The physical adsorption on molecular sieve materials in liquid phase (at normal or cryogenic circumstances) has a great importance at the production of high purity materials. In this lecture the evaluation of a high purity methane and an H2S free propane-butane production unit will be discussed. In the case of these two applications you can follow the procedure from the idea to the evaluation. The steps of projects were the next : mathematical modelling of the fixed bed unit operations together with thermodynamic equilibrium calculation of the system, the laboratories and pilot plant experiments the basic and detail engineering of the plant start up and operation of the plant The key component of the process is the fixed bed adsorption column. For the mathematical modelling of this unit house built kinetic model was used. The detailed design of the processes was done by the help of CAD software systems.