liquors that are attached on the filter cake all had been removed at filter cake, and therefore, the contained impurity of such filter cake seldom.
In the screening centrifuge decanter, mother liquor and washings can reclaim respectively, but may have the part washings sneaks in the mother liquor.The ability of the washing leaching cake that screening centrifuge decanter tool is very high also under high pressure is suitable for industrial application.
If use the screening centrifuge decanter, Gu pressure in the liquid separating step (B) and the pressure in the washing step (C) are basic identical.
[step (D)]
In the step (D), remain in by on the filter cake that makes by step (C)/or interior liquid be removed by evaporation.
Moisture eliminator used among the present invention has no particular limits,, as long as it can carry out any of drying operation described below, but be typically the possess discharge valve pressure drying device of (it abbreviates " valve " sometimes as).Discharge valve has no particular limits, as long as it can be transported to low-tension side from the high-tension side with powder.It can be successive type or batch-type.For example, it can be disclosed the sort of of WO91/09661.Except the single valve door, also available as a plurality of valves that United States Patent (USP) 5589079 is disclosed, disclosed valve or the valving of WO00/71226 or United States Patent (USP) 4127935 is also available.
In the discharge valve upstream, be equipped with filter cake reserved slit (filter cake chamber) usually.Washing and isolating filter cake are retained in the filter cake reserved slit in step (C).By opening valve, filter cake is extracted in the powder storage tanks then.The opening degree of valve is preferred controlled, so that total energy keeps a certain amount of filter cake in the filter cake reserved slit.
The working pressure of filter cake reserved slit and step (C) is basic identical.Pressure in the pressure ratio filter cake reserved slit in the powder storage tanks is low.By low pressure atmosphere is arrived in the press cake release (flushing) that adds in the filter cake reserved slit, be attached to the boiling point lowering of the liquid on the filter cake.Because the reduction of boiling point, sensible heat promptly is stored in the interior energy in terephthalic acid cake and/or attached thereon the liquid, is used to evaporate the liquid that is attached on the filter cake.Before filter cake was about to draw off from the filter cake reserved slit, the temperature of filter cake (TB) preferably was higher than the liquid boiling point (Bp) under atmospheric pressure that is attached on the filter cake.
In the discharge valve upstream, the pressure in the moisture eliminator remains on usually and is not less than normal atmosphere, preferably is not less than 0.2Mpa, further preferably is not less than 0.3Mpa; And be not higher than 22Mpa, preferably be not higher than 12Mpa, further preferably be not higher than 7Mpa, especially preferably be not higher than 1.5Mpa, most preferably be not higher than 1.2Mpa.
If the screening centrifuge decanter is used to carry out step (B) and step (C), then the pressure in step (B) and the step (C) remains on and is not less than normal atmosphere.When terephthalic acid cake was transported in the filter cake reserved slit, terephthalic acid cake should keep their pressure in the screening centrifuge decanter in step (D).Therefore, pressure in step (B) and step (C) and the pressure in the filter cake reserved slit of step (D) (being the pressure of valve upstream) all should be not less than normal atmosphere, preferably are not less than 0.2Mpa, further preferably are not less than 0.3Mpa; And be not higher than 22Mpa, preferably be not higher than 12Mpa, further preferably be not higher than 7Mpa, especially preferably be not higher than 1.5Mpa, most preferably be not higher than 1.2Mpa.If the pressure gap between the pressure in barometric point and the above steps is too small, then in when flushing, it is not enough that the release of interior energy is tending towards, and therefore is difficult to the liquid on the filter cake of being attached to of evaporation q.s.If pressure is too big, then must increase the withstand voltage properties of various device and parts, this can improve the expense of whole plant.
Before being about to discharging, the temperature of filter cake need remain on 50~350 degrees centigrade, and preferred 100~300 degrees centigrade, further preferred 130~250 degrees centigrade.Be attached to liquid boiling point Bp and preferred 5~200 degrees centigrade of the difference (being that TB deducts Bp) between the temperature T B of filter cake before being about to discharging under atmospheric pressure on the filter cake, further preferred 10~150 degrees centigrade, preferred especially 15~100 degrees centigrade.
The internal pressure of powder storage tanks preferably keeps 1 normal atmosphere, but in the flushing process, the gas that is produced when being attached to the liquid evaporation on the filter cake can increase to the pressure of powder storage tanks a little higher than normal atmosphere, and this gas can be discharged from.In the case, the pressure of powder storage tanks can be brought down below normal atmosphere.
The steam that part steps (D) produces can be recovered and recycle in the step of preparation terephthalic acid.The steam that step (D) produces comprises that mainly filter cake when washing with washings, remains in the steam of the washings on the filter cake.If use in the step (C) acetate as washings, its steam then, promptly acetic acid vapor can be by easily as the solvent of the oxidizing reaction of step (A).This steam is the reactor of supplying step (A) directly, and perhaps before the supply response device, it can be condensed in heat exchanger to reclaim its heat energy.
And at least a portion is clamped into the step that the crystal that contains terephthalic acid in the steam that step (D) produces could be recovered and resupply the preparation terephthalic acid.When in step (D), utilize to be stored in filter cake and/or to be attached to interior in the liquid on the filter cake can wash the crude terephthalic acid filter cake and be attached to liquid on the filter cake time with evaporation, the pressure of system can sharply descend in a short period of time.This crystal that may cause containing terephthalic acid is clamped in the steam of the liquid evaporation generation that is attached on the filter cake.In order to improve the productive rate of terephthalic acid, the terephthalic acid crystals that this steam is carried secretly preferably is recovered.The crystal that reclaims can resupply CTA or PTA preparation process.But because the resulting crystal of step (D) has experienced oxidizing reaction, if only by reclaiming terephthalic acid crystals, the preferred supplying step of this crystal (E) as bag filter.More preferably, the terephthalic acid crystals that is clamped in the steam that step (D) produces contacts with the solution that mainly contains acetate to make slurries, direct or indirect supplying step of the slurries that obtain thus (A) and/or step (B).
