CN102962096B - Method for regenerating catalyst for preparing propylene from methanol or dimethyl ether - Google Patents

Abstract

The invention relates to a method for regenerating a catalyst for preparing propylene from methanol or dimethyl ether. The method comprises the following steps: a, drying the deactivated catalyst for preparing propylene from methanol or dimethyl ether; b, calcining the catalyst in an oxygen-containing regeneration medium at 480-550 DEG C for 4-12h; and c, immersing the calcined catalyst with acid solution, and filtering the acid solution for immersing the catalyst. By optimizing the warming procedure, the formation of non-framework aluminum in the calcining process is reduced, and more acidity activity centers in the catalyst can be kept; and the calcined catalyst is immersed by using the acid solution, so that the deposited carbon in the catalyst can be removed more completely. In comparison with the catalyst regenerated only by using a conventional calcining regeneration method, the catalyst regenerated by the method has the advantages that the catalytic activity is remarkably improved and is almost completely recovered to the reaction activity before inactivation, so that the service life of the catalyst is greatly prolonged.

Description

The renovation process of a kind of methyl alcohol or dimethyl ether propylene catalyst

Technical field

The present invention relates to the renovation process of decaying catalyst in methyl alcohol or dimethyl ether propylene, particularly in methyl alcohol or dimethyl ether propylene because of carbon deposit and framework aluminum migration and the renovation process of the catalyst of inactivation.

Background technology

Traditionally, low-carbon alkene is mainly derived from petroleum cracking process, along with the continuous rise of International Crude Oil, domestic increasingly soaring to low-carbon alkene demand, as the resource such as naphtha, light diesel fuel of ethene, production of propylene raw material, be faced with more and more serious short situation, therefore develop, by the technique (MTP) of methyl alcohol or dimethyl ether production propylene, there is great potential and important meaning.

Catalyst is the core of coal-based methanol or dimethyl ether propylene technique, and at present the main catalyst used is HZSM-5 molecular sieve or the alkali metal of load different content, alkaline-earth metal, transition metal isoreactivity auxiliary agent are made on HZSM-5 molecular sieve catalyst.HZSM-5 is a kind of high-silicon type molecular sieve with unique texture, there is surface hydrophobicity, there is very strong adsorption capacity for nonpolar molecule, and become the three-dimensional apertures molecular sieve catalyst with acid catalysis and shape selectivity with the shape selective based on microcellular structure feature of its uniqueness and strong acid center.And acid site easily causes carbon deposit, cause the blocking in catalyst surface and duct, catalyst activity and selectivity is declined.

The common method of current process carbon deposited catalyst is calcining, but catalyst can release a large amount of heat in the process of calcination and regeneration, catalyst is easily caused to sinter due to hot-spot, catalyst grain size is made to become large on the one hand, high temperature also can cause framework aluminum to migrate to catalyst surface on the other hand, and the two all can cause catalyst activity to reduce.In addition, the catalyst of carbon deposit is when removing carbon deposit by calcining, and still can remain certain carbon deposit in catalyst, this part carbon deposit is still difficult to effective removal with the prolongation of calcination time or the rising of calcining heat.

Existing about in the regeneration document of catalyst, major part uses the method for calcination and regeneration, considers how to reduce hot-spot problem emphatically.USP4780195 suggestion is added a certain amount of water and is prevented sintering in calcination atmosphere.USP4202865 adopts the method for batch (-type) note oxygen to prevent catalyst overheating.USP5037785, under oxygen containing gas, adopts and swashs light-struck way to catalyst decoking.

A kind of cleaning agent containing monoethanolamine, ether, butanols and phenol is disclosed in CN1768955A, first the catalyst of coking deactivation is cleaned, be attached to catalyst surface with removal part or build the carbon deposit poor with ability with catalyst, then carrying out calcination and regeneration.But this method complicated operation, cleaning agent cost is high, and is all organic easy volatile solvent, and security is low.CN101584989A provides a kind of renovation process of preparing low carbon olefin hydrocarbon by methanol used catalyst, the method adopts the cleaning agent of organic solvent methyl alcohol, ether, acetone and gasoline preparation, catalyst under ultrasonic condition after soaking inactivation, effectively can remove the carbon deposit in catalyst surface and duct, but adopt ultrasound treatment patterns to cause catalyst breakage, and not easily realize large-scale application.

