Integrated process for producing 1,2-dichloroethylene
View Patent ↗Describes an integrated process for preparing 1,2-dichloroethylenes. In the described process organic feed material, e.g., C 2 -C 4 aliphatic hydrocarbons and/or chlorinated derivatives of such aliphatic hydrocarbons, is introduced into a first reaction zone 10 , e.g., a chlorination zone such as an oxychlorination zone, or a thermal cracking zone; first product effluent from the first reaction zone is forwarded to a second reaction zone 9 ; trichloroethane is introduced into the second reaction zone and into heat exchange contact with the first product effluent from the first reaction zone, which has a heat content sufficient to cause thermal dehydrochlorination of trichloroethane in the second reaction zone; and second product effluent is removed from the second reaction zone. 1,2-dichloroethylene is recovered by conventional distillation recovery methods from the second product effluent.
1. An integrated process for preparing 1,2-dichloroethylene comprising:
(a) providing a first reaction zone chosen from a chlorination zone and a thermal cracking zone, and a second reaction zone,
(b) introducing organic feed comprising lower aliphatic hydrocarbon, chlorinated derivative of lower aliphatic hydrocarbon, or mixtures of lower aliphatic hydrocarbon and chlorinated derivatives thereof into the first reaction zone,
(c) removing first product effluent from the first reaction zone and introducing first product effluent into the second reaction zone, said first product effluent having a heat content sufficient to cause thermal dehydrochlorination of trichloroethane in the second reaction zone,
(d) introducing trichloroethane into the second reaction zone and into heat exchange contact with first product effluent introduced into the second reaction zone, thereby to convert at least a portion of said trichloroethane to 1,2—dichloroethylene, and
(e) removing second product effluent comprising 1,2-dichloroethylene from the second reaction zone.
2. The process of claim 1 wherein the organic feed to the first reaction zone comprises primarily aliphatic hydrocarbons containing 2 carbon atoms and chlorinated derivatives thereof.
3. The process of claim 2 wherein the first reaction zone is an oxychlorination reaction zone.
4. The process of claim 3 wherein product effluent from the oxychlorination reaction zone comprises chlorinated olefinic hydrocarbons chosen from trichloroethylene, perchloroethylene, and mixtures of trichloroethylene and perchloroethylene.
5. The process of claim 3 wherein the organic feed to the first reaction zone comprises 1,2-dichloroethane, and the first product effluent from the first reaction zone comprises perchloroethylene and trichloroethylene.
6. The process of claim 3 wherein the organic feed to the first reaction zone comprises trichloroethane, and the first product effluent from the first reaction zone comprises-perchloroethylene and trichloroethylene.
7. The process of claim 2 wherein the average temperature within the second reaction zone is at least 250° C.
8. The process of claim 2 wherein the average temperature within the second reaction zone is less than 700° C.
9. The process of claim 7 wherein the average temperature within the second reaction zone ranges from 340° C. to 500° C.
10. The process of claim 7 wherein the average residence time within the second reaction zone of the trichloroethane introduced into the second reaction zone is at least 3 seconds.
11. The process of claim 10 wherein the average residence time within the second reaction zone of the trichloroethane introduced into the second reaction zone is less than 40 seconds.
12. The process of claim 10 wherein the average residence time within the second reaction zone of the trichloroethane introduced into the second reaction zone ranges from 5 to 40 seconds.
13. The process of claim 2 wherein the weight ratio of the trichloroethane introduced into the second reaction zone to the organic feed introduced into the first reaction zone is from 0.001 to 4.0.
14. The process of claim 1 wherein first product effluent removed from the first reaction zone in (c) is commingled with trichloroethane introduced into the second reaction zone.
15. An integrated process for preparing 1,2-dichloroethylene comprising
(a) providing a first oxychlorination reaction zone and a second reaction zone,
(b) introducing organic feed comprising primarily aliphatic hydrocarbons containing 2 carbon atoms and chlorinated derivatives thereof, oxygen-containing gas and chlorinating agent into said first reaction zone, thereby to produce a first product effluent comprising trichloroethylene and perchloroethylene,
(c) removing vaporous first product effluent from the first reaction zone and forwarding first product effluent to said second reaction zone, said forwarded first product effluent having a heat content at least sufficient to cause thermal dehydrochlorination of trichloroethane in said second reaction zone,
(d) introducing trichloroethane into the second reaction zone and into heat exchange contact with first product effluent forwarded from the first reaction zone, thereby to convert at least a portion of said trichloroethane to 1,2-dichloroethylene, and
(e) removing second product effluent comprising trichloroethylene, perchloroethylene and thermal dehydrochlorination products of trichloroethane from the second reaction zone, wherein the thermal dehydrochlorination products of trichloroethane include 1,2-dichloroethylene.
16. The process of claim 15 wherein first product effluent removed from the first reaction zone in (c) is commingled with the trichloroethane introduced into the second reaction zone.
17. The process of claim 16 wherein the commingled first product effluent and trichloroethane are in a vaporous state within the second reaction zone.
18. The process of claim 17 wherein the average temperature within the second reaction zone ranges from 340° C. to 500° C., and the average residence time of trichloroethane introduced into the second reaction zone in (d) is at least 3 seconds.
19. The process of claim 18 wherein the weight ratio of the trichloroethane introduced into the second reaction zone to the organic feed introduced into the first reaction zone is from 0.01 to 1.0.
20. The process of claim 19 wherein the weight ratio of the trichloroethane introduced into the second reaction zone to the organic feed introduced into the first reaction zone is from 0.01 to 0.5.