[step (E)]
In step (E), the crude terephthalic acid that is made by step (D) is dissolved in the main aqueous solvent, contacts at least a portion impurity of removing in the crude terephthalic acid filter cake with hydrogen by CTA under the condition that catalyzer exists.
When carrying out reduction reaction, solubleness is lower at normal temperatures owing to crude terephthalic acid, must be to its heating so that its be dissolved in the main aqueous solvent.Reduction reaction is carried out under 230~330 degrees centigrade usually, preferred 250~310 degrees centigrade.Reduction reaction also must be carried out under the pressure that is higher than the solvent vapour pressure to keep solvent to be in liquid state.Reduction reaction is carried out between 3~12Mpa usually, preferred 5~10Mpa.
In step (E), the 4-CBA that is included in the crude terephthalic acid is reduced into paratolunitrile.
[step (F)]
In step (F), the pressure and temperature of the reaction soln that is obtained by step (E) is lowered so that terephthalic acid crystallization in main aqueous solvent.
Crystallization can be carried out continuously or intermittently carry out.Typically, crystallization is carried out continuously, and pressure reduces by 2~6 times, preferred 3~5 times in the mode that progressively reduces simultaneously.In crystallisation process, because the flash distillation of solvent, the temperature of system reduces.Because the solubleness of paratolunitrile in water that 4-CBA reduction obtains is than terephthalic acid height, the terephthalic acid preferential precipitation.If but pressure is reduced to normal atmosphere, temperature will be reduced to about 100 degrees centigrade, cause paratolunitrile and terephthalic acid cocrystallization thus.Therefore, final crystallization pressure preferably is not less than 0.2Mpa, further preferably is not less than 0.3Mpa, especially preferably is not less than 0.5Mpa.Its upper limit preferably is not higher than 3Mpa, further preferably is not higher than 1Mpa, especially preferably is not higher than 0.7Mpa.The steam that produces in the crystallisation process can reclaim also recycle in the step of preparation terephthalic acid.
[step (G)]
Step (G) is a solid liquid separating step, and wherein, the slurries that contain terephthalic acid crystals that made by step (F) are separated into purified terephthalic filter cake and main aqueous reaction mother liquor.
Here used " purified terephthalic " refers to the terephthalic acid that 4-CBA was wherein carried out reduction reaction.Contained 4-CBA is not higher than the 30ppm of terephthalic acid in the common purified terephthalic.
Gu a liquid separating step carries out with the mode identical with step (B), identical pressure basically.But in step (G), the upper limit of pressure range especially preferably is not higher than 1Mpa, most preferably is not higher than 0.7Mpa.
Except that water as solvent, Gu the reaction mother liquor of a liquid resulting separation also contains the paratolunitrile that the acetate, heavy metal catalyst, byproduct of reaction 4-CBA, the 4-CBA that sneak in a spot of oxidizing reaction formerly obtain through reduction, or the like.
[step (H)]
In step (H), the purified terephthalic filter cake that is obtained by step (G) washs with washings, and except washings was mainly moisture, this step was identical with step (C).
[single general-purpose equipment]
Step (G) and step (H) are preferably carried out in single general-purpose equipment, and it can be used the sort of in the step (C).
A kind of as in these equipment, the screening centrifuge decanter is the integration apparatus that an a kind of solid liquid lock out operation and washing operation all can carry out.When the purified terephthalic filter cake that obtains when reaction passed the washing position of band strainer, washings was sprayed on the filter cake, with this washing leaching cake.After passing through strainer, washings can be separated from filter cake and be recovered.But the part washings may be sneaked in the mother liquor.
Washings has no particular limits, and can be that aqueous solvent also can be an oil-based solvent.But preferably as mother liquor, contain the liquid of water as its major constituent.Can wash with washings and remove owing to be attached to mother liquor on the filter cake, when filter cake was discharged out from the screening centrifuge decanter, the foreign matter content of filter cake had reduced.But the part washings can be attached on the filter cake.
[step (I)]
In step (I), all are attached on the purified terephthalic/or interior liquid all be removed by evaporation, except purified terephthalic replaces crude terephthalic acid is dried, step (I) is identical with step (D).
[practical place of the present invention]
The invention is characterized in: the crystal that can reclaim mother liquor, filtrate respectively and have small amount of liquid attached to it by simple operationss such as separation, washing and extractions.Because crystal can reclaim with small amount of liquid attached to it, therefore the volume that this just may omit independent moisture eliminator or reduce moisture eliminator can save energy.Mother liquor can be reclaimed without separating with filtrate.But since mother liquor in foreign matter content than high slightly in the filtrate, they preferably are separated from each other and recycle in different steps respectively.
The separable recovery of mother liquor and filtrate has brought to whole process flow and has been highly profitable and actual advantage.Advantage is following listed.
At least a portion washings (filterable washings) that is used for washing the crude terephthalic acid filter cake can reclaim and handle the step of back recycle in the preparation terephthalic acid with it or with it.Because the foreign matter content in the filtrate is lower than in the isolated mother liquor, it can be used as the direct feed of solvent of oxidizing reaction and gives step (A).Filtrate can be used as also that absorption agent absorbs and reclaims the terephthalic acid crystals that is clipped in the solvent vapour that step (D) produces.
Reclaim the crystal that contains terephthalic acid from the filtrate that is used for washing the crude terephthalic acid filter cake to small part, and also be possible the step that the crystal that reclaims resupplies the preparation terephthalic acid.Crystal can a liquid separates or impel terephthaldehyde's acid crystal to reclaim through reducing temperature or pressure by filtrate is directly consolidated.Any solid isolating common method of a liquid all can be in order to reach this purpose, such as centrifugal separation, filtration method or the precipitator method.The crystal that reclaims can resupply any oxidation step or hydrogen reduction step.But because therefore preferred oxidation step, particularly step (A) and/or the step (B) supplied with finished in these reactions basically.
