CN1927461A - Heteropoly acid containing hydrocracking catalyst and its preparation method - Google Patents

Abstract

The invention relates to a hydrocracking catalyst which contains heteropoly acid, with large diameter and high activity. Wherein, it comprises heteropoly acid, hydrogen component and carrier; the carrier is porous thermal-resistant inorganic material; the heteropoly acid is H3PW12O40 .nH2O, H3PMo12O40 .nH2O, H4SiW12O40 .nH2O or H4SiMo12O40 ..nH2O; the hydrogen component is transition metal element; the heteropoly acid is 20-70%, the hydrogen component is 1-20% and the left is carrier. And the production comprises: selecting inorganic thermal-resistant particle carrier as catalyst carrier, preparing the metal salt water solution of hydrogen component, emerging said carrier, drying the separated solid, baking; preparing heteropoly acid water solution; drying and baking the solid.

Description

Contain hydrocracking catalyst of heteropoly acid and preparation method thereof

Technical field

The present invention relates to the hydrocracking catalyst and the preparation method of long chain alkane.

Background technology

In petroleum refining industry, hydrocracking is the important process process of being produced the high-quality light-weight oil product by mink cell focus, and its technological core is a catalyst system therefor.Hydrocracking catalyst is a kind of bifunctional catalyst, has acid function and hydrogenating function concurrently.The acid function of used typical hydrocracking catalyst mainly is to be provided by molecular sieve now, and hydrogenation component is selected Mo-Ni or W-Ni for use.For example U.S. Pat 5,536, and 687, US5,447,623 and US5,350,501; European patent EP 0028938A1; Chinese patent CN1389545A and CN2393521A all relate to hydrocracking catalyst and preparation method thereof.Contain molecular sieve hydrocracking catalyst and have acidity by force, the advantage that specific surface is big causes reactant and product diffusional resistance to increase but its shortcoming is a molecular sieve bore diameter for a short time, distributes for apparent reactivity and product and brings negative effect.

Summary of the invention

Purpose of the present invention is intended to cause reactant and product diffusional resistance to increase for a short time at the existing molecular sieve bore diameter that contains the molecular sieve hydrocracking catalyst existence, bring problems such as negative effect for the distribution of apparent reactivity and product, highly active hydrocracking catalyst in a kind of large aperture and preparation method thereof is provided.

The hydrocracking catalyst that contains heteropoly acid of the present invention consist of heteropoly acid, hydrogenation component and carrier.Described heteropoly acid is H ₃PW ₁₂O ₄₀NH ₂O, H ₃PMo ₁₂O ₄₀NH ₂O, H ₄SiW ₁₂O ₄₀NH ₂O or H ₄SiMo ₁₂O ₄₀NH ₂O, the particularly H of Keggin structure ₃PW ₁₂O ₄₀NH ₂O or H ₃PMo ₁₂O ₄₀NH ₂The heteropoly acid H that O heteropoly acid, especially heat endurance are high ₃PW ₁₂O ₄₀NH ₂O.Described hydrogenation component can be selected transition metals such as Ni, Co for use, preferred Ni.Carrier is heat-resisting inorganic material of porous such as SiO ₂Or aluminium oxide, preferred SiO ₂Each components contents of catalyst is a heteropoly acid 20%～70% by mass percentage, and is preferred 40%～60%, and hydrogenation component (in simple substance) is 1%～20%, preferred 5%～10%, and surplus is a carrier.

The preparation method of the hydrocracking catalyst that contains heteropoly acid of the present invention is as follows:

1) selects inorganic heat proof material particulate vector such as SiO by the catalytic component proportioning ₂Or aluminium oxide is as catalyst carrier, according to the aqueous metal salt of the constituent content preparation hydrogenation component of catalyst, with this solution impregnating carrier 2～12h;

2) solids after the liquid-solid separation is dried 3～8h down at 80～150 ℃, again in 350～450 ℃ of following roasting 4～8h;

3) according to the constituent content preparation heteropoly acid aqueous solution of catalyst, by the prepared solids of step 2, leave standstill 2～12h with this solution impregnation; At 80～150 ℃ of following oven dry 3～8h, again through 350～450 ℃ of roasting 4～8h, last catalyst.

