Integration and optimisation for sustainable industrial processing within the circular economy

This Virtual Special Issue (VSI) contains some of the papers presented at the 23(rd) Conference of Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES ' 20), which was virtually held in Xi'an, China on the 17 to 21 August 2020, related to the scope of Renewable and Sustainable Energy Reviews. The works are not limited to review articles; most of them have significant contributions to knowledge development for integration and optimisation for sustainable industrial processing within the circular economy. Topics covered in this VSI also includes studies on salt hydrate-based gas-solid thermochemical energy storage technology, hybrid battery optimisation, and energy recovery under thermal waste-to-energy. In addition, work on novel and effective passive cooling strategy for photovoltaic panels, integrated gasification combined cycle (IGCC) power generation systems, heat pumps optimisation in low-temperature waste heat recovery, utilisation of solar heating systems for low-temperature heat demand industries, and double reheat for thermal power generation are presented. The articles on the energy strategies towards the circular economy (CE) show the content of biomass supply chain optimisation, renewable energy system towards carbon emissions neutral, stable energy use strategies. Lastly, nexus thinking for sustainable development under COVID-19 assesses the energy and environmental performance of waste personal protective equipment treatment and the optimisation of the energy-water-waste nexus at the district level for regional sustainability. These achievements communicate the most significant and relevant critical thinking in renewable and sustainable energy research and development.