CN1132192A - Technique for prepn. of high pureness meta-dimethyl benzene - Google Patents
Technique for prepn. of high pureness meta-dimethyl benzene Download PDFInfo
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Abstract
A process for preparing high-purity metaxylene from mixed xylene or o-xylene containing ethylbenzene (less than 1.0 wt.%) by isomerization-adsorptive separation, including rectification to separate o-xylene and light and heavy arenes, multi-column adsorption of residual p-xylene and metaxylene, and rectification of residue to separate out desorpting agent. Obtained metaxylene has a purity higher than 99%.
Description
The invention belongs to a kind of preparation technology of m-xylene.
There is several different methods from xylol, to isolate m-xylene at present, mainly contains rectifying substep freeze crystallization, sulfonation method, HF-BF
3Solvent extraction process etc.
USSR (Union of Soviet Socialist Republics) oil magazine (Nefti.1970, No.13,50～60 pages) report, the xylol raw material that will contain ethylbenzene is told o-Xylol through the two posts series connection rectifying of 100+50 theoretical tray, cut away ethylbenzene through three posts of 3 * 150 theoretical trays series connection rectifying again, remaining between, p-Xylol obtains m-xylene and p-Xylol respectively through freezing fractional crystallization and rectifying.This kind method is no problem technically, is exactly that energy expenditure is too big, generally seldom adopts.
Adopt sulfonation method to prepare m-xylene and realized industrialization already.German patent DE 1468913 reports are raw material with slag tar or fraction oil, through concentrated acid sulfonation, generate m-xylene sulfonic acid, just can obtain m-xylene through separating hydrolysis again.Sulfonation method need use sulfuric acid, to the equipment requirements harshness, and the acid sludge contaminate environment that generates, not a kind of ideal method therefore.
Japan GC company (KYOKA1-SHI, 1970,49 (515), 151～158 pages) uses HF-BF
3For the m-xylene in complexing agent and the raw material (MX) reaction generates MX-HF-BF
3Complex compound is isolated this complex compound and is heated decomposition, just can obtain the m-xylene that purity reaches 99.5 heavy %.The advantage of this method is that technology is reliable, product purity height, but HF-BF
3Corrodibility very strong, very harsh to the requirement of equipment, and easily cause personal injury.
In order to overcome above-mentioned shortcoming, begin the seventies to occur to be catalyzer and to be that sorbent material employing isomerization-fractionation by adsorption combined process prepares the new technology of xylene isomer, but all be to be used to prepare p-Xylol with the molecular sieve with solid acid.For example toray company (JP7700937) is with Pt/HM-Al
2O
3Being catalyzer, is sorbent material with the KY molecular sieve, adopts isomerization-fractionation by adsorption combined process to prepare p-Xylol.U.S. Mobil company (USP3,856,873) is that catalyzer carries out the dimethylbenzene non-hydro isomerizaiton and prepares p-Xylol with the ZSM-5 zeolite.Research Institute of Petro-Chemical Engineering had once carried out research (petrochemical complex, 1980 the 3rd phases, the 177th page of dimethylbenzene non-hydro isomerizaiton and fractionation by adsorption the seventies; Petrochemical complex, 1975 the 1st phases, the 65th page), promptly with C
8Aromatic hydrocarbons is raw material, is catalyzer with HZSM-5, with the KBaY molecular sieve be sorbent material through isomerization-fractionation by adsorption combined process, can obtain highly purified p-Xylol.The used sorbent material of dimethylbenzene fractionation by adsorption all optionally adsorbs p-Xylol in above-mentioned each technology, and purpose all is to obtain pure p-Xylol mutually from desorption, and inhale surplus mutually in because the adsorption selectivity of each component is close, can not obtain single pure component.
American UOP company is at USP4, and 940, thus reported the method that the preferentially adsorbed m-xylene is isolated p-Xylol in 830.They are sorbent material preferentially adsorbed m-xylene with the Y zeolite of Ni or Cu exchange, thereby p-Xylol then reaches isolating purpose as inhaling excess discharge adsorption column.The adsorption selectivity difference of other components was less during the weak point of this technology was to adsorb mutually, was difficult to each other separate, and therefore still can not obtain highly purified m-xylene.
In sum, be that sorbent material is produced in the prior art of xylene isomer with molecular sieve, highly purified p-Xylol can be obtained, but highly purified m-xylene can not be obtained.If the absorption charging contains ethylbenzene, then tell after the p-Xylol through fractionation by adsorption, remaining is the mixture of xylol and ethylbenzene.
