CN102744100A

CN102744100A - Fluidized bed catalyst for production of ethylene and propylene

Info

Publication number: CN102744100A
Application number: CN2011101000429A
Authority: CN
Inventors: 汪哲明; 陈希强; 肖景娴; 张铁柱
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2011-04-20
Filing date: 2011-04-20
Publication date: 2012-10-24
Anticipated expiration: 2031-04-20
Also published as: CN102744100B

Abstract

The invention relates to a fluidized bed catalyst for production of ethylene and propylene, and aims to mainly solve the technical problems of low naphtha conversion rate and low yields of ethylene and propylene during production of ethylene and propylene through catalytic cracking of naphtha in the prior art. The technical scheme of the invention adopts a catalyst composed of the following components by weight: 1) 15.0-50.0% of kaolin; 2) 10.0-30.0% of at least one of silica or alumina; 3) 2.0-15.0% of at least one of phosphorus, iron or rare earth oxides; and 4) 25.0-70.0% of ZSM-5 or ZSM-11 and Beta mixed zeolite. The technical scheme well solves the problems, and can be used in the industrial production of ethylene and propylene through catalytic cracking.

Description

Produce the fluid catalyst of ethene and propylene

Technical field

The present invention relates to a kind of fluid catalyst of producing ethene and propylene, specifically a kind ofly be active component, be raw material is produced ethene and propylene through catalytic pyrolysis process fluid catalyst with stone brain hydrocarbon with ZSM-5 or ZSM-11 and Beta mixed zeolite.

Background technology

Ethene, propylene are very important two kinds of petrochemical materials, and present global ethene and propylene mainly are to be produced by the steam cracking process.Because prior steam cracking reaction temperature is up to 820～1000 ℃, the process energy consumption is very high, accounts for 50% of whole ethylene industry energy consumption.This process is non-catalytic free radical thermal cracking mechanism, ethylene/propene lower (0.5～0.7) in its product.Current, face country petrochemical industry is proposed during the 11th Five-Year energy-saving and cost-reducing 20% requirement and the propylene demand that increases day by day, the prior steam cracking process is just standing acid test.Catalytic pyrolysis is to utilize catalyst naphtha to be carried out the process of producing low-carbon olefins by cracking.Compare with steam cracking, catalytic pyrolysis has reaction temperature low (600-780 ℃), and energy consumption significantly reduces and the product propylene/ethylene compares the advantage of high (0.6～1.3).This technology occurs, and the innovation of producing the ethylene, propylene process for the prior steam cracking has brought hope.

Russia organic synthesis research institute and catalytic cracking catalyst active component mainly are variable valency metal compounds such as manganese, vanadium, niobium, tin, iron, and wherein catalytic performance is optimum is to be potassium vanadate (or sodium) fluid catalyst of carrier with ceramic (andalusite-corundum).Though this catalyst has good heat resistance, the advantage of low coking rate and high stability, its cracking reaction temperature are during still up to 770 ℃.[Picciotti?M.[J].Oil?Gas?J，1997，95(25)：53～56.]。

Japan Toyo Engineering Corporation is from the THR-RC fluid catalyst, and typical chemistry consists of CaO: Al ₂O ₃: SiO ₂: Fe ₂O ₃MgO=51.46: 47.74: 0.06: 0.185: 0.25.This catalyst is raw material with the light petrol, and the reaction temperature of cracking is still up to 750 ℃.[Zhang Jian, etc. [J]. petrochemical industry is dynamic, 1995, (11): 24～30,34.] US4087350 disclosed that the fluid bed Mg of normal pressure and decompression residuum catalysis raising the output alkene is catalyst based, this catalyst reaction temperatures is up to 745, and the ethylene, propylene yield also has only 28.6%.

Patent CN02152479 has reported that the aperture that Li, alkaline earth, phosphorus and rare earth element are modified is the zeolite catalyst of 0.45～0.75nm, and this catalyst mainly is applicable to the technology of fixed bed hydrocarbon catalytic cracking system alkene.The crystallite dimension of the not mentioned zeolite of this catalyst.

Patent US6566693B1 has reported the catalyst of a kind of ZSM-5 of the phosphorous modification that is used for petroleum hydrocarbon catalytic pyrolysis system alkene, the crystallite dimension of the not mentioned used zeolite of this patent.

At present, catalytic pyrolysis is raw materials used---except the less n-alkane of molecular dimension, also contain part cycloalkane, branched paraffin and the bigger molecule of aromatic hydrocarbons equidimension in the naphtha.In the composition of naphtha, the molecular dimension of straight chain n-alkane is minimum, and the size of branched paraffin and cycloalkane is bigger, in reaction, will receive relatively large diffusion restriction.Existing patent report in fluid catalyst, is mainly originated as the main activity of cracking with the ZSM-5 molecular sieve of the less ten-ring in aperture.The port size of ZSM-5 zeolite is suitable with the molecular dimension of linear paraffin, thereby because the diffusion restriction effect in duct, the ZSM-5 zeolite is very limited to the conversion capability of larger-size cycloalkane and branched paraffin in the naphtha.

