CN1230583A - Non-hydrogenation method and equipment to remove the diene impurity in etherified material - Google Patents

Abstract

A non-hydrogenation refining method for removing diolefin impurities in etherification raw materials, which is to contact the etherification raw materials with an acidic solid catalyst under the conditions of 40-80°C and 0.3-1.5MPa, so that the diolefin impurities therein are selectively produced. The superposition reaction generates macroalkenes, and then the macroalkenes and light hydrocarbons are separated from each other. The acidic solid catalyst is selected from aluminum silicate or macroporous strongly acidic cation exchange resin. The method is suitable for the refining process of C ₄ and C ₅ fractions to remove diolefin impurities, and can also be used in conjunction with existing C ₄ and C ₅ etherification units.

Description

Remove the non-hydrogenation method and the application apparatus of diene impurity in the raw material of etherification

The present invention relates to a kind of non-hydrogenation method and enforcement of raw material of etherification, the equipment of using this method and ether-based device.Specifically, the inventive method is the non-hydrogenation method that removes diene impurity in the raw material of etherification, and a kind of catalytic fractionator of implementing this method is provided,, wherein said raw material of etherification is mainly the C of fluid catalytic cracking (FCC) or voluminous isomerizing olefins (MIO) technology ₅Cut or mixed C ₄Cut.

Fecund isomeric olefine (MIO) technology be a kind of be the FCC family technology of purpose with the volume increase isomeric olefine, its iso-butylene that produces and isopentene be more than a times of FCC.As C at FCC gasoline ₅In the cut, the content of active isopentene (2-methyl-1-butene alkene and 2-methyl-2-butene) is 14～15 heavy %, and the C of MIO gasoline ₅The content of the active isopentene of cut is up to 33～34 heavy %.

Low molecular weight olefins has very high photochemical reaction activity in gasoline fraction, can impel low level air ozone to generate, and increases CO, NO in the vehicle exhaust _xQuantity discharged, very big to environmental hazard.Reformulated gasoline (RFG) regulation olefin(e) centent in developed country is not more than 10 heavy %, and oxygen level is not less than 2 heavy %.Account for the total 70 heavy % that form of gasoline at China's FCC gasoline.So olefin(e) centent does not have oxygenatedchemicals substantially up to 40 heavy % in the gasoline.Therefore, for improving quality of gasoline and performance, add methyl alcohol and carry out etherificate in FCC gasoline, making the active isopentene etherificate generation methyl-tert amyl ether in the gasoline is a kind of good method.

In addition, FCC and MIO mixed C that technology is produced ₄Or the isomeric olefine in the gasoline fraction also can be as the high quality raw material of producing methyl tertiary butyl ether (MTBE) and tert amyl methyl ether(TAME) (TAME).

Etherification reaction belongs to electrophilic addition reaction, requires catalyzer that the protonic acid of q.s is provided, and the easy and methyl alcohol reaction of isomeric olefine that has the tertiary carbon structure in the raw material generates corresponding ethers.In the C 5 fraction of catalytic cracking (FCC) of mixing refining residual oil and voluminous isomeric olefine (MIO) technology, the content of diolefine is very high, reach 0.34～0.65 heavy %, with this raw material and methanol etherification, easily cause the catalyst for etherification inactivation, this mainly is because the reactivity worth of diolefine is active especially, under the strong acid effect, even under very low temperature and concentration also fast autohemagglutination, cyclisation and dehydrogenative condensation generate colloid and be adsorbed in the activity of such catalysts in the heart, make catalyst deactivation, the lost of life.In addition, also can cause etherificate product TAME to darken and have unpleasant stink.Therefore, must remove the diene impurity in the raw material of etherification, could guarantee that catalyst for etherification has long work-ing life.

The method of useful alumina removal raw material impurity in the existing raw material of etherification non-hydrogenation technology, as USP5,210,326 propose with superactivity alumina removal FCC technology C ₄, C ₅Mercaptan in the cut and nitrile nitride, but this technology acts on little to removing of diolefine.USP5,300,126 have proposed a kind of method that removes diolefine in the raw material of etherification, promptly in the FCC petroleum naphtha, add close diolefine body (dieophiles), as maleic anhydride, maleimide, vinyl cyanide, vinylbenzene, acrylamide, propenal etc. preferably use maleic anhydride, make diolefine and close diolefine body generate adducts, to reduce the content of diolefine in the raw material of etherification.

