Chemical Engineering Answers

3) A solution of washed raw cane sugar is coloured by the presence of impurities. It is to be decolourised by the treatment with an adsorptive carbon in a contact filtration plant. The data for an equilibrium isotherm is given below. The original solution has a colour concentration of 9.6 measured on an arbitrary scale and it is desired to reduce colour to 10% of its original value

Kg carbon/kg solution:

0

0.001

0.004

0.008

0.02

0.04

Colour units /kg solution

9.6

8.6

6.3

4.3

1.7

0.7

Convert the data to a suitable form for plotting the equilibrium isotherm and determine the quantity of fresh carbon required per 1000 kg of solution for a two stage counter-current operation?

Explain briefly with step by step process?

12)Use Cauchy integral formula for derivatives evaluate ∮c z²-2z/(z+1)^2 (z²+4)dz, where C is |z + 2) <2.

11)Evaluate∫C Im(Z)dz, where C is z = {(t-2i, 1≤t≤2. ; 2-i(4-t), 2<t≤3'

10)Using Residue theorem evaluate ∮c Z cosh πz/Z^(4)+5Z^(2)+4, where C is |z| = 3.

9)Find Laurent series expansion of the function 1/ z²+z-6 in the regions

1<|z-1 <4 and |z-1|> 4.

8)Show that u(x, y) = 4y + 3x²y-y³ is harmonic and find its conjugate harmonic function v(x, y).

7) Show that the function f(z)={(z̅ )^2,Z≠0. ; 0,Z=0 satisfies Cauchy-Rieman equations at z=0.Does f'(0) exists?

3) Find Laplace transform of the function f(t)={t, 0≤t<1 ; 2-t,1≤t≤2 and f(t+2)=f(t)

2. A mixture containing benzene and toluene with 40% benzene and 60% toluene is to be separated in a fractionating column to give a product containing 96% benzene, bottom product containing 95% toluene. Feed is mixture of two third vapor and one third liquid. Find out the number of theoretical stages required if the reflux ratio of 15 times the minimum is used. Relative volatility is 2.5(McCabe Thiele Method), explain step by step with lengthy process?