Catalyst carries out presulfurization before using, and its pre-vulcanization process is the CS with 5/95 (volume ratio) ₂/ H ₂As sulfiding gas, flow velocity 40～70mlmin ^-1, vulcanize 3～8h down at 300～500 ℃.Then switch and feed hydrogen, reaction system progressively adherence pressure to the required pressure of hydrocracking reaction, promote the temperature of beds more gradually to the required temperature of hydrocracking reaction after hydrogen flowing quantity is stable, and hydrogen flowing quantity transferred to the required flow of hydrocracking reaction, progressively cut the reacted hydrocarbon raw material again after stable.

In the aforesaid operations process, hydrocracking reaction pressure, reaction temperature, hydrogen hydrocarbon volume ratio and hydrocarbon charging air speed are determined by hydrocarbon feed character, purpose product requirement and the catalyst performance of reaction.Be generally: reaction pressure 1.0～10.0MPa, 270～400 ℃ of reaction temperatures, hydrogen hydrocarbon volume ratio 600～1800, hydrocarbon feed volume air speed 1.0～4.0h ^-1

The present invention selects for use composition comparatively simple, and structure is determined, not only has the architectural feature of complex and metal oxide concurrently, presents acidity and oxidation-reduction quality, and the also good heteropoly acid of its heat endurance is to provide acid function.Catalyst can be used for big molecule linear paraffin and contains for example hydrocracking and the hydroisomerizing reaction of various oil products of hydrocarbon mixture of big molecule linear paraffin.Its hydrogenation cracking activity is higher than the similar catalyst that contains molecular sieve.

Hydrogenation cracking activity is represented by the conversion ratio of n-decane, and selectivity is designated as C by " the alkane molal quantity that contains 5 carbon atoms and 5 above carbon atoms in the product is divided by the product total mole number " expression ₅₊Selectivity.This is because of in hydrocracking process, wishes that pyrolysis product is many and the second pyrolysis product is few, and when being the reacted hydrocarbon raw material with the n-decane, the alkane that contains 5 carbon atoms and 5 above carbon atoms in the product all is a pyrolysis product, so C ₅₊Selectivity has characterized the relative quantity of a pyrolysis product in the product.

The specific embodiment

The invention will be further described below by embodiment.

Embodiment 1

1) preliminary treatment of carrier: with the carrier specific surface is 380m ²G ^-1SiO ₂Particle soaks 4h in dilute acid soln, be washed till neutrality with distilled water, and dry 5h under 80～120 ℃ is in 550 ℃ of roasting 4h.Final sizing 40～60 purpose SiO ₂Standby.

2) Preparation of Catalyst: the carrier S iO that 80g is above-mentioned ₂Placing 600ml concentration is 0.5molL ^-1Nickel nitrate solution, leave standstill 12h, then in 120 ℃ of following oven dry 5h.With the oven dry after solids in muffle furnace with 10 ℃ of min ^-1Speed rise to 400 ℃, constant temperature 5h.Baked catalyst soakage in the phosphotungstic acid aqueous solution that contains 86g, is left standstill behind the 10h at 100 ℃ of dry 5h down, then at 430 ℃ of following roasting 4h.The chemical composition of institute's controlling catalyst, the heteropoly acid thing is listed in table 1 mutually.

3) appreciation condition: with the catalyst of preparation at the CS of 5/95 (volume ratio) ₂/ H ₂As vulcanizing 4h in 300 ℃ under the sulfiding gas.After sulfuration finishes, cut into hydrogen, stablize laggard n-decane at hydrogen flow rate, reaction process condition sees Table 2.Hydrocracking conversion ratio and the product of evaluate catalysts under reaction condition distributes.The n-decane conversion ratio reaches 65.7%, crackate C ₅+ selectivity reach 73.2%.(seeing Table 3)

Embodiment 2

In embodiment 1, with preparation process 2) in the 86g phosphotungstic acid to change the 37g phosphotungstic acid into be the cost example.The results are shown in Table 3.