And, reclaim at least a portion contains the acetate of separating by slurries being consolidated liquid separation from the crude terephthalic acid slurries mother liquor, and in the step of preparation terephthalic acid, carry out recycle with the mother liquor of recovery or with the mother liquor after its processing.For example, the oxidation solvent that such mother liquor can be used as step (A) is recycled, because it contains a lot of useful components, comprises catalyst for oxidation reaction and reaction medium.
Mainly contain by slurries being consolidated a liquid separates from least a portion and to reclaim the crystal that contains terephthalic acid in the mother liquor of the acetate from the crude terephthalic acid slurries, separated, and the crystal that reclaims to be resupplied in the step of preparation terephthalic acid also be possible.Crystal can be directly carry out an additional solid liquid lock out operation with separate the mother liquor that obtains through a solid liquid, and perhaps isolated mother liquor reclaims and obtains to carry out an additional solid liquid lock out operation after impelling crystallization again through cooling or step-down at mother liquor.An additional solid liquid lock out operation that carries out after impelling crystallization can carry out with any separation method commonly used, such as centrifugal separation, filtration method or the precipitator method.The crystal that reclaims can resupply any oxidation step or hydrogen reduction step, but preferred supplying step (A), because contain acetic acid solvent in the crystal.
The temperature and pressure and the temperature and pressure in the solid liquid sepn process that separate the mother liquor that obtains through a solid liquid are substantially the same.Isolating mother liquor is preferably supplied with oxidation step when keeping temperature and pressure.By with high temperature mother liquor supply response device, can reduce that oxidation reaction product is heated to predetermined required energy or the sensible heat of temperature of reaction.This helps the recovery of energy in the oxidation reaction process.If but all recycles of separation mother liquor, then contained impurity tends to accumulate in system in the mother liquor, thereby reduces the quality of the terephthalic acid of solid-liquid separation gained.Therefore, Bu Fen separation mother liquor (preferred 10~30%) must be cleaned to prevent the accumulation of impurity.Mother liquor after the purification contains acetic acid solvent and is used for the catalyzer of oxidizing reaction, and derives and next organic impurity from the p-Xylol impurities in raw materials, as M-nitro benzoic acid.Keep high temperature as fruit mother liquor, the mother liquor after the purification also may contain the terephthalic acid that is contained in the separation mother liquor.Mother liquor after the purification is condensed and has high boiling component as the residual solvent of residue with evaporation.Residue contains as the cobalt compound of catalyst component and manganic compound and organic impurity.Catalyst component can reclaim in follow-up catalyst recovery and circulation step and circulate.In order to reclaim the terephthalic acid that is dissolved in the high temperature mother liquor, by evaporating solvent, mother liquor is rinsed and condensation.When mother liquor came condensation by flushing and cools off, terephthalic acid can precipitate.Throw out can separate by a solid liquid and reclaims.Reclaim the solid ingredient that obtains thus and preferably supply with oxidation step.Behind the mother liquor that separates by a solid liquid through purifying, from residual separation solution, can selectively separate and reclaim active substance such as acetate, water and catalyzer, and separation that obtains thus and recover materials can recycles in the step of preparation terephthalic acid.
And, by the purified terephthalic slurries being carried out resulting, the main aqueous separation mother liquor at least a portion of solid-liquid separation is recovered and directly or handle the back recycle in the step of preparation terephthalic acid.Separate mother liquor and can carry out solid-liquid separation, distillation or purify, and the reduction reaction solvent cycle that can be used as step (E) is utilized with film.
And, from least a portion of the mother liquor that mainly contains the water of separating from purified terephthalic, can reclaim the crystal that contains terephthalic acid.The crystal that reclaims can resupply the step of preparation terephthalic acid.Crystal preferably by condensation and/or refrigerated separation mother liquor with the precipitation terephthalic acid crystals, then mother liquor is carried out solid-liquid separation and reclaims and obtain.Solid-liquid separation can adopt any method commonly used, such as centrifugal separation, filtration method and the precipitator method.Reclaim the crystal (secondary crystal) that obtains thus and can resupply oxidation step or hydrogen reduction step.But because their intermediate content is higher, so one of them of preferred supply oxidation step, especially step (A), resulting here mother liquor (secondary mother liquid) also can be direct or indirect is recycled as the solvent of the reduction reaction of step (E).
And, at least a portion that is used to wash the washings (filtrate) of refining terephthalic acid cake can reclaim and directly or recycle after treatment in the step of preparation terephthalic acid.Foreign matter content for the reclaim washings that obtains is lower, and it can be used as the reduction reaction solvent of step (E) easily.The filtrate that obtains that reclaims can be distilled or purify with film.It also can be used as the terephthalic acid crystals that absorption agent is used for absorbing and reclaiming the solvent vapour that sandwiches step (I) generation.
If be used to wash the washings of refining terephthalic acid cake contain just like, terephthalic acid by strainer, the crystal that contains terephthalic acid can be by solid-liquid separation from reclaiming to the washings of small part, and resupply the step of preparation terephthalic acid.Crystal can carry out solid-liquid separation after temperature or pressure make its crystallization and obtains by the direct solid-liquid separation of washings or through reducing.Solid-liquid separation can adopt any common method, such as centrifugal separation, filtration method and the precipitator method.The crystal that reclaims can resupply the preparation process of CTA or PTA, but since their reaction be done, so preferred supplying step (F) and/or separating step (G).
At least a portion of the steam that step (I) produces can reclaim also recycle in the step of preparation terephthalic acid.The steam that step (I) produces is mainly the washings steam that is attached on the filter cake in the washing process of step (H).Therefore, if in the step (H), water is as washings, and water vapour produces in step (I).Such water vapour can be used as the reduction reaction solvent of step (E) easily.Such steam is the reactor of supplying step (E) directly, and perhaps before the supply response device, it can be condensed in heat exchanger to reclaim its heat energy.
