CN1184797A - Method for alkylation of isomeric paraffine and olefine - Google Patents

Abstract

Under supercritical reaction condition, the isomeric paraffin hydrocarbon and olefine hydrocarbon contact with a catalyst with formula MxHk-mxYZ12O40.nH2O, in which M is selected from alkali metal, ammonium, alkali earth metal and one of Three A group metallic ion, Y is selected from phosphorus, silicon, germanium, arsenic atoms, Z is selected from tungsten, molybdenum atoms, K is 3 or 4, m is the valence of M ion, x is greater than zero to 4.0, mx is greater than zero and equal to or smaller than 4, n is a positive number between 0 to 10. The invented method is high in conversion rate and good in stability of catalyst activity.

Description

Process for alkylation of isoparaffin with olefin

The present invention relates to the addition of saturated and unsaturated hydrocarbons, and more particularly to the alkylation of isoparaffins with olefins.

It is known that, in industry, the alkylation reaction of isoparaffin, especially isoparaffin with lower molecular weight and olefin, especially olefin with lower molecular weight is carriedout by using concentrated sulfuric acid or hydrofluoric acid as catalyst to prepare paraffin with higher molecular weight, especially gasoline blending component with higher octane number, but the substitution of solid acid catalyst for sulfuric acid and hydrofluoric acid is a necessary trend and has become a major research topic in this field because concentrated sulfuric acid and hydrofluoric acid have strong corrosivity to equipment and serious environmental pollution problems.

In recent years, various novel catalysts for the above alkylation have been reported, for example, molecular sieve catalysts having a molecular sieve as an active component as disclosed in U.S. Pat. nos. 3,549,557, 3,644,565, 3,647,916, 3,917,738 and 4,384,161; SO disclosed in JP01,245,853, US3,962,133, US4,116,880, GB1,432,720, GB1,389,237₄ ^2-A promoted super acid catalyst; EP0,433,954, US3,678,120, US3,852,371, WO94/24075, US3,855,342 disclose liquid super acid or supported Lewis acid catalysts, etc., which have a rapid deactivation rate under the normal alkylation reaction conditions, decrease the olefin conversion rate from 100% to a very low level in several hours, even several tens of minutes, and have an unsatisfactory composition of the alkylation reaction product, while the liquid super acid or supported Lewis acid catalysts have a problem of halide loss and do not solve the corrosion problem of the equipment.

WO94/03415 discloses a process for the alkylation of an alkane with an alkene which comprises contacting an alkene-containing feedstock with a isoparaffin-containing feedstock in the presence of a crystalline microporous material under alkylation conditions which comprise a temperature at or above the critical temperature of the major component of said feedstock and a pressure at or above the critical pressure of the major component of said feedstock. The crystalline microporous materials include various zeolites including ZSM series zeolites, offretite zeolites, MCM zeolites, mordenite, REY zeolites, and layered materials including layered silicates, layered clays, and the like. When MCM zeolite is used as catalyst, the method can improve the conversion rate of butene and the activity stability of the catalyst, but the olefin conversion rate is still low and the conversion rate of butene is only 86.3-99.4 wt%.

CN1,125,640A discloses an isobutane and butene alkylation method, which uses alkali metal or ammonium salt of phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, silicomolybdic heteropoly acid as catalyst, the variation range (gram molecule) of alkali metal and ammonium ion is 0.5-3.0 of phosphorus series, 0.5-4 of silicon series.0, the temperature of the alkylation reaction is 30 ℃, and the ratio of alkane to alkene is 15: 1. By carrying out the alkylation reaction in a batch reactor according to the examples, the yield of alkylate is low, it is only 1.854 at the highest on an olefin basis, and the catalyst activity decreases rapidly with increasing number of reactions, i.e. the stability of the catalyst activity is low, as reported in example 1, where C is_s25H_0.5PW₁₂0.4378 g of olefin and 15 g of alkane with the alkane-alkene ratio are added into a reactor as a catalyst to react for 2 hours at 30 ℃ to obtain 0.8118 g of alkylate oil, the oil yield is 1.854, the catalyst is dried for 2 hours at 100 ℃ after being separated and then used again under the same conditions, and the oil yield is reduced to 1.384.

