-A thermodynamic cycle model is used to select an optimum adsorbent-refrigerant pair in respect of a chosen figure of merit that could be the cooling production (MJ m -3 ), the heating production (MJ m -3 ) or the coefficient of performance (COP). This model is based mainly on the adsorption equilibrium equations of the adsorbent-refrigerant pair and heat flows. The simulation results of 26 various activated carbon-ammonia pairs for three cycles (single bed, two-bed and infinite number of beds) are presented at typical conditions for ice making, air conditioning and heat pumping applications. The driving temperature varies from 80°C to 200°C.. The carbon absorbents investigated are mainly coconut shell and coal based types in multiple forms: monolithic, granular, compacted granular, fibre, compacted fibre, cloth, compacted cloth and powder. Considering a two-bed cycle, the best thermal performances based on power density are obtained with the monolithic carbon KOH-AC.with a driving temperature of 100°C, the cooling production is about 66 MJ m -3 (COP=0.

Solidified expanded natural graphite (ENG) has good heat and mass transfer characteristics and has recently been utilized as a matrix for heat and mass transfer performance intensification in adsorption refrigeration and air conditioning equipment. In order to gain an overall understanding of the heat and mass transfer process in solidified expanded natural graphite, the anisotropic thermal conductivities and permeabilities are investigated in two types of solidified block, i.e. discs of solidified expanded natural graphite (DSENG) and plates of solidified expanded natural graphite (PSENG), in which the heat conductive and mass transfer directions are parallel and perpendicular, respectively, to the pressing direction producing blocks. An unexpected phenomenon is found in the research, which is that the thermal conductivity sometimes decreases while the density of the solidified ENG increases, this only occurring for the heat conductive direction perpendicular to the pressing direction. Results also show that the direction has larger thermal conductivity also has a better permeability; the phenomena of anisotropic thermal conductivities are strongly dependent on density. The reasons are analyzed in the paper, and they are mainly related with the distribution of micro layers inside the samples.

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