CN1102452C - Method of delaying service life of catalyst - Google Patents

Abstract

The present invention relates to a method for extending the service life of a catalyst, which is particularly to suitable for catalysts for the hydrogenation treatment of heavy and poor residual oil. The method comprises the steps that during the normal operation of a residual oil catalyst, under the condition of no stop, the raw material of residual oil is changed into distillate oil containing a vulcanizing agent; the distillate oil enters a catalyst bed layer; after being vulcanized, the distillate oil is changed into the normal raw material of heavy and residual oil in order to reach the purpose of extending the service life of the residual oil catalyst.

Description

A kind of catalyst method in service life that prolongs

Technical field

The present invention relates to a kind of catalyst method in service life that prolongs.This method is applicable to catalyst bad, the heavy oil residue hydrotreatment is specially adapted to the catalyst of fixed bed residual hydrocracking.

Background technology

As everyone knows, world's crude oil becomes heavy gradually, becomes bad in recent years, adds that environmental regulation is more and more stricter to the requirement of oil product, and it is more and more important that residual hydrocracking seems.Yet because heavy, poor residuum density is big, viscosity is high, hydrogen-carbon ratio is low and be rich in undesirable components such as a large amount of metals, sulphur, nitrogen, causes its hydrotreatment difficulty to be far longer than distillate.Handle at present technology bad, heavy oil residue and mainly contain fixed bed, suspension bed, ebullated bed, moving bed and moving bed and add fixed bed, wherein fixed bed be most widely used general, also be the most ripe technology.But no matter employ technology, all can run into because of residual oil green coke and metal and on catalyst, deposit the problem that causes catalysqt deactivation.How to prolong catalyst service life, improving the oil plant economic benefit is one of current the biggest problem that faces.

Chinese patent CN104558A discloses a kind of fixed-bed type catalyst system of hydrotreating catalyst, with the physical mixture that contains high-voidage catalyst granules and low voidage catalyst granules, in different layers, particle is mixed by different amounts, thereby in the catalyst system of fixed-bed type, form layer structure, prolong the catalyst purpose in service life to reach.

Xue Fulong company has proposed catalyst classification filling (Grading), rope company of Top has proposed compound filling (Composite Filling), Shell Co. Ltd has proposed (Stacked Bed) stacked bed, in fact all be by its different physical behavior (shapes with different catalysts and/or similar catalyst and active carrier and/or inert carrier, size), catalyst activity and differential responses type are carried out the technology of classification filling, bring into play catalyst action to greatest extent to reach, reduce pressure drop, prolong catalyst life, improve the purpose of product quality.

Unite oily company (union oil company of california) and proposed use guard reactor technology; before main reactor, increase a guard reactor; in guard reactor, load residuum hydrogenating and metal-eliminating, Hydrobon catalyst; until the guard reactor pressure drop allows the upper limit; get rid of the guard reactor by-passing then until whole device catalyst changeout more, to prolong the catalyst runs cycle.

More than all with the classification of catalyst grating, inhomogeneity catalyst filling and the technology of using guard reactor for setting about a little, and reckon without the reaction mechanism of catalyst self.

Through research and evidence for many years, the inactivation of catalyst for hydrotreatment of residual oil mainly be since in the deposition of metal impurities and the hydroconversion process generation of coke cause.In the whole use of catalyst, the inactivation of catalyst is broadly divided into initial stage inactivation, stable state inactivation and final inactivation three phases suddenly.Use the initial stage at catalyst, the poly-inactivation of urgency that causes the obstruction of catalyst surface area minimizing and aperture to cause owing to a large amount of carbon deposits is called the initial stage inactivation, and this time spent in stage is shorter, approximately needs 800-1000 hour.In case the initial stage inactivation is gone over, inactivation is slack-off in longer a period of time, catalyst enters the stable state inactivation stage, this stage inactivation mainly is deposited on catalyst than causing on the macropore owing to carbon deposit and metal, metal impurities are deposited in catalyst surface and the catalyst space and cause the stable state inactivation of catalyst, and this stage is called the stable state inactivation phase of catalyst.Aggravation along with the metal impurities deposition, catalyst activity progressively descends, need to remedy the activity of such catalysts loss by improving reaction temperature, from the catalyst analysis result that fixed bed reactors are taken out, the beds top is seriously polluted, along with increase the duration of runs, pollute progressively and move backward, when polluting, will cause the unexpected inactivation of catalyst by whole beds.Studies show that the unexpected time in inactivation stage is shorter, greatly about about 1000 hours.

In sum, shorter during the initial stage inactivation, want to bring into play to greatest extent catalyst performance, must prolong the stable state inactivation phase of catalyst.And catalyst stable state inactivation mainly is because carbon deposit and the deposition of metal on the catalyst macropore cause, by to the metal impurities in the raw material, particularly nickel, vanadium studies show that, the metal deposition itself does not have intoxication to the demetalization reactivity, be increase along with deposition, the duct of meeting blocking catalyst.But from another perspective, metal deposit itself also has the self-catalyzed reaction generation.Test shows, when hydrogen sulfide content in the gas strengthens, metal deposit can form nickel sulfide, vanadic sulfide, and the active material of these two kinds of materials energy and catalyst itself forms new active material as VI and/or the fine coupling of VIII metal component, promote the raising of hydrogenation activity, so in reaction system, inject vulcanizing agent, will increase the content of hydrogen sulfide in the reaction zone gas, thereby impel impurity such as nickel, vanadium to generate new active material.Can effectively reduce coke content on the catalyst and residual oil is switched to distillate, be surprised to find the distillate injecting catalyst bed that to contain vulcanizing agent in the test and can effectively prolong catalyst life.

Summary of the invention

Purpose of the present invention is exactly according to last the above catalyst reaction mechanism, proposes a kind of method that prolongs catalyst life, particularly prolong with VIB and or the VIII metal be the weight of active component, the method for residual oil catalyst life.

Technical scheme of the present invention is as follows:

In the presence of hydrogen and catalyst, heavy, residual oil raw material is under the hydro-conversion condition, contact with catalyst, described catalyst be with VIB and or the VIII metal oxide be active metal component, with the porous refractory inorganic oxides is the catalyst of carrier, during catalyst stable state inactivation, to weigh, resid feed switches to the distillate that contains one or more vulcanizing agents, make it to pass the whole bed of catalyst, each notes sulfur content is the 1.0%-5.0% of total catalyst weight, be 2.5%-4.0% preferably, switch to described heavy after notes sulphur finishes again, resid feed is injected number of times at least once.

Described vulcanizing agent can be element sulphur, inorganic sulphide or organic sulfur compound.Preferably can satisfy following requirement:

1, face hydrogen and catalyst in the presence of, vulcanizing agent can be decomposed into hydrogen sulfide under lower reaction temperature, to improve the effect of sulfuration;

2, the vulcanizing agent sulfur content is higher, reduces the influence of other factor to catalyst;

3, cost is low, is easy to obtain;

4, toxicity is little, and safety in utilization is good.

According to above requirement, described vulcanizing agent can be selected from sulfur-containing compound, disulphide, polysulfide and the thiophenic acid compound of thio-alcohol; General is carbon disulfide, dimethyl disulfide, DMDS than what use always.

Described distillate better is 160-538 ℃ a petroleum distillate, and the impurity in this cut, asphalt content must be less than 1w%, and scope is less than 0.5w% preferably, and best scope is less than 0.1w%; The content of vulcanizing agent in described distillate is between 1.0-2.5w% in elemental sulfur, is between the 1.5-2.5w% preferably.

The operating time of annotating sulphur is selected also very important, and penetrate whole beds from distillate and pick up counting and generally need 20-120 hour, be 50-120 hour preferably, best is 80-120 hour.

During catalyst stable state inactivation, the number of times that injects vulcanizing agent in reaction system is generally 2-4 time at least once, is preferably 2-3 time, and what each blanking time was general is 1500-3000 hour, and be 1500-2000 hour blanking time preferably.

Described heavy residual oil hydrocatalyst be meant have weight, the single catalyst or the series catalyst of residuum hydrogenating and metal-eliminating, hydrodesulfurization, hydrodenitrogeneration and hydrocracking function.These catalyst generally all are to be carrier with porous inorganic oxide such as aluminium oxide, the oxide of group vib and/or VIII family metal oxide such as W, Mo, Co, Ni etc. is an active component, the catalyst that optionally adds other various auxiliary agents such as P, Si, elements such as F, B, for example CEN, the FZC series of being produced by Fushun Petrochemical Research Institute pilot scale base weighs, residuum hydrogenating and metal-eliminating catalyst, and ZTN, the ZTS catalyst series produced by first chemical fertilizer factory of Qilu Petrochemical company just belong to this class catalyst.At present in fixed bed residual hydrogenation technology, it often is the supporting use of multiple catalyst, Hydrodemetalation catalyst, Hydrobon catalyst, hydrodenitrogenation catalyst are wherein arranged, and the filling order generally is that feedstock oil is contacted with HDM, hydrodesulfurization, hydrodenitrogeneration, hydrocracking catalyst successively.Technology with these several catalyst mix fillings is also arranged certainly.

Residue fixed-bed hydrogenation normal operating condition is: reaction temperature 340-420 ℃, and preferably 360-410 ℃; Reaction pressure is 10-16MPa, and that best is 13-15MPa; Hydrogen to oil volume ratio is 500-2000, and that best is 700-1500; Volume space velocity is 0.1-1.0h during liquid ^-1, that best is 0.2-0.4h ^-1

When injecting the described distillate that contains vulcanizing agent, its operating condition is: operating pressure, recycle hydrogen amount are identical in the time of can be with normal running, between 0.6-1.5 when the volume space velocity opereating specification is normal running times, the 0.8-1.2 when scope is normal running preferably doubly.Reaction temperature can be according to the boiling range decision of selected distillate, and general operating temperature range is 260-350 ℃, is 300-350 ℃ preferably.

The present invention can be used for different structure reaction zone, preferably fixed bed reactors.

This method is applicable to the life-span that prolongs hydrotreating catalyst, and particularly prolonging with VIB and/or VIII metal oxide is active metal component, is the weight of carrier, the life-span of poor residuum hydrotreating catalyst with the aluminium oxide.Wherein, this method process of relating to catalyst a kind of, two kinds or their process integration that can be above to be mentioned; Also can be that fixed bed, ebullated bed, moving bed, fixed bed add moving bed process.

The specific embodiment

Embodiment 1

Overlap on the identical pilot-plant at A, B two, adopt the complete series catalyst for hydrotreatment of residual oil of Fushun Petrochemical Research Institute's exploitation to carry out service life evaluation testing.Used feedstock oil, operating condition, catalyst and the filling scheme thereof of A, B two covering devices is all identical, wherein, the filling situation of each anticatalyst is: one instead loads CEN-2, CEN4, FZC-16, CEN-5, CEN6 from top to bottom, filling ratio (V) is: 1: 1.5: 2.2: 2.4: 13, two instead load ZTS01 and ZTS02 from top to bottom, filling ratio (V) is: 7.5: 1, three instead loaded ZTN01 from top to bottom, and the filling ratio (V) of three reactors is 45: 20: 35.Above-mentioned CEN-2, CEN4, FZC-16, CEN-5, CEN6 catalyst are to be produced by Fushun Petrochemical Research Institute pilot scale base, and ZTS01, ZTS02 and ZTN01 are produced by first chemical fertilizer factory of Qilu Petrochemical company.The standard operation condition of device is: reaction pressure 15.7MPa, and 385 ℃ of reaction temperatures, hydrogen-oil ratio is 758 (v/v), volume space velocity 0.2h-1 during liquid.Subtracting slag with the Iran of mixing is raw material, and the main character of feedstock oil is listed in following table 1.In the steady running of slag input oil in the time of 3000 hours, A, B two covering devices are under the standard operation condition, with feedstock oil in the table 1 obtain hydrogenated oil take off the impurity data after, under the condition identical with standard operation conditioned response pressure, hydrogen-oil ratio, with 10 ℃/h each anti-temperature is reduced to 350 ℃, A overlaps with 0.12h ^-1, B overlaps with 0.30h ^-1Volume space velocity in device, inject and contain DMDS (DMDS) vacuum distillate (VGO), wherein, contain sulfuration dosage and guarantee that the simple substance S content in the vacuum distillate accounts for 2% of its gross weight, the reduced pressure distillate oil nature sees Table 2.After the off-test, swap-in code test feedstock oil, stable back is analyzed hydrogenated oil under the standard operation condition, injects the operating condition and the result of the test that contain the vulcanizing agent distillate and lists in table 3.

When using with a kind of feedstock oil, under the situation that volume space velocity, hydrogen-oil ratio are constant when standard operation pressure, liquid, the percentage of admixture that takes off of hydrogenated oil progressively descends along with the increase meeting of the duration of runs, for making hydrogenated oil satisfy the requirement of fed downstream, must improve reaction temperature and come the loss of activity of compensate for catalyst, and temperature improves the inactivation that will accelerate catalyst.Can improve the percentage of admixture that takes off of hydrogenated oil with test method of the present invention, in other words improve the temperature raising speed that percentage of admixture can delay catalyst of taking off of hydrogenated oil, promptly prolong the service life of catalyst.

Table 1: test raw material oil main character

Density, Kg/m3	981.6
		S，m％	2.83
N，m％	0.28
		Carbon residue, m%	13.49
(Ni+V)，μg/g	118.8
		Four components, m%
Saturated hydrocarbons	37.1
		Aromatic hydrocarbon	40.5
Colloid	19.2
		Asphalitine	3.2

Table 2: reduced pressure distillate oil nature

Boiling range ASTM D-1160, ℃
		Initial boiling point	356
10％/30％	389/434
		50％/70％	467/495
90％/95％	524/536
		Do	555
S，m％	0.10
		N，m％	0.06
Four components, %
		Saturated hydrocarbons	84.5
Aromatic hydrocarbon	15.1
		Colloid	0.3
Asphalitine	0.1

Table 3: test technology condition and result of the test

Notes contain the process conditions of vulcanizing agent distillate:
				Reaction pressure, MPa	15.7
Reaction temperature, ℃	350
				Hydrogen-oil ratio, v/v	758
The duration of runs, h	3000
				Experimental rig		The A cover	The B cover
Volume space velocity, h -1	-	0.12	0.30
				Operating time, h	-	90	40
Result of the test:
					Annotate the sulphur front-end hydrogenation and generate oil	Annotate the sulphur back end hydrogenation and generate oil
Desulfurization degree, %	90.8	91.6	91.2
				Denitrification percent, %	55.7	56.8	56.1
Take off carbon yield, %	68.9	69.7	69.2
				Demetallization per, %	88.5	89.4	88.8

Embodiment 2

After finishing according to the condition test of embodiment 1, adopt with embodiment 1 in identical experimental rig, catalyst filling scheme, standard operation condition, test raw material oil remain in operation, when 5000 hours of slag input oil steady running, obtain hydrogenated oil take off the impurity data after, under the condition identical with standard operation conditioned response pressure, reaction temperature, hydrogen-oil ratio, volume space velocity, with 10 ℃/h each anti-temperature is reduced to 350 ℃, stable back is injected to device and is contained carbon disulfide (CS ₂) vacuum distillate (VGO), sulfur content is 1.0w% in the A cover intermediate distillates, sulfur content is 2.0w% in the B cover, the reduced pressure distillate oil nature sees Table 2.After the off-test, swap-in code test feedstock oil (table 1), stable back is analyzed hydrogenated oil, injects the operating condition and the result of the test of the distillate that adds vulcanizing agent and lists in table 4.

Table 4: test technology condition and result of the test

Notes contain the process conditions of vulcanizing agent distillate:
				Reaction pressure, MPa	15.7
Volume space velocity, h -1	0.2
				Hydrogen-oil ratio, v/v	758
The duration of runs, h	5000
				Operating time, h	-	60
Reaction temperature, ℃		350
				Experimental rig		The A cover	The B cover
Sulfur content in the distillate, m%	-	1.0	2.0
				Result of the test:
	Annotate the sulphur front-end hydrogenation and generate oil	Annotate the sulphur back end hydrogenation and generate oil
				Desulfurization degree, %	85.9	86.5	86.8
Denitrification percent, %	53.6	54.0	54.5
				Take off carbon yield, %	64.7	65.1	65.6
Demetallization per, %	86.9	87.5	87.8