The invention aims to provide a method for alkylating isoparaffin and olefin, which has high olefin conversion rate and high catalyst activity stability, based on the prior art.

The method for alkylating isoparaffin and olefin provided by the invention comprises the step of contacting a reaction raw material containing isoparaffin and a reaction raw material containing olefin with a catalyst under the condition that the reaction temperature is not lower than the critical temperature and the reaction pressure of isoparaffin in the dry reaction raw material are not lower than the critical pressure of isoparaffin in the reaction raw material, and the key point is that the catalyst has the following general formula:

M_xH_k-mxYZ₁₂O₄₀·nH₂O

wherein M is selected from one of alkali metal ions, ammonium ions, alkaline earth metal ions and IIIA group metal ions; y is selected from one of phosphorus atom, silicon atom, germanium atom and arsenic atom; z is one or two of tungsten atoms and molybdenum atoms; k is equal to 3 or 4, M is the valence state of M ion, x is any number between more than zero and 4.0, and 0<mx is less than or equal to 4; n is a positive integer of 0 to 10.

According to the method provided by the invention, M in the catalyst can be selected from one of alkali metal ions, ammonium ions, alkaline earth metal ions and IIIA group metal ions, preferably one of alkali metal ions and ammonium ions, the alkali metal ions refer to lithium, sodium, potassium, rubidium or cesium ions, the alkali metal ions refer to beryllium, magnesium, calcium, strontium or barium ions, the IIIA group metal ions refer to aluminum ions, gallium ions, indium ions and thallium ions, and M in the catalyst is more preferably potassium ions, cesium ions, sodium ions or ammonium ions.

Y in the general formula of the catalyst is selected from one of phosphorus atom, silicon atom, germanium atom and arsenic atom, and is preferably phosphorus atom or silicon atom.

In the general formula of the catalyst, x is any number between more than zero and 4.0, preferably any number between 1.0 and 4.0 and satisfies 1 ≦ mx ≦ 4, more preferably any number between 2.0 and 4.0 and satisfies 2 ≦ mx ≦ 4.

The reaction raw material containing isoparaffin can be pure isoparaffin, and also can contain other components which do not affect alkylation reaction, the concentration of isoparaffin in the reaction raw material can be changed in a large range, and the isoparaffin theoretically can include C₄Of the above isoalkanes, the isoalkane is preferably C in view of industrial requirements₄～C₆One or more of isoparaffin, such as isobutane, 2-methylbutane, 2-methylpentane, 3-methylpentane, 2-dimethylpentane, etc., wherein isobutane is more preferred. The olefin-containing reaction feed may be a pure olefin or may contain other components which do not interfere with the alkylation reaction, the concentration of olefin in the reaction feed may vary widely, and the olefin may theoretically include C₃The above various monoolefins, the olefin being preferably C in view of industrial requirements₃～C₆One or more monoenes, the position of the double bond in the olefin is not required, such as propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, various hexenes, etc., with propylene, butene or mixtures thereof being more preferred.

The reaction temperature of the method provided by the invention is not lower than the critical temperature of isoparaffin in the reaction raw materials, preferably 135-400 ℃, and more preferably 135-250 ℃; the reaction pressure is not lower than the critical pressure of the isoparaffin in the reaction raw materials, preferably 36-110 ℃ atmospheric pressure, and more preferably 36-90 atmospheric pressure.

The molar ratio of the isoparaffin to the olefin in the method provided by the invention can be 2.0-100, preferably 10-90. The weight space velocity (WHSV) of the reaction raw materials can be 0.1-20 hours^-1Preferably 0.5 to 8 hours^-1。

The alkylation reaction of isoparaffin and olefin can be carried out in various reactors, such as a fixed bed reactor, a batch tank reactor, a moving bed reactor, a liquefied bed reactor or a three-phase slurry bed reactor.

The catalyst M used in the method provided by the invention_xH_3-mxYZ₁₂O₄₀·nH₂O can be prepared as follows;

(1) weighing predetermined amount of heteropoly acid containing phosphorus, silicon, germanium or arsenic and tungsten and/or molybdenum to prepare quantitative water solution A.

(2) Weighing predetermined amount of alkali metal, ammonium, alkaline earth metal ion or IIIA group metal water-soluble salt to prepare quantitative water solution B.

(3) And slowly dripping the solution B into the solution A under strong stirring, continuing stirring for 10-60 minutes after the addition is finished, filtering and washing the obtained precipitate, and drying at 30-100 ℃ to obtain the catalyst used by the method.

Compared with the existing alkylation method of isoalkane and olefin by using solid acid as catalyst, the method provided by the invention has the advantages of high conversion rate of olefin and good activity stability of catalyst, for example, according to the inventionThe method is provided, the reaction temperature is 136 ℃, the reaction pressure is 50 atm, and the weight space velocity of the reaction raw material is 2.45 hours^-1C, in a molar ratio of alkane to alkene of 47.0_s25H_0.5PW₁₂O₄₀Alkylation of isobutane with butene for the catalyst, butene (C)₄ ⁼) The conversion rate of the catalyst can reach 100 percentby weight, the reaction is not reduced after 60 hours of operation, and the composition of the reaction product is close to that of C when a sulfuric acid method is used₅The yield of the alkane reaches 1.99 to 2.01 (g/g of converted butene), which is close to the theoretical value of 2.03 (g/g of converted butene), the conversion rate of the butene and C₅The alkane yield is obviously higher than that of the methods disclosed in WO94/03415 and CN 1125640A; in addition, theWhen the same catalyst and reaction raw materials are adopted at the critical temperature and the pressure below (120 ℃, 30 atm), and the alkylation reaction of isobutane and butene is carried out under similar conditions, the butene conversion rate is rapidly reduced after 40 hours of operation, and the catalyst is rapidly deactivated (as shown in figure 1). In addition, the method provided by the invention also has the advantages of no corrosion to equipment and no environmental pollution.

FIG. 1 is C_s25H_0.5PW₁₂O₄₀When the catalyst is used, the method provided by the invention and the time-dependent change chart of the conversion rate of butylene in the alkylation reaction of isobutane and butylene under the condition of being lower than the critical reaction condition are adopted.

The following examples further illustrate the invention but are not intended to limit the invention thereto.

The compositions of the isoparaffin and olefin feeds used in the alkylation reactions in the examples are set forth in table 1.

TABLE 1

Isobutane-containing reaction feedstock		Butene-containing reaction feedstock
				Components	Content, by weight%	Components	Content, by weight%
Propane Isobutane N-butane Butene (butylene)	1.82 94.85 2.21 1.12	Normal and isomeric butene N-butane Cis-2-butene Trans-2-butene	2.92 11.62 57.70 27.76

Comparative example 1

And (3) carrying out alkylation reaction of isobutane and butene by using concentrated sulfuric acid as a catalyst.

73.3 g of 95 wt% sulfuric acid (analytically pure, a product of Beijing plum chemical plant) was weighed into an autoclave type reactor, 18.0 g of a reaction raw material containing isobutane and 3.48 g of a reaction raw material containing butene were added under strong stirring at a reaction temperature of 10 ℃ and a reaction pressure of 7.0MPa to react for 2 hours, a gas composition in the reaction kettle was analyzed by a SP-3420 gas chromatograph, the column was an OV-01 capillary cross-linked column, the liquid composition was analyzed by a HP-5890 gas chromatograph, the column was an OV-01 capillary column, the composition of the reaction raw materials was listed in Table 1, and the reaction conditions and the reaction results were listed in Table 3.

