Comparative Study on Oven and Solar Drying of Agricultural Residues and Food Crops

Abstract

The current study examined reduction of moisture from agricultural energy and food crops in a conventional oven to a solar dryer at various treatment periods at temperature between 40 ± 10 oC. Sugarcane bagasse and Phragmites Australis had initial moisture of 50.8 % and 6.07 % by dry weight, respectively, with higher heating values (HHV) 6548.5 kJ/kg and 17653.02 kJ/kg respectively. The moisture content of bagasse and phragmites were decreased by 51.31% and 68.69% respectively using oven drying, while the moisture content of bagasse and phragmites was reduced by 48.01% and 66.22% respectively, using solar drying with 5 hrs treatment time. Corresponding increase in HHV’s observed in bagasse to 11195.6 KJ/kg (oven drying) and 10998.1 KJ/kg (solar drying), while HHV of phragmites increased to 18706.79KJ/kg (oven drying) and 18685.36KJ/kg (solar drying). Green chillies had a moisture content reduction by 33.69 % (oven) and 8.28 % (solar), whereas grapes had a reduction by 31.20 % (oven) and 7.88 % (solar) with 5 hrs treatment time. The oven drying approach revealed higher carbohydrate content in food crops when compared to solar drying, while both treatments showed a similar drop in protein, fat, and vitamin C contents. Statistical and energy analysis observed that comparing solar drying; the oven drying eliminates slightly higher moisture content and have less drying energy requirements. The amount of heat energy required for drying unit mass of bagasse was 0.476 kJ/kg (oven) and 0.556 kJ/kg (solar), for phragmites it was 0.074 kJ/kg (oven) and 0.092 kJ/kg (solar), for chilles 0.524 kJ/kg (oven) and 0.576 kJ/kg (solar) and for grapes 0.123 kJ/kg (oven) and 0.157 MJ/kg (solar). According to the results solar drying required greater quantity of heat energy than oven drying. Mass transfer analysis showed drying constant of bagasse and phragmites were higher initially, then showed reducing trend with respect time. Furthermore, it was observed that the effective diffusivity and mass transfer coefficient were found reducing with respect to increasing drying treatment time. The research findings of renewable solar drying, on the other hand, are comparable to those of oven drying, demonstrating that there is still enough untapped heat energy available for its utilization in biomass thermo-chemical conversion methods.

Biohythane Production from Domestic Wastewater Sludge and Cow Dung Mixture Using Two-Step Anaerobic Fermentation Process

“…These sensors were connected to an Arduino UNO that was programmed to log data over time and measure the gas concentration. The volume of gas was measured using the water displacement method with properly calibrated acrylic cylinders with a length of 45 cm and a diameter of 3.6 cm at a room temperature of 28 • C ± 1 • C as per the method mentioned in earlier studies [28]. After the completion of the bioH 2 production reaction, the digestate (1200 mL) from the first reactor was mixed with 100 mL of cow dung and introduced into the second reactor to produce biogas under AD conditions for 25 days.…”

“…If the pH is too high (alkaline), the enzymes responsible for bioH 2 production may become inactivated and cause a reduction in bioH 2 production [19]. Therefore, ideal pH levels for bioH 2 production vary depending on the type of microorganism used [28]. The influence of pH plays an important role in the reaction because changes in pH cause reaction imbalances that have an ultimate impact on the bioH 2 production.…”

Design, Fabrication, and Operation of a 10 L Biodiesel Production Unit Powered by Conventional and Solar Energy Systems

“…After separation, the biodiesel was washed with warm water at 50 • C to remove the glycerol and other contaminants. Finally, the water-washed biodiesel was dried in a locally designed and fabricated solar cabinet dryer that has a capacity of 0.105 m 3 for 3 h to remove the moisture content [17]. The light meter measured the solar irradiance flux (W/m 2 ) falling on the solar collector attached to the dryer (ST1307 Standard Instruments, Hong Kong, China).…”

Analysis of Thermodynamic Events Taking Place during Vacuum Drying of Corn

“…It can, therefore, be concluded that drying is an important and demanding aspect of agricultural production [1] for food producers and livestock breeders. The parameters of drying agricultural crops [2,3] have been investigated to increase the efficiency of the process or to ensure a minimum impact on the nutritional content. Among the wide spectrum of agricultural crops, attention is paid to the drying of cereals [4,5], lemons [6], olive pomaces [7], eggplants [8] and corn.…”