In naphtha was formed, the content of branched paraffin and cycloalkane was up to 50～70%.Low to the conversion capability of this series molecule, cause with the ZSM-5 molecular sieve be the existing techniques of active component be applied to the naphtha catalytic pyrolysis produce olefin hydrocarbon exist the naphtha conversion ratio low with ethene, problem that propene yield is low.

Summary of the invention

Technical problem to be solved by this invention is that existing fluid catalyst is being used for the process of preparing ethylene propylene from catalytic pyrolysis; Exist the naphtha conversion ratio low with ethene, technical problem that propene yield is low; A kind of new production ethene and the catalyst of propylene are provided, this catalyst have the naphtha conversion ratio high with ethene, advantage that propene yield is high.

For solving the problems of the technologies described above, the technical scheme that the present invention adopts is following: a kind of fluid catalyst of producing ethene and propylene comprises following component by weight percentage: a) 15.0～60.0% kaolin; B) 10.0～30.0% be selected from least a in silica or the aluminium oxide; C) 0.5～15.0% be selected from least a in phosphorus, iron or the rare earth oxide; D) at least a and Beta mixed zeolite among 25～70% ZSM-5 that are selected from or the ZSM-11, wherein the mass ratio of at least a and Beta zeolite among ZSM-5 or the ZSM-11 is 9～0.5: 1.

Catalytic pyrolysis described in the technique scheme is produced the fluid catalyst of ethene and propylene, preferably at least a consumption in phosphorus and iron or lanthanum element oxide by weight percentage preferred range be 2.0～8.0%; The silica alumina ratio SiO of ZSM-5, ZSM-11 or Beta zeolite ₂/ Al ₂O ₃Be 20～100, the quality of at least a and Beta zeolite among ZSM-5 or the ZSM-11 is 5～0.5: 1 than preferred range.

Preparation of catalysts method of the present invention is following: ZSM-5 and the Beta mixed zeolite of Hydrogen that takes by weighing aequum is with being selected from least a precursor solution-treated of phosphorus, iron or rare earth oxide 0.5～6 hour; Solid-to-liquid ratio 1: 1～4; Evaporate to dryness solution obtains modifying the back mixed zeolite after 500～700 ℃ of roastings then.The P elements oxide derives from a kind of in phosphoric acid, phosphoric acid hydrogen ammonia, ammonium dihydrogen phosphate (ADP) or the ammonium phosphate.With the kaolin of aequum, be selected from a kind of in silica or the aluminium oxide; Composite zeolite and the water that element oxide is modified in load mixes to such an extent that to obtain solid content be 20～50% slurries; After emulsification mixes; Regulate pH value 3～6, gained slurries spray-dried particle diameter that obtains under 130～200 ℃ of temperature is 10～200 microns a fluid bed microspherical catalyst.

Compare with the ZSM-5 zeolite fluid catalyst of using in the prior art; The present invention adopts ZSM-5 and the Beta mixed zeolite active component as catalytic cracking fluid bed catalyst; The bigger Beta molecular sieve in aperture can carry out a cracking to larger-size raw molecule wherein and be converted into intermediate product; The ZSM-5 molecular sieve that intermediate product then can be diffused into the small-bore carries out secondary cracking, thereby makes this catalyst have higher naphtha conversion ratio and ethene, propene yield.Simultaneously; Introducing through rare earth, phosphorus or ferrous metal element oxide; Can modify the acid centre of catalyst; Regulate the density and the acid strength of the acid centre of catalyst, take place, improved selection of catalysts property and ethene, propene yield thereby reach side reactions such as suppressing hydrogen migration and carbon distribution.

The present invention is an active component through adopting ZSM-5 and Beta mixed zeolite, serves as the fluid catalyst of modification component with phosphorus, rare earth or Fe element oxide, is raw material with naphtha and water, at 650 ℃, and weight space velocity=1.0 hour ^-1Water is that the conversion ratio of naphtha can reach 58.5% under the condition of 4: 1 and normal pressure with the weight ratio of oil, can improve 9% than the catalyst of prior art for preparing; The diene yield can reach 29.6%; Catalyst than prior art for preparing can improve 6%, and activity of such catalysts and ethene, propylene diene yield are significantly improved, and have obtained better technical effect.

Through embodiment the present invention is done further elaboration below.But these embodiment limit scope of the present invention.