The purpose of this invention is to provide a kind of non-hydrogenation method that utilizes the selective superposition technology to remove diene impurity in the raw material of etherification.

Another object of the present invention provides a kind of above-mentioned catalytic fractionator that removes the raw material of etherification diene impurity that is used for.

The non-hydrogenation method that removes diene impurity in the raw material of etherification provided by the invention is: raw material of etherification is contacted with acidic solid catalyst under 40～80 ℃, 0.3～1.5MPa condition, make diene impurity generation selective superposition reaction wherein generate macromole alkene, again macromole alkene and lightweight raw material of etherification are separated from each other.

Described raw material of etherification is the C of fluid catalytic cracking (FCC) and voluminous isomeric olefine (MIO) technology ₄Or C ₅Cut, diene content is 0.3～0.7 heavy % in the cut.

Described acidic solid catalyst is amorphous silicic aluminium or macropore strong acid cation exchange resin.Wherein amorphous silicic aluminium is preferably spherical, also can be other particulate state or type bodies such as sheet, column.The main component of amorphous silicic aluminium comprises the Na of 0.1～0.25 heavy % ₂The Fe of O, 0.05～0.09 heavy % ₂O ₃Al with 9.0～11.0 heavy % ₂O ₃Silicon-dioxide with surplus.Described Zeo-karb is that this resin has bigger loading capacity through the vinylbenzene of the macroporous netlike structure of sulfonation processing and the multipolymer of divinylbenzene, and its loading capacity is 4.4～4.6H ⁺Milligramequivalent/gram.

Described selective superposition reaction realizes that by catalysed fractionation promptly the building-up reactions of diolefine carries out in catalytic fractionator, the suitable temperature of reaction is 40～80 ℃, is preferably 65～80 ℃; Pressure is 0.3～1.5Mpa, is preferably 0.5～1.2MPa, and reaction velocity is 1.0～10.0 hours ^-1

When raw material of etherification is C ₄During cut, the temperature of catalysed fractionation cat head is that 60～75 ℃, conversion zone are that 65～80 ℃, tower still temperature are 140～150 ℃, and reaction pressure is 0.8～1.2Mpa, and reaction velocity is 1.0～10.0 hours ^-1, reflux ratio is 2.0～5.0.

When raw material of etherification is C ₅During cut, the temperature of catalysed fractionation cat head is that 60～70 ℃, conversion zone are that 65～80 ℃, tower still temperature are 140～150 ℃, and reaction pressure is 0.5～0.8Mpa, and reaction velocity is 1.0～10.0 hours ^-1, reflux ratio is 2.0～5.0.

For implementing above-mentioned process for purification better, the invention provides a kind of catalytic fractionator, this catalytic fractionator is formed by common separation column transformation, and acidic solid catalyst bed of the present invention is loaded on top.The loading position of beds distributes 60～65 ℃ in the tower temperature and locates, and separates with tower tray or filler with stainless steel card and woven wire, and the hole order size of woven wire should be suitable for the granularity of catalyzer, does not leak with catalyzer and is advisable.The beds tower wall at two ends up and down is provided with the dress agent or unloads the hand hole of agent.The loadings of catalyzer in catalytic rectifying tower pressed the weight hourly space velocity of cat head effluent and calculated in 1.0～5.0 hours-1,1/ catalyst weight is calculated during promptly with cat head effluent weight, after can adopting conventional device external regeneration process regeneration behind the catalyst deactivation, reload separation column and continue to use.

The inventive method also can with the supporting use of ether-based device of existing production TAME or MTBE, the i.e. mixed C that produces with the catalytically cracked gasoline that is rich in alkene and voluminous isomeric olefine technology gasoline or this two kinds of technologies ₄Be raw material, produce TAME or MTBE.The invention provides for this reason a kind of with raw material of etherification refining with etherification reaction bonded process unit, this device is provided with catalytic fractionator in the methyltertiarvbutyl ether reactor upstream, acidic solid catalyst bed of the present invention is loaded on the top of tower, the loading position of bed is located at the distribution of tower temperature and locates this column overhead separation of C for 60～65 ℃ ₄Or C ₅The pipeline of cut is divided into two-way, and one the tunnel links to each other with methyltertiarvbutyl ether reactor, and another road and catalytic fractionator top are connected to reflux pipeline.The mixed C that FCC gasoline or MIO gasoline or this two kinds of technologies produce ₄After entering catalytic fractionator, can remove diene impurity wherein, and separation of C ₄Or C ₅Cut, wherein an isolated active isopentene of cat head or an iso-butylene part enter methyltertiarvbutyl ether reactor by pipeline, and another part passes back into catalytic fractionator by pipeline.