Embodiment 3

In embodiment 1, with preparation process 2) in phosphotungstic acid content to change the 70g phosphotungstic acid into be the cost example.The results are shown in Table 3.

Embodiment 4

In embodiment 3, with preparation process 2) in load phosphotungstic acid after sintering temperature change 380 ℃ into, i.e. cost example.

Embodiment 5

In embodiment 1, with preparation process 2) in the 86g phosphotungstic acid change the 86g phosphomolybdic acid into, i.e. cost example.

Embodiment 6

In embodiment 1, with preparation process 2) in the 86g phosphotungstic acid change the 86g silico-tungstic acid into, i.e. cost example.

Embodiment 7

In embodiment 1, with preparation process 2) in the 86g phosphotungstic acid change the 86g silicomolybdic acid into, i.e. cost example.

Embodiment 8

In embodiment 1, with preparation process 2) in the 0.5molL of 600ml ^-1Nickel nitrate solution change 300ml into, i.e. cost example.

Embodiment 9

In embodiment 1, with preparation process 2) in the 0.5molL of 600ml ^-1Nickel nitrate solution change 600ml nickel oxalate solution, i.e. cost example into.

Embodiment 10

1) preliminary treatment of carrier: with the carrier specific surface is 300m ²G ^-1Aluminium oxide standby behind 600 ℃ of roasting 4h.

2) Preparation of Catalyst: it is 0.5molL that the alumina catalyst support that 80g is above-mentioned places 600ml concentration ^-1Nickel nitrate solution, leave standstill 3～12h, then in 120 ℃ of following oven dry 5h.With the oven dry after solids in muffle furnace with 10 ℃ of min ^-1Speed rise to 400 ℃, constant temperature 5h.Baked catalyst soakage in containing the 86g phosphotungstic acid aqueous solution, is left standstill behind the 10h at 100 ℃ of dry 5h down, then at 440 ℃ of following roasting 4h.The chemical composition of institute's controlling catalyst, the heteropoly acid thing is listed in table 1 mutually.

3) appreciation condition: with the catalyst of preparation at the CS of 5/95 (volume ratio) ₂/ H ₂As vulcanizing 4h in 300 ℃ under the sulfiding gas.After sulfuration finishes, cut into hydrogen, stablize laggard n-decane at hydrogen flow rate.Estimating hydrocracking conversion ratio and the product of each catalyst under reaction condition distributes.(selectivity of gained conversion ratio and crackate sees Table 3)

Embodiment 11

In embodiment 1, with preparation process 2) in the 0.5molL of 600ml ^-1Nickel nitrate solution change the cobalt nitrate solution of 600ml, i.e. cost example into.

Embodiment 12

In embodiment 10, with preparation process 2) in the 0.5molL of 600ml ^-1Nickel nitrate solution change the cobalt nitrate solution of 600ml, i.e. cost example into.

Comparative example 1

The method preparation that this routine catalyst is provided according to patent CN1389545A.Raw materials used and the reaction process condition of evaluation of catalyst activity sees Table 2.Estimate the CS of catalyst system therefor in 5/95 (volume ratio) ₂/ H ₂As vulcanizing 4h in 300 ℃ under the sulfiding gas.After sulfuration finishes, cut into hydrogen, stablize laggard n-decane in hydrogen gas speed.Estimating hydrocracking conversion ratio and the product of each catalyst under reaction condition distributes.The result is a n-decane conversion ratio 31.7%, C ₅+ selectivity 77.3%.

By the selectivity (seeing Table 3) of gained conversion ratio and crackate as can be seen: adopt institute of the present invention controlling catalyst under same reaction condition and close selective conditions, higher hydrogenation cracking activity to be arranged.

The physico-chemical property of each routine catalyst of table 1

	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4
					Heteropoly acid have a phase	The Keggin structure	The Keggin structure	The Keggin structure	The Keggin structure
Chemical composition
					Used heteropoly acid, Wt%	60	30	50	50
Used carrier, Wt%	26	56	36	36
					Ni，Wt％	10	10	10	10
	Embodiment 5	Embodiment 6	Embodiment 7	Embodiment 8
					Heteropoly acid have a phase	The Keggin structure	The Keggin structure	The Keggin structure	The Keggin structure
Chemical composition
					Used heteropoly acid, Wt%	60	60	50	50
Used carrier, Wt%	26	26	36	43
					Ni，Wt％	10	10	10	5
	Embodiment 9	Embodiment 10	Embodiment 11	Embodiment 12
					Heteropoly acid have a phase	The Keggin structure	The Keggin structure	The Keggin structure	The Keggin structure
Chemical composition
					Used heteropoly acid, Wt%	60	60	50	50
Used carrier, Wt%	26	26	36	36
					Ni，Wt％	10	10	0	0
Co，Wt％	0	0	10	10

Table 2. feedstock property and reaction process condition thereof

Raw material	N-decane
		Reaction pressure, MPa	2.0
WHSV，h -1	4.94
		Hydrogen to oil volume ratio	1500
Reaction temperature, ℃	300
		Curing temperature, ℃	300

The hydrogenation cracking activity of each routine catalyst of table 3. and selectivity

Catalyst	Embodiment 1	Embodiment 2	Embodiment 3	Embodiment 4	Embodiment 5
						The n-decane conversion ratio, %	65.7	42.7	60.3	57.9	63.7
C 5+ selectivity, %	73.2	79.5	77.7	76.1	72.3
						Catalyst	Embodiment 6	Embodiment 7	Embodiment 8	Embodiment 9	Embodiment 10
The n-decane conversion ratio, %	52.4	50.7	47.5	58.9	66.7
						C 5+ selectivity, %	72.8	76.3	77.7	69.1	75.3
Catalyst	Embodiment 11	Embodiment 12	Comparative example 1
						The n-decane conversion ratio, %	51.4	55.4	31.7
C 5+ selectivity, %	67.9	69.9	77.3

Claims (9)

1. the hydrocracking catalyst that contains heteropoly acid is characterized in that it consists of heteropoly acid, hydrogenation component and carrier, and described carrier is the heat-resisting inorganic material SiO of porous ₂Or aluminium oxide, heteropoly acid is H ₃PW ₁₂O ₄₀NH ₂O, H ₃PMo ₁₂O ₄₀NH ₂O, H ₄SiW ₁₂O ₄₀NH ₂O or H ₄SiMo ₁₂O ₄₀NH ₂O, hydrogenation component is a transition metal, and each components contents of catalyst is a heteropoly acid 20%～70% by mass percentage, is 1%～20% in the simple substance hydrogenation component, and surplus is a carrier.

2. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 1 is characterized in that described heteropoly acid is H ₃PW ₁₂O ₄₀NH ₂O or H ₃PMo ₁₂O ₄₀NH ₂O.

3. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 2 is characterized in that described heteropoly acid is H ₃PW ₁₂O ₄₀NH ₂O.

4. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 1 is characterized in that described hydrogenation component is Ni or Co.

5. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 4 is characterized in that described hydrogenation component is Ni.

6. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 1 is characterized in that described carrier is SiO ₂

7. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 1 is characterized in that the carrier specific surface is greater than 300m ²G ^-1

8. the hydrocracking catalyst that contains heteropoly acid as claimed in claim 1 is characterized in that each components contents of catalyst is a heteropoly acid 40%～60% by mass percentage, is 5%～10% in the simple substance hydrogenation component, and surplus is a carrier.

9. the preparation method who contains the hydrocracking catalyst of heteropoly acid as claimed in claim 1 is characterized in that the steps include:

1) selects inorganic heat proof material particulate vector such as SiO by the catalytic component proportioning ₂Or aluminium oxide is as catalyst carrier, according to the aqueous metal salt of the constituent content preparation hydrogenation component of catalyst, with this solution impregnating carrier 2～12h;

2) solids after the liquid-solid separation is dried 3～8h down at 80～150 ℃, again in 350～450 ℃ of following roasting 4～8h;

3) according to the constituent content of the catalyst preparation heteropoly acid aqueous solution, by the prepared solids of step 2, leave standstill 2～12h with heteropoly acid aqueous solution dipping, at 80～150 ℃ of oven dry 3～8h down, again through 350～450 ℃ of roasting 4～8h, last catalyst.