CN101491772B

CN101491772B - Catalyst for naphtha catalytic cracking

Info

Publication number: CN101491772B
Application number: CN2008100329225A
Authority: CN
Inventors: 谢在库; 马广伟; 胡永君; 陈亮; 滕加伟
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology; China Petrochemical Corp
Priority date: 2008-01-23
Filing date: 2008-01-23
Publication date: 2011-09-21
Anticipated expiration: 2028-01-23
Also published as: CN101491772A

Abstract

The invention relates to a catalyst for the catalytic cracking of naphtha, and mainly solves the problems of high using temperature of a catalyst and low yield of ethylene and propylene of the prior catalytic cracking reaction for preparing ethylene and propylene. The invention better solves the problems by adopting a technical proposal that the catalyst is formed by loading at least one element or an oxide of the element of the VA group elements in the periodic table onto a ZSM-5/mordenite symbiotic molecular sieve, a ZSM-5/beta zeolite symbiotic molecular sieve or a ZSM-5/Y zeolite symbiotic molecular sieve. Moreover, the catalyst can be used in the industrial production of ethylene and propylene through the catalytic cracking of naphtha.

Description

The catalyst that is used for the naphtha catalytic pyrolysis

Technical field

The present invention relates to a kind of catalyst that is used for naphtha catalytic pyrolysis preparing ethylene propylene.

Background technology

Along with the development of society, the market demand of China's ethylene, propylene sharply increases, and the import volume of ethylene, propylene and downstream product thereof increases year by year, and the home products occupation rate of market is less than half.Whole world ethene is raw material with naphtha (or ethane) mainly at present, adopts steam heat cracking technique (under the temperature about 800 ℃) production, and its output surpasses 90% of total output.Catalytic pyrolysis is compared with the steam heat cracking, and this process reaction temperature is than low 50～200 ℃ approximately of standard cracking reactions, and therefore than common steam cracking less energy consumption, cracking furnace pipe inwall coking rate will reduce, thereby but prolong operation cycle increases the boiler tube life-span; CO2 emission also can reduce, and can adjust the product mix flexibly, can increase the total recovery of ethene and propylene, and production cost of ethylene reduces significantly.

U.S. Pat P6211104 and domestic patent CN1504540A adopt a kind of 10～70 weight % clays that contain, 5～85 weight % inorganic oxides, 1～50 weight % molecular sieve is formed catalyst, various raw materials to traditional steam heat cracking, the activity, the especially ethene that well are converted into light olefin have been demonstrated.With molecular sieve be by 0～25 weight %Y zeolite of high silica alumina ratio or have the ZSM molecular sieve of MFI structure, form by phosphorus/Al, Mg or Ca dipping, but the ethylene, propylene selectivity of catalyst and yield are not high.

Japan Asahi Chemical Industry (patent CN1274342A) has announced that a kind of high silica alumina ratio, the molecular sieve of aperture between 0.5～0.65 nanometer are catalyst, be the feedstock production ethylene, propylene with the light hydrocarbons that contains alkene, but the ethylene, propylene yield is lower.

Exxon Mobil (00816642.0) announces that a kind of aperture of a kind of usefulness contains the hydrocarbon raw material of naphtha less than the zeolite treatment of 0.7 nanometer, produces ethylene, propylene between 550-600 ℃, and conversion of raw material is lower.

Mobil Oil Corporation (CN1413244A) has announced that a kind of mesopore phosphate material with modification is that catalyst and elementary catalytic pyrolysis material combine, the hydrocarbon raw material of catalytic pyrolysis sulfur-bearing prepares micromolecular hydrocarbon mixture, but the serviceability temperature of catalyst, conversion of raw material and product yield are all lower.

Summary of the invention

Technical problem to be solved by this invention is that the catalyst activity that uses in the existing naphtha catalytic pyrolysis preparing ethylene propylene reaction is lower, poor stability, the problem that the yield of ethylene, propylene is lower, serviceability temperature is high, a kind of new catalyst that is used for preparing ethylene propylene from catalytic pyrolysis is provided, this catalyst has the catalytic activity height, good stability, ethylene, propylene yield height, advantage such as serviceability temperature is low.