Embodiment 3

After finishing according to the condition test of embodiment 2, adopt with embodiment 2 in identical experimental rig, the catalyst filling scheme, the standard operation condition, test raw material oil remains in operation, when the 7000h of A covering device slag input oil steady running, with feedstock oil in the table 1 obtain hydrogenated oil take off the impurity data after, with standard operation conditioned response pressure, hydrogen-oil ratio, under the identical condition of volume space velocity, with 10 ℃/h each anti-temperature is reduced to 350 ℃, inject the vacuum distillate (VGO) that contains DMDS (DMDS) to device 350 ℃ of reaction temperatures, and then reaction temperature dropped to 260 ℃ with the cooling rate of 10 ℃/h, stable back is injected to device and is contained dimethyl disulphide (DMDS) heavy diesel fuel, wherein, the amount of injecting vulcanizing agent will satisfy the S content that makes vacuum distillate and account for 2% of its gross weight, the reduced pressure distillate oil nature sees Table 2, and the heavy diesel fuel main character sees Table 5.After the off-test, swap-in code test feedstock oil, stable back is analyzed hydrogenated oil, injects the operating condition and the result of the test that contain the vulcanizing agent distillate and lists in table 6.

Table 5: the main character of heavy diesel fuel

Boiling range ASTM D-86, ℃
		Initial boiling point	225
10％/30％	258/279
		50％/70％	300/320
90％/95％	335/346
		Do	349
S，μg/g	140.8
		N，μg/g	148

Table 6: test technology condition and result of the test

Notes contain the process conditions of vulcanizing agent distillate:
			Reaction pressure, MPa	15.7
Reaction temperature, ℃	350
			Hydrogen-oil ratio, v/v	758
The duration of runs, h	7000
			Annotate distillate	Annotate VGO	Pay attention to diesel oil
Volume space velocity, h -1	0.2	0.12
			Operating time, h	50	40
Result of the test:
				Annotate the sulphur front-end hydrogenation and generate oil	Annotate the sulphur back end hydrogenation that finishes and generate oil
Desulfurization degree, %	80.5	81.4
			Denitrification percent, %	52.8	53.3
Take off carbon yield, %	62.9	63.5
			Demetallization per, %	84.1	85.8

Claims (8)

1, a kind of method that prolongs catalyst life, comprise: in the presence of hydrogen and catalyst, heavily, residual oil raw material is under the hydro-conversion condition, contact with catalyst, described catalyst is to be active metal component with VIB and/or VIII metal oxide, with the porous refractory inorganic oxides is the catalyst of carrier, during catalyst stable state inactivation, heavy, residual oil raw material are switched to the distillate that contains one or more vulcanizing agents, make it to pass the whole bed of catalyst, switch to described heavy, residual oil raw material again; The number of times that injects vulcanizing agent in reaction system is 1-4 time, annotates the 1.0%-5.0% that sulfur content is a total catalyst weight at every turn, and be 1500-3000 hour each blanking time; Described during reactor is annotated sulphur, operating pressure, recycle hydrogen amount are identical during with normal running, between the 0.6-1.5 when volume space velocity is normal running times, and reaction temperature 260-350 ℃; Described distillate is 160-538 ℃ a petroleum distillate, and the impurity in this cut, asphalt content are less than 1w%, and the content of vulcanizing agent in described distillate is between 1.0-2.5w%; The operating time of described notes sulphur, penetrating from distillate that whole beds picks up counting is 20-120 hour.

2,, it is characterized in that described vulcanizing agent is selected from element sulphur, inorganic sulphide or organic sulfur compound according to the method for the described prolongation catalyst life of claim 1.

3,, it is characterized in that described vulcanizing agent is selected from the sulfur-containing compound of thio-alcohol, disulphide, polysulfide and thiophenic acid compound according to the method for the described prolongation catalyst life of claim 1.

4,, it is characterized in that described vulcanizing agent is selected from carbon disulfide, dimethyl disulfide, DMDS according to the method for the described prolongation catalyst life of claim 1.

5,, it is characterized in that described each notes sulfur content is total catalyst weight 2.5%-4.0% according to the method for the described prolongation catalyst life of claim 1.

6, according to the method for the described prolongation catalyst life of claim 1, it is characterized in that described during reactor is annotated sulphur, operating pressure, recycle hydrogen amount are identical during with normal running, the 1.0-1.5 when volume space velocity is normal running doubly, reaction temperature is 300-350 ℃.

7, according to the method for the described prolongation catalyst life of claim 1, it is characterized in that described notes sulphur number of times is 2-3 time, be 1500-2000 hour each blanking time.

8. according to the method for the described prolongation catalyst life of claim 1, it is characterized in that the described notes sulphur operating time, penetrating from distillate that whole beds picks up counting is 50-120 hour.