Example 1

The alkylation reaction of isobutane with butene is carried out according to the process provided by the present invention.

22.81 g of phosphotungstic acid (H)₃PW₁₂O₄₀·21H₂O, analytical grade, from kyo nova chemicals works) and 2.85 grams Cs₂CO₃(analytically pure, from North chemical plant) 0.35 and 0.87 mol/L solutions were prepared with water, respectively, and Cs was added under vigorous stirring₂CO₃The solution was slowly added dropwise to the phosphotungstic acid solution and the reaction was carried out as in formula (I) (where M is Cs, x ═ 2.5).

(I)Cs₂CO₃After the solution is dripped, the solution is continuously stirred for 30 minutes, white precipitate obtained by filtration is washed by 20 times of distilled water and dried for 24 hours at 50 ℃ to obtain Cs₂₅H_0.5PW₁₂O₄₀·5H₂And O. The prepared Cs₂₅H_0.5PW₁₂O₄₀·5H₂And (3) grinding O, tabletting and forming on a tabletting machine, crushing, and screening particles of 20-40 meshes to obtain the catalyst used by the method.

Weighing 10.0 g Cs_2.5H_0.5PW₁₂O₄₀(dry basis) was charged into a 25-ml fixed-bed reactor, a nitrogen flow was introduced, the temperature and pressure were raised to the desired values and pressures, and the reaction mixture was held for 16 hours, two precision metering pumps (from Eldex lab, inc.) were used to pump in predetermined amounts the reaction mixture containing isobutane and butene, respectively, a SP-3420 gas chromatograph was used to analyze the reaction off-gas at regular intervals, and a liquid product was taken out at regular intervals and analyzed by a HP-5890 gas chromatograph for its composition, the composition of the reaction mixture was as given in table 1, and table 2 gives the composition of C in the reaction mixture₄The critical temperature and pressure of hydrocarbons (ex CRC Handbook of Chemistry and physics, Editor, R.C. Weast and D.R.Lide, 1990), the reaction conditions and the results are shown in Table 3, FIG. 1 (line ▲) showsC₄ ^＝Graph of conversion as a function of time.

The results in Table 3 show that the process of the invention provides a butene conversion and product distribution close to the sulfuric acid process, C, which is widely used in industry₅ ⁺The yield can reach 2.00 g/g of converted C₄ ^＝Approximately 2.03 g/g of converted C₄ ^＝The method provided by the invention has no problems of equipment corrosion and environmental pollution.

TABLE 2

C4Hydrocarbons	Critical temperature of	Critical pressure, atmospheric pressure
			Isobutane	135.0	35.9
N-butane	152.0	37.5
			1-butene	146.4	39.7
Trans-2-butene	160.0	40.5
			Cis-2-butene	155.0	41.5
Isobutene	144.7	40.7

TABLE 3

Catalyst and process for preparing same	Cs25H0.5PW12O40							95% sulfuric acid
									Reaction temperature of	136.0							10.0
Reaction pressure, atmospheric pressure	50.0							7.0
									Molar ratio of alkane to alkene	47.0							6.0
Weight space velocity, hour-1	2.45							-
									Reaction time, hours	6	10	24	32	48	52	60	2
C4 ＝Conversion, weight%	100	100	100	100	100	100	100	100
									C5 +Yield of G/g converted C4 ＝	2.00	1.99	2.02	1.97	1.99	1.97	1.98	2.00
C5 +Product distribution, weight% C5 C6 C7 C8 C9 - C8 ＝ TMP/DMHx	3.17 0.93 1.86 63.94 30.10 0.00 2.2		1.67 0.61 1.52 64.10 32.10 0.00 2.0		1.72 0.82 2.36 65.40 29.70 0.00 2.2		1.80 0.92 2.87 63.61 30.80 0.00 2.1	0.20 1.10 2.80 63.87 31.40 0.00 2.6

^*TMP/DMH is the molar ratio of trimethylpentane to dimethylhexane (see below)

