Catalyst for preparing chloroethylene by cracking 1,2-dichloroethane and a preparation and regeneration method thereof

Abstract

A catalyst for preparing chloroethylene by cracking 1,2-dichloroethane and a preparation and regeneration method thereof are disclosed in the present application. A catalyst for preparing chloroethylene by cracking 1,2-dichloroethane includes a carrier and a nitrogen-containing carbon as an active component of the catalyst with the nitrogen-containing carbon being loaded on the carrier. The method for preparing the catalyst includes: supporting an organic matter on an inorganic porous carrier and then performing a carbonization-nitridation process by pyrolysis in an atmosphere containing the nitrogen-containing compound. The method for regenerating the catalyst includes: calcinating the catalyst with deactivated carbon deposit in an oxidizing atmosphere to remove all the carbonaceous portions on the surface, and repeating the above preparation process of the catalyst. The catalyst reduces reaction temperature, reduces energy consumption, reduces production cost, and improves selectivity and conversion rate and is inexpensive and reproducible, and has a long service life.

Claims

1. A regeneration method of the catalyst for preparing chloroethylene by cracking 1,2-dichloroethane comprising a carrier and a nitrogen-containing carbon material as an active component of the catalyst; and the nitrogen-containing carbon material is loaded on the carrier; the carrier is at least one selected from inorganic porous materials; in the nitrogen-containing carbon material, a nitrogen element is doped in the carbon material in a form of covalent bond, the regeneration method comprising: calcinating a deactivated catalyst in an atmosphere containing oxygen after deactivating the catalyst in a catalytic cracking reaction of 1,2-dichloroethane for preparing chloroethylene; using the solid obtained after calcination as a carrier to prepare a regenerated catalyst according to a preparation method in supporting an organic precursor on the inorganic porous material of the solid as the carrier and then carrying out a carbonization-nitridation reaction by pyrolysis in an atmosphere containing a nitrogen-containing compound; wherein the inorganic porous material is at least one selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide, and zirconium oxide.

2. The regeneration method according to claim 1, wherein the calcination conditions are: a calcination temperature in a range from 300° C. to 800° C., and a calcination time in a range from 0.2 hour to 10 hours.

3. The regeneration method according to claim 1, wherein the calcination conditions are: a calcination temperature in a range from 450° C. to 700° C. and a calcination time in a range from 0.5 hour to 6 hours.

4. The regeneration method according to claim 1, wherein the mass percentage of the nitrogen element in the nitrogen-containing carbon material is in a range from 0.1% to 20%.

5. The regeneration method according to claim 1, wherein the mass percentage of the nitrogen element in the nitrogen-containing carbon material is in a range from 1% to 9%.

6. The regeneration method according to claim 1, wherein the mass percentage of the nitrogen-containing carbon material in the catalyst is in a range from 1% to 40%.

7. The regeneration method according to claim 1, wherein the mass percentage of the nitrogen-containing carbon material in the catalyst is in a range from 8% to 30%.

8. The regeneration method according to claim 1, wherein the pyrolysis conditions are: a pyrolysis temperature in a range from 400° C. to 1000° C., and a pyrolysis time in a range from 0.2 hour to 10 hours.

9. The regeneration method according to claim 1, wherein the pyrolysis conditions are: a pyrolysis temperature in a range from 600° C. to 900° C., and a pyrolysis time in a range from 0.5 hour to 6 hours.

10. The regeneration method according to claim 1, wherein the nitrogen-containing compound is at least one selected from the group consisting of ammonia gas, hydrazine, an organic compound containing a C—N bond, an organic compound containing C═N, and an organic compound containing C≡N.

11. The regeneration method according to claim 1, wherein the nitrogen-containing compound is at least one selected from the group consisting of ammonia gas, hydrazine, acetonitrile, cyanamide, pyridine, pyrrole, ethylenediamine or methylamine.

12. The regeneration method according to claim 1, wherein the organic precursor is at least one selected from the group consisting of hydrocarbon compound, polymer, an organic compound containing at least one group of *—CX, *—OH, *—C≡N, *—C≡N, *—C—O—* bond, *—C—NH.sub.2, *—C—NH—C—*, *—C—N—C—*; wherein X in *—CX represents a halogen, which is at least one selected from the group consisting of F, Cl, Br, and I.