Sandwich that crystalline at least a portion that contains terephthalic acid in the steam that step (I) produces can be recovered and recycle in the step of preparation terephthalic acid.Be stored in filter cake and/or be attached to the interior energy of the liquid on the filter cake when the purified terephthalic filter cake is rinsed in step (I) with utilization, when boiling off the liquid that is attached on the filter cake, pressure in the system sharply descends in a short period of time, and this crystal that may cause containing terephthalic acid sandwiches in the steam that is attached to the liquid on the filter cake.In order to improve the productive rate of terephthalic acid, the terephthalic acid crystals that this steam is carried secretly preferably reclaims.The crystal that reclaims can resupply the preparation process of CTA or PTA.But because resulting crystal has passed through reduction reaction and washing, it can be used as the finished product.Terephthalic acid crystals preferably with the form of slurries, reclaims by slurries are contacted with main aqueous solution.The slurries that obtain thus can supplying step (E)~(G).
[preferred implementation]
With reference now to Fig. 1, preferred implementation according to preparation method of the present invention is described.
Among Fig. 1, numeral 1 is the used oxidation reactor of step (A); 2 is crystallizer tank; 3 for carrying out the separator/washer of step (B) and step (C); 4 is the powder storage tanks.Between separator/washer 3 and powder storage tanks, have filter cake reserved slit and discharge valve (all not shown).Separator/washer 3 prepared crude terephthalic acid filter cakes wash into powder storage tanks 4 from the filter cake reserved slit, and the liquid that here is attached on the filter cake is evaporated.Numeral 5 is the used reduction reactor of step (E); 6 is the used crystallizer tank of step (F); 7 for carrying out the separator/washer of step (G) and step (H); 8 is moisture eliminator.Between separator/washer 7 and moisture eliminator 8, have filter cake reserved slit and discharge valve (all not shown).Separator/washer 7 prepared purified terephthalic are rinsed moisture eliminator 8 and are attached to all liquid on the filter cake with evaporation.Moisture eliminator 8 also plays the powder storage tanks simultaneously.For the liquid that is attached on the filter cake mainly is water, simply it can not be evaporated fully by flushing, so filter cake carries out drying in moisture eliminator 8.
Numeral 11 is represented solvent recovering system (as distillation column).The mother liquor that it stays after with oxidizing reaction becomes single component with the mixture separation that contains acetate that obtains from other position of flow process.Mother liquor contains the acetate as solvent, water and high boiling component such as impurity and the catalyst for oxidation reaction that oxidizing reaction produces.Acetate can be supplied with oxidation reactor 1 by pipeline 110.Water can be conveyed into by pipeline 112, and, goes out of use or recycle when purifying or after purifying as process water.Remain in the impurity of bottom land, then after having reclaimed useful component such as catalyzer, go out of use.
The washings (mainly containing acetate) that is used for separator/washer 3 can be transported to oxidation reactor by pipeline 131 after washing.To separate with washings through the terephthalic acid of strainer if desired, then washings is transported in the solid-liquid separator 31 by pipeline 132.Isolating terephthalic acid of institute and acetate recycle on stream.
When terephthalic acid cake was washed into the powder storage tanks, the liquid that is attached on the filter cake evaporated and gasifies with sandwiching part terephthalic acid in gas.The gas that contains terephthalic acid crystals is reverted back to liquid state and is transported to solid-liquid separator 41 it be separated into terephthalic acid and mainly contain the solution of acetate.On the other hand, in solid withdrawer 42, the terephthalic acid crystals that sandwiches in gas contacts with acetate to obtain slurries, and gas is condensed.Slurries and phlegma are supplied to oxidation reactor by pipeline 101.
Be transported to solid-liquid separator from separator/washer 7 mother liquors that separate, that be used for reduction reaction by pipeline 121.In solid-liquid separator 21, terephthalic acid and the reaction intermediate that is precipitated out by condensation and/or refrigerated separation mother liquor such as paratolunitrile is separated and reclaim.Main aqueous residue reaction mother liquor goes out of use, perhaps purifies by evaporation or with film, and as the process water recycle.Contained active substance in the water can be reclaimed by ion-exchange or absorption as catalyst for oxidation reaction or paratolunitrile.
The used filtrate (solution is mainly moisture) of separator/washer 7 is transported to solid-liquid separator 51 by pipeline 151 after washing.In solid-liquid separator 51, contain the solid ingredient of the terephthalic acid that sees through from strainer and washings by separated from one another.Isolated terephthalic acid of institute and water can be distinguished recycle in flow process.In this case, solid ingredient preferably is returned in the crystallizer tank 6, and isolated washings preferably is returned in the reduction reactor 5 simultaneously.The washings itself that contains terephthalic acid also can be recovered during the course and need not pass through solid-liquid separator 51.
When terephthalic acid cake was rinsed into moisture eliminator 8, the liquid that is attached on the filter cake evaporated and gasifies with sandwiching part terephthalic acid in gas.The gas that contains terephthalic acid is condensed into liquid state and is transported to solid-liquid separator 61, and is separated into terephthalic acid and main aqueous liquid attached to it.On the other hand, in solid recovery system 62, the terephthalic acid crystals that sandwiches in gas contacts with water to obtain slurries, and condensation of gas becomes liquid simultaneously.Slurries and phlegma can be transported to any one of reduction reactor 5, crystallizer tank 6 or separator/washer 7.
Any one of solid-liquid separator 21,31,41,51,61 all may be equipped with clearer.By solid separated from one another and liquid, or independent solid or independent liquid all can resupply any one step of preparation terephthalic acid by pipeline 101,102,103,105,106,107,171,175,176 and/or 177.Solid may be in the same place by remix with liquid, and, when walking around solid-liquid separation step, solidliquid mixture also can directly be supplied with any one step of preparation terephthalic acid by pipeline 101,102,103,105,106,107,171,175,176 and/or 177.Its part also can go out of use.Final product is by pipeline 109 dischargings.
[embodiment]
Describe now embodiments of the invention, must be understood that by people, the present invention be not limited to for embodiment.