Comparative example 2

This comparative example illustrates the advantage of the process provided by the present invention over the prior art

The alkylation reaction of isobutane and butene was carried out under the reaction conditions of critical temperature and pressure of isoparaffin, the catalyst and the amount, the reaction raw material, and the reaction apparatus were the same as those of example 1 except that the reaction conditions were 120 ℃ of reaction temperature, 30.0 atm of reaction pressure, 45.5 mole ratio of alkane to olefin, and 2.35 hours of weight space velocity^-1The reaction conditions and the reaction results are shown in Table 4, and the change in the butene conversion with the reaction time is shown in FIG. 1 as 2 (. DELTA.curve).

The results of fig. 1 show that, by adopting the method provided by the invention, the butene conversion rate can reach 100 wt%, and the butene conversion rate is not reduced after the reaction is operated for 60 hours, while the same reaction is carried out under the condition of being lower than the critical temperature and pressure of isobutane,the butene conversion rate is rapidly reduced after the reaction is operated for 40 hours, and the catalyst is rapidly deactivated.

From the results in Table 4, it can be seen that the alkylation of isobutane with butenes was carried out below the critical temperature and pressure of isobutane, C after 40 hours of operation₅ ⁺The yield drops from around 2.00 g/g to 1.41 g/g, indicating that a significant amount of olefin polymerization has occurred, and comparison with the results in Table 3 shows that the process of the present invention is superior to the prior art.

TABLE 4

Catalyst and process for preparing same	Cs25H0.5PW12O40
								Reaction temperature of	120℃
Reaction pressure, atmospheric pressure	30.0
								Molar ratio of alkane to alkene	45.5
Weight space velocity, hour-1	2.35
								Reaction time, hours	4	8	24	40	48	50	52
C4 =Conversion, weight%	100	100	100	100	87.8	81.2	72.4
								C5 +Yield of G/g converted C4 -	2.00	1.97	1.96	1.97	1.84	1.70	1.41
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	0.52 0.75 2.03 63.30 33.40 0.00 2.1		1.02 2.47 2.20 62.11 32.20 0.00 1.9		0.39 0.72 1.74 58.30 31.96 6.89 1.7		0.42 0.89 2.01 49.80 36.40 10.48 1.4

Example 2

The alkylation reaction of isobutane with butene is carried out according to the process provided by the present invention.

The reaction apparatus, the reaction raw materials, the catalyst and the amounts thereof were the same as in example 1 except that the reaction conditions were different, the initial temperature and pressure of the reaction were 136.0 ℃ and 50 atm, the reaction pressure was increased to 80 atm while keeping the temperature constant after 10 hours of the reaction, the reaction was continued to 32 hours, the reaction pressure was decreased to 50 atm, the reaction temperature was increased to 200 ℃ while the reaction was continued to 48 hours, and then the reaction temperature was decreased to 136 ℃. Other conditions of the reaction and the reaction results are shown in Table 5.

The results in Table 5 show that the process of the present invention can be carried out at temperatures and pressures above the isoparaffin critical temperature and pressure, and that the reaction temperature and pressure can vary over a wide range.

TABLE 5

Catalyst and process for preparing same	Cs25H0.5PW12O40
					Reaction temperature of	136.0	136.0	200.0	136.0
Reaction pressure, atmospheric pressure	50	80	50	50
					Molar ratio of alkane to alkene	47.0	47.0	47.0	47.0
Weight space velocity, hour-1	2.45	2.45	2.45	2.45
					Reaction time, hours	10	32	48	65
C4 ＝Conversion, weight%	100	100	100	100
					C5 +Yield of G/g converted C4 ＝	2.01	2.00	2.02	1.99
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	1.78 0.75 1.64 65.74 30.09 0.00 2.2	2.14 0.82 1.83 67.41 27.80 0.00 2.1	1.89 0.91 2.05 64.83 30.32 0.00 2.2	1.84 0.87 2.14 66.28 28.87 0.00 2.1

Example 3

The alkylation reaction of isobutane and butene is carried out according to the method provided by the invention.