13. The regeneration method according to claim 1, wherein the organic precursor is at least one selected from the group consisting of acrylonitrile, chloroethylene, dichloroethylene, vinylpyridine, acrylamide, acrylic compounds, vinyl ester compounds, aniline compounds, pyrrolic compounds, urea resin, phenol resin, melamine resin, polyurethane and furan resin in a form of a monomer or polymer, glucose, fructose, xylose, sucrose, dextran, lignin, organic pyrolysis oil and pitch.

14. The regeneration method according to claim 1, wherein the method for supporting the organic precursor on the inorganic porous material is at least one selected from the following methods: (i) an impregnation method; (ii) a spraying method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic illustration of the catalyst of the present invention, the preparation, application and regeneration process thereof.

DETAILED DESCRIPTION

(2) The technical solutions of the present application will be further described below with reference to the examples. The following examples are only some of the preferred embodiments of the present invention, and the present invention is not limited to the contents of the embodiments. It will be apparent to those skilled in the art that various changes and modifications may be made within the scope of the concept of the technical solution of the present invention. Any changes and modifications made are within the scope of the present invention.

(3) In the examples, the silica gel pellet is purchased from Qingdao Ocean Chemical Co., Ltd., and the silica gel pellet has a particle diameter in a range from 2 mm to 4 mm a colour of white.

(4) In the examples, the conversion rate of 1,2-dichloroethane is calculated according to the following method: the conversion rate of 1,2-dichloroethane=the molar number of 1,2-dichloroethane (mol) consumed in the reaction/the molar number of 1,2-dichloroethane (mol) introduced into the reactor.

(5) The selectivity to vinyl chloride is calculated according to the following method:

(6) Selectivity of chloroethylene=the molar number of chloroethylene (mol) generated in the reaction/the molar number of 1,2-dichloroethane (mol) consumed in the reaction.

(7) x-ray photoelectron spectroscopy is measured using an ESCALAB 250Xi instrument.

EXAMPLE 1

(8) Preparation of Nitrogen-Containing Carbon Catalyst Sample CAT-1.sup.#

(9) 0.4 g of oxalic acid was added into 40 mL of furan methanol at room temperature, dissolved, and then 60 mL of xylene was added. 150 mL of silica gel pellet was added into the beaker and immersed for 6 hours, filtered, and heated to 90° C. to carry out a polymerization reaction for 12 hours. Precursor I was obtained.

(10) The precursor I was placed in a quartz tube, then the quartz tube was placed in a tube furnace, nitrogen gas was introduced into the quartz tube, and heated to a temperature of 450° C., and the temperature was maintained for 3 hours. The gas path was switched for introducing ammonia gas into the quartz tube, and then the temperature was raised to 600° C. at a heating rate of 5° C./min and maintained for 3 hours to perform a carbonization-nitridation process to obtain the catalyst, which was designated as sample CAT-1.sup.#. The mass percentage of the nitrogen element in the supported nitrogen-containing carbon material was 6.5%.

(11) Activity Test of Supported Nitrogen-Containing Carbon Catalyst Sample CAT-1.sup.#

(12) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor loaded with the catalyst CAT-1.sup.# by a constant flow pump, the temperature of reactor was 260° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 180 h.sup.−1. The test results showed that the conversion rate of dichloroethane was 54% and the selectivity to chloroethylene was more than 99%.

(13) Regeneration and Activity Test of Catalyst Sample CAT-1.sup.#

(14) The deactivated catalyst was calcined in air for 1 hour at 600° C., and the obtained solid sample was designated as sample ZCAT-1.sup.#-Z1.

(15) The silica gel pellet was replaced by the sample ZCAT-1.sup.#-Z1, and the other preparation steps and conditions were the same as the sample CAT-1.sup.#, and the obtained regenerated catalyst was designated as the sample ZCAT-1.sup.#-1.

(16) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor supported with the catalyst ZCAT-1.sup.#-1 by a constant flow pump, the temperature of reactor was 260° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 180 h.sup.−1. The test results showed that the catalytic activity of ZCAT-1.sup.#-1 was not lowered as compared with CAT-1.sup.#.