For solving the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of catalyst that is used for preparing ethylene propylene from catalytic pyrolysis by weight percentage, comprises following active component:

A) at least a in the coexisting molecular sieve of the coexisting molecular sieve of 80～99.5% the coexisting molecular sieve that is selected from ZSM-5 and modenite, ZSM-5 and β zeolite or ZSM-5 and Y zeolite; With carry thereon

B) surplus is selected from least a element or its oxide in the periodic table of elements VA family element.

In the technique scheme, coexisting molecular sieve is at least a in ZSM-5/ mercerization zeolite symbiosis molecular screen, ZSM-5/ beta zeolite coexisting molecular sieve and the ZSM-5/Y zeolite coexisting molecular sieve; The weight percentage preferable range of ZSM-5 is 60%～99.5% in the used coexisting molecular sieve, and more preferably scope is 80%～99%; The SiO of used coexisting molecular sieve ₂/ Al ₂O ₃The mol ratio preferable range is 10～300, and more preferably scope is 12～50; By weight percentage, the consumption preferable range of coexisting molecular sieve is 85～99%.VA family element preferred version is selected from least a among P, As, Sb or the Bi, and more preferably scheme is for being selected from P; By weight percentage, the consumption preferable range of VA family element is 0.5～5%.The catalyst preferred version is also to comprise at least a or its oxide that is selected from periodic table of elements IVB family's element or the VB family element in the catalyst; IVB family element preferred version is selected from least a among Ti, Zr or the Hf, and VB family element preferred version is selected from least a among V, Nb or the Ta; By weight percentage, the consumption preferable range that is selected from least a or its oxide in periodic table of elements IVB family's element or the VB family element is for being 0.01～2%, and more preferably scope is 0.1～1%.

The raw material that the preparation coexisting molecular sieve uses: the silicon source is metasilicate, silicate sodium or Ludox, the aluminium source is aluminium salt or aluminate, the template agent is at least a in 4-propyl bromide, TPAOH, triethylamine, n-butylamine, tetraethyl ammonium hydroxide, ethylenediamine or the ethamine, and the pH value of regulating colloidal sol with diluted acid is 10～13.The coexisting molecular sieve modification is with the acid solution or the salting liquid of corresponding active component element.

The synthetic method of coexisting molecular sieve is, get the silicon source and the aluminium source of aequum by material proportion, make solution with dissolved in distilled water respectively, then two kinds of solution are mixed, the powerful stirring adds one or more template agent of aequum then, stirs after 30 minutes with rare acid for adjusting pH value in 10～13 scopes, supply distilled water again, add the corresponding crystal seed of aequum.Colloidal sol is put into autoclave, control temperature crystallization a period of time of 120～180 ℃ after, take out 4 hours, 550 ℃ roastings of 2 times, 120 ℃ oven dry of washing 3 hours, can obtain corresponding coexisting molecular sieve.With concentration is 5% ammonium nitrate solution, and 70 ℃ of exchanges twice, 550 ℃ of roastings are 3 hours then, repeat twice after, make the Hydrogen coexisting molecular sieve.

The present invention since adopted acid strong, have multi-stage artery structure, ethylene, propylene selectivity good coexisting molecular sieve be carrier, select for use and have the element of restraining dealuminzation, strengthening hydrothermal stability of molecular sieve, with transition metal coexisting molecular sieve is carried out modification with the easy transition of the big electronics of charge density, strengthen the hydrothermal stability and the acidity of coexisting molecular sieve, make the catalyst acid density that makes big, acid strength height, acid stable are difficult for running off, and are suitable for alkane cracking and become ethylene, propylene.

