Question

The gas-phase, elementary reaction: 2A + 1/2B ----> C + 2D will be conducted in a constant volume, isothermal batch reactor. The reactor is initially charged with a stoichiometric ratio of A and B. The reaction is moderately exothermic and the heat of reaction will be removed via cooling water. The following data is available:

Initial Conditions: Initial concentration of A = Cao, initial concentration of B = Cbo

Cooling water: inlet temperature = Ta1, outlet temperature = Ta2, water heat capacity = Cp, water flow rate = m

Reactor conditions: reactor volume = V, heat transfer coefficient = U, heat transfer area = A, reactor pressure = Po=P

Material Properties: Heat capacities: Cpa, Cpb, Cpc, Cpd, heat of reaction = deltaHr, molecular weight of reactants and products = MWa, MWb, MWc, MWd, rate constant=k

a) plot the expected flow rate of coolant required to maintain isothermal conditions versus the reaction conversion.

b) Dvelop the expression that will allow the determination of the required flow rate of cooling water versus the reaction conversion.

Answer 1

here we have to develope an expression that will relate the reaction coversion with requied rate of cooling for maintaining isothermal conditions

as we know process is isothermal that mean reaction temp is constant

this is maintained by cooling as rection is exothermic

heat of reaction =

for complete converion of 2 moles of a

if the coversion is X

heat of reaction will be =

as much as heat is produced that much should be removed by cooling

so

Q==

this will give use required Q & if any one of T of water is not given

as it is isothermal batch reactor

t=

to plot graph of rate of cooling vs conversion

just put X=0,0.1,0.2,03........,1

& calculate related rate of cooling

plot it against graph

& join it by free hand .you will get smooth curve