The reaction apparatus, reaction raw materials, catalyst and their amounts were the same as in example 1 except that the reaction conditions were different, the molar ratio of the starting alkane to the olefin was 47.0, and the space velocity of the starting weight was 2.45 hours^-1And the space velocity is reduced to 1.05 hours after the reaction is carried out for 24 hours^-1The space velocity is increased to 6.15 hours after the reaction is carried out for 32 hours^-1After the reaction was carried out for 40 hours, the space velocity was simultaneously reduced to 2.45 hours^-1And reducing the molar ratio of alkane to alkene to 21.5, and carrying out the reaction for 48 hours^-1Then, the space velocity was maintained constant to increase the mole ratio of alkane to olefin to 85.0, and after 56 hours of reaction, the mole ratio of alkane to olefin was decreased to 47.0, and the reaction conditions and the reaction results are shown in Table 6.

The results in Table 6 show that the molar ratio of alkane to alkene and the weight space velocity of the reaction feed for the process provided by the present invention can vary over a wide range.

TABLE 6

Catalyst and process for preparing same	Cs25H0.5PW12O40
							Reaction temperature of	136.0	136.0	136.0	136.0	136.0	136.0
Reaction pressure, atmospheric pressure	50	50	50	50	50	50
							Molar ratio of alkane to alkene	47.0	47.0	47.0	21.5	85.0	47.0
Weight space velocity, hour-1	2.45	1.05	6.15	2.45	2.45	2.45
							Reaction time, hours	24	32	40	48	56	75
C4 ＝Conversion, weight%	100	100	100	100	100	100
							C5 +Yield of G/g converted C4 ＝	2.02	2.00	2.01	1.99	2.00	2.00
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	1.75 0.84 1.72 66.21 29.48 0.00 2.0	2.11 1.42 2.32 68.94 25.21 0.00 2.3	1.52 0.65 1.64 62.59 33.60 0.00 2.0	1.67 0.79 1.84 64.15 31.55 0.00 2.1	2.35 1.52 2.67 68.41 25.06 0.00 2.4	1.65 0.92 1.94 65.83 29.66 0.00 2.2

Example 4

The alkylation reaction of isobutane and butene is carried out according to the method provided by the invention.

91.23 g of phosphotungstic acid (same as example 1) and 5.80 g of K were weighed out₂CO₃(analytically pure Tianjin four-way chemical plant product) is added with 80 ml and 70 ml of water respectively to prepare two solutions, and K is stirred intensively₂CO₃The solution is slowly dripped into phosphorus-tungstenIn acid solution, the reaction proceeds according to formula (I) (where M is K, x is 3.0), K₂CO₃Stirring for 30 min after the solution is added dropwise, filtering, washing the precipitate with 20 times of distilled water, and drying at 50 deg.C for 24 hr to obtain product C₃PW₁₂O₄₀·8H₂O, prepared K₃PW₁₂O₄₀·8H₂And O, grinding, tabletting and forming, then crushing, and screening 20-40 mesh particles to obtain the catalyst used by the method.

Using 10.0 g of K₃PW₁₂O₄₀·8H₂O (dry basis) as a catalyst, using the same reaction device and reaction raw materials as in example 1, at a reaction temperature of 136.0 ℃, a reaction pressure of 50.0 atmospheric pressure, an alkane-alkene molar ratio of 47.1 and a weight space velocity of 2.44 hours^-1The alkyl reaction of isobutane with butene was carried out under the conditions shown in table 7, and the reaction conditions and the reaction results were shown.