It is raw material with xylol or with the o-Xylol that purpose of the present invention just provides one, the processing method of preparation high pureness meta-dimethyl benzene.
The present invention is a raw material with ethyl-benzene level xylol or o-Xylol seldom, prepares highly purified m-xylene by isomerization-fractionation by adsorption combined process, promptly earlier excises light aromatic hydrocarbons and C with rectifying before fractionation by adsorption
9Above heavy aromatics, and rectifying separation goes out o-Xylol, the remaining p-Xylol and the mixture of m-xylene carry out fractionation by adsorption, and the control absorption separation condition makes can obtain highly purified m-xylene from inhaling excess.
Fig. 1 is for being the process flow diagram of raw material production high pureness meta-dimethyl benzene with the xylol.Wherein 1 for preheating stove, and 2 is isomerization reactor, and 3 is light aromatic hydrocarbons knockout tower, and 4 is the o-Xylol knockout tower, and 5 is the heavy aromatics knockout tower, and 6 is adsorption separation device, and 7 is desorption thing knockout tower, and 8 for inhaling the excess knockout tower, and B represents benzene, and T represents toluene, C
9 +Expression C
9And C
9Above heavy aromatics, OX represents o-Xylol, and PX represents p-Xylol, and MX represents m-xylene.
Fig. 2 is for being the process flow diagram of raw material production high pureness meta-dimethyl benzene with the o-Xylol, and wherein the meaning of each mark is identical with Fig. 1.
Fig. 3 is not for containing the m-xylene adsorptive separation technology schematic flow sheet of displacement section.
Fig. 4 is the m-xylene adsorptive separation technology schematic flow sheet that contains the displacement section.
When preparing meta-xylene take mixed xylenes as raw material, undertaken by process flow diagram shown in Figure 1. Be that the mixed xylenes raw material is introduced into ortho-xylene knockout tower 4. Contain ortho-xylene and C in the tower 49 +Materials at bottom of tower enter heavy separation column 5, the materials at bottom of tower C in the tower 59 +As the accessory substance moving-out device. Overhead paraxylene in the tower 4 and meta-xylene (PX+MX) enter adsorption separation device 6, through adsorbing separation, obtain inhaling excess and desorption thing. The suction excess enters to inhale and just obtains highly purified meta-xylene (MX) product after excess knockout tower 8 steams desorbing agent. And the desorption thing enters desorption thing knockout tower 7 steam desorbing agent after, remaining paraxylene (PX) and the overhead ortho-xylene (OX) of mixture in heavy separation column 5 of meta-xylene (MX) enter and preheat stove 1, then enter isomerization reactor 2, isomerized products enters light aromatic hydrocarbons knockout tower 3, the overhead benzene of tower 3 and toluene (B+T) are as the accessory substance moving-out device, materials at bottom of tower enters ortho-xylene knockout tower 4 with the mixed xylenes raw material that newly advances, and finishes a cycle period with this. The desorbing agent that wherein steams in tower 7 and the tower 8 loops back adsorption separation device 6 to be continued to use. When containing the displacement section in the adsorption separation device, can as required the part in tower 7 materials at bottom of towers be looped back adsorption separation device 6 and use as displacer.
Although the isomerization reaction in this technique does not produce ethylbenzene, in order to guarantee the purity of meta-xylene in the product, the ethyl-benzene level that must control in the mixed xylenes raw material preferably weighs % less than 0.7 less than 1.0 heavy %; Should control simultaneously benzene in the raw material, toluene, and C9 +The content of aromatic hydrocarbons is preferably all less than 1.0 heavy %, if light arene content is higher in the raw material, raw material can be introduced into tower 3 and separates light aromatic hydrocarbons and enter later on tower 4 again.
Light aromatic hydrocarbons knockout tower 3 in this technology, o-Xylol knockout tower 4, heavy aromatics knockout tower 5, desorbing agent knockout tower 7 and 8 and this technology in isomerization reaction all operate by operational condition of the prior art, wherein (B+T) content in the tower 3 bottoms material should be less than 0.5 heavy %, OX content in the tower 4 cat head materials should be less than 1.0 heavy %, the C in the tower 5 cat head materials
9 +Content should be less than 0.5 heavy %, desorbing agent content in the tower 7 bottoms material needn't be controlled too tight, but preferably less than 1.0 heavy %, but the desorbing agent content in tower 8 bottom products should be controlled at below the 0.5 heavy % so that the purity of product m-xylene reaches the specification of quality of regulation.