EXAMPLE 2

(17) Preparation of Nitrogen-Containing Carbon Catalyst Sample CAT-2.sup.#

(18) The preparation method of this example was the same as that of Example 1 except that the treatment conditions of ammonia gas in the carbonization-nitridation process were at a temperature of 800° C. and maintained for 1.5 hours. The obtained catalyst was designated as sample CAT-2.sup.#. The mass percentage of the nitrogen element in the supported nitrogen-containing carbon material was 9%.

(19) Activity Test of Supported Nitrogen-Containing Carbon Catalyst Sample CAT-2.sup.#

(20) The activity test process differed from Example 1 only in that the temperature of reactor was 260° C. and the volumetric space velocity (GHSV) of 1,2-dichloroethane was 157 h.sup.−1. The test results showed that the conversion rate of dichloroethane was 72% and the selectivity to chloroethylene was more than 99%.

(21) Regeneration and Activity Test of Catalyst Sample CAT-2.sup.#

(22) The deactivated catalyst was calcined in air for 1 hour at 450° C., and the obtained solid sample was designated as sample ZCAT-2.sup.#-Z1.

(23) The silica gel pellet was replaced by the sample ZCAT-2.sup.#-Z1, and the other preparation steps and conditions were the same as the sample CAT-2.sup.#, and the obtained regenerated catalyst was designated as the sample ZCAT-2.sup.#-1.

(24) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor supported with the catalyst ZCAT-2.sup.#-1 by a constant flow pump, the temperature of reactor was 260° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 157 h.sup.−1.

(25) The test results showed that the catalytic activity of ZCAT-2.sup.#-1 was not lowered as compared with CAT-2.sup.#.

EXAMPLE 3

(26) Preparation of Nitrogen-Containing Carbon Catalyst Sample CAT-3.sup.#

(27) The preparation method of this example was the same as that of Example 1 except that the amount of furan methanol was 25 mL, the amount of oxalic acid was 0.25 g, and the amount of xylene was 75 mL. The obtained catalyst was designated as sample CAT-3 #. The mass percentage of the nitrogen element in the supported nitrogen-containing carbon material was 7%.

(28) Activity Test of Supported Nitrogen-Containing Carbon Catalyst Sample CAT-3.sup.#

(29) The activity test process differed from Example 1 only in that the temperature of reactor was 240° C. and the volumetric space velocity (GHSV) of 1,2-dichloroethane was 171 h.sup.−1. The test results showed that the conversion rate of dichloroethane was 36% and the selectivity to chloroethylene was more than 99% under the action of nitrogen-containing carbon catalyst 3.sup.#.

(30) Regeneration and Activity Test of Catalyst Sample CAT-3.sup.#

(31) The deactivated catalyst was calcined in air for 0.25 hour at 700° C., and the obtained solid sample was designated as sample ZCAT-3.sup.#-Z1.

(32) The silica gel pellet was replaced by the sample ZCAT-3.sup.#-Z1, and the other preparation steps and conditions were the same as the sample CAT-3.sup.#, and the obtained regenerated catalyst was designated as the sample ZCAT-3.sup.#-1.

(33) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor supported with the catalyst ZCAT-3.sup.#-1 by a constant flow pump, the temperature of reactor was 240° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 171 h.sup.−1.

(34) The test results showed that the catalytic activity of ZCAT-3.sup.#-1 was not lowered as compared with CAT-3.sup.#.

EXAMPLE 4

(35) Preparation of Nitrogen-Containing Carbon Catalyst Sample CAT-4 #

(36) 50 g of alumina was placed in a 100 g of aqueous solution containing 25 g of sucrose, and the water was evaporated to dryness at 100° C. to obtain a precursor 4.

(37) The precursor 4 was placed in a quartz tube and then the quartz tube was placed in a tube furnace. Argon gas containing 1% (mass percentage) of pyridine was introduced into the quartz tube and heated to 800° C. and the temperature was maintained for 3 hours to perform a carbonization-nitridation process to obtain the catalyst, which was designated as sample CAT-4.sup.#. The mass percentage of the nitrogen element in the supported nitrogen-containing carbon material was 4%.

