Question

(Comprehensive Problem on multiple reactions with heat effects) Styrene can be produced from ethylbenzene by the following reaction:

ethylbenzene ↔ styrene +H₂ (1)
However, several irreversible side reactions also occur: ethylbenzene ↔ benzene +ethylene (2)
ethylbenzene +H₂ ↔ toluene+ methane (3)
J. Snyder and B. Subramaniam. Chem. Eng. Sci., 49, 5585 (1994). Ethylben- zene is fed at a rate of 0.00344 kmol/s to a 10.0-m³ PFR (PBR) along with inert steam at a total pressure of 2.4 atm. The steam/ethylbenzene molar ratio is initially [ie., parts (a) to (c)l 14.5:1 but can be varied. Given the following data, find the exiting molar flow rates of styrene, benzene, and toluene along with Ss BT for the following inlet temperatures when the reactor is operated adiabatically
(a) To 800 K
(b) To 930 K
(c) To =1100 K
Find the ideal inlet temperature for the production of styrene for a steam/ethylbenzene ratio of 58:1. (Hint: Plot the molar flow rate of sty rene versus To. Explain why your curve looks the way it does.)

Answer 1

The ideal inlet temperature for the production of styrene is found by plotting the molar flow rate of styrene against the inlet temperature and identifying the peak yield. Factors influencing this include reaction thermodynamics and the specified steam-to-ethylbenzene ratio.

Step-by-step explanation:

The question seems to pertain to the production of styrene from ethylbenzene. To determine the ideal inlet temperature for this chemical reaction, you would ideally create a plot of the molar flow rate of styrene versus the inlet temperature, To. The steam-to-ethylbenzene ratio provided (58:1) plays a crucial role in this assessment as it reflects the reaction conditions.

The curve of this plot will demonstrate how different inlet temperatures affect the yield of styrene, and the point at which the yield is highest indicates the ideal temperature. This plot shape is influenced by the thermodynamics of the reaction, including mass and energy balances, the kinetic rate of reaction, and the heat of reaction. Unfortunately, without specific data on reaction rates, heat of reaction, and system constraints, I cannot provide an exact ideal inlet temperature.