CN103721762A - Catalyst regeneration method capable of reducing carbon dioxide discharge and improving selectivity - Google Patents

Abstract

The invention discloses a catalyst regeneration method capable of reducing carbon dioxide discharge and improving selectivity. The catalyst regeneration method is characterized in that a catalyst with coke is subjected to pure oxygen-based partial regeneration in a coke combustion tank, and the partially regenerated catalyst goes through a dilute phase tube, then enters into a dense bed of a regenerator and then is subjected to residual coke burning; the dense bed is provided with a cooler for controlling a temperature of the dense bed; after cyclone separation, flue gas orderly enters into a flue gas energy recovery system and a carbon dioxide separation system; after carbon dioxide separation, a capturing process is carried out; and the regenerated catalyst is cooled and activated and then is fed into a reactor for recycle. The catalyst regeneration method realizes complete regeneration of a catalyst and uniform distribution of catalyst activity so that coke as a catalytic cracking by-product and a dry gas yield are reduced. The catalyst regeneration method greatly reduces carbon emission and even realizes zero emission of carbon.

Description

A kind of reduction CO2 emission also improves optionally catalyst recovery process

Technical field

The present invention relates to contain in a kind of hydrocarbon process the renovation process of Pd/carbon catalyst.More particularly, the present invention relates to the catalyst recovery process realizing carbon dioxide discharge-reduction in mink cell focus catalytic cracking process and improve catalyst selectivity.

Background technology

Now, the development of global petroleum refining industry faces the lot of challenges such as oil price fluctuates, crude oil in poor quality trend is aggravated, oil quality specification improves, energy-saving and emission-reduction requirement becomes sternly, bio-fuel develops rapidly, and minimizing CO2 emission, mitigation of climate change have become the only way that petroleum refining industry transformed mode of economic growth, kept sustainable development.In October, 2009, country has announced the action target of controlling greenhouse gas emission, arrives the year two thousand twenty nationwide units GDP CO ₂discharge declined 40% to 45% than 2005, and clearly proposed per GDP carbon dioxide emission reduction 17% during " 12 ", and country likely imposes " carbon tax " during " 12 " in good time simultaneously.Therefore in petroleum refining and chemical process, effectively minimizing carbon emission seems and is even more important, and traps, seals up for safekeeping and manage CO ₂refinery's vital task in future will be become.Carbon emission in processing of heavy oil process is mainly the carbon emission of catalytic cracking burning, hydrogen production process and the energy consumption of technical process.Catalytic cracking unit is the core process units of refinery, because catalyst burns, becomes CO ₂one of main source of discharge.

US2011/0155642 A1 discloses a kind of catalytic cracking process process that reduces CO2 emission, adopt coke-burning riser series connection dense bed regenerating unit, pure oxygen and at the regeneration techniques of coke-burning riser multiple spot delivery of supplemental oxygen, this technology Special attention will be given to has increased a tank in regeneration and circuit to be generated respectively, it is degassed that the tank of circuit of wherein regenerating adopts nitrogen to carry out regenerated catalyst, and the tank of circuit to be generated burns efficiency by temperature before introducing reclaimable catalyst and regenerated catalyst and mixing to improve reclaimable catalyst regeneration to improve.But the introducing of regeneration circuit nitrogen finally inevitably can make nitrogen play a reversed role in flue gas by regenerator, obviously lost the advantage of pure oxygen regeneration, only burn efficiency and increase, but the recovery of carbon dioxide has increased difficulty.

US4542114 discloses a kind of integral process process that reclaims the flue gas compositions such as carbon dioxide, can realize and in burning process, go back hydrogen manufacturing and carbon dioxide product, eliminate sulphur, the aerial discharge of nitrogen oxide completely, its pure oxygen mist that adopts carbon dioxide to dilute carries out catalyst and burns to produce rich carbonated flue gas simultaneously.But this technique does not increase interior heat collecting device for realizing in regenerator, emphasize wherein the preferred 30-24% of oxygen concentration 60-21% in mist, thereby part has lost the advantage that adopts purity oxygen regeneration, burns efficiency as increased substantially, and reduces regenerator size etc.