Multicolumn fractionation by adsorption flow process is adopted in the separation of m-xylene in this technology, can be gas phase operation, also can be liquid-phase operation.Six adsorption columns that drawn among Fig. 3, according to the flow process among Fig. 3, six adsorption columns are connected successively, are divided into adsorption zone and desorption district by material import and export, and adsorption zone and desorption district have two and four adsorption columns respectively.Absorption charging (PX+MX) enters post 1 through feed valve, and the communicating valve through 2 on post 1 and post enters post 2 again, is emitted to inhale excess and enter by post 2 baiting valves and inhales excess knockout tower 8.Desorbing agent enters post 3 through feed valve, pass through post 4, post 5, post 6 more successively, emit the desorption thing and enter desorption thing knockout tower 7 from the baiting valve at 6 ends of post, the communicating valve that reach post 6 and post 1 between between post 2 and the post 3 this moment is closed, be that adsorption zone and desorption distinguish, remaining intercolumniation communicating valve is opened.In this one-period, require the dimethylbenzene absorption charging and the desorption dosage of the intact defined of pump simultaneously.Behind the intact specified amount of pump, each is imported and exported the while pass a post backward, post 2, post 3 are adsorption zone at this moment, post 4, post 5, post 6, post 1 are the desorption district, and promptly the intercolumniation communicating valve that reaches between post 3 and the post 4 between post 1 and the post 2 is closed, and all the other intercolumniation communicating valves are opened, raw material enters from post 2, from post 3 blowings; Desorbing agent enters from post 4, from post 1 blowing.So cyclical operation can obtain highly purified m-xylene product.
Six adsorption columns that drawn among Fig. 3, but this technology is not confined to six post fractionation by adsorption, can be the multicolumn fractionation by adsorption beyond six posts, wherein adsorption zone contains two adsorption columns at least, and three adsorption columns are contained in the desorption district at least.The working method of the multicolumn fractionation by adsorption beyond six posts is identical with the method for above-mentioned six post fractionation by adsorption, just contained adsorption column number and above-mentioned different in adsorption zone and the desorption district at this moment.
In order to improve the yield of m-xylene, in adsorption separation system, can add displacement zone, be about to p-Xylol and be injected in the adsorption column that adsorbs the dimethylbenzene raw material, the m-xylene that is attracted on the sorbent material is replaced, thereby reach the purpose that improves the m-xylene once through yield.Have the adsorption separation system of displacement section, its process flow diagram is seen Fig. 4.Fig. 4 eight adsorption columns that drawn, but as previously mentioned, this technology is not confined to eight post fractionation by adsorption, wherein displacement zone contains two adsorption columns at least, and adsorption zone contains two adsorption columns at least, and three adsorption columns are contained in the desorption district at least.According to the flow process among Fig. 4, eight adsorption columns are connected successively, be divided into displacement, absorption, three districts of desorption by material import and export, have two, two and four adsorption columns respectively.The displacer p-Xylol enters post 1 by feed valve, and the communicating valve that passes through 2 on post 1 and post again enters post 2, and the communicating valve that passes through 3 on post 2 and post again enters post 3; Absorption charging (PX+MX) enters post 3 by feed valve with the displacement liquid from post 2, and the communicating valve that passes through 4 on post 3 and post again enters post 4, is emitted to inhale excess and enter by post 4 baiting valves and inhales excess knockout tower 8.Desorbing agent enters post 5 through feed valve, emits the desorption thing and enters desorption thing knockout tower 7 from post 8 bottom baiting valves behind post 6, post 7, post 8, and between post 4 and the post 5, the intercolumniation communicating valve between post 8 and the post 1 is closed at this moment, and remaining intercolumniation communicating valve is opened.In this one-period, require p-Xylol displacer, dimethylbenzene absorption charging and the desorbing agent of the intact specified amount of while pump, after pump is intact, each is imported and exported the while pass a post backward, adjust the corresponding open and-shut mode of each valve, this moment, post 2,3 was a displacement zone, and post 4,5 is an adsorption zone, and post 6,7,8,1 is the desorption district, so cyclical operation can obtain highly purified m-xylene product continuously, and the once through yield of m-xylene than Fig. 3 not the situation of the section of displacement obviously improve.