Above-mentioned ether-based device can be by existing C ₄, C ₅The ether-based device transformation forms, promptly C ₄Smart separation column or C in the ether-based device ₅Depentanizer in the ether-based device is transformed into catalytic fractionator and gets final product.Describe in detail below in conjunction with accompanying drawing.

Fig. 1 removes divinyl impurity and separation of C for the catalysed fractionation of four-column process flow ₄The process flow sheet of cut

Fig. 2 removes the process flow sheet that diene impurity in the gasoline fraction is produced the TAME device

As shown in Figure 1, from the mixed C of gas separation unit₄Cut, comprise iso-butane, isobutene, 1-butylene and butadiene, be introduced into thick fractionating column 1, tell propane, propylene from cat head, bottom stream enters catalytic fractionator 2, acidic solid catalyst bed 3 of the present invention is loaded on the top of this tower, and the light component that enters catalytic fractionator 2 rises in tower and enters beds 3, and butadiene selective superposition wherein generates C₈Diene enters at the bottom of the tower, C₄Cut is separated in catalytic fractionator 2, light component iso-butane, isobutene, 1-butylene and less than the butadiene of 200ppm from cat head after cooling, a part refluxes, a part is as the raw material of follow-up ether-based device. Ether-based device mainly is made up of methyltertiarvbutyl ether reactor and etherificate catalytic distillation tower. The restructuring branch of catalytic fractionator 2 bottoms enters depentanizer 4, and the light component in the depentanizer 4 is distillated by cat head and enters C₄Fractionating column 5, C₅Component is flowed out by depentanizer 4 bottoms.

As shown in Figure 2, be rich in device that olefin gasolines produces TAME mainly by catalytic fractionator 2, methyltertiarvbutyl ether reactor 8 and etherificate catalytic distillation tower 9 form. Acidic solid catalyst bed 3 of the present invention is loaded on the top of catalytic fractionator 2, is rich in the FCC gasoline of alkene or MIO gasoline and enters catalytic fractionator 2, C with liquid phase near the temperature of bubble point₅Light component rises in tower and enters beds 3, and pentadiene selective superposition wherein generates big molecular olefine and enters tower bottom flow and go out the blended gasoline of attaching most importance to, C₅Cut is separated in tower, C₅Light component flows out from cat head, be the high-quality TAME raw material of diene content less than 200ppm, this raw material is after condenser 7 condensations, a part passes back into catalytic fractionator 2, a part enters methyltertiarvbutyl ether reactor 8 and carries out etherification reaction, and the etherification reaction product is discharged by methyltertiarvbutyl ether reactor 8 bottoms and entered etherificate catalytic distillation tower 9, and unreacted methyl alcohol is discharged by cat head in etherificate catalytic distillation tower 9, reclaim after condenser 10 condensations, product TAME discharges at the bottom of by tower.

Catalytic fractionator 2 can be by C in the above-mentioned ether-based device₄Smart fractionating column or C in the cut separator₅Depentanizer transformation in the ether-based device forms, and transforms simple and easy to doly, only needs to load acidic solid catalyst of the present invention on the top of tower and gets final product, and catalyst is selected from bead alumina silicate or macropore strong acid cation exchanger resin.

The present invention adopts the selective superposition technology effectively to remove diene impurity in the etherificate raw material of etherification, and need not add any close alkadienes body or other materials, can be catalytically cracked gasoline or the mixed C of 4000～6000ppm with diene content with the inventive method₄Become diene content less than the high-quality raw material of etherification of 200ppm, thereby prolong the service life of catalyst for etherification.

Catalytic fractionator for the raw material of etherification non-hydrogenation method provided by the invention will remove subtractive process and the C of alkadienes₄Or C₅The separation process of cut combines, and catalytic fractionator both can remove the diene impurity in the raw material of etherification, again can separation of C₄Or C₅Cut is for follow-up etherification reaction provides quality raw materials. This catalytic fractionator and the combination of existing ether-based device in the service life that can improve catalyst for etherification, are saved equipment investment, are reduced operating procedure.

Further specify process for purification of the present invention below by example.

Comparative Examples 1

This example is a raw material with FCC gasoline, does not use catalyzer to carry out C ₅The blank fractionation experiment of cut.

The small-sized separation column of stainless steel triangle wire as filler used in experiment, long 600 millimeters of body of the tower, 25 millimeters of internal diameters.Tower head is equipped with the condensing reflux divider, is the still kettle of 3 liters at the bottom of the tower.The tower still heats with the temperature adjustable electrically heated cover of KDM type, and body of the tower is incubated with nichrome wire, and tower still and body of the tower are all regulated controlled temperature with MAX-901311 intelligent temperature controller.With 1500 milliliters of FCC gasoline tower still of packing into, its composition sees Table 1.After in overhead condenser, feeding tap water, still kettle at the bottom of the heating tower, the control heat-up rate is not more than 5 ℃/minute, occurs after 30 minutes refluxing, and regulating reflux ratio is 3, and control distillation pressure is 0.65MPa, and tower top temperature is 62 ℃, 145 ℃ of tower still temperature.The cat head effluent is 500 milliliters, and isopentene is wherein formed and diene content sees Table 2.

Example 1

This example is a catalyzer with unformed bead pure aluminium silicate, is raw material with FCC gasoline, carries out C ₅The catalytic separation of cut removes the experiment of diolefine simultaneously.

Measuring the tower temperature in the fractionation experiment in comparing example 1 distributes, locate for 65 ℃ in the tower temperature, promptly locate to load 38 milliliters of bead pure aluminium silicate (trade names LXC-11, Lanzhou oil-refining chemical head factory catalyst plant is produced) apart from 180 millimeters of cats head, weight is 25.84 grams, 42 millimeters of catalyst bed floor heights.The 1500 milliliters of FCC gasoline of packing in still kettle at the bottom of the tower are operated by the fractionating step in the Comparative Examples 1, and the control tower top temperature is 62 ℃, reaction bed temperature is 67 ℃, and tower still temperature is 145 ℃, and pressure is 0.65MPa, reflux ratio is 3, and reaction velocity is 3.5 hours ^-1, overhead product is 500 milliliters, isolated C ₅Isopentene composition and diene content see Table 2 in the cut.

As shown in Table 2, the C that cuts through catalysed fractionation ₅Cut, dialkene removal rate reach 94.12 heavy %.Double-bond shift between the isopentene isomer is not remarkable, and this helps the etherification reaction of active isopentene.

Comparative Examples 2

This example is a raw material with MIO gasoline, carries out C ₅The fractionation blank assay of cut.Used fractionation plant and operational condition are all with Comparative Examples 1, and used MIO gasoline composition sees Table 1, and the overhead product composition sees Table 2.

Example 2

This example is a catalyzer with unformed bead pure aluminium silicate, is raw material with MIO gasoline, carries out C ₅Fraction separation removes the experiment of diolefine simultaneously.

With example 1 described catalytic fractionator, press the C of the working method catalytic separation MIO gasoline of example 1 ₅Cut, the isolated C of cat head ₅Isopentene composition and diene content see Table 2 in the cut.

Contrast as can be known with the data of Comparative Examples in the table 22, through the C of catalysed fractionation ₅In the cut, the diolefine decreasing ratio is 93.75 heavy %, and double-bond shift and bone valency isomerism are not remarkable between the isopentene isomer, and total amylene amount significantly increases than FCC technology.

Example 3

This example is catalyzer with the Zeo-karb, is raw material with MIO gasoline, carries out C ₅The catalytic separation of cut is the experiment of dialkene removal simultaneously.

