Corrigendum: Applied insight: studying reducing the carbon footprint of the drying process and its environmental impact and financial return.

[This corrects the article DOI: 10.3389/fbioe.2024.1355133.].

Applied insight: studying reducing the carbon footprint of the drying process and its environmental impact and financial return.

Harnessing solar energy is one of the most important practical insights highlighted to mitigate the severe climate change (CC) phenomenon. Therefore, this study aims to focus on the use of hybrid solar dryers (HSDs) within an environmentally friendly framework, which is one of the promising applications of solar thermal technology to replace traditional thermal technology that contributes to increasing the severity of the CC phenomenon. The HSD, based on a traditional electrical energy source (HSTEE) and electrical energy from photovoltaic panels (HSPVSE), was evaluated compared to a traditional electrical (TE) dryer for drying some medicinal and aromatic plants (MAPs). This is done by evaluating some of the drying outputs, energy consumed, carbon footprint, and financial return at 30, 40, and 50°C. The best quality of dried MAP samples in terms of essential oil (EO, %) and microbial load was achieved at 40°C. The HSTEE dryer has reduced energy consumption compared to the TE dryer by a percentage ranging from 37% to 54%. The highest CO2 mitigated ratio using the HSTEE dryer was recorded in thyme, marjoram, and lemongrass samples, with values ranging from 45% to 54% at 30, 40, and 50°C. The highest financial return obtained from energy consumption reduction and carbon credit footprint was achieved at 50°C, with values ranging from 5,313.69 to 6,763.03 EGP/year (EGP ≈ 0.0352 USD) when coal was used as a fuel source for the generation of electricity. Moreover, the HSPVSE dryer achieved a 100% reduction in traditional energy consumption and then reduced CO2 emissions by 100%, which led to a 100% financial return from both energy reduction and carbon credit. The highest financial returns were observed at 50°C, with values ranging from 13,872.56 to 15,007.02, 12,927.28 to 13,984.43, and 11,981.99 to 12,961.85 EGP/year (EGP ≈ 0.0352 USD) for coal, oil, and natural gas, respectively. The HS dryers show potential for environmental conservation contribution; furthermore, earning money from energy savings and carbon credit could help improve the living standards and maximize benefits for stakeholders.

Towards an optimal hybrid solar method for lime-drying behavior.

Lime is one of the most commonly consumed medicinal plants in Indonesia, which must be dried to preserve its quality, but mostly by using traditional, ineffective drying method. Therefore, this study aims to investigate lime drying process a hybrid solar drying method. The hybrid solar dryer consisted of a solar dryer and Liquefied Petroleum Gas as the supplementary heater. The drying process was conducted until there was no significant weight decrease, with the drying temperature of 40, 50, 60, 70, and 80 °C. Thin-layer modeling and quality analysis were also conducted. The experimental results indicated that 5 h was required to sufficiently dry the lime at 80 °C, while drying at 40 °C took 24 h to finish. The drying rate curve of lime suggested that lime drying mostly happened during the falling-rate period. Moreover, the average efficiency of the hybrid solar dryer ranged from 5.36% to 38.61%, which increased with temperature. From the 10 thin-layer drying models used, the Wang and Singh model was the most suitable to describe the drying behavior of lime. The effective diffusivity values of the limes and the activation energy value during hybrid solar drying were within their respective acceptable range for agricultural products. However, as the drying temperature was increased from 40 to 80 °C, the total phenolic content and vitamin C content decreased, from 87.3 to 27.8 mg GAE/100 g dry limes and 0.118 to 0.015 ppm, respectively. It can be concluded that hybrid solar dryer is able to sufficiently dry the lime, with acceptable drying time and dryer efficiency, although using high drying temperature will decrease the quality of dried lime. Further modifications and improvements to the hybrid solar dryer are required to maximize the quality of dried lime while still maintaining fast and effective drying process.

Exergetic sustainability and economic analysis of hybrid solar-biomass dryer integrated with copper tubing as heat exchanger.

The aim of this study is to present a new hybrid solar-biomass dryer and carry out thermal analysis based on energy and exergo-sustainability analysis considering all the available exergy stream of solar radiation, air stream through the collector, and exergy of the moisture in the product. The research also presented the environmental impact and economic analysis of using the dryer. Performance evaluations show that at collector efficiency of 20.81%-21.89 %, the developed solar dryers can save between 10 - 21hrs of drying time in drying 5 mm thick plantain slices to 15 % moisture content from initial moisture content of 66 % w.b when compared to drying under the open sun. The improvement potential ranged from 0.036 to 20.6W while the waste exergy ratios and sustainability index ranged from 0.38 - 0.55 and 2.3-6.11 respectively. Application of the solar dryers can save between 44 -3074 of CO2 entering the atmosphere per year while 2.94 to 205.43$ could also be saved at 10-100% rate of usage when compared to diesel fired dryer. The total energy consumption for drying ranges between 5.52 and 35.47 MJ, while the specific energy consumption ranged from 4.3 to 26.2 kWh/kg. The exergy efficiency ranges from 5.6 - 95.13 % during the sunshine hours.