If the value of the absorption factor is less than one,the iiii and the jjjj will converge near the bottom plates of the absorber,so that there will be a limited amount of separation possible.
If the absorption factor is greater than one,any separation will able to be achieved(assuming enough stages are used ) .If the absorption factor is very high then the solute concentration in the liquid will be low,the amount of solvent liquid required will be high,and therefore the economic viability of the process is reduce.The correct choice of the value of A detailed study of the solvent costs,product requirements,costs of each stage,etc.However a good estimate of A is between 1.25 and 2.0