TABLE 7

Catalyst and process for preparing same	K3.0PW12O40
								Reaction temperature of	136.0
Reaction pressure, atmospheric pressure	50.0
								Molar ratio of alkane to alkene	47.1
Weight space velocity, hour-1	2.44
								Reaction time, hours	4	10	24	40	60	80	100
C4 ＝Conversion, weight%	100	100	100	100	100	100	100
								C5 +Yield of G/g converted C4 ＝	2.00	1.99	1.98	1.98	1.99	1.97	1.96
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	0.72 0.84 1.85 63.12 33.47 0.00 2.1		0.78 1.02 2.08 62.51 33.61 0.00 2.0	0.88 0.99 1.99 61.30 34.84 0.00 1.9		0.92 1.11 2.11 62.80 33.06 0.00 1.8	0.85 1.00 2.24 60.89 35.02 0.00 1.9

Example 5

The alkylation reaction of isobutane with butene is carried out according to the process provided by the present invention.

34.10 g of phosphomolybdic acid (H)₃PMo₁₂O₄₀·17H₂O, analytical grade, from kyo nova chemicals works) and 6.52 grams Cs₂CO₃(same as example 1) two solutions were prepared by adding 30 ml and 70 ml of water, respectively, and Cs was added under vigorous stirring₂CO₃The solution was slowly added dropwise to the molybdophosphoric acid solution and the reaction was carried out according to formula (II) (where M is Cs, x ═ 2.5).

(II)Cs₂CO₃After the solution is dripped, the solution is continuously stirred for 30 minutes, filtered, washed and precipitated by 20 times of distilled water and dried for 24 hours at 50 ℃ to obtain a product Cs₂₅H_0.5PMo₁₂O₄₀·6H₂And O. The prepared Cs₂₅H_0.5PMo₁₂O₄₀·6H₂And (3) grinding O, tabletting and forming, then crushing, and screening 20-40 mesh particles to obtain the catalyst used by the method.

Using 10.0 g Cs₂₅H_0.5PMo₁₂O₄₀(dry basis) as catalyst, using the same reaction device and reaction raw materials as in example 1, at a reaction temperature of 136.0 ℃, a reaction pressure of 50.0 atmospheric pressure, an alkane-alkene molar ratio of 47.5 and a weight space velocity of 2.45 hours^-1Conditions of (2)The alkylation of isobutane with butene was carried out under the conditions and the results shown in table 8.

TABLE 8

Catalyst and process for preparing same	Cs25H0.5PMo12O40
						Reaction temperature C	136.0
Reaction pressure, atmospheric pressure	50.0
						Molar ratio of alkane to alkene	47.5
Weight space velocity, hour-1	2.45
						Reaction time, hours	4	16	24	48	56
C4 ＝Conversion, weight%	100	100	100	100	100
						C5 +Yield of G/g converted C4 ＝	1.97	1.96	1.98	1.99	1.96
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	0.74 1.84 1.98 53.02 42.42 0.00 1.8		0.68 1.62 2.18 51.11 44.41 0.00 1.7	0.64 1.52 1.87 50.41 45.56 0.00 1.6	0.75 1.40 2.21 50.89 44.75 0.00 1.6

Example 6

The alkylation reaction of isobutane and butene is carried out according to the method provided by the invention.

34.64 g of silicotungstic acid (H) are weighed₄SiW₁₂O₄₀·15H₂O, analytical grade, from Shanghai reagent II) and 4.48 g Cs₂CO₃(same as example 1) 30 ml and 50 ml of water were added to prepare solutions, and Cs was added under vigorous stirring₂CO₃The solution was slowly added dropwise to the tungstosilicic acid solution and the reaction proceeded as in formula (III) (where M is Cs, x ═ 2.5).

(III)Cs₂CO₃After the solution is dripped, the solution is continuously stirred for 30 minutes, filtered, washed by 20 times of distilled water for precipitation and dried for 24 hours at 50 ℃ to obtain a product Cs₂₅H_1.5SiW₁₂O₄₀·7H₂And O. The prepared Cs₂₅H_1.5SiW₁₂O₄₀·7H₂And O, grinding, tabletting and forming, then crushing, and screening 20-40 mesh particles to obtain the catalyst used by the method.

