A novel bio-waste-driven multigeneration cycle integrated with a solar thermal field and atmospheric water harvesting cycle: An effort to mitigate the environmental impacts of the wastewater treatment plants

Poor management in the municipal waste disposal is a serious crisis for the health of the ecosystem and society. The implementation of the waste-to-energy projects can simultaneously recover the available energy in waste and significantly mitigate the environmental impacts of releasing waste into the environment. In this article, a novel bio-waste-driven multigeneration cycle (BW-MGC) integrated with a solar thermal field for the production of various valuable products from sewage sludge is introduced and evaluated (from thermodynamic, environmental and economic points of view). Herein, the biogas and syngas are obtained through the anaerobic digestion and gasification processes, respectively. Besides that, hydrogen energy and water production cycles are based on the water-gas shift reaction and atmospheric water harvesting cycle (AWHC) units, respectively. In the offered project, the heating capacity and a part of the electricity are obtained through the waste heat recovery system. The offered project provides a new process with a novel structure and configuration to produce useful products. Moreover, it can jointly address the simultaneous issues of energy, water, and environment. The offered plant can produce 18.1 MW of electricity, 18.72 l/h of water, and 0.9 kg/s of hydrogen fuel. The energy efficiency of the system in such design conditions was calculated as 36.12%, while the exergy efficiency was 40.9%. Further, the exergy sustainability factor, total products unit cost, and levelized total CO2 emissions are calculated as 0.5281, 0.05168 USD/kWh, and 0.2124 kg/kWh, respectively.