US5565089 discloses a kind of catalytic cracking catalyst process of regenerating, first with air, to enter regenerator to carry out catalyst and burn, then the carbon dioxide in reclaiming flue gas, recycled carbon dioxide and be incorporated to gradually oxygen-containing gas stream until in regenerator temperature normal, last direct oxygen injection and carbon dioxide carry out burning of catalyst.This process of regenerating is only paid close attention to the improvement of regenerative process gas handling system aspect and the processing of flue gas, does not consider the problem of the aspects such as regenerator structure or concrete regeneration technology process and catalytic cracking catalyst circulation.

CN1600431A discloses a kind of incomplete regen-eration smoke combustion technology, employing supplements the way of air in the incomplete regen-eration flue gas between catalyst regenerator and flue gas turbine inlet, CO in incomplete regen-eration flue gas is burnt away, thereby make flue-gas temperature be increased to 660-760 ℃, finally make flue gas turbine inlet temperature reach 640-700 ℃, improve cigarette machine organic efficiency, thereby reduce plant energy consumption with recovered flue gas pressure energy to greatest extent.Adopt the present invention, according to the concentration of unit scale and CO and/or entraining hydrocarbon, supplement air capacity 20-300Nm ³/ min, can effectively improve flue-gas temperature 20-80 ℃, improves cigarette engine efficiency.For single hop incomplete regen-eration, in flue, supplement air and also can make flue gas carry hydro carbons secretly fully to burn, eliminate its impact on cigarette machine, but can not effectively reduce CO2 emissions.

Because conventional catalyst coke burning regeneration method is to pass into air or oxygen-containing gas is regenerated in fluid bed, and air is mainly by O ₂and N ₂form, so in the regenerated flue gas producing after catalyst coke burning regeneration, contain a large amount of N ₂, CO ₂with a small amount of O ₂and CO.And the flue gas of this composition is due to CO ₂concentration is low, so CO ₂separating difficulty is large, cost is high, cannot be isolated collection, can only after entering energy-recuperation system, directly discharge, thereby cause greenhouse effects.

In addition,, from the development of regenerator, pursue the at utmost recovery that realizes regenerated catalyst activity, to realize the maximum conversion ability of hydro carbons always.But the activity of catalyst is the concept represent of a macroscopical conversion ratio, does not embody the pursuit of object product selectivity.While for example regenerating, can realize regenerated catalyst activation recovering the highest, but this regenerated catalyst may be because its high activity causes high coke and dry gas yied when participating in reaction, this does not wish to see.Therefore while regenerating, need to pursue a kind of uniformity that catalyst activity recovers, realize in other words a kind of being uniformly distributed acid on regenerated catalyst, thereby realize low coke and dry gas yied, high object product selectivity.Therefore, be necessary to develop a kind of reduction CO2 emission and improve optionally catalyst recovery process.

Summary of the invention

The object of the invention is to provide on the basis of existing technology a kind of reduction CO2 emission and improve optionally catalyst recovery process.

Reduction CO2 emission provided by the invention also improves the optionally regenerating unit pattern of catalyst recovery process employing burning tank, dilute phase pipe string connection dense bed, and burning tank is fast bed operation, and dense bed is bubbling bed operation, and the method comprises:

(1) the band Pd/carbon catalyst from catalytic cracking unit stripping section first adopts pure oxygen gas regeneration in burning tank, and coke combustion reaction occurs, and the ratio of burning in burning tank is 40-50%;

(2) from burning tank, catalyst and flue gas out enters dense-phase bed through dilute phase pipe, dense-phase bed bottom further supplements pure oxygen gas, the catalyst of incomplete regen-eration is further burnt in dense-phase bed, holomorphosis, the ratio of burning of dense-phase bed is 50-60%;

(3) dense-phase bed arranges heat collector catalyst is carried out to heat-obtaining, to control the temperature of dense-phase bed, is no more than 750 ℃ and is preferably no more than 720 ℃;

(4) from burning tank bottom, supplement or replenishment cycles flue gas not, when replenishment cycles flue gas, keep oxygen concentration from regenerator cyclone separation system flue gas to be out not less than 30% and be preferably not less than 40%;

(5) flue gas enters smoke energy recovering system after cyclone separator separation, enters subsequently carbon dioxide separating system, after separating carbon dioxide, traps;

(6) regenerator sloped tube arranges catalyst activation system, and this system comprises catalyst cooler and activator, enters reactor cycles again use from regenerator regenerated catalyst out after catalyst activation system.

