PROCESS FOR THE PRODUCTION OF HYDROGEN CHLORIDE, ETHYLENE AND VINYL CHLORIDE FROM ETHANE

Abstract

A process is provided for the chlorination of ethane using chlorine as the chlorinating agent to produce ethylene, hydrogen chloride (HCl) and vinyl chloride monomer (VCM).

Claims

1. A continuous process for producing ethylene, hydrogen chloride and vinyl chloride monomer comprising a) reacting a feed comprising chlorine with ethane in a reaction zone to produce a crude product wherein the crude product comprises i. product components comprising hydrogen chloride, ethylene, VCM, and heavies; and ii. a partial recycle fraction comprising hydrogen chloride and ethylene; b) fractionally separating from the crude product the partial recycle; and c) fractionally separating from the crude product the product components.

2. The process of claim 1 wherein the heavies are separated from the product components.

3. The process of claim 1 wherein the fractionally separated partial recycle is recycled to the reaction zone.

4. The process of claim 1 wherein the reaction is conducted at near adiabatic condition.

5. The process of claim 1 wherein the inlet temperature ranges from 200-350° C.

6. The process of claim 1 further wherein the molar ratio of chlorine to ethane in the feed is greater than 1.1 but less than 2.0.

7. The process of claim 1 wherein the reactor comprises an exit temperature ranging from 350-700° C.

8. The process of claim 1 wherein the feed stream components are pre-mixed prior to being fed in the reactor.

9. The process of claim 1 wherein the feed stream components are not pre-mixed prior to being fed in the reactor.

10. The process of claim 1 wherein the HCl and ethylene products are reacted in a downstream process to produce 1,2-dichloroethane.

11. The process of claim 1 wherein the heavies are further reacted to produce trichloroethylene, vinylidene chloride, and/or perchloroethylene.

12. The process of claim 1 further wherein greater than 95% of the chlorine is converted into products.

13. The process of claim 1 wherein greater than 95% of ethane is converted into products.

14. The process of claim 12 further wherein greater than 95% of ethane is converted into products.

Description

EXAMPLE

Process for the Chlorination of Ethane

[0029] Ethane is chlorinated to produce ethylene, HCl and VCM in a thermal chlorination jet-stirred reactor. The jet-stirred reactor is simulated as described elsewhere (see Chapter 8.7 in “Cleaner Combustion: Developing Detailed Kinetics Models,” F. Battin-Leclerc, J. M. Simmie, E. Blurock (Ed) (2013)) using kinetics reported by Dahl et al. [Ind. Eng. Chem. Res. 2001, 40, 2226-2235]. The thermodynamic properties are obtained from reported literature values (seehttp://webbook.nist.gov/chemistry/) and thermochemical kinetics approach (see S. W. Benson “Thermochemical Kinetics: Methods for the Estimation of Thermochemical Data and Rate Parameters,” 1976). The reactor model is imbedded inside a process flow sheet simulation (see http://www.aspentech.com/products/aspen-plus.aspx) such that impacts of recycle can be evaluated.

[0030] The reactor pressure of 40 psia and feed is preheated to higher than 200° C. and reactor exit temperature is maintained by adjusting chlorine flow rate. Table 1 shows the expected production rate of vinyl chloride, ethylene and heavies products. Note that by preheating the feed components such that the mixed feed stream temperature as shown and maintaining Cl.sub.2/ethane molar ratio of less than 1.9, the product yield to ethylene and VCM from ethane is greater than 80% as shown in Table 1. This is much higher selectivity than previously reported (i.e. U.S. Pat. No. 2,628,259—table III) where only 60% selectivity to ethylene and VCM is obtained. With ethane conversion of greater than 88%, the results shown in Table 1 provides much higher total yield than those shown in CA2097434 where only 50% of ethane is converted.

TABLE-US-00001 TABLE 1 Process Operating Conditions and Product Composition Ex. 1 Ex. 2 Ex. 3 Ex. 4 Cl.sub.2/Ethane Molar Ratio 1.13 1.27 1.41 1.27 Partial Recycle Fraction/ 3.33 3.33 5 5 Fresh Ethane, (mass ratio) Ethyl chloride 0.075 0.027 0.034 0.09 Recycle/Ethane, (mass ratio) Reactor flow/reactor 240 245 318 314 volume, kgmole/hr/m{circumflex over ( )}3 Inlet Temperature, ° C. 230 230 230 230 Exit Temperature ° C. 501 539 533 496 Chlorine Conversion >99%   >99%   >99%   >99%   Ethane Conversion 88% 95% 98% 93% Total Product composition, wt % HCl 64.9 66.6 66.1 64.8 Other 3.3 1.3 0.4 1.7 Ethylene 16.5 15.4 12.9 14.5 VCM 9.8 12.8 15.5 12.3 Heavies 5.5 3.9 5.1 6.7 Ethane yield to C.sub.2H.sub.4 & 82% 91% 92% 86% VCM Heavies composition, wt % 1,2-dichloroethane 6.1 0.1 0.1 6.2 1,1-dichloroethane 54.8 20.8 11.8 48.8 1,1,1-trichloroethane 31.0 52.0 57.4 35.7 1,1,2-trichloroethane 1.9 1.0 0.8 2.3 1,1-dichloroethylene 5.6 22.9 26.0 6.3 Trans-1,2- 0.3 1.6 1.9 0.4 dichloroethylene Cis-1,2-dichloroethylene 0.2 1.6 2.0 0.3