P-Xylol, 5 times of weight are fed in the acetate of p-Xylol and as Cobaltous diacetate, manganese acetate and the hydrogen bromide of catalyzer and can produce in the liquid-phase oxidation reactor in workshop of terephthalic acid with 39 tons speed per hour, and be 197 degrees centigrade in temperature, pressure is oxidizing reaction 90 minutes (average retention time) under the condition of 1.45Mpa.Catalyzer uses with such amount: the total content of cobalt metal is the 280ppm of weight of solvent, and the total content of manganese is the 280ppm of weight of solvent, and the total content of bromine is the 700ppm of weight of solvent.
Gas as for carry out oxidizing reaction with molecular oxygen can use air.Airborne oxygen content is 21%.Pressurized air is supplied to reactor, and the volume content of oxygen is 5% from the gas (back refers to waste gas sometimes) of reactor discharging.Then, slurries successive through oxidation is transported in the additional oxidation reactor of low temperature, and air (oxygen content: 21%) also be supplied to as oxidizing reaction gas, with at 190 degrees centigrade, 1.3Mpa condition under carry out the additional oxidizing reaction 35 minutes (average retention time) of low temperature, thereby the volume content of oxygen is 6% in the waste gas.
The slurries that made by the additional oxidizing reaction of low temperature under atmospheric pressure carry out solid-liquid separation continuously in three grades of intermediate treatment grooves, the crude terephthalic acid particle is dry in moisture eliminator as thermal source with steam.
Institute's exsiccant terephthaldehyde granulates is converted into water-soluble serous, adds hydrogen purification then in the reduction reaction atmosphere of 280 degrees centigrade and 8Mpa.Then, it is carried out continuous crystallisation.In last crystallizer tank, pressure is reduced to 0.62Mpa, and temperature is reduced to 160 degrees centigrade.
[embodiment 1]
The slurries that contain purified terephthalic that aforesaid way obtains are admitted in the incorporate screening centrifuge decanter of separator/washer in (screening separating centrifuge), and filter cake is by flush valve (discharge valve) then.Used flush valve is disclosed the sort of of WO91/09661.At the pressure that is configured in the filter cake reserved slit of valve upstream is 0.64Mpa, and the powder storage tanks that is configured in the valve downstream then is exposed under the normal atmosphere.Valve is opened a second at every turn, discharging 23kg filter cake.Slurries supply with in the screening centrifuge decanter with 4.5 tons speed per hour and washings (water) with per hour 2.0 tons of supplies.
The mother liquor that whizzer is separated contains the impurity of 900ppm, in order to wash the impurity that isolated washing filter cakes liquid then contains 240ppm.The filter cake of discharging contains the impurity of 115ppm.Their content liquid (being attached to the weight of the weight/drying back filter cake of the liquid on the filter cake) is 4.3%.
[comparative example 1]
Except not using the washings, test is carried out under the condition identical with embodiment 1.The filter cake of discharging contains the impurity of 160ppm.
[comparative example 2]
Suppose the inseparable recovery of mother liquor and washings, contained impurity is 590ppm in the recovery liquid.
[comparative example 3]
Suppose and do not use flush valve,,, infer that the content of liquid is 8.8% then according to thermal equilibrium if interiorly can be not useable for evaporating the liquid that is attached on the filter cake.
[result]
When embodiment 1 compares with comparative example 1, screen centrifuge decanter as can be seen and in washing filter cakes, play a very important role.When comparative example 1 compares with comparative example 2, by independently reclaiming washings, can utilize the low washings of foreign matter content easily as can be seen.When embodiment 1 compares with comparative example 3, by energy in using, can save a lot of energy as can be seen.These advantages are by obtaining during use screening centrifuge decanter in conjunction with interior.
[embodiment 2]
The terephthalic acid slurries that make by the low-temperature oxidation reaction are introduced directly into screening centrifuge decanter (screening separating centrifuge) when walking around crystallizer tank.Pressure in the screening centrifuge decanter remains on about 0.93Mpa.Slurries are with per hour 20 tons speed supply, and washings (acetate) is with per hour 18 tons speed supply.
In the screening centrifuge decanter,, slurries are separated into filter cake and mother liquor by solid-liquid separation.Filter cake washs with washings (acetate).The filter cake that is washed is transported to the filter cake reserved slit, and the pressure of filter cake reserved slit remains on about 0.93Mpa.In the bottom of filter cake reserved slit, the flush valve disclosed be equipped with as WO91/09661, by opening flush valve, the filter cake that is stored in the filter cake reserved slit is sent to the powder storage tanks that is exposed under the normal atmosphere.When filter cake when the filter cake reserved slit is sent to the powder storage tanks, be stored in the liquid that is attached on the filter cake and the interior heat energy that can be released and be attached to the liquid on the filter cake as evaporation in the filter cake.After the flushing, the content liquid of filter cake (being attached to the dry weight of the weight/filter cake of the liquid on the filter cake) is 0.2%.
Therefore, in the preparation process of CTA, under high pressure,, can eliminate necessary crystallizer tank and moisture eliminator in CTA preparation process up to now by separating and washing terephthalic acid slurries.This can simplify whole plant.
[embodiment 3]
In embodiment 2, the reaction mother liquor of screening in the centrifuge decanter is separated and reclaim under the pressure of 185 degrees centigrade temperature and 0.93Mpa.By purifying the reaction mother liquor of 20wt%, can be in oxidation reactor with the reaction mother liquor recycle of remainder.
That is exactly not to be depleted as the required energy of oxidizing reaction by under high pressure separating and wash the terephthalic acid slurries, can effectively use the energy that is stored in the reaction mother liquor.
[embodiment 4]
In embodiment 2, when filter cake in when flushing, the solution major part that mainly contains acetate that is attached on the filter cake is evaporated with 2 tons speed per hour.The filter cake of drying part is sandwiched in the acetic acid vapor after the evaporation.Acetic acid vapor is introduced in the solid recovery system from its bottom by pipeline then, and liquid acetate is sprayed into from the top of solid recovery system, so that the acetate that sprays contacts with the terephthalic acid that sandwiches in acetic acid steam, obtains slurries thus.Resulting slurries are directly supplied with oxidation step.
Acetic acid vapor by the solid recovery system contains a spot of methyl acetate by-product.Therefore, by reclaiming acetate in the steam and methyl acetate and they being supplied with oxidation step, can reduce the loss of acetic acid solvent.