Using 10.0 g Cs₂₅H_1.5SiW₁₂O₄₀(dry basis) as catalyst, using the same reaction device and reaction raw materials as in example 1, at a reaction temperature of 136.0 ℃, a reaction pressure of 50.0 atmospheric pressure, an alkane-alkene molar ratio of 47.7 and a weight space velocity of 2.44 hours^-1The alkylation of isobutane with butene was carried out under the conditions shown in table 9.

TABLE 9

Catalyst and process for preparing same	Cs25H1.5SiW12O40
							Reaction temperature of	136.0
Reaction pressure, atmospheric pressure	50.0
							Molar ratio of alkane to alkene	47.7
Weight space velocity, hour-1	2.44
							Reaction time, hours	4	12	24	48	56	74
C4 ＝Conversion, weight%	100	100	100	100	100	100
							C5 +Yield of G/g converted C4 ＝	1.92	1.90	1.88	1.91	1.87	1.85
C5 +Product distribution, weight% C5 C6 C7 C8 C9 + C8 ＝ TMP/DMH	0.51 1.37 1.18 52.41 44.53 0.00 1.9		0.48 1.22 1.23 52.20 44.87 0.00 1.6	0.54 1.07 1.13 50.85 46.41 0.00 1.6	0.35 1.51 1.28 50.32 46.54 0.00 1.5	0.27 0.89 1.05 48.53 49.26 0.00 1.4

Claims (10)

1. A process for the alkylation of isoparaffins with olefins comprising contacting a reaction feed comprising isoparaffins and a reaction feed comprising olefins with a catalyst at a reaction temperature not lower than the critical temperature of the isoparaffins in the reaction feed and a reaction pressure not lower than the critical pressure of the isoparaffins in the reaction feed, characterized in that the catalyst has the following general formula:

M_xH_k-mxYZ₁₂O₄₀·nH₂o wherein M is selected from the group consisting of alkali metal ions, ammonium ions, alkaline earth metal ions and group IIIA goldBelongs to one of ions, and Y is selected from one of a phosphorus atom, a silicon atom, a germanium atom and an arsenic atom; z is one or two of tungsten atoms and molybdenum atoms, k is 3 or 4, M is the valence state of M metal ions, and x is any number between zero and 4.0 and satisfies 0<mx<4; n is a positive integer of 0 to 10.

2. The process according to claim 1, wherein M in the general catalyst formula is selected from the group consisting of potassium, cesium, sodium and ammonium ions.

3. The process according to claim 1, wherein Y in the general catalyst formula is selected from the group consisting of a phosphorus atom and a silicon atom.

4. The process according to claim 1, wherein M in the general catalyst formula is selected from potassium ions or cesium ions and Y is selected from phosphorus atoms or silicon atoms.

5. The method of claim 1, wherein the isoparaffin is C₄～C₆The isoalkane, alkene means C₃～C₆The single-bond olefin of (1).

6. The process according to claim 5, wherein said isoparaffin is isobutane and the olefin is selected from the group consisting of propylene, butene and mixtures thereof.

7.The method of claim 1, wherein the process conditions of the method are a reaction temperature of 135-400 ℃, a reaction pressure of 36-110 atm, a molar ratio of isoparaffin to olefin of 2.0-100, and a weight space velocity of the reaction raw material of 0.1-20 hours^-1。

8. The method of claim 7, wherein the reaction temperature is 135-250 ℃, the reaction pressure is 36-90 atm, the molar ratio of isoparaffin to olefin is 10-90, and the weight space velocity of the reaction raw material is 0.5-8 hours^-1。

9. The process according to any one of claims 1 to 8, wherein x in the general catalyst formula is any number between 1.0 and 4.0 and satisfies 1. ltoreq. mx. ltoreq.4.

10. The method according to claim 9, wherein x is an arbitrary number from 2.0 to 4.0 and satisfies 2. ltoreq. mx. ltoreq.4.

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