Summary of the invention

In view of this, the object of the present invention is to provide the renovation process of a kind of methyl alcohol or dimethyl ether propylene catalyst, to solve the problem that regenerated catalyst activity was removed not thoroughly, affected to carbon deposit in existing catalyst regeneration techniques.

For achieving the above object, the present invention is by the following technical solutions:

A renovation process for methyl alcohol or dimethyl ether propylene catalyst, comprising:

The methyl alcohol of a, dry inactivation or dimethyl ether propylene catalyst;

B, containing in oxygen regenerating medium in 480-550 DEG C of calcined catalyst 4-12 hour;

C, the catalyst after calcining to be soaked in acid solution, then filter out and soak the acid solution of catalyst.

Preferably, described renovation process also comprises steps d, washs to cleaning solution pH value be not less than 6.5 to the catalyst after filtering.

Preferably, described renovation process also comprises step e: the product that drying steps c obtains under the condition identical with step a, then calcines under the condition identical with step b.

Preferably, described renovation process also comprises step f: the product that drying steps d obtains under the condition identical with step a, then calcines under the condition identical with step b.

Preferably, in step a by described catalyst at 100-150 DEG C of dry 6-12 hour.

Preferably, described is be selected from least one in the gaseous mixture of nitrogen and air, helium and air, argon gas and air and nitrogen and oxygen containing oxygen regenerating medium; Described is 1-5% containing the molar content of oxygen in oxygen regenerating medium.

Preferably, in step b, the heating schedule calcining described catalyst is: with the speed of 5-10 DEG C/min from room temperature to 280-320 DEG C, then with the ramp of 2-4 DEG C/min to 380-420 DEG C, constant temperature 2-4h, then with the ramp of 1-2 DEG C/min to 480-550 DEG C, constant temperature 4-8h terminates.

Preferably, acid solutions described in step c is 0.5-5mol/L, and soak time is 1-5 hour, and soaking temperature is 30-90 DEG C, and described acid solution is a kind of in citric acid, acetic acid or oxalic acid solution or their combination.

Preferably, in the catalyst after regeneration, carbon content is less than 0.5wt%.

Preferably, described catalyst is HZSM-5, SAPO-34 or mordenite molecular sieve catalyst, or described catalyst is the catalyst of HZSM-5, SAPO-34 or mordenite molecular sieve load.

Method of the present invention is adopted to regenerate the catalyst of process, very effectively can remove the carbon deposit in catalyst, and by the optimization of calcination procedure, decrease the formation of non-framework aluminum in calcination process, remain the acid activated centre in catalyst more, compared with the catalyst of the calcination and regeneration method merely through routine, catalytic activity significantly improves, almost return to the reactivity before inactivation completely, thus substantially prolongs the service life of catalyst.In addition, organic acid of the present invention need not wash after catalyst filtration, can remove completely after calcining.

Accompanying drawing explanation

Fig. 1 be according to embodiment 1,5,7 and 8 prepare catalyst Z 1, Z5, Z11 and Z12 XRD spectra;

Fig. 2 be according to embodiment 1,5,7 and 8 prepare catalyst Z 1, Z5, Z11 and Z12 NH ₃-TPD spectrogram.

Detailed description of the invention

The present invention is implemented by following steps:

Step a, the methyl alcohol of dry inactivation or dimethyl ether propylene catalyst.Preferably, by the catalyst of described inactivation at 100-150 DEG C of dry 6-12 hour; Particularly, can carry out drying, vacuumize while drying in vacuum drying chamber to decaying catalyst, in reduction subsequent calcination process, steam is to the destruction of catalyst backbone aluminium.

