Removal of pollutant mixtures from air streams with an indirect heating and cooling temperature swing adsorption process

摘要

A process of pollutant removal from air streams by means of ISA (Temperature Swing Adsorption) cycles is presented. TSA processes use a column filled with an adsorbent and consist of two main phases: an adsorption step during which the pollutants are adsorbed, followed by a desorption step during which the column is heated up in order to clean the bed before the next adsorption step. In this experimental study, the column includes an internal heat exchanger that allows indirect cooling and heating of the adsorbent bed which is made of activated carbon. The air stream is simulated by dry nitrogen and the pollutants are CO_2 and ethane (simulating a VOC) at various concentrations. Experiments with a mixture of pollutants proved that the column allows to separate efficiently ethane and CO_2, and to produce the same quality of purified nitrogen as for the single component cases (i.e. 99.995%). Different desorption methods were tested in order to analyse their effect on the heat consumption, desorption time and pollutant outlet concentration. All these results were used to define a protocol which was applied to an adsorption/desorption cycle experiment.