Vinyl chloride feedstock: thermal pyrolysis (cracking) of ethylene dichloride primarily produces which compound?

Introduction / Context:
Vinyl chloride monomer (VCM) is the key feedstock for manufacturing PVC. One major industrial route is the cracking (thermal pyrolysis) of ethylene dichloride (EDC, 1,2-dichloroethane).

Given Data / Assumptions:

• Process: high-temperature EDC cracking.
• Target product: VCM.
• By-products include HCl that can be recycled.

Concept / Approach:
The dehydrochlorination reaction of EDC yields vinyl chloride and hydrogen chloride. The simplified stoichiometry is: 1,2-dichloroethane → vinyl chloride + HCl. This is performed in fired cracking furnaces, followed by rapid quench and product recovery.

Step-by-Step Solution:
Recognise EDC as the direct precursor to VCM via thermal cracking.Identify primary product pair: VCM and HCl.Choose vinyl chloride as the correct answer.

Verification / Alternative check:
Alternative routes (e.g., oxychlorination of ethylene to EDC) integrate with EDC cracking in balanced PVC complexes.

Why Other Options Are Wrong:
Trichloroethylene and ethylene oxide arise from different chemistries.Ethanolamine forms from ethylene oxide and ammonia, not from EDC pyrolysis.

Common Pitfalls:
Confusing chlorinated solvent production routes with vinyl chloride monomer manufacture.

Final Answer:
Vinyl chloride