Energetics of Drying Animal’s Hide and Skin via Different Dryer Designs

Aims of the Study: The aim of this study was to evaluate the total energy requirement, specific energy consumption, activation energy and system efficiency for drying of hide and skin using various drying methods including solar drying, oven drying, hot air conventional drying and direct sun drying.

Materials and Methods: Cattle hide, Donkey hide and Sheepskin with initial moisture content of 64%, 70%, and 60% respectively (all wet basis) was dried to a final moisture content of 5.26% (after 660 min), 6.25% (after 720 min) and 4.76% (after 540 min) in an oven dryer. Energy and specific energy consumption under the different drying conditions of the hides and skins were compared.

Results and Discussion: The activation energy ranged from 20.961 kJ/mol to 27.363 kJ/mol for cattle hide, 23.246 kJ/mol to 26.039 kJ/mol for sheep skin and 26.414 kJ/mol to 31.344 kJ/mol for donkey hide. The maximum total energy consumption and specific energy consumption for the hides and skin studied were 1355.2 kWh and 3880.6 kWh/kg respectively. The overall system drying efficiency was 78%, 81% and 83% for cattle hide, sheep skin and donkey hide respectively.

Conclusion of the Findings: The activation energy of cattle hide was higher than the activation energy of donkey hide followed by sheep skin. The specific energy consumption and total energy consumption increased with increase in the air speed and decreased with increase in temperature. The values obtained in this work are consistent with the values reported by other authors and will form the basis for optimal dryer designs. The system efficiency decreased with drying time and was faster with sheep skin than cattle hide and donkey hide while the thermal efficiency of the dryers is highest in the solar cabinet dryer and least in the oven dryer.

Recommendation: Some other types of dryers should be compared with the solar cabinet dryer to determine the best economical dryer design that will give the best quality product.