(38) Activity Test of Supported Nitrogen-Containing Carbon Catalyst Sample CAT-4 #

(39) The activity test process differed from Example 1 only in that the temperature of reactor was 260° C. and the volumetric space velocity (GHSV) of 1,2-dichloroethane was 133 h.sup.−1. The test results showed that the conversion rate of dichloroethane was 54% and the selectivity to chloroethylene was more than 99%.

(40) Regeneration and Activity Test of Catalyst Sample CAT-4.sup.#

(41) The deactivated catalyst was calcined in a mixed atmosphere containing 15% O.sub.2 and 85% N.sub.2 for 2 hours at 600° C., and the obtained solid sample was designated as sample ZCAT-4.sup.#-Z1.

(42) The silica gel pellet was replaced by the sample ZCAT-4.sup.#-Z1, and the other preparation steps and conditions were the same as the sample CAT-4.sup.#, and the obtained regenerated catalyst was designated as the sample ZCAT-4.sup.#-1.

(43) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor supported with the catalyst ZCAT-4.sup.#-1 by a constant flow pump, the temperature of reactor was 260° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 133 h.sup.−1.

(44) The test results showed that the catalytic activity of ZCAT-4.sup.#-1 was not lowered as compared with CAT-4.sup.#.

EXAMPLE 5

(45) Preparation of Nitrogen-Containing Carbon Catalyst Sample CAT-5.sup.#

(46) 50 g of zirconium oxide was placed in 100 g of anhydrous ethanol solution containing 15 g of phenolic resin, and anhydrous ethanol was evaporated to dryness at 80° C. to obtain a precursor 5.

(47) The precursor 5 was placed in a quartz tube and then the quartz tube was placed in a tube furnace. Nitrogen gas containing 5% (mass percentage) of acetonitrile was introduced into the quartz tube and heated to 750° C. and the temperature was maintained for 3 hours to perform a carbonization-nitridation process. Thereafter, the catalyst was obtained and designated as sample CAT-5.sup.#. The mass percentage of the nitrogen element in the supported nitrogen-containing carbon material was 2%.

(48) Activity Test of Supported Nitrogen-Containing Carbon Catalyst Sample CAT-5.sup.#

(49) The activity test process differed from Example 1 only in that the temperature of reactor was 250° C. and the volumetric space velocity (GHSV) of 1,2-dichloroethane was 133 h.sup.−1. The test results showed that the conversion rate of dichloroethane was 36% and the selectivity to chloroethylene was more than 99%.

(50) Regeneration and Activity Test of Catalyst Sample CAT-5.sup.#

(51) The deactivated catalyst was calcined in air for 2 hours at 600° C., and the obtained solid sample was designated as sample ZCAT-5.sup.#-Z1.

(52) The silica gel pellet was replaced by the sample ZCAT-5.sup.#-Z1, and the other preparation steps and conditions were the same as the sample CAT-5.sup.#, and the obtained regenerated catalyst was designated as the sample ZCAT-5.sup.#-1.

(53) 1,2-dichloroethane liquid was preheated and vaporized in the evaporator, and then introduced into a fixed bed reactor supported with the catalyst ZCAT-5.sup.#-1 by a constant flow pump, the temperature of reactor was 260° C., the volumetric space velocity (GHSV) of 1,2-dichloroethane was 133 h.sup.−1.

(54) The test results showed that the catalytic activity of ZCAT-5.sup.#-1 was not lowered as compared with CAT-5.sup.#.

EXAMPLE 6

(55) XPS Characterization of Catalyst Sample CAT-1 #˜CAT-5 #

(56) The sample CAT-1.sup.#˜CAT-5.sup.# was analyzed by x-ray photoelectron spectroscopy, and the results are showed as follows:

(57) There are at least five nitrogen-containing functional groups in CAT-1.sup.#˜CAT-5.sup.#: pyridine type functional group (398.6 eV), amine or amide type group (399.6 eV), pyrrole type group (400.3 eV), substituted type N atom (401.3 eV, N replaces a C atom in the graphite sheet framework), pyridine oxide type functional group (398.6 eV), indicating that the nitrogen element is doped in the carbon material in a form of covalent bond.

(58) The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed by the preferred embodiments as above, they are however not used to limit the present application. A slight change or modification utilizing the technical content disclosed above made by the person skilled in art, without departing from the technical solution of the present application, is equivalent to the equivalent embodiment, and falls within the scope of the technical solution.