Answer to Question #233508 in Chemical Engineering for Lokika

Question

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.

Answer 1

To determine the quantity of fresh carbon required per 1000 kg of solution for a two stage counter-current operation, we compute we use the equation:

 

From this we get:

L_s=G_S x0.0195= 19.5kgs

It implies that 19.5Kgs of fresh carbon fis needed for the 1000Kgs solution per to allow this two stage counter-current operation.

We can plot the equilibrium isotherm as shown below: