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Go to Editorial ManagerThe depleting of the conventional sources of energy and the excess use of HCF components lead to the need for new techniques both for conservation of energy sources for the future and for decreasing the its harmful effects on the environment. This study investigated the adsorption capabilities of activated carbon. The adsorption of methanol on this substance was tested for their application in the adsorption refrigeration system based on solar energy._x000D_ Adsorption refrigeration system has been designed and manufactured with the energy source being solar energy. Methanol/activated carbon pairs have been used in experiments. The present work focused on the performance of the adsorption refrigeration system considering the temperature attained in the evaporator and the cooled spaced cabinet. The amounts of activated carbon used was (8 kg), while the amount of methanol were (1, 1.25, and 1.5) kg. The experiments were done in different days of the year. The amount of adsorption of methanol (as a result of decreasing the evaporator and cooled spaced temperature) was found to depend on the generator pressure and its increase as the primary generator pressure decreases. The best mass of methanol used was (1 kg) which give the lowest temperature obtained at the evaporative surface was ( 3.4 oC ) at the day ( 4/4/2017 ). The results shown that even in cloudy days there is a benefit from using such a system because the temperature attained is enough to start the adsorption process. The lowest temperature obtained at the evaporative surface was (3.4 oC) at the day (4/4/2017) for methanol mass of (1 kg) at an opening time of the valve between the evaporator and the generator (9:30am). The increase of methanol amount used in the experiment led to a good decrease in temperature attained in cooled spaced, but this is related to the time of connecting the evaporator and generator.
The removal of Congo red dye from industrial wastewater before its discharge to the environment is a critical problem, as it is non-biodegradable, toxic, and carcinogenic. Activated carbon was synthesized from a suggested sustainable source (sugarcane waste) and used as an adsorbent for the dye. Isotherm adsorption models and adsorption kinetics were investigated, and a simulated adsorption column model was proposed and developed based on the modified general rate model. The batch results showed that the highest removal rate achieved was 87.1% of the initial dye concentration (30 mg/L). The Freundlich isotherm model best described the equilibrium data, as evidenced by the high correlation coefficient (0.9535). Meanwhile, the maximum adsorption capacity was found to be 149.25 mg/g using the Langmuir isotherm. Furthermore, the kinetic results indicate that the pseudo-second-order model accurately describes the concentration-time relationship. A simulated maximum dynamic adsorption capacity of 0.096 mg/g was achieved at an optimal volumetric flow rate of 0.1 mL/min, with a dye concentration of 30 mg/L and a bed length of 39.69 cm. The continuous column efficiency increased with column length, reaching a maximum of 75% at 66.15 cm. Also, as the dye concentration increased, the column efficiency and dynamic adsorption capacity decreased. The study demonstrated an innovative approach to removing Congo red dye from its aqueous solution in a neutral medium using sustainably produced activated carbon derived from a sustainable source. A continuous removal process was simulated by developing a mathematical model based on adsorption curves and adsorption kinetics, which successfully described the adsorption process. This type of modeling, rather than relying on pre-existing equations, enables more efficient, scalable design.