Review of solar dryers for agricultural products in Asia and Africa: An innovation landscape approach.

Solar drying is one of the most efficient and cost-effective, renewable, and sustainable technologies to conserve agricultural products in Asian and sub-Saharan African (SSA) countries. This review paper presents the different types of solar dryers that are widely used in Africa and Asia. In addition, the pre-eminent effects of their use on product quality, as well as their economic, environmental, and social impacts, are highlighted. Since financial, external, and structural factors play a key role in the adoption and scaling of solar dryers, this paper also discusses the impact of these factors on the effectiveness of solar drying technologies in selected Asian and SSA countries.

Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia.

The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories.