Development and Experimental Results of a Thermal Oil Based Roasting System for Decentralized Processing of Groundnuts

Raza, Ali; Majeed, Faizan; Munir, Anjum; Hensel, Oliver

doi:10.3390/app9204342

Cited by 5 publications

(2 citation statements)

References 26 publications

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“…Results showed that the baking temperature achieved was 180 C, and it was also found out that the energy efficiency in the receiver increased with the baking time. The development and experimental analysis of a thermal oil-based roasting system were done by Raza et al [83]. The continuous solar roaster was composed of a Scheffler concentrator, heat receiver, storage tank, and a roasting unit.…”

Section: Parabolic Dish Cookers With Shtesmentioning

confidence: 99%

A review of parabolic solar cookers with thermal energy storage

Lentswe¹,

Mawire²,

Owusu³

et al. 2021

Heliyon

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Biomass and fossil fuels are mostly used in rural areas of developing countries for cooking. These energy resources have negative impacts on the environment and human health mainly due to deforestation and greenhouse gas emissions. A cleaner and environmentally-friendly form of cooking is solar cooking using the sun's energy. Parabolic solar cookers perform better than other solar cookers such as box solar cookers since higher temperatures are achieved in a shorter duration. These higher temperatures allow most types of cooking processes such as; boiling, frying, roasting, and baking to be possible. The major problem with most conventional solar cookers is that cooking is not possible during off-sunshine periods. Integrating solar cookers with thermal energy storage (TES) makes cooking during off-sunshine periods possible. This paper presents a comprehensive review of parabolic solar cookers with TES which is a sustainable cooking solution for developing countries. Previous work on both parabolic trough and parabolic dish solar cookers with TES is presented. Solar cookers with storage are classified according to the two main types of TES technologies which are; sensible heat thermal energy storage (SHTES) and latent heat thermal energy storage (LHTES). The main conclusions of the review are that; parabolic dish solar cookers with TES are more common than parabolic trough cookers, more studies have been done using latent heat storage as compared to sensible heat storage, limited modelling work has been presented, most of the parabolic cookers used aluminum sheets as the reflecting material, large scale experimental studies are limited and fewer studies tackled the techno-economic and socio-economic aspects. The review also highlights research gaps on parabolic solar cookers with TES in terms of the modelling, combined TES (sensible and latent heat), different reflector materials, large-scale experimental setups, and techno-economic and socio-economic analyses. Other important aspects to consider for parabolic solar cookers with TES include; the choice of sensible or latent heat storage materials, environmental impact, types of food to be cooked, and social acceptance.

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Section: Parabolic Dish Cookers With Shtesmentioning

confidence: 99%

A review of parabolic solar cookers with thermal energy storage

Lentswe¹,

Mawire²,

Owusu³

et al. 2021

Heliyon

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“…The daily average DNI ranging from 5.5 to 7.5 kWh/m 2 with yearly sunshine of more than 300 days [23] provides an excellent opportunity for the development of innovative technologies to meet this challenging and need-based assignment. Up to now, there has been very little work on the value addition of post-harvest using solar thermal energy moving toward medium to the high-temperature range for the processing of perishable agricultural products [24] and roasting of nuts and beans [6,25,26]. This massive solar potential can be utilized through decentralized applications of solar thermal energy especially in rural areas through the development of innovative solar technologies for decentralized applications in coffee processing, which can scale up the farm-gate processing facilities for coffee growers of tropics.…”

Section: Introductionmentioning

confidence: 99%

Development and Experiments on a Batch-Type Solar Roaster—An Innovative Decentralized System for Coffee Roasting

et al. 2022

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About 70% of the harvested coffee is exported to the industrialized nations for value addition due to lack of processing and logistic facilities in developing coffee producer countries, thus leaving behind a marginal economic return for the growers. This research was conducted to investigate the roasting capacity of an innovatively developed batch-type directly solar radiated roasting system for the decentralized processing of coffee using solar energy. Central composite rotatable design (CCRD) was employed to design the experiments to optimize the coffee roasting process. Experimental results revealed that with an average solar direct normal irradiance (DNI) of 800 W/m2, the roaster was capable of roasting a batch of 2 kg coffee beans in 20, 23, and 25 min subjected to light roasts, medium roasts, and dark roasts, respectively at a drum speed of two revolutions per minute (rpm). The batch-type solar roaster has the capacity to roast 28.8–36 kg of coffee beans depending on dark to light roasting conditions on a clear sunny day with DNI ranging from 650 to 850 W/m2. The system thermal efficiency during coffee roasting was determined to be 62.2%, whereas the roasting efficiency at a corresponding light roast, medium roast, and dark roast was found to be 97.5%, 95.2%, and 91.3%, respectively. The payback period of the solar roaster unit was estimated to be 1038 working sunshine hours, making it viable for commercialization.

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