In order to check and rate activity of such catalysts, the related catalyst compressing tablet of invention, break into pieces, sieve after, get 20～40 purpose particles with standby.The C that adopts Shanghai Gaoqiao petro-chemical corporation to produce ₄～C ₁₀The naphtha of hydrocarbon is a raw material, naphtha physical index such as table 1.With internal diameter is 12 millimeters down examination of fixed bed reactors normal pressure, is 600～650 ℃ in reaction temperature, and reaction pressure is 0.001MPa～0.5MPa, weight space velocity 0.25～4 hour ^-1, under the condition of water/feedstock oil weight ratio 1～4: 1, naphtha being carried out catalytic pyrolysis, the ethylene, propylene yield can reach 55%, has obtained better technical effect.

Table 1 feed naphtha index

Project	Data
		Density (20 ℃) kilogram/rice ³	704.6
Boiling range is boiling range ℃ just	40
		Whole boiling range ℃	160
Saturated vapor pressure (20 ℃) kPa	50.2
		Alkane % (weight %)	65.18

N-alkane % (weight %) in the alkane	＞32.5
		Cycloalkane % (weight %)	28.44
Alkene % (weight %)	0.17
		Aromatic hydrocarbons % (weight %)	6.21

The present invention is further elaborated below by embodiment.

The specific embodiment

[embodiment 1]

Get 284 gram sodium metasilicates, become solution A with 300 gram dissolved in distilled water, get 33.3 gram aluminum sulfate, make solution B with 100 gram distilled water, B solution is slowly poured in the A solution, the powerful stirring, add 24.4 gram ethylenediamines then, after stirring a period of time, regulate the pH value 11.5 with dilute sulfuric acid, the mole proportioning of control colloidal sol is: Si: Al: ethylenediamine: H ₂O=1: 0.1: 0.4: 40, add the crystal seed that contains ZSM-5 and modenite presoma, stir and after 30 minutes mixed solution is put into autoclave, 180 ℃ of insulations 40 hours, take out 4 hours, 550 ℃ roastings of 2 times, 120 ℃ oven dry of washing 3 hours then, make the coexisting molecular sieve of ZSM-5 and modenite, with the XRD diffraction quantitatively as can be known in the coexisting molecular sieve ZSM-5 and modenite weight content be respectively 95% and 5%.With concentration is 5% ammonium nitrate solution, and 70 ℃ of exchanges twice, 550 ℃ of roastings are 3 hours then, repeat twice after, make Hydrogen ZSM-5 and mercerization zeolite symbiosis molecular screen, be designated as FH-1.

[embodiment 2]

Get 284 gram sodium metasilicates, become solution A with 300 gram dissolved in distilled water, get 16.7 gram aluminum sulfate, make solution B with 100 gram distilled water, B solution is slowly poured in the A solution, the powerful stirring, add 12.2 gram ethylenediamines and 29.4 gram tetraethyl ammonium hydroxides (mixed templates is designated as M) then, after stirring a period of time, regulate the pH value 11 with dilute sulfuric acid, the mole proportioning of control colloidal sol is: Si: Al: M: H ₂O=1: 0.05: 0.4: 40, add 2.8 gram β zeolite seed crystals, mixed solution is put into autoclave, 160 ℃ of insulations 40 hours, take out 4 hours, 550 ℃ roastings of 2 times, 120 ℃ oven dry of washing 3 hours then, make ZSM-5/ beta zeolite coexisting molecular sieve, with the XRD diffraction quantitatively as can be known in the coexisting molecular sieve ZSM-5 weight percentage be 94.6%, the β zeolite is 5.4%.With concentration is 5% ammonium nitrate solution, and 70 ℃ of exchanges twice, 550 ℃ of roastings are 3 hours then, repeat twice after, make Hydrogen ZSM-5/ beta zeolite coexisting molecular sieve, be designated as FH-2.

