Novel ammonia sorbents “porous matrix modified by active salt” for adsorptive heat transformation: 3. Testing of “BaCl2/vermiculite” composite in a lab-scale adsorption chiller

A composite adsorbent composed of BaCl2 impregnated into expanded vermiculite has been synthesized and tested in a laboratory scale adsorption chiller. Previous work has established the promising theoretical performance of this adsorbent with ammonia as a refrigerant, in terms of equilibrium uptake, suitable equilibrium temperatures for use in air conditioning applications and good reaction dynamics. Analysis of the adsorption phase revealed a simple exponential approach to equilibrium uptake which was not previously observed in larger scale experiments. It was demonstrated that this material can provide effective operation of the chiller using a low potential heat source (80–90 °C) giving COP as high as 0.54 ± 0.01 and SCP ranging from 300 to 680 W/kg. The specific cooling power depends strongly on the driving temperature difference and the cycle duration.