The operating condition of described burning tank is: temperature 550-720 ℃, and catalyst mean residence time is preferred 30.0-80.0 second 20.0-90.0 second, the gas superficial linear velocity of burning tank is that 1.0-3.0m/s is preferably 1.2-2.0m/s.In burning tank, interior heat collector can be set, also can not arrange, depend on that whether the temperature of burning tank is over 750 ℃.

The operating condition of described dense-phase bed is: 600～750 ℃ of temperature, and catalyst mean residence time is 1.0-4.0 minute preferred 1.0-3.0 minute, gas superficial linear velocity is that 0.4-0.8m/s is preferably 0.4-0.6m/s.The heat collector of dense-phase bed setting is interior heat collector or/and external warmer, and heat collector is one or more.

The operating condition of described catalyst activation system is: the catalyst cooler structure in activation system is similar to external warmer, the wherein close operation mutually of catalyst, and density is 300-700kg/m ³, cooling medium can be water or other medium.Cooler need to guarantee that regenerated catalyst temperature after cooling is 550-640 ℃, and optimum is 560-630 ℃.Activator is a fluidized bed plant, and fluidizing agent is middle pressure superheated vapour, and its pressure is 3.0-3.5MPa, and temperature is 400-450 ℃.Catalyst is close operation mutually in activator, and density is 300-500kg/m ³, the catalyst time of staying is therein 2-8 minute, preferably 3-6 minute.

Described catalyst comprises zeolite, inorganic oxide and optional clay, and each component accounts for respectively total catalyst weight and is: the heavy % of the heavy %-50 of zeolite 1, the heavy % of the heavy %-99 of inorganic oxide 5, the heavy % of the heavy %-70 of clay 0.Its mesolite is active component, be selected from mesopore zeolite and/or optional large pore zeolite, mesopore zeolite accounts for the heavy % of 10 heavy %-100 of zeolite gross weight, the preferably heavy % of 20 heavy %-80, large pore zeolite accounts for the heavy % of 0 heavy %-90 of zeolite gross weight, the preferably heavy % of 20 heavy %-80.Mesopore zeolite is selected from one or more mixtures and/or the ZRP zeolite in ZSM series zeolite, also can carry out modification to the transition metal such as the nonmetalloids such as phosphorus and/or iron, cobalt, nickel for above-mentioned mesopore zeolite.Large pore zeolite selects one or more the mixture in this group zeolite that super steady Y, high silicon Y that free Rare Earth Y (REY), rare earth hydrogen Y (REHY), distinct methods obtain form.

Inorganic oxide, as catalyst carrier, is selected from silica and/or alundum (Al2O3) or both mixtures.

Clay, as bonding agent, is selected from one or more in kaolin, imvite, diatomite, saponite, rectorite, sepiolite, hydrotalcite and bentonite.

Compare with existing renovation process, major advantage of the present invention is following two aspects:

1, the method not only can make catalyst holomorphosis, can significantly reduce carbon emission simultaneously, and even zero carbon emission, reduces greenhouse effects.

2, the method can significantly reduce especially regenerator reserve of device catalyst inventory, greatly reduces the size of static equipment and moving equipment, reduces investment, reduces floor space.

3, because purity oxygen concentration in regenerative system is high, thereby make to burn efficiency, increase substantially, the recovery time shortens, and reduces fragmentation, the wearing and tearing of catalyst, has improved the service efficiency of catalyst.

4, the activity that the method can realize regenerated catalyst is uniformly distributed, thereby coke and dry gas yied in the product of catalytic cracking are reduced.

Accompanying drawing explanation

Accompanying drawing is reduction CO2 emission provided by the invention and improves optionally catalyst recovery process schematic flow sheet.