[embodiment 3]

Get 284 gram sodium metasilicates, become solution A with 300 gram dissolved in distilled water, get 33.3 gram aluminum sulfate, make solution B with 100 gram distilled water, B solution is slowly poured in the A solution, the powerful stirring, add 24.4 gram ethylenediamines then, stir after 20 minutes, regulate the pH value 11.5 with dilute sulfuric acid, the mole proportioning of control colloidal sol is: Si: Al: ethylenediamine: H ₂O=1: 0.1: 0.4: 40, add 2.8 gram Y zeolite seed crystals, mixed solution is put into autoclave, 130 ℃ of insulations 40 hours, take out 4 hours, 550 ℃ roastings of 2 times, 120 ℃ oven dry of washing 3 hours then, make ZSM-5/Y zeolite coexisting molecular sieve.Quantitatively contain the ZSM-5 of 94.5% weight and the Y zeolite of 5.5% weight in the coexisting molecular sieve as can be known with the XRD diffraction.With concentration is 5% ammonium nitrate solution, and 70 ℃ of exchanges twice, 550 ℃ of roastings are 3 hours then, repeat twice after, make Hydrogen ZSM-5/Y zeolite coexisting molecular sieve, be designated as FH-3.

[embodiment 4～7]

The Hydrogen ZSM-5/Y zeolite coexisting molecular sieve that the Hydrogen ZSM-5/ mercerization zeolite symbiosis molecular screen that embodiment 1 is made, the Hydrogen ZSM-5/ beta zeolite coexisting molecular sieve that embodiment 2 makes and embodiment 3 make mixes according to a certain percentage, make mechanical impurity, as shown in table 2.

Table 2

Embodiment	The coexisting molecular sieve kind	Ratio (weight ratio)	Sample number into spectrum
				Embodiment 4	ZSM-5/ modenite+ZSM-5/ β zeolite	1∶1	FH-4
Embodiment 5	ZSM-5/ modenite+ZSM-5/Y zeolite	1∶1	FH-5
				Embodiment 6	ZSM-5/ β zeolite+ZSM-5/Y zeolite	1∶1	FH-6
Embodiment 7	ZSM-5/ modenite+ZSM-5/ β zeolite+ZSM-5/Y zeolite	1∶1∶1	FH-7

[embodiment 8～25]

According to the method for embodiment 1, embodiment 2 and embodiment 3,, make a collection of Hydrogen coexisting molecular sieve respectively by changing the amount of raw material proportioning, pH value and adding crystal seed, as shown in table 3.

Table 3

Embodiment	The coexisting molecular sieve type	SiO ₂/Al ₂O ₃Mol ratio	ZSM-5 content (weight %)	Sample number into spectrum
					Embodiment 8	The ZSM-5/ modenite	12	61.5	FH-8
Embodiment 9	The ZSM-5/ modenite	16	73.6	FH-9
					Embodiment 10	The ZSM-5/ modenite	40	85.4	FH-10
Embodiment 11	The ZSM-5/ modenite	100	96.8	FH-11
					Embodiment 12	The ZSM-5/ modenite	300	99.2	FH-12
Embodiment 13	ZSM-5/ β zeolite	12	98.0	FH-13
					Embodiment 14	ZSM-5/ β zeolite	20	90.4	FH-14
Embodiment 15	ZSM-5/ β zeolite	60	60.5	FH-15
					Embodiment 16	ZSM-5/ β zeolite	100	99.0	FH-16
Embodiment 17	ZSM-5/ β zeolite	300	85.3	FH-17
					Embodiment 18	The ZSM-5/Y zeolite	12	60.2	FH-18

Embodiment 19	The ZSM-5/Y zeolite	16	71.8	FH-19
					Embodiment 20	The ZSM-5/Y zeolite	50	85.3	FH-20
Embodiment 21	The ZSM-5/Y zeolite	100	97.3	FH-21
					Embodiment 22	The ZSM-5/Y zeolite	300	99.5	FH-22

[embodiment 23]

Get ZSM-5/ mercerization zeolite symbiosis molecular screen 20 grams that embodiment 1 makes, add 323 milliliters of the phosphoric acid of 0.1 mol, stir evaporates to dryness at 70 ℃ then, behind the drying and roasting, make the ZSM-5/ mercerization zeolite symbiosis molecular screen catalyst of phosphorus modification.The catalyst compressing tablet, break into pieces, sieve after, get 20～40 purpose particles and put into fixed bed reactors, be that 650 ℃, reaction pressure are 0.02MPa, weight space velocity 1 hour in reaction temperature ^-1And check and rate under water/condition of 3: 1 of naphtha weight ratio, the results are shown in Table 4.