Claims (16)

1. one kind prepares method of terephthalic acid, and it comprises:
(A) in based on the solvent that contains acetate, under the condition that catalyzer exists, contain the step of the slurries of terephthalic acid crystals with acquisition with the molecular oxygen oxidation of p-xylene;
(B) be not less than under the atmospheric pressure, said slurries be separated into the solid-liquid separating step of the mother liquor that contains the crude terephthalic acid filter cake and mainly contain acetate;
(C) being not less than under the barometric point, clean the step of said crude terephthalic acid filter cake with washings; And
(D) evaporation cleans that the back is any to be remained on the said crude terephthalic acid filter cake/or the step of interior liquid,
It is characterized in that:
Said step (B) and step (C) are carried out in single general-purpose equipment, and said terephthalic acid cake or remain on the said terephthalic acid cake/or interior liquid had interior can be used as evaporation of residual in the step (D) in said terephthalic acid cake/or at least a portion of energy of liquid.
2. one kind prepares method of terephthalic acid, and it comprises:
(E) by under the condition that exists at catalyzer, said crude terephthalic acid is contacted with hydrogen in main aqueous solvent, thus to the small part minimizing crude terephthalic acid the step of impurity;
(F) by reducing the pressure and temperature of reaction soln, the crystallization terephthalic acid is to make the step of the slurries that contain terephthalic acid crystals in main aqueous solvent;
(G) being not less than under the atmospheric pressure, said slurries are separated into the solid-liquid separation step of purified terephthalic filter cake and main aqueous mother liquor;
(H) being not less than under the atmospheric pressure, clean the step of said purified terephthalic filter cake with washings; And
(I) evaporation cleans that the back is any to be remained on the said purified terephthalic filter cake/or the step of interior liquid,
It is characterized in that:
Said step (G) and step (H) are carried out in single general-purpose equipment, and said terephthalic acid cake or remain on the terephthalic acid cake/or interior liquid had interior can be used as evaporation of residual in the step (I) in said terephthalic acid cake/or at least a portion of energy of liquid.
3. one kind prepares method of terephthalic acid, and it comprises:
(A) in based on the solvent that contains acetate, under the condition that catalyzer exists, contain the step of the slurries of terephthalic acid crystals with acquisition with the molecular oxygen oxidation of p-xylene;
(B) be not less than under the atmospheric pressure, said slurries be separated into the solid-liquid separating step of the mother liquor that contains the crude terephthalic acid filter cake and mainly contain acetate;
(C) being not less than under the atmospheric pressure, clean the step of said crude terephthalic acid filter cake with washings;
(D) evaporation cleans that the back is any to be remained on the said crude terephthalic acid filter cake/or the step of interior liquid;
(E) by under the condition that exists at catalyzer, said crude terephthalic acid is contacted with hydrogen in main aqueous solvent, thus to the small part minimizing crude terephthalic acid the step of impurity;
(F) by reducing the pressure and temperature of reaction soln, the said terephthalic acid of crystallization is to make the step of the slurries that contain terephthalic acid crystals in main aqueous solvent;
(G) said slurries are separated into the solid-liquid separation step of purified terephthalic filter cake and main aqueous mother liquor;
(H) clean the step of said purified terephthalic filter cake with washings; And
(I) evaporation cleans that the back is any to be remained on the purified terephthalic filter cake/or the step of interior liquid, it is characterized in that:
Said step (B) and step (C) are carried out in single general-purpose equipment, and said terephthalic acid cake or remain on the terephthalic acid cake/or interior liquid had interior can be used as evaporation of residual in the step (D) in terephthalic acid cake/or at least a portion of energy of liquid.
4. one kind prepares method of terephthalic acid, and it comprises:
(A) in based on the solvent that contains acetate, under the condition that catalyzer exists, contain the step of the slurries of terephthalic acid crystals with acquisition with the molecular oxygen oxidation of p-xylene;
(B) be not less than under the atmospheric pressure, said slurries be separated into the solid-liquid separating step of the mother liquor that contains the crude terephthalic acid filter cake and mainly contain acetate;
(C) clean the step of said crude terephthalic acid filter cake with washings;
(D) evaporation cleans that the back is any to be remained on the said crude terephthalic acid filter cake/or the step of interior liquid;
(E) by under the condition that exists at catalyzer, said crude terephthalic acid is contacted with hydrogen in main aqueous solvent, thus to the small part minimizing crude terephthalic acid the step of impurity;
(F) by reducing the pressure and temperature of reaction soln, the crystallization terephthalic acid is to make the step of the slurries that contain terephthalic acid crystals in main aqueous solvent;
(G) being not less than under the atmospheric pressure, said slurries are separated into the solid-liquid separation step of purified terephthalic filter cake and main aqueous mother liquor;
(H) being not less than under the atmospheric pressure, clean the step of said purified terephthalic filter cake with washings; And
