Preparation of composite adsorbent of sawdust and CaCl2 by carbonization method for creating pore

Abstract

To solve the problem of swelling and agglomeration of CaCl2 during the process of ammonia adsorption and improve the performance of mass transfer, we present a new method for the preparation of adsorbent. The CaCl2 is first immerged into sawdust by soaking method, then the composite adsorbent is prepared by carbonizing the mixture of CaCl2 and sawdust. The SEM image and elements analysis indicated that the new adsorbent has high porosity and uniform distribution of CaCl2 due to carbonization under temperature of 700°C. The performance testing of ammonia adsorption showed that under the conditions of evaporation temperature of −5°C and condensation temperature of 40°C, the ammonia uptake reaches 0.204, 0.253 and 0.285 kg/kg, the specific cooling power (SCP) is 868.96, 540.02 and 405.16 W/kg, and the average adsorption rate is 6.79×10−4, 4.22×10−4 and 3.17×10−4 kg/kg/s when the adsorption time is 5, 10 and 15 min, respectively. The problems of swelling and agglomeration of CaCl2 are solved.