No abstract

No abstract

Summary This review paper focuses on converting plastic wastes into clean hydrogen via gasification for better sustainability. In this regard, various aspects of hydrogen production from plastic wastes are discussed and comparatively evaluated, including the state‐of‐the‐art and comparative evaluation, environmental and economical dimensions, global warming aspects, policies and strategies, a case study including energetic and exergetic performance evaluations, challenges and opportunities, and future directions possibly in the area. Additionally, this paper outlines what contributions it makes to the current literature about hydrogen production from plastic wastes by using gasification technologies. Moreover, this paper provides a detailed case study indicating exergetic sustainability aspects for hydrogen production from plastic wastes by applying plasma gasification whose data are taken from the literature. As a result of this case study, some exergetic sustainability indicators are studied for evaluation and comparison purposes. The exergetic sustainability index is found to be decreasing from 0.77 to 0.41 with the fact that exergetic efficiency drops from 0.43 to 0.28 while the environmental impact factor rises from 1.29 to 2.41 with the increase of waste exergy ratio from 0.56 to 0.70. Furthermore, plasma co‐gasification can be recommended as an environmentally‐benign solution for clean hydrogen production from plastic wastes. Highlights Plastic wastes is an important source of hydrogen. Gasification can efficiently be deployed for hydrogen production from plastic wastes. In order to evaluate potential gasification techniques, energetic, economic, environmental, and sustainability aspects should be considered. Plasma gasification appears to be more efficient and effective solution over other methods for higher amount of hydrogen production from plastic wastes.

No abstract

In this study, technical and economic performance analyses are conducted in order to determine the optimum collector surface area for indoor swimming pools. Required heat and economical conditions are taken into consideration while performing these evaluations. A brief summary of solar energy source and heat transfer equations for the Olympic pools are given. An Olympic swimming pool is assumed to be in different cities, and energy losses are calculated. For our sample Olympic pool, convective heat loss obtained is −3.86 kW and evaporative heat loss obtained is 265 kW. Total heat loss always maximum in January from 384 kW to 455.1 kW. Solar energy gain (assumption 1000 m2 collector area) and energy gain from boiler for different cities are calculated as maximum solar energy gain in July between 160 and 175 kW and minimum in January between 54.9 and 82 kW. High investment costs for solar power systems are responsible for low value of the reduction rate. Also, according to the energy demand and economical conditions, technical evaluations are performed in order to obtain optimum surface collector area, and economical analyses are conducted using unified cost method.