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Sarkari MCQs Government Exam Question Bank
Question no. 7750

An irreversible liquid reaction A + B → P is carried out adiabatically in a mixed flow reactor with a feed containing 4 kmole/m3 of each reactant at 8 m3/h. If the exit stream temperature must not exceed 390 K, what is the maximum permissible inlet feed temperature? (Given: ΔH = –50 kJ/mol, mixture density = 1000 kg/m3, specific heat = 2 kJ/(kg·K), independent of temperature/composition)?

Select your answer for: An irreversible liquid reaction A + B → P is carried out adiabatically in a mixed flow reactor with a feed containing 4 kmole/m3 of each reactant at 8 m3/h. If the exit stream temperature must not exceed 390 K, what is the maximum permissible inlet feed temperature? (Given: ΔH = –50 kJ/mol, mixture density = 1000 kg/m3, specific heat = 2 kJ/(kg·K), independent of temperature/composition)?
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Answer: B. 290

Explanation

Adiabatic energy balance and reactor equations relate feed temperature to the heat of reaction. Solving the energy balance with the given thermodynamic parameters yields the inlet temperature. The calculated maximum permissible inlet feed temperature equals two hundred ninety Kelvin. Adiabatic mass and energy balances determine reactor performance without external heat loss. Specific heat capacity and mixture density convert enthalpy changes into temperature values. Limiting the maximum exit temperature protects equipment materials from thermal degradation.

Chemical plant operators calculate safe operating windows to prevent catalyst sintering. Reactor safety systems rely on accurate thermodynamic modeling of exothermic reactions. Optimizing feed temperatures balances conversion efficiency with strict metallurgical limits. Option A represents a lower inlet temperature that does not match the calculated energy balance. Option B is the correct calculated maximum permissible inlet feed temperature value. Option C is the maximum allowable exit temperature specified in the problem statement.

Subject
Engineering
Category
Chemical Engineering
Topic
—
Difficulty
medium

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