This work investigates the characteristics of nonimaging hybrid compound parabolic collector (HCPC) for enhancement of heat transfer to the reactor of solar adsorption refrigeration system (SARS) in low latitude and cloudy region. A HCPC is simulated and developed to heat cylindrical reactor of SARS. The HCPC is used to heat the reactor with solar energy during high insolation while auxiliary heating system is used during low insolation. Simulation results show that the reactor adsorbent (activated carbon) is heated to average temperatures between 70 and 85 C when the solar radiance is between 350 and 450 W/m 2 . However, the experimental results are observed to be slightly deviated from the simulated results due to environmental factors, such as wind speed, cloud, and dust, which cannot be correctly predicted. It is inferred that HCPC is effective in heating SARS cylindrical reactor to start adsorption refrigeration process in low latitude and cloudy region.

In the present work, an attempt is made to use non-contact charcoal in the reduction of run-off mine goethite ore at heating temperatures above 570 °C. The reduction mechanism was adopted, following Levenspiel’s relations for the shrinking core model at different stages of reduction. The non-contact charcoal reduction approach is adopted to maximize the benefit of using CO/CO2 gases from charcoal for reduction without the need for beneficiation and concentration. The rate-controlling steps for the reduction kinetics of average particle sizes 5, 10, 15, and 20 mm at 570, 700, 800, 900, and 1000 °C were studied after heat treatment of the ore-wood charcoal at a total reduction time of 40 min using activated carbon reactor. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses were done to investigate the spectrometric phase change and metallic components of the ore sample after reduction, respectively. The average percentage of the metallic iron content (56.6, 60.8, and 61.7%) and degree of metallization (91.62, 75.96, and 93.6%) are achieved from the SEM/EDX analysis of the reduced ore sample at reduction temperatures of 570, 800, and 1000 °C, respectively. The results indicate the tendency for high carbon deposit at the wustite stage of the reduction process at the lowest of temperature 570oC and the residence time of at 10 min. This study demonstrates that diffusion through the ash layer is the controlling resistance of the overall reduction process.