Step b, is calcining described catalyst 4-12 hour containing in oxygen regenerating medium in 480-550 DEG C; According to an embodiment of the invention, described is 1-5% containing the molar content of oxygen in oxygen regenerating medium, and described can be any suitable gas with oxygen in above-mentioned scope containing oxygen regenerating medium.Instantiation can be at least one in the gaseous mixture being selected from nitrogen and air, helium and air, argon gas and air and nitrogen and oxygen.One skilled in the art will appreciate that and can to regulate according to reaction bed temperature in roasting containing the oxygen content in oxygen regenerating medium, to avoid the too high permanent catalyst deactivation caused of temperature in roasting.Oxygen content and regulate and control method thereof can adopt the conventional method in this field, are not described in detail in this.

According to an embodiment of the invention, in stepb, preferably, the heating schedule calcining described catalyst is: with the speed of 5-10 DEG C/min from room temperature to 280-320 DEG C, then with the ramp of 2-4 DEG C/min to 380-420 DEG C, constant temperature 2-4h, then with the ramp of 1-2 DEG C/min to 480-550 DEG C, constant temperature 4-8h terminates.Catalyst calcination also can cause framework aluminum to migrate to catalyst surface, catalyst activity is reduced, roasting process can cause the migration of framework of molecular sieve aluminium, mainly the coordination structure of aluminium there occurs change, and wherein framework aluminum has four coordination structures, and non-framework aluminum has six coordination structures, the change of coordination structure and the temperature of roasting and heating rate have relation, temperature is higher, and framework aluminum is more easily polymerized and migration formation non-framework aluminum occurs, and the difference of heating rate also can cause different results.Therefore, the heating schedule calcined by optimization of catalysts, effectively can reduce the migration of framework aluminum.

Step c, soaks the catalyst acid solution after calcining, then filters out the acid solution soaking catalyst, to obtain catalyst.According to an embodiment of the invention, described acid solutions is 0.5-5mol/L, and soak time is 1-5 hour, and soaking temperature is 30-90 DEG C, and preferred described acid solutions is 1-3mol/L; If acid solutions is too low, exchange efficiency can be affected; If acid solutions is too high, the structure of framework aluminum can be destroyed, affect catalytic activity.Non-framework aluminum in described acid solution and catalyst after calcination reacts, and to be difficult to the carbon deposit got rid of in non-framework aluminum in Removal of catalyst and non-framework aluminum by calcining, kills two birds with one stone, and makes carbon content in the catalyst after regenerating be less than 0.5wt%; And after being soaked by acid solution, the crystalline structure of described catalyst does not change.

Preferably, described acid solution is one in citric acid, acetic acid or oxalic acid solution or combination.Above-mentioned organic acid is except having stronger acidity, and catalyst can wash after filtration, and described organic acid can remove completely in calcination process, and cost is low, simple to operate and nontoxic.

In an embodiment of the invention, regeneration methods of the invention also comprises steps d: the catalyst obtained step c washs to cleaning solution pH value and is not less than 6.5, to reduce acid solution in the catalyst residual, particularly when in acid solution containing during by calcining the material that can not remove completely.

In yet another embodiment of the present invention, regeneration methods of the invention also comprises step further: the product that drying steps c or steps d obtain under the condition identical with step a, then calcines under the condition identical with step b.

In addition, regeneration methods of the invention is particularly useful for HZSM-5, SAPO-34 or mordenite molecular sieve catalyst, and those skilled in the art are easy to expect, the catalyst for HZSM-5, SAPO-34 or mordenite molecular sieve load is suitable for too.

Below in conjunction with accompanying drawing, by embodiment, the invention will be further elaborated, but obvious scope of the present invention is not limited in following examples.

Embodiment 1

Get the HZSM-5 molecular sieve catalyst (MTPROP-1, Germany's south chemistry) of coking deactivation, be placed in vacuum drying chamber in 120 DEG C of dryings 6 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 1% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 5 DEG C/min from room temperature to 300 DEG C, be warming up to 400 DEG C with the speed of 2 DEG C/min from 300 DEG C, constant temperature 2h, be warming up to 550 DEG C with the speed of 1 DEG C/min from 400 DEG C, constant temperature 6h terminates, and the catalyst obtained is designated as Z1.

Embodiment 2

The HZSM-5 molecular sieve catalyst of coking deactivation is placed in vacuum drying chamber in 150 DEG C of dryings 6 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 5% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 10 DEG C/min from room temperature to 300 DEG C, be warming up to 400 DEG C with the speed of 4 DEG C/min from 300 DEG C, constant temperature 2h, be warming up to 550 DEG C with the speed of 2 DEG C/min from 400 DEG C, constant temperature 4h terminates, and the catalyst obtained is designated as Z2.

Embodiment 3

The HZSM-5 molecular sieve catalyst of coking deactivation is placed in vacuum drying chamber in 100 DEG C of dryings 8 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 2% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 5 DEG C/min from room temperature to 480 DEG C, and constant temperature 12h terminates, and the catalyst obtained is designated as Z3.

Embodiment 4

The HZSM-5 molecular sieve catalyst of coking deactivation is placed in vacuum drying chamber in 120 DEG C of dryings 6 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 5% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 10 DEG C/min from room temperature to 550 DEG C, and constant temperature 4h terminates, and the catalyst obtained is designated as Z4.

Embodiment 5

Catalyst Z 1 is put into 90 DEG C, 0.5mol/L citric acid solution soak 5 hours.After filtration by catalyst in 100 DEG C of dryings 12 hours, then roasting 6 hours under the atmosphere of 480 DEG C and oxygen content 2% in Muffle furnace, the catalyst obtained is designated as Z5.

Embodiment 6

Catalyst Z 2 is put into 50 DEG C, 5mol/L citric acid solution soak 1 hour.After filtration by catalyst in 120 DEG C of dryings 8 hours, then roasting 6 hours under the atmosphere of 480 DEG C and oxygen content 2% in Muffle furnace, the catalyst obtained is designated as Z6.

Embodiment 7

Get the SAPO-34 molecular sieve catalyst (Shanghai Zhuoyue Chemical Science Co., Ltd) of coking deactivation, be placed in vacuum drying chamber in 120 DEG C of dryings 6 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 1% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 5 DEG C/min from room temperature to 320 DEG C, be warming up to 420 DEG C with the speed of 2 DEG C/min from 320 DEG C, constant temperature 2h, be warming up to 480 DEG C with the speed of 1 DEG C/min from 420 DEG C, constant temperature 8h terminates, and the catalyst obtained is designated as Z7.

Embodiment 8

Catalyst Z 7 is put into 30 DEG C, 3mol/L acetic acid solution soak 5 hours.After filtration by catalyst in 100 DEG C of dryings 12 hours, then roasting 8 hours under the atmosphere of 480 DEG C and oxygen content 1% in Muffle furnace, the catalyst obtained is designated as Z8.

Embodiment 9

Get the mordenite molecular sieve catalyst (Shanghai zeolite molecular sieve Co., Ltd) of coking deactivation, be placed in vacuum drying chamber in 150 DEG C of dryings 6 hours; Dried catalyst is warming up to 550 DEG C in Muffle furnace, and is roasting under the atmosphere of 5% in oxygen content.The heating schedule of described Muffle furnace is: with the speed of 8 DEG C/min from room temperature to 280 DEG C, be warming up to 380 DEG C with the speed of 2 DEG C/min from 280 DEG C, constant temperature 4h, be warming up to 530 DEG C with the speed of 2 DEG C/min from 380 DEG C, constant temperature 8h terminates, and the catalyst obtained is designated as Z9.

Embodiment 10

Catalyst Z 9 is put into 50 DEG C, 4mol/L oxalic acid solution soak 5 hours.After filtration by catalyst in 100 DEG C of dryings 12 hours, then roasting 6 hours under the atmosphere of 480 DEG C and oxygen content 2% in Muffle furnace, the catalyst obtained is designated as Z10.

Comparative example 1

The HZSM-5 catalyst getting coking deactivation is designated as Z11, gets fresh HZSM-5 catalyst and is designated as Z12.

QL-HW2000B infrared carbon sulfur analyzer (Qilin Analytical Instrument Co., Ltd., Nanjing) is adopted to measure the carbon deposit content in catalyst.Measurement result is in table 1.

Carbon content in table 1 catalyst

Catalyst	Carbon deposit content (wt%)
		Z1	2.15
Z2	2.24
		Z5	0.43
Z6	0.52
		Z7	2.17
Z8	0.37
		Z9	2.20

Z10	0.42
		Z11	15.38

Contrast visible, the carbon deposit content in Z1 and Z2 is significantly less than the carbon deposit content of Z11, illustrates to effectively reduce carbon deposit in decaying catalyst after calcining; Found by analysis, after calcining, still have part carbon deposit to be difficult to remove in catalyst, and the carbon deposit content in Z5, Z6, Z8 and Z10 is less than the carbon deposit content of Z1, Z2, Z7 and Z9 respectively further, and the carbon deposit eliminated further after peracid solutions is soaked in catalyst is described.

System400 magnetic nuclear resonance analyzer (German BRUKER company) is adopted to detect Z1, Z2, Z3, Z4, Z7 and Z9, to measure framework aluminum in molecular sieve and non-framework aluminum content, in table 2, wherein non-framework aluminum moves to molecular sieve surface and formed from framework aluminum.

Table 2 decaying catalyst is through calcining back skeleton aluminium and non-framework aluminum content

Catalyst	Framework aluminum content (%)	Non-framework aluminum content (%)
			Z1	42.0	3.0
Z2	41.8	3.2
			Z3	40.0	5.0
Z4	37.8	7.2
			Z7	50.2	4.5
Z9	45.5	4.7

From table 2, by the control to calcination process, the generation of non-framework aluminum effectively can be reduced.

SHIMADZU Lab XRD-6000 type X-ray diffraction (XRD) instrument adopting Japanese Shimadzu Corporation to produce measures above-mentioned catalyst Z 1, Z5, Z11 and Z12 respectively.Wherein pipe pressure 40kv, tube current 30mA, CuK α radiation, sweep limits 2 θ: 5 ~ 90 °, sweep speed is 4 °/min.Result as shown in Figure 1.See Fig. 1, the catalyst Z 1 after calcining is consistent with the crystalline structure of fresh catalyst Z12 with the catalyst further across acid solution process, and lattice damage does not occur, and this is the basis can recovering catalyst activity through regeneration.

Tianjin is adopted first to weigh the NH that company's T P5000 type chemical adsorption instrument carries out Z1, Z5, Z11 and Z12 ₃-TPD acid characterization, as shown in Figure 2, can find out, acidity of catalyst is by being followed successively by weak by force: fresh catalyst Z12> acid treatment catalyst Z 5> catalyst after calcination Z1> decaying catalyst Z11, calcine the acidity only can recovered to a certain degree, after peracid treatment, acidity can better be recovered.

Catalyst breakage is become 40-60 order, carries out on-line analysis in the upper GC-9560 gas-chromatography adopting Shanghai Hua Ai chromatographic apparatus company to produce of micro anti-evaluation device (Beijing Tuo Chuan petrochemical industry Science and Technology Ltd.), react 72 hours the results are shown in Table 3.Reaction condition: reaction temperature is 480 DEG C, reaction pressure is normal pressure, and the feed rate of material benzenemethanol is 5g/h, and the feed rate of raw water is 2.5g/h.

