An irreversihle reaction (2A - B) is performerd in an isothermal, variahle volum
ID: 717937 • Letter: A
Question
An irreversihle reaction (2A - B) is performerd in an isothermal, variahle volume continuous- stirred tank reactor (CSTR). A feed stream containing pure reactant A enters the CSTR at a volumetric flow rate o and molar concentration CAD. The product stream leaves the reactor at a volumetric flow rate q with reactant and product concentrations of CA and C3. The reaction rate of A per unit volume is r- kCA5. Assume the feed and product streams have the same densities (a) Derive a dynamic model for the CSTR. (b) Perform a degrees of freedom analysis (c) Identify the model constants, input variables and output variables (d) Ifqo and CAo are disturhances, propose a control strategy for the CSTR, and clearly identify the controlled and manipulated variables. Draw a schematic P&ID diagram (not a block diagram) of the control system. Clcarly labcl and usc appropriate symbols for all of the omponents of the control system. 1o. hCA q. CA, CBExplanation / Answer
Inlet volumetric flow rate = qo
Initial molar concentration = CAo
Outlet volumetric flow rate = q
Reactant molar concentration = CA
Product molar concentration = CB
rate per unit volume: r = k CA0.5, tank volume = V,
density of feed and product streams are same = D
a) Derive a dynamic model for the CSTR
Total Mass Balance:
Rate of accumulation of mass in tank = rate of mass in - rate of mass out
d(DV)/dt = D*qo - D*q. {D = density is constant}
dV/dt = qo - q —————————(1) Component Balance:
Component Balance for A:
IN - OUT - Generation = Accumulation
qoCAO - qCA - rV = d/dt(CAV)
qoCAO - qCA - rV = CA*d(V)/dt + V*d(CA)/dt
put dV/dt from equateon (1):
qoCAO - qCA - rV = CA(qo - q) + V*dCA/dt
V*dCA/dt = qoCAO - qCA - rV - CA*qo + CA*q
dCA/dt = (qoCAO - kCA0.5 - CA*qo)/V ——————{ r = rate/Volume)
Component Balance for B:
IN - OUT - Generation = Accumulation
0 - qCB + r.V = d/dt(CBV)
dCB/dt = (kCA0.5 - qCB)/V ——————{ r = rate/Volume)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.