[embodiment 24～30]

Get the coexisting molecular sieve of different the foregoing description preparation,, make catalyst and appraisal result is as shown in table 4 according to method modification and the examination of embodiment 23.

[embodiment 31]

Get ZSM-5/Y zeolite coexisting molecular sieve 20 grams that embodiment 20 makes, 29 milliliters of phosphatase 11s that add 0.1 mol add 38.3 milliliters of the bismuth nitrates of 0.05 mol again, stir evaporates to dryness at 70 ℃ then, behind the drying and roasting, make the ZSM-5/Y zeolite coexisting molecular sieve catalyst of phosphorus and bismuth modification.Method examination according to embodiment 23 the results are shown in Table 4.

[embodiment 32]

Get the ZSM-5/Y coexisting molecular sieve of embodiment 21 preparation,, make catalyst and appraisal result is as shown in table 4 according to method modification and the examination of embodiment 31.

Table 4

Embodiment	The numbering of specimen in use	The type of modifying element and content (weight %)	Yield of ethene (weight %)	Propene yield (weight %)	Diene yield (weight %)
						Embodiment 23	FH-1	5％P	27.25	27.12	54.37
Embodiment 24	FH-3	0.5％P	27.47	25.66	53.13
						Embodiment 25	FH-5	1％P	27.93	25.94	53.87
Embodiment 26	FH-6	0.1％P	28.67	24.72	53.39
						Embodiment 27	FH-11	2％P	29.15	23.67	52.82
Embodiment 28	FH-15	10％P	29.44	21.35	50.79
						Embodiment 29	FH-17	1％Bi	25.26	24.37	49.63

Embodiment 30	FH-18	2％Sb	24.79	22.63	47.42
						Embodiment 31	FH-20	2％P+2％Bi	27.48	26.64	54.12
Embodiment 32	FH-21	1％P+1％Sb+1％Bi	28.71	24.76	53.47

[embodiment 33～46]

Get the coexisting molecular sieve of different the foregoing description preparation,, make catalyst and appraisal result is as shown in table 5 according to method modification and the examination of embodiment 31.

Table 5

Embodiment	The numbering of specimen in use	The type of modifying element and content (weight %)	Yield of ethene (weight %)	Propene yield (weight %)	Diene yield (weight %)
						Embodiment 33	FH-2	1％P+0.5％Ti	26.56	27.69	54.25
Embodiment 34	FH-4	4P％+1％Zr	27.34	26.12	53.46
						Embodiment 35	FH-7	10％P+0.1％Hf	27.76	24.53	52.29
Embodiment 36	FH-8	4％P+0.5％Zr+0.5％Ti	26.87	23.65	50.52
						Embodiment 37	FH-9	5％P+0.4％Ti+0.4％Zr+0.4％Hf	27.25	24.18	51.43
Embodiment 38	FH-10	2％P+2％Bi+1％Ti+0.5％Zr	26.94	28.45	55.39
						Embodiment 39	FH-12	2％P+1％V	19.51	28.79	48.30
Embodiment 40	FH-13	6％P+0.5％Nb	24.64	27.11	51.75
						Embodiment 41	FH-14	2％P+0.2％V+0.2％Nb+0.2％Ta	28.82	25.73	54.55
Embodiment 42	FH-16	4％P+2％Bi+0.5％V+0.5％Nb	27.58	23.45	51.03
						Embodiment 43	FH-1	5％P+1％Ti+0.5％V	27.49	27.31	54.80
Embodiment 44	FH-2	2％P+2％Bi+0.5％Zr+0.2％Nb	28.72	24.66	53.38
						Embodiment 45	FH-3	2％P+1％Bi+0.5％Ti+ 0.2％Zr+0.5％V+0.2％Nb	26.38	27.92	54.30
Embodiment 46	FH-19	2％P+2％Bi+0.4％Ti+0.2％Hf 0.4％Zr+0.2％V+0.2％Nb+0.2％Ta	27.48	27.22	54.70

[embodiment 47]

Get the catalyst that embodiment 1 makes, press the method examination of embodiment 23, begin sampling after 1 hour in reaction, appraisal result such as table 6 were taken a sample once in 1 hour in every then interval.

