Techno-economic and emission analysis of solar assisted desiccant dehumidification: An experimental and numerical study

In humid climates, it is challenging to maintain moisture content in the air for human thermal comfort and industrial applications. Commercial dehumidifiers rely on conventional electric heaters to regenerate desiccant material, which accounts for significant energy consumption by such dehumidifiers. As a green solution to this problem, the present study integrates a flat plate solar air collector (FPSAC) with a desiccant dehumidifier to effectively use solar thermal energy and reduce electrical consumption. Performance evaluation of glazed and unglazed FPSAC-assisted desiccant dehumidifier has been conducted at process air flow rates of 33, 51 and 62 m³/h with a constant regeneration flow rate of 42 m³/h. Both glazed and unglazed FPSAC assisted desiccant dehumidification systems had the highest dehumidification effectiveness and percentage increase in temperature at the flow rate of 33 m³/h, while the highest moisture removal capacity was at 51 m³/h. Maximum dehumidification effectiveness, percentage temperature increase, and moisture removal capacity for the glazed case were 0.4, 66.67%, and 6.14 kg/h, respectively. Experimental results showed that the glazed FPSAC-integrated desiccant dehumidification system outperforms unglazed FPSAC in all performance evaluation parameters. Using Transient System Simulation software (TRNSYS), the proposed glazed and unglazed assisted desiccant dehumidification system was modeled and validated with experimental results. Furthermore, a techno-economic analysis of the solar hybrid desiccant dehumidification system has been carried out. The FPSAC used in this study showcased a 33.57% yearly solar fraction with a solar hybrid system having a payback period of 4.23 years. In addition, the hybrid system can reduce greenhouse gas emissions yearly by 0.352 tons of CO₂ equivalents.