The specific embodiment

Below in conjunction with accompanying drawing, further illustrate method provided by the present invention, but the present invention is not therefore subject to any restriction.

Accompanying drawing is reduction CO2 emission provided by the invention and improves optionally catalyst recovery process schematic flow sheet.

In accompanying drawing, each numbering is described as follows:

1,10,11,12,13,18,20,21,27,28,29 all represent pipeline; 2 is burning tank; 3 is dilute phase pipe; 4 is dense-phase bed; 5 is dilute-phase zone; 6 is regenerator; 7 and 17 are cyclone separation system; 8 is smoke energy recovering system; 9 is carbon dioxide separating system; 14 is riser reactor; 15 is stripping section; 16 is settler; 19 is oil and gas separating system; 22 is external warmer; 30 is catalyst cooler; 31 is activator.

As shown in drawings, reclaimable catalyst enters burning tank 2 through inclined tube 1 to be generated, pure oxygen gas enters burning tank 2 through pipeline 20, contact concurrent green coke charcoal combustion reaction, up with reclaimable catalyst, flue gas and incomplete regen-eration catalyst enter the dense-phase bed 4 of regenerator 6 through dilute phase pipe 3, purity oxygen also enters the bottom of dense-phase bed 4 through pipeline 21, thereby the catalyst of incomplete regen-eration is further burnt, regenerate.For controlling the temperature of dense-phase bed, be provided with external warmer 22.The flue gas of dense-phase bed leaves regenerator through regenerator dilute-phase zone 5, cyclone separation system 7.From a regenerator flue gas part out, directly enter smoke energy recovering system 8 and recover energy, another part returns to the bottom of dense-phase bed 4 through pipeline 10 circulations, can realize the lifting of the carbon dioxide in flue gas concentration that enters carbon dioxide separating system 9.From energy-recuperation system 8 flue gas out, enter carbon dioxide separating system 9, realize the trapping of carbon dioxide.Regenerated catalyst after regeneration enters catalyst cooler 30 through regenerator sloped tube 11, after catalyst is cooling, by inclined tube 27, enter activator 31, overheated steam also enters activator 31 through pipeline 29, regenerated catalyst after activation enters riser reactor 14 bottoms through inclined tube 28, it is up that pre-lift medium enters riser reactor bottom lifting regenerated catalyst through pipeline 12, feedstock oil enters riser reactor through pipeline 13 and contacts with regenerated catalyst and carry out catalytic cracking reaction, reaction oil gas is successively through settler 16, cyclone separation system 17 and oil-gas pipeline 18 enter oil and gas separating system 19 and obtain various products.Reclaimable catalyst enters inclined tube 1 to be generated and turns back to burning tank 2 and regenerate after stripping section 15 strippings, thereby realize, recycles.

The following examples will be further described the present invention, but not thereby limiting the invention.The feedstock oil using in embodiment and comparative example is decompression residuum, and its character is listed in table 1.Catalyst is produced by catalyst branch company of Sinopec Group Shandong catalyst plant, and goods number is MLC-500, and its character is listed in table 2.

Embodiment

Embodiment carries out on catalytic cracking demonstration plant, as shown in drawings.Demonstration plant does not have smoke energy recovering system and carbon dioxide separating system.20 centimetres of the internal diameters of burning tank wherein, the internal diameter of dense-phase bed is 50 centimetres.According to renovation process proposed by the invention, catalyst is regenerated, at burning tank and dense-phase bed, pass into respectively pure oxygen gas, from regenerator cyclone separation system flue gas partial out, return to dense-phase bed bottom simultaneously.The temperature of burning tank is 650 ℃, and regenerator dense-phase bed temperature is 640 ℃.Catalyst is 60 seconds in the time of staying of burning tank, at the mean residence time of dense-phase bed, is 2 minutes.In burning tank, gas superficial linear velocity is 1.4m/s, and in dense-phase bed, gas superficial linear velocity is 0.6m/s.The density of catalyst of the catalyst cooler in activation system is 550Kg/m3, and catalyst temperature after cooling is 620 ℃.Middle pressure superheated water steaming device pressure 3.4MPa in activation system, 425 ℃ of temperature, density of catalyst 350kg/m in activator ³, the time of staying of catalyst in activator is 3 minutes.Catalyst from activation system out enters reactor, and the feedstock oil listed with table 1 contacts, and carries out catalytic cracking reaction, and regeneration condition, reaction condition, regenerated catalyst carbon content and flue gas composition, product distribute and all list in table 3.