[embodiment 48]

Get the sample that embodiment 23 makes, according to the method examination of Comparative Examples 1, result such as table 6.

[embodiment 49]

Get the sample that embodiment 43 makes, according to the method examination of Comparative Examples 1, result such as table 6.

Table 6

Comparative Examples	The 1st sub-sampling diene total recovery (weight %)	The 2nd sub-sampling diene total recovery (weight %)	The 3rd sub-sampling diene total recovery (weight %)
				Embodiment 47	53.65	51.72	49.59
Embodiment 48	54.37	53.41	52.02
				Embodiment 49	54.80	53.97	52.88

[comparative example 1]

Get the SiO that Shanghai petrochemical industry research institute produces ₂/ Al ₂O ₃Mol ratio is 40 ZSM-5 molecular sieve, according to the method modification of embodiment 38, makes the catalyst of phosphorus, bismuth, titanium and modified zirconia, checks and rates result such as table 7 according to the mode of embodiment 38.

[comparative example 2]

Get the SiO that Shanghai petrochemical industry research institute produces ₂/ Al ₂O ₃Mol ratio is 20 modenite, according to the method modification of embodiment 43, makes the catalyst of phosphorus, titanium and vanadium modification, checks and rates result such as table 7 according to the mode of embodiment 43.

[comparative example 3]

Get the SiO that Shanghai petrochemical industry research institute produces ₂/ Al ₂O ₃Mol ratio is 40 β zeolite, according to the method modification of embodiment 33, makes the catalyst of phosphorus and titanium modification, checks and rates result such as table 7 according to the mode of embodiment 33.

[comparative example 4]

Get the SiO that Shanghai petrochemical industry research institute produces ₂/ Al ₂O ₃Mol ratio is 20 Y zeolite, according to the method modification of embodiment 24, makes the catalyst of phosphorus modification, checks and rates result such as table 7 according to the mode of embodiment 24.

Table 7

Comparative example	Used molecular sieve type	The type of modifying element and content (weight %)	Yield of ethene (weight %)	Propene yield (weight %)	Diene yield (weight %)
						Comparative example 1	ZSM-5	2％P+2％Bi+1％Ti+0.5％Zr	24.14	24.45	48.59
Comparative example 2	Modenite	5％P+1％Ti+0.5％V	23.32	23.45	46.77
						Comparative example 3	The β zeolite	1％P+0.5％Ti	22.17	23.52	45.69
Comparative example 4	The Y zeolite	0.5％P	22.21	23.26	45.47

Claims

1. catalyst that is used for the naphtha catalytic pyrolysis, form by following active component by weight percentage:

A) at least a in the coexisting molecular sieve of the coexisting molecular sieve of 85～99% the coexisting molecular sieve that is selected from the ZSM-5/ modenite, ZSM-5/ β zeolite or ZSM-5/Y zeolite; With carry thereon

B) 0.01～2% be selected from least a or its oxide in periodic table of elements IVB family's element or the VB family element;

C) surplus is selected from least a element or its oxide in the periodic table of elements VA family element;

Wherein, in ZSM-5/ mercerization zeolite symbiosis molecular screen, ZSM-5/ beta zeolite coexisting molecular sieve and the ZSM-5/Y zeolite coexisting molecular sieve, the weight percentage of ZSM-5 molecular sieve is 60～99.5%; The SiO of coexisting molecular sieve ₂/ Al ₂O ₃Mol ratio is 10～300.

2. according to the described catalyst that is used for the naphtha catalytic pyrolysis of claim 1, it is characterized in that IVB family element is selected from least a among Ti, Zr or the Hf; VB family element is selected from least a among V, Nb or the Ta.

3. according to the described catalyst that is used for the naphtha catalytic pyrolysis of claim 1, the consumption at least a or its oxide that it is characterized in that being selected from by weight percentage in periodic table of elements IVB family's element or the VB family element is 0.1～1%.