Preparation of composite adsorbent with high performance of heat and mass transfer

To develop a new composite adsorbent with high performance, fir sawdust and CaCl2 are selected as raw materials. The mass transfer is enhanced by carbonizing and activating the sawdust and heat transfer is enhanced by adding expanded graphite into the adsorbent. The effect of the preparation temperature and the expanded graphite content on the adsorption performance is investigated. The results show that the new adsorbent exhibits a high adsorption performance due to its high porosity, uniform distribution and high content of CaCl2 and high thermal conductivity. Also, the experimental results indicate that the rate of ammonia adsorption on the adsorbent depends on the expanded graphite content and the carbonization and activation temperature. The adsorbent prepared at 500A degrees C and with the expanded graphite content of 30% has the best performance in terms of the adsorption refrigeration, which adsorbs ammonia as high as 0.37 g g(-1) at 10 min