Composite adsorbents of CaCl 2 and sawdust prepared by carbonization for ammonia adsorption refrigeration

Composite adsorbents of CaCl2 and sawdust prepared by carbonization for adsorption refrigeration with NH3 as refrigerant are tested, and the effects of carbonization temperature on the sorption capacity and rate are analyzed. The results show that the amount of pores in the sawdust of the composite adsorbents carbonized, apart from the content of CaCl2, is the most dominant factor influencing the NH3 sorption on composite adsorbents. The optimum carbonization temperature is 700°C, which gives the maximal NH3 sorption capacity as high as 0.774 kg of NH3 per kg of the composite, and the specific cooling power is approximately between 338 and 869 W/kg with the cycle duration varying from 5 to 20 minutes. The present study demonstrates that the composite absorbent of CaCl2 and sawdust prepared by carbonization is more promising and competitive for adsorption refrigeration application.