Used displacer can be the pure p-Xylol that adds in the displacement section, it also can be the desorption thing of from knockout tower 7, telling (PX+MX), because when adsorption separation system contains the displacement section, the purity of p-Xylol can be used as displacer fully and uses than higher in this desorption thing.The amount of displacer is decided according to residual m-xylene amount in the adsorption column in the displacement section, and should not influence the purity of inhaling m-xylene in the excess.As being sorbent material with KBaY and under 160～200 ℃, carrying out Gas Phase Adsorption when separating that the consumption of displacer is displacer/sorbent material=0～0.25 (gram/gram, every post, the phase weekly)
Among the present invention fractionation by adsorption sorbent used can be the various molecular sieve type sorbent materials of preferentially adsorbed p-Xylol in the prior art, as KY, KBaY etc.
In order to guarantee that the purity of m-xylene in the product reaches the specification of quality of regulation, dimethylbenzene charging (PX+MX) amount during fractionation by adsorption can not be too much, simultaneously for the utilization ratio that improves sorbent material and the output and the yield of m-xylene, the temperature in the time of need be according to selected sorbent material and fractionation by adsorption is determined maximum feed amount and reasonable inlet amount by test.For example when being sorbent material with the KBaY molecular sieve, and carry out Gas Phase Adsorption when separating under 160～200 ℃, the inlet amount of dimethylbenzene (PX+MX) is dimethylbenzene/sorbent material=0.1～0.5 (gram/gram, phase weekly, every post).
The used desorbing agent of fractionation by adsorption can be all desorbing agents of energy desorption dimethylbenzene in the prior art among the present invention, and it is relevant with selected sorbent material.Desorbing agent commonly used has toluene, p-Diethylbenzene etc., wherein toluene preferably.The consumption of desorbing agent depends on the dimethylbenzene residual quantity on the sorbent material, and this amount should not influence the specification of quality that excess is inhaled in next circulation, and the consumption of desorbing agent is generally desorbing agent/sorbent material=0.3～6.0 (gram/gram, every post, phase weekly).
The used temperature and pressure of adsorption separation process is selected according to the condition and range of prior art among the present invention, and they still adopt liquid-phase operation relevant with adopting gas phase operation, and are also relevant with selected sorbent material.As when adopting gas phase operation, and when using the KBaY molecular sieve as sorbent material, the fractionation by adsorption temperature is 160～200 ℃, and pressure is normal pressure.When selecting the air speed of absorption air speed and desorption air speed and displacer, should guarantee to adsorb, the efficient of desorption, consider technologic mutual coupling again.The volume space velocity scope is during each liquid that can select for use: adsorption volume air speed=0.18～1.0 o'clock
-1, desorption volume space velocity=0.7～15 o'clock
-1, displacer volume space velocity=0～0.3 o'clock
-1
Isomerization reaction among the present invention is carried out according to prior art, can be gas phase or liquid phase reaction, also can be non-hydrogen or faces H-H reaction, but should control the especially generation of ethylbenzene of by product as far as possible.
When being the feedstock production m-xylene with the o-Xylol, undertaken by technical process shown in Figure 2, be that the o-Xylol raw material is introduced into and preheats stove 1, enter isomerization reactor 2 then, isomerized products enters light aromatic hydrocarbons knockout tower 3, the overhead product benzene of tower 3 and toluene (B+T) are as the by product moving-out device, and the bottoms material enters o-Xylol knockout tower 4.Contain o-Xylol and C in the tower 4
9 +The bottoms material enter heavy aromatics knockout tower 5, the bottoms material C in the tower 5
9 +As the by product moving-out device.Overhead product PX+MX in the tower 4 enters adsorption separation device 6 as the absorption charging, through after the fractionation by adsorption, obtain inhaling excess and desorption thing, inhaling excess enters and inhales excess knockout tower 8 and steam desorbing agent and just obtain highly purified m-xylene (MX) product, and the desorption thing enters desorption thing knockout tower 7 steam desorbing agent after, the remaining p-Xylol (PX) and the overhead product o-Xylol (OX) of mixture in heavy aromatics knockout tower 5 of m-xylene (MX) loop back and preheat stove 1, as the isomerization reaction charging, finish a loop cycle with the o-Xylol raw material that newly advances with this.Wherein the desorbing agent that steams in tower 7 and the tower 8 loops back adsorption separation device 6 continuation uses.When containing the displacement section in the adsorption separation device, can as required the part in the tower 7 bottoms material be looped back adsorption separation device 6 and use as displacer.