The product distribution that table 3 adopts the preparing propylene from methanol of different catalysts to react

Catalyst	Methanol conversion	Ethene	Propylene
				Z11	21.37%	0.56%	2.33%
Z12	99.50%	12.38%	40.98%
				Z1	65.72%	2.02%	21.35%
Z2	65.52%	2.03%	21.28%
				Z3	63.86%	2.01%	21.15%
Z4	64.22%	2.01%	21.18%
				Z5	98.96%	11.78%	39.69%
Z6	99.03%	12.11%	39.25%
				Z8	99.42%	39.70%	41.36%
Z10	99.15%	20.84%	28.13%

The catalytic activity of regenerated catalyst characterizes with methanol conversion:

Quantity of methyl alcohol/methyl alcohol the initial amount of methanol conversion=conversion.

Compared with the catalyst Z 11 of inactivation, the methyl alcohol reaction result of Z1 and Z2 shows: the activity merely through a roasting regeneration rear catalyst significantly improves, but catalytic activity is lower (<70%) still, after second time regeneration (identical with first time regeneration condition), the activity of catalyst is still without improve.Show that simple roasting is difficult to recover completely the activity of catalyst.And the catalyst of roasting under different Elevated Temperature Conditions, because the non-framework aluminum content generated is different, the catalyst activity of Z1 with Z2 also improve as compared to Z3 with Z4.In addition, after peracid solutions immersion treatment, catalyst Z 5, Z6, Z8 and Z10 almost return to the reactivity before inactivation completely, thus substantially prolongs the service life of catalyst, reduce further production cost.

Although describe embodiments of the present invention by preferred embodiment, but one skilled in the art should appreciate that, can carry out in these embodiments changing and not deviating from principle of the present invention and spirit, scope of the present invention be by claim and equivalents thereof.

Claims (7)

1. a renovation process for methyl alcohol or dimethyl ether propylene catalyst, comprising:

The methyl alcohol of a, dry inactivation or dimethyl ether propylene catalyst;

B, containing in oxygen regenerating medium in 480-550 DEG C of calcined catalyst 4-12 hour;

C, the catalyst after calcining to be soaked in acid solution, then filter out and soak the acid solution of catalyst;

Wherein, described catalyst is HZSM-5, SAPO-34 or mordenite molecular sieve catalyst, or described catalyst is the catalyst of HZSM-5, SAPO-34 or mordenite molecular sieve load;

Described renovation process also comprises step e: the product that drying steps c obtains under the condition identical with step a, then calcines under the condition identical with step b;

Acid solutions described in step c is 0.5-5mol/L, and soak time is 1-5 hour, and soaking temperature is 30-90 DEG C, and described acid solution is a kind of in citric acid, acetic acid or oxalic acid solution or their combination.

2. renovation process as claimed in claim 1, it is characterized in that, described renovation process also comprises steps d: wash to cleaning solution pH value the catalyst after filtering and be not less than 6.5.

3. renovation process as claimed in claim 2, it is characterized in that, described renovation process also comprises step f: the product that drying steps d obtains under the condition identical with step a, then calcines under the condition identical with step b.

4. the renovation process according to any one of claim 1-3, is characterized in that, in step a by described catalyst at 100-150 DEG C of dry 6-12 hour.

5. renovation process as claimed in claim 1, is characterized in that, described is be selected from least one in the gaseous mixture of nitrogen and air, helium and air, argon gas and air and nitrogen and oxygen containing oxygen regenerating medium; Described is 1-5% containing the molar content of oxygen in oxygen regenerating medium.

6. the renovation process according to any one of claim 1-3, it is characterized in that, in step b, the heating schedule calcining described catalyst is: with the speed of 5-10 DEG C/min from room temperature to 280-320 DEG C, then with the ramp of 2-4 DEG C/min to 380-420 DEG C, constant temperature 2-4h, then with the ramp of 1-2 DEG C/min to 480-550 DEG C, constant temperature 4-8h terminates.

7. renovation process as claimed in claim 1, it is characterized in that, in the catalyst after regeneration, carbon content is less than 0.5wt%.