(I) evaporation cleans that the back is any to be remained on the purified terephthalic filter cake/or the step of interior liquid,
It is characterized in that:
Said step (G) and step (H) are carried out in single general-purpose equipment, and said terephthalic acid cake or remain on the terephthalic acid cake/or interior liquid had interior can be used as evaporation of residual in the step (I) in terephthalic acid cake/or at least a portion of energy of liquid.
5. one kind prepares method of terephthalic acid, and it comprises:
(A) in based on the solvent that contains acetate, under the condition that catalyzer exists, contain the step of the slurries of terephthalic acid crystals with acquisition with the molecular oxygen oxidation of p-xylene;
(B) be not less than under the atmospheric pressure, said slurries be separated into the solid-liquid separating step of the mother liquor that contains the crude terephthalic acid filter cake and mainly contain acetate;
(C) being not less than under the atmospheric pressure, clean the step of said crude terephthalic acid filter cake with washings;
(D) evaporation cleans that the back is any to be remained on the said crude terephthalic acid filter cake/or the step of interior liquid;
(E) by under the condition that exists at catalyzer, said crude terephthalic acid is contacted with hydrogen in main aqueous solvent, thus to the small part minimizing crude terephthalic acid the step of impurity;
(F) by reducing the pressure and temperature of reaction soln, the said terephthalic acid of crystallization is to make the step of the slurries that contain terephthalic acid crystals in main aqueous solvent;
(G) being not less than under the atmospheric pressure, said slurries are separated into the solid-liquid separation step of purified terephthalic filter cake and main aqueous mother liquor;
(H) being not less than under the barometric point, clean the step of said purified terephthalic filter cake with washings; And
(I) evaporation cleans that the back is any to be remained on the purified terephthalic filter cake/or the step of interior liquid, it is characterized in that:
Said step (B) and step (C) are carried out in single general-purpose equipment; Said step (G) and step (H) are carried out in single general-purpose equipment, and said terephthalic acid cake or remain on the terephthalic acid cake/or interior liquid had interior can be used as evaporation of residual in step (D) and the step (I) in terephthalic acid cake/or at least a portion of energy of liquid.
6. as any one described preparation method of terephthalic acid in the claim 1,3,4,5, it is characterized in that used washings contains acetate in the said step (C).
7. as any one described preparation method of terephthalic acid in the claim 1,3,4,5 and 6, it is characterized in that at least a portion of the steam that produces in the said step (D) is recovered and handles the back recycle in the step of preparation terephthalic acid with it or with it.
8. preparation method of terephthalic acid as claimed in claim 7 is characterized in that, at least a portion of the steam that produces in the said step (D) is recovered and handles the back recycle in step (A) with it or with it.
9. as any one described preparation method of terephthalic acid in the claim 1,3,4,6 and 8, it is characterized in that, the crystalline at least a portion that contains terephthalic acid that sandwiches in the steam that produces in said step (D) is recovered, and the crystal that is reclaimed resupplies in the step of preparation terephthalic acid.
10. preparation method of terephthalic acid as claimed in claim 9 is characterized in that, the crystalline at least a portion that contains terephthalic acid that sandwiches in the steam that produces in the said step (D) is recovered, and the crystal that is reclaimed resupplies in the step (A).
11., it is characterized in that the washings that is used for said step (H) is mainly moisture as any one described preparation method of terephthalic acid in the claim 2~10.
12. as any one described preparation method of terephthalic acid in the claim 2~11, it is characterized in that at least a portion of the steam that produces in the said step (I) is recovered and handles the back recycle in the step of preparation terephthalic acid with it or with it.
13. preparation method of terephthalic acid as claimed in claim 12 is characterized in that, at least a portion of the steam that produces in the said step (I) is recovered and handles the back recycle in said step (E) with it or with it.
14. as any one described preparation method of terephthalic acid in the claim 2~13, it is characterized in that, the crystalline at least a portion that contains terephthalic acid that sandwiches in the steam that produces in the said step (I) is recovered, and the crystal that is reclaimed resupplies in the step of preparation terephthalic acid.
15. preparation method of terephthalic acid as claimed in claim 14, it is characterized in that, the crystalline at least a portion that contains terephthalic acid that sandwiches in the steam that produces in the said step (I) is recovered, and the crystal that is reclaimed resupplies said step (E) and/or step (F).
16., it is characterized in that said single general-purpose equipment or each said single general-purpose equipment are the screening centrifuge decanter as any one described preparation method of terephthalic acid in the claim 1~15.
CNB2003801025896A 2002-11-14 2003-11-14 Process for producing terephthalic acid Expired - Lifetime CN100383105C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP330754/2002 2002-11-14
JP2002330753 2002-11-14
JP330753/2002 2002-11-14