Change the beds in the catalytic fractionator in the example 1 into the Zeo-karb that trade names are S-54 (the stable resin processing plant in Daxing, Beijing produces), the loadings of resin is 28 grams, its loading position is 60 ℃ of tower temperature distributions, apart from 180 millimeters places of cat head, and the catalyst bed layer height is 8.5 millimeters.Pack in still kettle at the bottom of the tower 1500 milliliters MIO gasoline is operated by the step of example 1, and that different is control reaction pressure 0.7MPa, 64 ℃ of tower top temperatures, 68 ℃ of reaction bed temperatures, 152 ℃ of tower still temperature, reflux ratio 3, reaction velocity 4.2 hours ^-1The cat head effluent is 270 milliliters, and the isopentene of effluent is formed and diene content sees Table 2.

Example 4

This example is catalyzer with the Zeo-karb, is raw material with MIO gasoline, carries out C ₅The experiment of fraction dialkene removal.Experiment condition is with example 3, and the trade names of different is used Zeo-karb are D-72 (Nankai University's production).Gained effluent isopentene is formed and diene content sees Table 2.

Example 5

This example is with FCC C ₄Fraction is a raw material, is catalyzer with the D-72 Zeo-karb, carries out C ₄The experiment of fraction dialkene removal.Experimental installation is with example 3, and the red-tape operati condition is: 60 ℃ of tower top temperatures, and 65 ℃ of reaction bed temperatures, 146 ℃ of column bottom temperatures, pressure 0.85Mpa, reflux ratio 3.5 is during reaction velocity 2.8 ^-1Isolated C ₄Fractional composition sees Table 3.

Example 6

This example is for removing the C behind the diolefine with the inventive method ₅Cut and the C that does not remove diolefine ₅The etherificate contrast experiment of cut.

Etherification reaction carries out on the small stationary bed bioreactor, and reactor is 35 * 9 millimeters of φ, long 600 millimeters stainless steel tube, adopts three sections electric furnaces heating, uses the temperature controller control reaction temperature, makes with extra care C with diene content 6500ppm respectively ₅With purified MIO C of the present invention ₅Cut is a raw material of etherification, mix the methyl alcohol of converting 13.04 heavy %, use the micro pump injecting reactor then, catalysts is RZE-1 zeolite (it is synthetic to press the CN1127242A method), product receives with collector with pressure, and raw material and product are all analyzed with the SP-3400 gas chromatograph.Etherification reaction technology condition and contrast and experiment are listed in table 4.

The selectivity method of calculation of transformation efficiency and TAME are as follows in the table 4:

By table 4 data as can be known, the C after the inventive method is refining ₅Cut can carry out etherification reaction more than 1000 hours continuously, and unpurified C ₅Cut only can react 167 hours, and catalyst for etherification just loses activity gradually.Behind the slow inactivation of catalyst for etherification, need improve the transformation efficiency that temperature of reaction could keep methyl alcohol and active isopentene gradually.Unpurified raw material of etherification, temperature of reaction are brought up to 90 ℃ gradually from 60 ℃, and the reaction times is 551 hours, and with the inventive method the raw material after refining, temperature of reaction is brought up to 90 ℃ gradually from 60 ℃, the reaction times was 3013 hours.Therefore, use process for purification of the present invention to remove C ₅Diene impurity in the cut can prolong work-ing life of catalyst for etherification greatly.

In addition, process for purification of the present invention is convenient to implement, and only needs catalysed fractionation can remove diene impurity.With USP5,300,126 compare, and need not to add any close diolefine body, can prolong the work-ing life of catalyst for etherification.Gasoline is compared with MIO gasoline at the bottom of tower after the catalysed fractionation, and alkali nitrogen, total nitrogen obviously reduce, and it is heavy that anterior boiling range becomes, and is available as blended gasoline and uses.After the catalysed fractionation at the bottom of the tower contrast of the character of gasoline and MIO gasoline list in table 5.

Table 1

	FCC gasoline	MIO gasoline
			Butylene butane 3-methyl-1-butene 2-methyl-1-butene alkene 2-methyl-2-butene 1-amylene is anti--and amylene-2 is suitable-amylene-2 cyclopentene isopentane pentane pentamethylene 2-Methyl-1-pentene pentadiene iso-amylene amylene C5Total amount	????1.57 ????0.33 ????0.32 ????1.61 ????3.13 ????0.32 ????1.61 ????2.45 ????0.30 ????7.86 ????1.18 ????1.14 ????0.67 ????0.32 ????5.04 ????10.15 ????20.65	????2.30 ????0.40 ????0.35 ????3.15 ????7.54 ????0.93 ????3.15 ????7.54 ????6.11 ????0.79 ????0.71 ????0.22 ????11.04 ????17.12 ????24.73

