(453d) Evaluation of the Performance of Chemically Modified Agrowaste for Solar Refrigeration Applications in Developing Countries

The refrigeration of food and medicine is a necessity for all human settlements. The traditional refrigeration systems use electrical energy and refrigerants that could cause ozone layer depletion and global warming. Thus, solar refrigeration systems have been developed as an alternative to provide cooling by using thermal energies from solar irradiation. The simple solar refrigeration system consists of an evaporator, a condenser, a throttling valve, an adsorption bed and a solar collector. The adsorption bed comprises of solid material that adsorb a vapor (e.g., water, methanol, ethanol), which is desorbed later by solar heating. The desorbed vapor is condensed and collected into the condenser. After, the throttling valve is open causing a sudden pressure reduction that turns the liquid into vapor. The evaporation heat required is taken from the evaporator box causing the cooling effect and then the cycle begins again.

The affinity between the adsorbent (solid material) and the adsorbate (vapor) is an important factor for the refrigeration efficiency. Several researches have investigated the performance of different working pairs (adsorbent-adsorbate) in solar refrigeration systems. The most common working pairs include water-silica gel, water-zeolite, and methanol-activated carbon, among others.

The present paper explores the potential application of agrowastes as adsorbents for solar refrigeration applications since these materials are issue of concern in developing countries such as Mexico. Additionally, Mexico has a high solar irradiation (6 kWh/m²-day) that is a natural resource that could be used for refrigeration in communities with lack of electricity. In order to evaluate the affinity between agrowastes-vapor working pairs, maximum adsorption capacity are determined using the volumetric method.