When being the feedstock production m-xylene with the o-Xylol, except the difference of position, feed(raw material)inlet, other all technical process and operation steps condition thereof are all identical with the operation steps condition with the technical process when being raw material with the xylol described above.
No matter adopt technology provided by the invention is to be raw material with xylol, is raw material with o-Xylol still, under proper condition, can obtain the m-xylene product of purity greater than 99 weight %.Sulfonation method and HF-BF with present production m-xylene
3Solvent extraction process is compared, and technology of the present invention does not have particular requirement to equipment, does not have serious problem of environmental pollution.Compare with rectifying substep freeze crystallization, technology of the present invention is simpler, and energy expenditure is less.Can implement explained hereafter m-xylene provided by the invention with the existing same device of producing p-Xylol, not need extra investment.
The following examples will the present invention is described further.
The explanation of this example can be used for a kind of isomerization reaction condition among the present invention.
(trade names are AF-5 with the high-silica zeolite catalyzer, the production of dying of Shanghai seven factories) 15 restrain in the 50 milliliters of small stationary bed bioreactors of packing into, feed the xylol raw material and carry out xylene isomerization reaction, and carry out continuous run in long period, situation about changing according to catalyst activity between on-stream period is suitably adjusted temperature of reaction.1000 hours running average results that under gas phase operation condition and liquid-phase operation condition, carry out isomerization reaction have respectively been listed in the table 1.
The composition of used xylol raw material in the present embodiment (heavy %) is: ethylbenzene 0.68, p-Xylol 21.35, m-xylene 16.21, o-Xylol 61.57.
IMX represents the m-xylene isomerization rate in the table 1, BYP vice product rate, and it is defined as:
Table 1
| Temperature of reaction reaction pressure weight hourly space velocity IMX BYP remarks (℃) (MPa) (time -1) (heavy %) (heavy %) |
| 280～320 0.2～0.3 1.0 48.81 1.18 gas phase operation 300～350 3.9～4.0 1.0 48.34 2.96 liquid-phase operations |
The isolating operational condition of Gas Phase Adsorption that does not contain the displacement section among this example explanation the present invention.
Get 300 gram (butt) NaY molecular sieves (Qilu Petrochemical company catalyst plant is produced), with 1200 milliliters of 5% heavy KCl solution 90～100 ℃ of exchanges one hour, by this condition repeated exchanged 4 times again, then with 2 BaCl that weigh %
2Solution 1800ml 90～100 ℃ down exchange once, the molecular sieve after the exchange spends the cationic water washing after do not have chlorion, 100 ℃ of oven dry down, obtains the KBaY molecular sieve.This KBaY molecular sieve and wilkinite are pressed molecular sieve: after the weight ratio water of wilkinite=8: 2 is mediated, be extruded into the bar of 2 millimeters of diameters, drying is broken into 20～30 purpose particles, 500 ℃ of following calcinations 4 hours, promptly obtain the used KBaY sorbent material of this example again.
Above-mentioned KBaY sorbent material is packed in the adsorption separation device shown in Figure 3, and this device is provided with six adsorption columns, divides absorption and two districts of desorption, wherein adsorption zone is 2 posts, the desorption district is 4 posts, and the volume of each post is 100 milliliters, fills above-mentioned KBaY sorbent material (about 29 grams) in each post.
With the isomerization product among the embodiment 1 through after separating light aromatic hydrocarbons and heavy aromatics and distilling o-Xylol, obtain consisting of the heavy % in ethylbenzene=0.56, the heavy % in m-xylene=66.94, the heavy % in p-Xylol=32.28, the fractionation by adsorption raw material of the heavy % in o-Xylol=0.22.This raw material is fed in the above-mentioned adsorption separation device that sorbent material is housed, with toluene is desorbing agent, do not carry out the Gas Phase Adsorption separation according to what prior figures 3 was described with the fractionation by adsorption operating process of displacement section, fractionation by adsorption result under the different operating condition lists in table 2, table 3, table 4 and the table 5, wherein respectively
Table 2 is the separating resulting under the different fractionation by adsorption temperature, and wherein the dimethylbenzene inlet amount is dimethylbenzene/sorbent material=0.27 (gram/gram, every post, the phase weekly), and the dimethylbenzene liquid hourly space velocity is 0.65 o'clock
-1, the consumption of desorbing agent toluene is toluene/sorbent material=0.96 (gram/gram, every post, the phase weekly), pressure is normal pressure.