Comparative example

Comparative example is also to carry out on the catalytic cracking demonstration plant of same structure, there is no smoke energy recovering system and carbon dioxide separating system and catalyst activation system.The internal diameter of burning tank and dense bed is different with embodiment, 40 centimetres of the internal diameters of burning tank, and the internal diameter of dense-phase bed is 200 centimetres, other physical dimension is identical with embodiment.Pair reclaimable catalyst identical with embodiment of renovation process routinely regenerated, and burning tank and dense-phase bed pass into respectively air, and the middle part temperature of burning tank is 685 ℃, and regenerator dense-phase bed temperature is 690 ℃.Catalyst is 3 minutes in the time of staying of burning tank, at the mean residence time of dense-phase bed, is 8 minutes.In burning tank, gas superficial linear velocity is 1.5m/s, and in dense-phase bed, gas superficial linear velocity is 0.5m/s.Catalyst after regeneration enters reactor, and the feedstock oil listed with table 1 contacts, and carries out catalytic cracking reaction, and regeneration condition, reaction condition, regenerated catalyst carbon content and flue gas composition, product distribute and all list in table 3.

From the result contrast of operating condition and table 3, can find out, compare with comparative example, the present invention significantly reduces, installs general reserve in burning tank size and regeneration dense bed size and significantly reduces, consumes under the obvious prerequisite reducing of wind index, adopt renovation process proposed by the invention, on regenerated catalyst, carbon content reduces more, in addition in the flue gas that, this catalyst recovery process produces, do not contain CO and N ₂, gas concentration lwevel, up to 57%, is conducive to the separated and trapping of carbon dioxide.In addition, embodiment, owing to adopting catalyst activation system, compares ratio dry gas yied and reduces by 0.6 percentage point, and coke yield reduces by 0.7 percentage point, gasoline and diesel yield increase, and total liquid is received (liquefied gas, gasoline, diesel yield sum) increases by 1.1 percentage points.

Table 1

Feedstock oil title	Decompression residuum
		Density (20 ℃), kg/m 3	920.9
Kinematic viscosity, millimeter 2/ second
		100℃	114.4
Carbon residue, heavy %	8.2
		Condensation point, ℃	25
Total nitrogen, heavy %	0.33
		Sulphur, heavy %	0.21
Carbon, heavy %	86.91
		Hydrogen, heavy %	12.55
Tenor, ppm
		Nickel	8.8
Vanadium	0.1
		Iron	1.8
Copper	＜0.1
		Sodium	3.0
Boiling range, ℃
		HK (initial boiling point)	415
10％	545
		30％	/
50％	/
		70％	/
KK (end point of distillation)	/

Table 2

Catalyst goods number	MLC-500
		Chemical composition, heavy %
Aluminium oxide	50.2
		Sodium oxide molybdena	0.321
Apparent density, kg/m 3	700
		Pore volume, mL/g	0.38
Specific area, m 2/g	229
		Abrasion index, during heavy % -1	1.9
Size consist, heavy %
		0～40 micron	17.3
40～80 microns	49.3
		80 microns of >	33.4

Table 3

	Embodiment	Comparative example
			Device catalyst general reserve, ton	1	5
Cracking hydrocarbon reaction member
			Outlet temperature of riser, ℃	500	500
Catalyst/feed weight ratio	6	6
			Reaction time, second	3	3
Water vapour/raw material weight ratio	0.05	0.05
			Product distributes, heavy %
Dry gas	3.0	3.6
			Liquefied gas	14.0	14.8
Gasoline	39.2	38.4
			Diesel oil	28.3	27.2
Heavy oil	6.8	6.6
			Coke	8.7	9.4
Regeneration unit
			Burning tank internal diameter, cm	20	40
Dense bed internal diameter, cm	50	200
			Consumption wind index, Nm 3/kg	3	14
Carbon content on regenerated catalyst, heavy %	0.02	0.08
			Regenerated flue gas forms, %
N 2	0	79.4
			CO 2	57.28	15.44
CO	0	1.09
			O 2	42.72	4.07

Claims (12)

1. one kind is reduced CO2 emission and improves optionally catalyst recovery process, it is characterized in that the method adopts the regenerating unit pattern of burning tank, dilute phase pipe string connection dense bed, burning tank is fast bed operation, and dense bed is bubbling bed operation, and the method comprises:

(1) the band Pd/carbon catalyst from catalytic cracking unit stripping section first adopts pure oxygen gas regeneration in burning tank, and coke combustion reaction occurs, and the ratio of burning in burning tank is 40-50%;

(2) from burning tank, catalyst and flue gas out enters dense-phase bed through dilute phase pipe, dense-phase bed bottom further supplements pure oxygen gas, the catalyst of incomplete regen-eration is further burnt in dense-phase bed, holomorphosis, the ratio of burning of dense-phase bed is 50-60%;

(3) dense-phase bed arranges heat collector catalyst is carried out to heat-obtaining, to control the temperature of dense-phase bed, is no more than 750 ℃ and is preferably no more than 720 ℃;

(4) from burning tank bottom, supplement or replenishment cycles flue gas not, when replenishment cycles flue gas, keep oxygen concentration from regenerator cyclone separation system flue gas to be out not less than 30% and be preferably not less than 40%;

(5) flue gas enters smoke energy recovering system after cyclone separator separation, enters subsequently carbon dioxide separating system, after separating carbon dioxide, traps;

(6) regenerator sloped tube arranges catalyst activation system, and this system comprises catalyst cooler and activator, enters reactor cycles again use from regenerator regenerated catalyst out after catalyst activation system.

2. according to the method for claim 1, it is characterized in that the operating condition of described burning tank is: temperature 550-720 ℃, catalyst mean residence time is 20.0-90.0 second, gas superficial linear velocity is 1.0-3.0m/s.

3. according to the method for claim 2, it is characterized in that the operating condition of described burning tank is: catalyst mean residence time is 30.0-80.0 second, and gas superficial linear velocity is 1.2-2.0m/s.

4. according to the method for claim 1, it is characterized in that the operating condition of described dense-phase bed is: 600～750 ℃ of temperature, catalyst mean residence time is 1.0-4.0 minute, gas superficial linear velocity is 0.4-0.8m/s.

5. according to the method for claim 4, it is characterized in that the operating condition of described dense-phase bed is: catalyst mean residence time is 1.0-3.0 minute, gas superficial linear velocity is 0.4-0.6m/s.

6. according to the method for claim 1, it is characterized in that the described heat collector of step (3) is interior heat collector or/and external warmer, heat collector is one or more.

7. according to the method for claim 1, it is characterized in that the temperature of step (3) control dense-phase bed is no more than 720 ℃.

8. according to the method for claim 1, it is characterized in that the oxygen concentration in the described flue gas of step (4) is not less than 40%.

9. according to the method for claim 1, it is characterized in that catalyst close operation mutually in described catalyst cooler, density is 300-700kg/m ³.

10. according to the method for claim 1, it is characterized in that catalyst close operation mutually in described activator, density is 300-500kg/m ³, the catalyst time of staying is therein 2-8 minute; Fluidizing agent is middle pressure superheated vapour, and its pressure is 3.0-3.5MPa, and temperature is 400-450 ℃.

11. according to the method for claim 10, it is characterized in that the time of staying of catalyst in described activator is 3-6 minute.

12. according to the method for claim 1, it is characterized in that described catalyst comprises zeolite, inorganic oxide and optional clay, each component accounts for respectively total catalyst weight and is: the heavy % of the heavy %-50 of zeolite 1, the heavy % of the heavy %-99 of inorganic oxide 5, the heavy % of the heavy %-70 of clay 0.