Thermal effects on the breakthrough curve of a hydrogen ternary system at a fixed bed

The thermal effect on the breakthrough curve of a hydrogen ternary mixture (H-2/CH4/CO; 60:30:10 vol%) was investigated experimentally and theoretical ly at a fixed bed in the range of 4 to 16 kg(f)/cm(2) adsorption pressure a nd 4.5-9.1 LSTP/min feed flow rate. To understand the adsorption dynamics a nd the thermal effect by the heat of adsorption, a non-isothermal dynamic m odel incorporating mass, energy, and momentum balances was used and was com pared with isothermal and adiabatic models. The adsorption thermal effects on adsorption dynamics were compared between an activated carbon bed and a zeolite 5A bed. In the activated carbon bed, the roll-up of CO by CH4 and t he separation of mass transfer zones between CO and CH4 occurred and the H- 2 breakthrough curve showed a stepwise decrease and tailing. However, a sma ll roll-up of CH4 and a wide breakthrough of CO in the experimental range w as shown in the zeolite bed without the separation of two temperature wave fronts. The breakthrough time was elongated by an increase in adsorption pr essure and by a decrease in feed flow rate in each adsorbent bed, but the e xtent of elongation was different due to the difference between the affinit ies of CO and CH4 to each adsorbent. Also, in the activated carbon bed, the extent of roll-up became wider with a decrease in feed flow rate and becam e steeper with an increase in adsorption pressure. Depending on the thermal condition in each bed, concentration and temperature profiles showed diffe rent behavior.