Table 3 is the separating resulting under the different absorption air speeds, and wherein temperature is 170 ℃, and all the other conditions are with table 2.
Table 4 is the separating resulting under the dimethylbenzene different feeds amount, and wherein the dimethylbenzene liquid hourly space velocity is 0.54 o'clock
-1, all the other conditions are with table 3.
Table 5 is the separating resulting of desorbing agent toluene different amounts, and wherein the dimethylbenzene inlet amount is dimethylbenzene/sorbent material=0.27 (gram/gram, every post, the phase weekly), and all the other conditions are with table 4.
Table 2
| The fractionation by adsorption temperature (℃) | Cycle number | Inhale m-xylene once through yield (%) in the excess oil | Inhale m-xylene purity in the excess oil (heavy %) |
| ????165 ????185 | The 68 72nd | ????????55 ????????55 | ???????99.7 ???????99.4 |
Table 3
| The dimethylbenzene liquid hourly space velocity (time -1) | Cycle number | Inhale m-xylene once through yield (%) in the excess oil | Inhale m-xylene purity in the excess oil (heavy %) |
| ????0.54 ????0.81 | The 45 49th | ????????55 ????????54 | ??????99.8 ??????99.7 |
Table 4
| Dimethylbenzene/sorbent material (gram/gram, every post, phase weekly) | Cycle number | Inhale m-xylene once through yield (%) in the excess oil | Inhale m-xylene purity in the excess oil (heavy %) |
| ?????????0.27 ?????????0.30 ?????????0.33 | The 64 the 58 53rd | ???????55 ???????55 ???????55 | ??????99.7 ??????99.3 ??????99.0 |
Table 5
| Dimethylbenzene/sorbent material (gram/gram, every post, phase weekly) | Cycle number | Inhale m-xylene once through yield (%) in the excess oil | Inhale m-xylene purity in the excess oil (heavy %) |
| ????????0.96 ????????0.81 ????????0.72 | The 41 the 37 33rd | ????????55 ????????55 ????????54 | ??????99.9 ??????99.8 ??????99.7 |
Use the effect of displacement section in the present embodiment explanation fractionation by adsorption.
KBaY sorbent material among the embodiment 2 is packed in the adsorption separation device shown in Figure 4, this device has 8 adsorption columns, divide displacement, absorption, three districts of desorption, wherein displacement zone is 2 posts, adsorption zone is 2 posts, the desorption district is 4 posts, and the volume of each post is 100 milliliters, fills this sorbent material (29 gram) approximately in each post.
Adopt the fractionation by adsorption raw material among the embodiment 2, with toluene is desorbing agent, with pure p-Xylol is displacer, carries out fractionation by adsorption according to the fractionation by adsorption operation steps that has the displacement section that prior figures 4 is described, and wherein volume space velocity is as follows during the liquid of each charging: the displacer p-Xylol is 0.32 o'clock
-1, raw material dimethylbenzene is 0.4 o'clock
-1, desorbing agent toluene is 1.72 o'clock
-1, switching cycle is 12 minutes, and the fractionation by adsorption temperature is 170 ℃ (gas phase operation), and pressure is normal pressure.After running is stable, record the C that inhales in the excess oil
6M-xylene purity is 99.1 heavy % in the aromatic hydrocarbons, is 99.0% for absorption charging m-xylene once through yield.
From present embodiment as can be seen, adsorption separation process adopts after the displacement section, can improve the once through yield of m-xylene greatly.
Claims (10)
1. the preparation technology of a m-xylene, it is characterized in that using ethyl-benzene level to be raw material less than the xylol of 1.0 heavy %, adopt fractionation by adsorption-isomerization combined process, earlier tell o-Xylol through rectifying, the mixture of overhead product p-Xylol and m-xylene carries out fractionation by adsorption, cut its suction excess and obtain the product m-xylene, the o-Xylol that its desorption thing and above-mentioned rectifying are told carries out isomerization reaction together and obtains xylol, and the xylol that this isomerization reaction is obtained carries out fractionation by adsorption by above-mentioned steps again with the above-mentioned xylol raw material that newly advances.
2. according to the technology of claim 1, contain rectifying in wherein said fractionation by adsorption-isomerization combined process and tell the step that heavy aromatics is told in light aromatic hydrocarbons and rectifying.
3. according to the technology of claim 2, adopt the molecular sieve type sorbent material of preferentially adsorbed p-Xylol in the wherein said adsorption separation process.
4. according to the technology of claim 3, adopt the multicolumn adsorption separation device in the wherein said adsorption separation process.
5. according to claim 1,2,3 or 4 technology, can contain the displacement section in the wherein said adsorption separation device.
6. the preparation technology of a m-xylene, it is characterized in that using ethyl-benzene level to be raw material less than the o-Xylol of 1.0 heavy %, adopt isomerization-fractionation by adsorption combined process, earlier the o-Xylol raw material is obtained xylol through isomerization reaction, to tell o-Xylol through rectifying through xylol, the mixture of overhead product p-Xylol and m-xylene carries out fractionation by adsorption, cut its suction excess and obtain the product m-xylene, the o-Xylol that its desorption thing and above-mentioned rectifying are told returns the isomerization reaction device again and carries out isomerization reaction again with the above-mentioned o-Xylol raw material that newly advances.
7. according to the technology of claim 6, contain rectifying in wherein said isomerization-fractionation by adsorption combined process and tell the step that heavy aromatics is told in light aromatic hydrocarbons and rectifying.
8. according to the technology of claim 7, adopt the molecular sieve type sorbent material of preferentially adsorbed p-Xylol in the wherein said adsorption separation process.
9. according to the technology of claim 8, adopt the multicolumn adsorption separation device in the wherein said adsorption separation process.
10. according to claim 6,7,8 or 9 technology, can contain the displacement section in the wherein said adsorption separation device.
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| CN1939883B (en) * | 2005-08-10 | 2012-12-05 | 法国石油公司 | Process for separating meta-xylene from a feed of aromatic hydrocarbons |
| CN105829269A (en) * | 2013-12-17 | 2016-08-03 | Bp北美公司 | Energy efficient naphthene recycle via the use of a side draw fractionation tower and partial condensation |
| CN105085155B (en) * | 2014-05-05 | 2018-03-20 | 中国石油化工股份有限公司 | A kind of production method of paraxylene |
| CN111138238A (en) * | 2020-01-03 | 2020-05-12 | 朱志荣 | Process method for producing m-xylene by mixing carbon octa-arene |
| CN114805006A (en) * | 2022-05-13 | 2022-07-29 | 中国石油大学(北京) | Method and device for separating p-xylene from xylene mixture |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200454B (en) * | 1991-09-05 | 1993-02-21 | Inst Of France Petroleum | |
| IT1262941B (en) * | 1992-06-15 | 1996-07-22 | Enichem Spa | PROCEDURE FOR THE SEPARATION OF MIXTURES OF AROMATIC HYDROCARBONS C8 |
-
1995
- 1995-03-30 CN CN95103051A patent/CN1045286C/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1089272C (en) * | 1998-06-10 | 2002-08-21 | 中国石油化工集团公司 | Adsorbent for preparing meta-xylene by adsorption and separation and its preparing process |
| CN1939883B (en) * | 2005-08-10 | 2012-12-05 | 法国石油公司 | Process for separating meta-xylene from a feed of aromatic hydrocarbons |
| CN101732883B (en) * | 2010-01-21 | 2012-05-30 | 天津天大天海化工新技术有限公司 | Adsorptive rectification tower for decoloring aromatic solvent oil and process method thereof |
| CN105829269A (en) * | 2013-12-17 | 2016-08-03 | Bp北美公司 | Energy efficient naphthene recycle via the use of a side draw fractionation tower and partial condensation |
| CN105829269B (en) * | 2013-12-17 | 2017-12-08 | Bp北美公司 | The energy-saving ring alkane recycling for evaporating tower and partial condensation using sideing stream |
| CN105085155B (en) * | 2014-05-05 | 2018-03-20 | 中国石油化工股份有限公司 | A kind of production method of paraxylene |
| CN111138238A (en) * | 2020-01-03 | 2020-05-12 | 朱志荣 | Process method for producing m-xylene by mixing carbon octa-arene |
| CN111138238B (en) * | 2020-01-03 | 2022-06-07 | 朱志荣 | Process method for producing m-xylene by mixing carbon octa-arene |
| CN114805006A (en) * | 2022-05-13 | 2022-07-29 | 中国石油大学(北京) | Method and device for separating p-xylene from xylene mixture |
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|---|---|
| CN1045286C (en) | 1999-09-29 |
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