Coconut is a biomass resource that is abundant in tropical countries. In 2020, the Philippines planted 347 million coconut trees that produced 14.7 million tons of coconuts. The coconut shells (endocarp) are considered a waste material, which comprise 15.18% of each fruit and account for 2.2 million tons. The calorific value of raw coconut shells is 30.79MJ/kg. When torrefied at 275°C for 30 minutes holding time, the calorific value reached the optimal of 34.37MJ/kg, representing an increase of 11.64%. The mass yield (My) was 90.10% and the energy density was 111.64%, resulting in an energy yield of 100.59%.

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Concentrated solar power is an alternative renewable energy technology that converts solar energy into electrical energy by using a solar concentrator and a solar receiver. Computational fluid dynamics have been used to numerically design concentrated solar power. This is a powerful numerical analysis approach that is widely used in energy and environmental engineering applications. In this paper, we review previous work on the applications of computational fluid dynamics in the design of concentrated solar power technology. We performed a bibliometric analysis of journal articles relevant to applications to analyze the current trend of utilization of computational fluid dynamics in these technologies. Then, we conducted a comprehensive analysis focused on the design of solar dish technology using computational fluid dynamics. Furthermore, we reviewed in detail the optical modeling of solar concentrators and solar receivers. Of the 83 retrieved publications from Scopus database, 80 were journal articles, and only three were review papers. Among these 80 journal articles, only 54 were relevant to this study, and 23 were relevant to solar dish technology. The documents were analyzed according to their number of citations, journal sources, and keyword evolution and network map. The information presented in this paper is useful to further recognize the contributions of computational fluid dynamics to the development of concentrated solar power, particularly to solar dish technology. In addition, we also discuss the challenges and future research directions to make solar energy a more sustainable source of renewable energy.

Woody and herbaceous biomasses have been utilized as biomass energy plant feedstocks that generate electricity for years. The coconut tree, classified as woody biomass, flourishes throughout tropical regions. Every year, each tree can produce an average of 70 nuts or a maximum of 150 nuts, with each fruit consisting of 15.18% shell. The Philippines has approximately 2.2 million tons of coconut shells each year. The study aims to determine the energy yield of the coconut shells when torrefied. The coconut shells were crushed, torrefied, and analyzed elementally. Initially, the calorific value of raw coconut shells was 30.79 MJ/kg and improved to 34.37 MJ/kg after torrefying at 275°C and held for 30 minutes. The optimal mass yield was 90.10%, while the energy density was 111.64%, resulting in an energy yield of 100.59%. Torrefaction improved the calorific value of coconut shells by 11.63% and optimized the energy yield to 100.59%.