The specific embodiment

[embodiment 1]

The weight of catalyst a is formed: 3.0%P ₂O ₅: 2.0%La ₂O ₃: 20.0%ZSM-5: 5.0%Beta:20.0%Al ₂O ₃: 50.0% kaolin.Take by weighing ZSM-5 (the silica alumina ratio SiO of aequum ₂/ Al ₂O ₃Be=20), Beta zeolite (silica alumina ratio SiO ₂/ Al ₂O ₃=20), handled 2 hours with the aqueous solution of ammonium dihydrogen phosphate (ADP), lanthanum nitrate, then at 120 ℃ of following evaporate to dryness solution, 550 ℃ of following roastings 6 hours.Composite zeolite after modifying mixed with kaolin, aluminium colloidal sol and the water of aequum to obtain solid content be 20% slurries; Regulating pH value is 3.0, and obtaining particle diameter in 4 hours 150 ℃ times spray-dried, 600 ℃ of roastings then is 10～200 microns fluid bed microspherical catalyst a.

Estimate the rerum natura of raw material-naphtha and list in table 1.The performance of different catalysts producing olefin hydrocarbon by catalytic pyrolysis adopts fluidized-bed reactor, is 650 ℃ in reaction temperature, and weight space velocity is 1.0h ^-1, water and weight of oil than be 4.0 and the condition of normal pressure under check and rate, reaction result is listed in table 3.

Table 1 steam cracking is specialized in the rerum natura of naphtha

Physical parameter	Typical data
		Initial boiling point ℃	40
The end point of distillation ℃	162
		Sulfur content (m/m)	0.0097
Arsenic content (ug/Kg)	1.07
		Alkane content/%	65.18
N-alkane/%	32.54
		Alkene/%	0.17
Cycloalkane/%	28.44
		Aromatic hydrocarbons/%	6.21
Color (Saybolt number)	30

[embodiment 2～8]

Employing is similar to the method preparation of embodiment 1, the catalyst b～h among the embodiment 2～8, and the visible table 2 of the composition of catalyst, the evaluation method of the catalyst of embodiment 2～8 is identical with embodiment 1, and reaction result is seen table 3.

The composition of table 2 embodiment 1～8 catalyst

[comparative example 1]

With ZSM-5 (silica alumina ratio SiO ₂/ Al ₂O ₃Be 50) according to the preparation method of embodiment 7 get each constituent content identical catalyst Comparative Examples 1, appreciation condition is equal to embodiment 1～8.

[comparative example 2]

With ZSM-5 (silica alumina ratio SiO ₂/ Al ₂O ₃Be 75) obtain the identical catalyst Comparative Examples 2 of each constituent content according to the preparation method of embodiment 8, appreciation condition is equal to embodiment 1～8.

The performance of the producing ethene, propylene through catalytic cracking of table 3 different catalysts

Catalyst	Conversion ratio/%	Ethene+productivity of propylene (weight)/%
			a	35.0	17.2
b	40.3	21.2
			c	52.3	25.8
d	45.2	22.3
			e	55.8	26.2
f	58.5	29.6
			g	51.2	25.3
h	48.2	23.5
			Comparative example 1	32.5	14.3
Comparative example 2	34.2	16.1

Can be found out that by table 3 fluid catalyst that contains phosphorus, iron or rare earth element modification of the present invention's preparation is a raw material with the naphtha, at 650 ℃, weight space velocity is 1.0 hours ^-1, water is 4: 1 with the weight of oil ratio, under the reaction condition of normal pressure; The conversion ratio of naphtha can reach 58.5%; Catalyst than prior art for preparing can improve 9%, and the diene yield can reach 29.6%, can improve 6% than the catalyst of prior art for preparing; Activity of such catalysts and ethene, propylene diene yield are significantly improved, and have obtained better technical effect.

Claims

1. fluid catalyst of producing ethene and propylene comprises following component by weight percentage:

A) 15.0～50.0% kaolin;

B) 10.0～300% be selected from least a in silica or the aluminium oxide;

C) 2.0～15.0% to be selected from phosphorus, iron or rare earth oxide at least a;

D) 25.0～the 70.0% at least a and Beta mixed zeolites that are selected among ZSM-5 or the ZSM-11, wherein the mass ratio of at least a and Beta zeolite among ZSM-5 or the ZSM-11 is 9～0.5: 1.

2. the fluid catalyst of production ethene according to claim 1 and propylene, at least a consumption that it is characterized in that being selected from phosphorus and iron or the lanthanum element oxide is 2.0～8.0% by weight percentage.

3. the fluid catalyst of production ethene according to claim 1 and propylene is characterized in that the silica alumina ratio SiO of ZSM-5, ZSM-11 or Beta zeolite ₂/ Al ₂O ₃Be 20～100.

4. the fluid catalyst of producing olefin hydrocarbon by catalytic pyrolysis according to claim 1 is characterized in that the mass ratio of at least a and Beta zeolite among ZSM-5 or the ZSM-11 is 5～0.5: 1.