Related Child Applications (2)

Application Number Title Priority Date Filing Date
CN 200810082532 Division CN101244999B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid
CN2007101609799A Division CN101186573B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid

Publications (2)

Publication Number Publication Date
CN1708472A true CN1708472A (en) 2005-12-14
CN100383105C CN100383105C (en) 2008-04-23

Family

ID=35581825

Family Applications (3)

Application Number Title Priority Date Filing Date
CN 200810082532 Expired - Lifetime CN101244999B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid
CNB2003801025896A Expired - Lifetime CN100383105C (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid
CN2007101609799A Expired - Lifetime CN101186573B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN 200810082532 Expired - Lifetime CN101244999B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid

Family Applications After (1)

Application Number Title Priority Date Filing Date
CN2007101609799A Expired - Lifetime CN101186573B (en) 2002-11-14 2003-11-14 Process for producing terephthalic acid

Country Status (1)

Country Link
CN (3) CN101244999B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100441560C (en) * 2005-09-05 2008-12-10 株式会社日立制作所 Continuous preparation method for aromatic dicarboxylic acid
CN101774907A (en) * 2009-01-09 2010-07-14 谭伟业 Unrefined phthalic acid powder delivery system and application method thereof
CN105130791A (en) * 2006-09-15 2015-12-09 奇派特石化有限公司 A process to produce an enrichment feed

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102421741B (en) * 2009-04-24 2014-03-26 英威达技术有限公司 Methods, processes, and systems for treating and purifying crude terephthalic acid and associated process streams
JP2015160829A (en) * 2014-02-27 2015-09-07 三菱化学株式会社 Method of producing terephthalic acid

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3729284B2 (en) * 1995-09-22 2005-12-21 三菱瓦斯化学株式会社 Method for producing high purity terephthalic acid
JP3864563B2 (en) * 1998-06-11 2007-01-10 三井化学株式会社 Method for producing high purity terephthalic acid
JP2001139514A (en) * 1999-11-16 2001-05-22 Mitsubishi Chemicals Corp Method for producing aromatic dicarboxylic acid

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100441560C (en) * 2005-09-05 2008-12-10 株式会社日立制作所 Continuous preparation method for aromatic dicarboxylic acid
CN105130791A (en) * 2006-09-15 2015-12-09 奇派特石化有限公司 A process to produce an enrichment feed
CN101774907A (en) * 2009-01-09 2010-07-14 谭伟业 Unrefined phthalic acid powder delivery system and application method thereof

Also Published As

Publication number Publication date
CN101186573B (en) 2011-12-14
CN101244999A (en) 2008-08-20
CN101186573A (en) 2008-05-28
CN100383105C (en) 2008-04-23
CN101244999B (en) 2013-03-27

Similar Documents

Publication Publication Date Title
CN105001073B (en) Low energy consumption material consumption, the PTA production methods and system of few waste discharge
CN1305830C (en) Method of removing iron contaminants from liquid streams during the manufacture and/or purification of aromatic acids
CN1085889A (en) The preparation method of refining terephthalic acid
CN1310867C (en) Process for the oxidative purification of terephthalic acid
CN1066651A (en) Preparation is suitable for being reduced into the method for the crude terephthalic acid of pure terephthalic acid (PTA)
CN1910130A (en) Process for production of a dried carboxylic acid cake suitable for use in polyester production
CN1910129A (en) Process for production of a carboxylic acid/diol mixture suitable for use in polyester production
EP0764627A1 (en) Process for producing highly pure terephthalic acid
CN1914145B (en) Method for producing aromatic carboxylic acid
US20060014979A1 (en) Process for producing terephthalic acid
CN102395553A (en) Method for recovering crystals from a crystallization slurry
CN1960960A (en) Method for producing high-purity terephthalic acid
CN1708472A (en) Process for producing terephthalic acid
CN1145620C (en) Process to afford gamma butyrolactone and tetrahydrofuran
CN1751015A (en) Method for producing aromatic carboxylic acid
CN109879712B (en) Synthesis method of 1, 9-decadiene
CN204874349U (en) PTA production system that low energy consumption material consumption, few wastes material discharged
EP1870393B1 (en) Apparatus and method for recovering acetic acid and catalyst in process for preparation of 2,6-Naphthalenedicarboxylic acid
CN1518478A (en) Process for producing compound
JP2017095391A (en) Manufacturing method of aromatic dicarboxylic acid
CN1307109C (en) Method for recovering aromatic carboxylic acid in waste water
TW201209031A (en) Process and system
CN103121950B (en) The process for purification of crude terephthalic acid
CN2791044Y (en) Device for producing terephthalic acid
US7396457B2 (en) Apparatus and method for recovering acetic acid and catalyst in process for preparation of 2,6-naphthalenedicarboxylic acid

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CP01 Change in the name or title of a patent holder
CP01 Change in the name or title of a patent holder

Address after: Within Japan Tokyo Chiyoda pill 1 chome No. 1

Co-patentee after: TOMOE ENGINEERING Co.,Ltd.

Patentee after: MITSUBISHI CHEMICAL Corp.

Address before: Within Japan Tokyo Chiyoda pill 1 chome No. 1

Co-patentee before: TOMOE ENGINEERING Co.,Ltd.

Patentee before: MITSUBISHI RAYON Co.,Ltd.

TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20170912

Address after: Within Japan Tokyo Chiyoda pill 1 chome No. 1

Co-patentee after: TOMOE ENGINEERING Co.,Ltd.

Patentee after: MITSUBISHI RAYON Co.,Ltd.

Address before: Japan's Tokyo port, 33 No. 8 Chicago

Co-patentee before: TOMOE ENGINEERING Co.,Ltd.

Patentee before: MITSUBISHI CHEMICAL Corp.

CX01 Expiry of patent term
CX01 Expiry of patent term

Granted publication date: 20080423