Method for producing propylene and ethylene through catalytic cracking of olefins

Abstract

The invention provides a novel method for producing propylene and ethylene through catalytic cracking of olefins, which comprises the steps of: taking C4-C12 olefins as raw materials; and performing acatalytic cracking reaction of the olefins on the raw materials through a catalyst bed to generate the propylene and the ethylene under the conditions that the reaction temperature is between 450 and650 DEG C, the reaction pressure is between 0 and 0.3MPa, the weight space velocity of the olefins is between 1 and 14 h<-1>, and the weight ratio of water to the olefins is 0.1-10, wherein a catalyst comprises a ZSM-5 molecular sieve, an adhesive and a phosphorus element supported on the catalyst, the silicon-aluminum molar ratio SiO2 / Al2O3 of the ZSM-5 molecular sieve is 10-300, and the grain diameter of crystal grains of the ZSM-5 molecular sieve is between 10 and 800nm. The method has longer reaction operation time while maintaining the high yield of the propylene and the ethylene, and can be used for industrialized production.

Description

technical field

[0001] The invention relates to a method for producing propylene and ethylene by catalytic cracking of olefins, in particular to a method for producing propylene and ethylene by catalytic cracking of C4-C12 olefins as raw materials. 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, the demand for propylene is growing strongly, driven by the growth in demand for polypropylene and alkylaromatic compounds. Analysts point out that if the production of pro...

Examples

preparation example Construction

[0046] The preparation method of H-type ZSM-5 molecular sieve:

[0047] 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

[0058] 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. Mix the HZSM-5 molecular sieve with silicon oxide and cinnamon powder in proportion, 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 ZSM-5 Rods of molecular sieve and silica. Take a certain amount of cylindrical particles, impregnate the particles with a solution containing phosphoric acid at room temperature, filter and separate, dry at 120°C and roast at 550°C. The L citric acid solution was treated in a water bath at 90°C for 3 hours, and after solid-liquid separation, it was calcined at 600°C for 4 hours to obtain the desired catalyst E.

Embodiment 2

[0060] The raw powder of ZSM-5 molecular sieve (mole ratio of silicon to aluminum is 100, particle size is 200nm) is processed according to the above preparation method to obtain HZSM-5 molecular sieve. Mix the HZSM-5 molecular sieve with silicon oxide and cinnamon powder in proportion, 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 ZSM-5 Rods of molecular sieve and silica. Take a certain amount of cylindrical particles, impregnate the particles with a solution containing phosphoric acid at room temperature, filter and separate, dry at 120°C and roast at 550°C. The desired catalyst F was obtained by treating L citric acid solution in a water bath at 80°C for 5 hours, separating solid and liquid at 600°C for 4 hours.

technical field

[0001] The invention relates to a method for producing propylene and ethylene by catalytic cracking of olefins, in particular to a method for producing propylene and ethylene by catalytic cracking of C4-C12 olefins as raw materials. 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, the demand for propylene is growing strongly, driven by the growth in demand for polypropylene and alkylaromatic compounds. Analysts point out that if the production of pro...

Examples

preparation example Construction

[0046] The preparation method of H-type ZSM-5 molecular sieve:

[0047] 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

[0058] 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. Mix the HZSM-5 molecular sieve with silicon oxide and cinnamon powder in proportion, 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 ZSM-5 Rods of molecular sieve and silica. Take a certain amount of cylindrical particles, impregnate the particles with a solution containing phosphoric acid at room temperature, filter and separate, dry at 120°C and roast at 550°C. The L citric acid solution was treated in a water bath at 90°C for 3 hours, and after solid-liquid separation, it was calcined at 600°C for 4 hours to obtain the desired catalyst E.

Embodiment 2

[0060] The raw powder of ZSM-5 molecular sieve (mole ratio of silicon to aluminum is 100, particle size is 200nm) is processed according to the above preparation method to obtain HZSM-5 molecular sieve. Mix the HZSM-5 molecular sieve with silicon oxide and cinnamon powder in proportion, 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 ZSM-5 Rods of molecular sieve and silica. Take a certain amount of cylindrical particles, impregnate the particles with a solution containing phosphoric acid at room temperature, filter and separate, dry at 120°C and roast at 550°C. The desired catalyst F was obtained by treating L citric acid solution in a water bath at 80°C for 5 hours, separating solid and liquid at 600°C for 4 hours.

Images