THERMAL SCIENCE

International Scientific Journal

EXERGOECONOMIC EVALUATION OF REAL PROCESSES FOR COFFEE ROASTING

ABSTRACT
Exergoeconomic methods provide an effective approach for identifying, evaluating and reducing thermodynamic inefficiencies and costs in an energy system. The aim of this paper is to show the potential for cost reduction on the demand side, using the exergoeconomic method in the example of real processes for coffee roasting. More than 6.5·109 kg of coffee beans is roasted worldwide annually, mostly in batch roasters. Near the end of the roast, roasting coffee emits volatile organic compounds, carbon monoxide and other pollutants, which in many industrialized countries have to be oxidized in afterburners. Afterburners release exhaust gases with a temperature of 250-450 °C, depending on the roasting process and the method of exhaust gas cleaning. The aim of this paper is to use exergy analysis and exergoeconomic performance evaluation to determine the energy use for coffee roasting and the afterburning process, and evaluate the way to utilize waste heat and reduce costs in the factory. For roasters with the capacity of up to 4 tons of green coffee beans per hour, the potential of heat recovery is 1.1 MW and the possibility to save money is around 60,000 € per year. This case study is similar to many others worldwide, and the results of this analysis could lead to more general conclusions.
KEYWORDS
PAPER SUBMITTED: 1970-01-01
PAPER REVISED: 2016-08-03
PAPER ACCEPTED: 2016-10-22
PUBLISHED ONLINE: 2016-12-25
DOI REFERENCE: https://doi.org/10.2298/TSCI16S5271V
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Supplement 5, PAGES [S1271 - S1283]
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© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence