ENERGY AND EXERGY ANALYSES ON DRYING OF OLIVE LEAVES (OLEA EUROPAEA L.) IN TRAY DRIER

Abstract

Recently, olive leaves have a high potential for industrial exploitation in the food industry. The main process in olive leaf treatment is drying. Because drying is an energy‐intensive process, analyzing and improving the drying systems is important. In this study, olive leaves were dried in a tray drier and the performance of the drying process was evaluated using energy and exergy analyses methods. The effects of the drying air temperature and the velocity on the performance of the drying process were discussed. While the energy utilization ratio values varied between 14.05% and 26.21%, the exergetic efficiencies varied between 55.95% and 75.12%. It was inferred that exergetic efficiencies increased as the drying air temperature decreased and the drying air velocity increased. They were influenced mainly by the drying air temperature. PRACTICAL APPLICATIONS Although olive trees cover ∼8 million ha in the whole world and scientific studies show the importance of olive leaves, there are few examples of using olive leaves industrially. The main process in olive leaf treatment is drying, and there has been no information on the thermodynamic analysis of the drying of olive leaves in the open literature according to the authors' knowledge. Thermodynamic analysis is an important step for designing and optimizing the olive leaf treatment. It is believed that such a study would contribute the industrial exploitation of olive leaves.

Energetic and exergetic performance analysis and modeling of drying kinetics of kiwi slices

“…The exergy efficiency for microwave drying of kiwi slices for the conditions studied was in the range of 11.35-24.68 % (Table 3) while the energy efficiency was higher for the same conditions (P ≤ 0.05). These results were similar with the results in the literature (Akpinar et al 2006;Corzo et al 2008;Erbay and Icier 2009;Bozkurt 2009). The energy efficiency values mainly showed the heat losses to the environment and energy losses caused by irreversibility.…”

Mathematical modelling and estimation of effective moisture diffusivity and activation energy, exergy analysis of thin layer drying of pineapple

“…The obtained results were good consistent with data reported by Corzo et al (2008) for Coroba slice drying, Aviara et al (2014) for cassava starch drying, lesser time required for drying of product with increase in drying and Erbay & Icier (2011) for olive leaves drying. The variation in exergy efficiency with respect to temperature is inversely to the Figure 4 Plot of lnMR against drying time at various drying air temperatures Figure 5 Effective moisture diffusivity as a function of drying air temperatures Figure 6 Plot of LnDeff against reciprocal of temperature (1/T) for estimation of activation energy energy consumption.…”

Exergetic performance analysis of ohmic cooking process

“…Exergy analysis becomes more crucial, especially for the industrial (large-scale) high temperature heating applications, and it can reveal whether or not and by how much it is possible to design more efficient thermal systems by reducing the sources of existing inefficiencies. Several researchers (Dincer and Sahin, 2004;Akpinar et al, 2005a,b;Corzo et al, 2008;Erbay and Icier, 2009) concluded that exergy analysis gave more reliable evaluation about the performance of thermal processing of food products rather than energy analysis. The minimization of the exergy losses, or equivalently the entropy generation, has a broader objective than the minimization of energy losses within a plant (Tekin and Bayramoglu, 1998).…”

“…Exergy is a measure of the potential of a stream to cause change, as a consequence of not being completely stable relative to the reference environment (Erbay and Icier, 2009). It is the measure of the availability of the energy in the system.…”