Catalyst for olefin catalytic cracking to produce propylene and ethylene and application thereof

Abstract

The invention discloses a catalyst for olefin catalytic cracking to produce propylene and ethylene and an application method thereof. The catalyst comprises a ZSM-5 molecular sieve of which the silicon aluminum molar ratio of SiO2 / Al2O3 is 10 to 300 and the crystal grain diameter is 10 to 800 nanometers, and rare earth and alkaline-earth metal elements loaded thereon. The catalyst is applied to a process for performing olefin catalytic cracking reaction through a catalyst bed to produce the propylene and the ethylene by using C4-C12 olefin as a raw material under the conditions of reaction temperature of 450 to 650 DEG C, reaction pressure of 0 to 0.3 MPa, the weight space velocity of hydrocarbon materials of 1 to 14 h and the weight ratio of water / hydrocarbon materials of 0.1 to 10. The catalyst provided by the invention can keep high propylene and ethylene yield, has longer reaction operation time at the same time, and can be used for industrialized production.

Description

technical field

[0001] The invention relates to a catalyst for producing propylene and ethylene by catalytic cracking and its application, in particular to a catalyst for producing propylene and ethylene by catalytic cracking of C4-C12 olefins and its application. Background technique

[0002] According to statistics, the world's ethylene production capacity in 1995 was 79.32 million tons / year, and it is expected to be 110.38 million tons / year by 2010. With the increase of ethylene production, the output of carbon four and above carbon four olefins by-products of steam cracking continues to increase. Affected by changes in the chemical product market and transportation costs and other factors, it is a must to carry out in-situ deep processing of these low value-added materials. A better way to use it. At the same time, affected by the increase in demand for polypropylene and alkylaromatic compounds, the demand for propylene is growing vigorously. By 2008, the demand for pro...

Examples

preparation example Construction

[0057] The preparation method of H-type ZSM-5 molecular sieve:

[0058] After the ZSM-5 molecular sieve raw powder with the required silicon-aluminum ratio and particle size was roasted at 550°C to remove the template agent, the ratio of molecular sieve (g) to exchange solution (ml) was 1:10, and NH 4 NO 3 The solution (0.8mol / L) was exchanged in a 90°C water bath for 5 hours, and filtered; the filter cake was exchanged twice with the same amount of exchange liquid as before, filtered, and washed with distilled water until there was no NO in the filtrate. 3 - Existence, drying at 110°C, and calcining at 550°C to obtain HZSM-5 molecular sieve.

Embodiment 1

[0072] The raw powder of ZSM-5 molecular sieve (mole ratio of silicon to aluminum is 180, particle size is 400nm) is processed according to the above preparation method to obtain HZSM-5 molecular sieve. The HZSM-5 molecular sieve and silicon oxide (specific surface area > 200M 2 / g of high-purity silica) and squat powder are mixed in proportion, after mixing, add an appropriate amount of dilute nitric acid, after mixing, extrude into a cylindrical shape with a diameter of 3mm, dry at 120°C and roast at 550°C to obtain a molecular sieve containing ZSM-5 and silicon oxide strips. Take a certain amount of cylindrical particles, and use Ca(NO 3 ) 2 and Ce(NO 3 ) 3 The solution impregnated the particles, filtered and separated, dried at 120°C and calcined at 550°C, impregnated with Ca and Ce, treated with water vapor at 500°C for 5 hours, and treated with 0.2mol / L citric acid solution in a 90°C water bath for 3h , after solid-liquid separation and calcined at 600°C for 4 hours...