Table 2 Table 3

Form heavy %	Raw material	Product
			Propane	????0.03	????0.03
Propylene	????0.01	????0.01
			Trimethylmethane	????16.32	????16.41
Normal butane	????6.28	????6.32
			N-butene	????14.57	????14.65
Iso-butylene	????24.40	????24.53
			Instead-butene-2	????19.26	????19.37
Suitable-butene-2	????14.14	????14.22
			1,3-butadiene	????0.55	????0.00
The above component of C5	????4.44	????4.46

Table 4 Table 5

Character	Gasoline at the bottom of the tower	MIO gasoline
			Density (20 ℃), gram per centimeter 3Alkali nitrogen, the ppm total nitrogen, the ppm total sulfur, the ppm colloid, restrain/100 milliliters of octane values, motor method organon boiling range, ℃ initial boiling point 10% 30% 50% 70% 90% is done	????0.7726 ????7.3 ????12 ????318 ????2.6 ????80.6 ????93.8 ????66 ????85 ????100 ????123 ????147 ????171 ????196	????0.7278 ????22 ????26 ????382 ????4.6 ????81.8 ????95.8 ????37 ????49 ????62 ????82 ????120 ????164 ????202

Claims (10)

1. A non-hydrogenation refining method for removing diolefin impurities in etherification raw materials, which is characterized in that the etherification raw materials are contacted with an acidic solid catalyst under the conditions of 40-80°C and 0.3-1.5MPa to make the diolefins therein The impurities undergo selective superimposition reaction to generate macromolecular olefins, and then macromolecular olefins and light hydrocarbons are separated from each other. 2. The method according to claim 1, characterized in that the etherification raw material includes the _C4 or _C5 fraction of the fluidized catalytic cracking or multi-production isoolefin process, and the content of diolefins is 0.3-0.7 Heavy%. 3. The method according to claim 1 or 2, characterized in that the acidic solid catalyst is aluminum silicate or macroporous strongly acidic cation exchange resin. 4. The method according to claim 3, characterized in that the aluminum silicate is amorphous aluminum silicate, which contains 0.10-0.25% by weight of Na ₂ O, 0.05-0.09% by weight of Fe ₂ O ₃ and 9.0 to 11.0% by weight of Al ₂ O ₃ . 5. The method according to claim 1 or 2, characterized in that the temperature of the selective superimposition reaction is 65-80°C, the pressure is 0.5-1.5 MPa, and the reaction space velocity is 1.0-10.0 hours ^-1 . 6. The method according to claim 1 or 2, characterized in that said selective superposition reaction is carried out in a catalytic fractionation tower. 7. The method according to claim 6, characterized in that when the etherification raw material is a C4 fraction, the temperature at the top of the tower is 60-75°C, the temperature at the reaction section is 65-80°C, and the temperature at the bottom of the tower is 140-150°C , the reaction pressure is 0.8-1.2 MPa, the reaction space velocity is 1.0-10.0 hours ^-1 , and the reflux ratio is 2.0-5.0. 8. The method according to claim 6, characterized in that when the etherification raw material is a C5 fraction, the temperature at the top of the tower is 60-70°C, the temperature at the reaction section is 65-80°C, and the temperature at the bottom of the tower is 140-150°C , the reaction pressure is 0.5-0.8 MPa, the reaction space velocity is 1.0-10.0 hours ^-1 , and the reflux ratio is 2.0-5.0. 9. A catalytic fractionation tower used in the non-hydrogenation refining method of claim 1, characterized in that the upper part of the tower is equipped with an acidic solid catalyst bed, the bed is set at the temperature distribution of the tower at 60-65 °C, and a stainless steel flower plate Separated from steel mesh and trays or packing, this catalytic fractionator can separate _C4 or _C5 fractions while removing diene impurities. 10. The catalytic fractionation tower according to claim 9, characterized in that the acidic solid catalyst is aluminum silicate or macroporous strongly acidic cation exchange resin, and the loading amount of the catalyst is calculated according to the weight hourly space velocity of 1 to 5 hours ⁻¹ .

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