Ethylene and chlorine $($streams $1$ and $2)$ are fed in stoichiometric amounts at $25C$ and $1$ atm to a $1\mathrm{.}5$atm bubble column reactor $(R-100)$ that circulates the reactant gases via sparger dispersion through liquid $1,2-$dichloroethane that is maintained at $90C$ by a cold$-$water stream $($E$100).$ The bubble column reactor design maximizes ethylene mass transfer and its use in industry is well$-$characterized $($Orejas$,2001).$ The product stream exiting the direct chlorination reactor is a $97\%$ pure $1,2-$dichloroethane stream $($stream $3)$ with limited side reaction and unreacted feed compounds. R$-100$ also contains ferric chloride that acts as a Lewis acid catalyst, polarizing chlorine to increase its electrophilic activity and encourage attack on ethylene's double bond $($Wachi & Asai, Kinetics of $1,2-$Dichloroethane Formation from Ethylene and Cupric Chloride, $1994).$

The $1,2-$dichloroethane stream is joined by a recycle $($producing stream $4)$ and fed through a centrifugal pump $($P$-100$; stream $5)$ and a fired$-$heat evaporator $($E$-101$; stream $6)$ to achieve pressurization to $26$atm, complete vaporization, and a temperature increase to $500C.$ This stream is flown into a pyrolysis furnace at the same temperature and pressure, where it is primarily converted to vinyl chloride. Although a catalytic pyrolysis method exists, similar conversion levels can be reached without a catalyst, making the non$-$catalytic approach a simpler, less expensive, and more favorable method $($Dreher$,$ Torkelson, & Beutel, $2012$; Rus, $2013).$ The furnace contents are transferred to a quench tank $(V-100$; stream $7),$ which is maintained at $6C$ and $12$ atm by circulating the liquid condensate exiting the pyrolysis furnace through a refrigerant$-$cooled condenser system $($P$-101,$ E$-102).$ The quench tank is a vital component of this process: Without rapid cooling the pyrolysis reaction will continue, degrading desirable vinyl chloride and producing additional unwanted side products.

The quench contents are fed to a $7-$stage distillation column above stage $2$ at $12$ atm $($T$100$ ; stream $8)$ where $HCl$ is recovered at $97\%$ purity in the distillate $($stream $9)$ and the remainder of the pyrolysis products are fed in the bottoms stream to a second, similar, $9-$stage distillation column above stage $3$ at $4\mathrm{.}8$ atm $($T$-101$; stream $10).$ This column yields a $97\mathrm{.}6\%$ pure vinyl chloride stream in the distillate $($stream $11)$ and the $1,2-$dichloroethane$-$rich bottoms stream is recycled ahead of the centrifugal pump $($stream $12).$ The energy flow framework diagram $($EFD$)$ and process flow diagram $($PFD$)$ for direct chlorination process are given in Figure $1$ and $2,$ respectively. Summaries data for all the processes is given in Table $1.$