Embodiment 2

[0074] Treat the original powder of ZSM-5 molecular sieve (silicon-aluminum molar ratio is 80, particle size is 200nm) according to the above preparation method: change the roasting temperature of molecular sieve raw powder from 550°C to 450°C, change the exchange time from 5h to 3h, after exchange The roasting temperature of the filter cake was changed to 650°C, and other conditions remained unchanged to obtain HZSM-5 molecular sieve. The HZSM-5 molecular sieve and silicon oxide (specific surface area > 200M 2 / g of high-purity silica) and squat powder are mixed in proportion, after mixing, add an appropriate amount of dilute nitric acid, after mixing, extrude into a cylindrical shape with a diameter of 3mm, dry at 120°C and roast at 550°C to obtain a molecular sieve containing ZSM-5 and silicon oxide strips. Take a certain amount of cylindrical particles, at room temperature with Mg(NO 3 ) 2 and La(NO 3 ) 3 The solution impregnated the particles, filtered and separated,...

technical field

[0001] The invention relates to a catalyst for producing propylene and ethylene by catalytic cracking and its application, in particular to a catalyst for producing propylene and ethylene by catalytic cracking of C4-C12 olefins and its application. Background technique

[0002] According to statistics, the world's ethylene production capacity in 1995 was 79.32 million tons / year, and it is expected to be 110.38 million tons / year by 2010. With the increase of ethylene production, the output of carbon four and above carbon four olefins by-products of steam cracking continues to increase. Affected by changes in the chemical product market and transportation costs and other factors, it is a must to carry out in-situ deep processing of these low value-added materials. A better way to use it. At the same time, affected by the increase in demand for polypropylene and alkylaromatic compounds, the demand for propylene is growing vigorously. By 2008, the demand for pro...

Examples

preparation example Construction

[0057] The preparation method of H-type ZSM-5 molecular sieve:

[0058] After the ZSM-5 molecular sieve raw powder with the required silicon-aluminum ratio and particle size was roasted at 550°C to remove the template agent, the ratio of molecular sieve (g) to exchange solution (ml) was 1:10, and NH 4 NO 3 The solution (0.8mol / L) was exchanged in a 90°C water bath for 5 hours, and filtered; the filter cake was exchanged twice with the same amount of exchange liquid as before, filtered, and washed with distilled water until there was no NO in the filtrate. 3 - Existence, drying at 110°C, and calcining at 550°C to obtain HZSM-5 molecular sieve.

Embodiment 1

[0072] The raw powder of ZSM-5 molecular sieve (mole ratio of silicon to aluminum is 180, particle size is 400nm) is processed according to the above preparation method to obtain HZSM-5 molecular sieve. The HZSM-5 molecular sieve and silicon oxide (specific surface area > 200M 2 / g of high-purity silica) and squat powder are mixed in proportion, after mixing, add an appropriate amount of dilute nitric acid, after mixing, extrude into a cylindrical shape with a diameter of 3mm, dry at 120°C and roast at 550°C to obtain a molecular sieve containing ZSM-5 and silicon oxide strips. Take a certain amount of cylindrical particles, and use Ca(NO 3 ) 2 and Ce(NO 3 ) 3 The solution impregnated the particles, filtered and separated, dried at 120°C and calcined at 550°C, impregnated with Ca and Ce, treated with water vapor at 500°C for 5 hours, and treated with 0.2mol / L citric acid solution in a 90°C water bath for 3h , after solid-liquid separation and calcined at 600°C for 4 hours...

Embodiment 2

[0074] Treat the original powder of ZSM-5 molecular sieve (silicon-aluminum molar ratio is 80, particle size is 200nm) according to the above preparation method: change the roasting temperature of molecular sieve raw powder from 550°C to 450°C, change the exchange time from 5h to 3h, after exchange The roasting temperature of the filter cake was changed to 650°C, and other conditions remained unchanged to obtain HZSM-5 molecular sieve. The HZSM-5 molecular sieve and silicon oxide (specific surface area > 200M 2 / g of high-purity silica) and squat powder are mixed in proportion, after mixing, add an appropriate amount of dilute nitric acid, after mixing, extrude into a cylindrical shape with a diameter of 3mm, dry at 120°C and roast at 550°C to obtain a molecular sieve containing ZSM-5 and silicon oxide strips. Take a certain amount of cylindrical particles, at room temperature with Mg(NO 3 ) 2 and La(NO 3 ) 3 The solution impregnated the particles, filtered and separated,...

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