Styrene $($C$8$H$8)$ is produced from dehydrogenation reaction of ethylbenzene $($C$8$H$10)$ with the present

of catalyst. A general procedure of producing it is as follows:

A fresh feed stream consists of C$8$H$10$ and steam $($H$2$O$)$ at a mole ratio of $1$:$1$ is mixed with a recycle

stream and enters a reactor $($R$).$ The steam acts as an inert and cleaning compound for the catalyst

surface. The production process is designed for $70-80\%$ overall conversion and single$-$pass

conversion of $30-40\%.$ The reactor outlet stream enters a first separator $($S$1)$ which produces $2$

streams. The first stream consists of H$2$ and H$2$O is discarded for further process, while the second

stream consists of C$8$H$8$ and C$8$H$10$ enters a second separator $($S$2).$ The S$2$ produces $2$ streams,

the first stream consists of C$8$H$8$ and C$8$H$10$ is collected as product while the second stream consists

of $90$ mol$\%$ C$8$H$10$ and the balance C$8$H$8$ is recycled and mixed with the fresh feed stream in a mixer

$($M$).($ draw the diagram$)$