Resumo

QUINTANAR OLGUIN, Juan  e  ROA DURAN, Refugio. Thermal and financial evaluation of the drying process of coffee bean in a active solar dryer type greenhouse. Rev. Mex. Cienc. Agríc [online]. 2017, vol.8, n.2, pp.321-331. ISSN 2007-0934.  https://doi.org/10.29312/remexca.v8i2.53.

The most common way to perform the drying process for dry parchment coffee from coffee cherries, is exposing the product to sunlight directly and weathering, where the final quality is not always optimal. An alternative to improve the process has been the use of solar energy through the use of solar dryers. The aim of this study was to evaluate the thermal and financial efficiency of the drying process of grain coffee washing in an active solar dryer type greenhouse. The study was conducted during the 2014 coffee harvest in a solar dryer type greenhouse with integrated collector part of the structure with forced air circulation. The grain was placed in trays made with wooden frame and 80% shade cloth with dimensions of 0.3*0.85 m, which served as drying beds. The grain proportion was 19.5 kg m-2. In 44 hours of sunshine (5 days on average), a moisture content of parchment coffee of 11% was obtained. The thermal efficiency of the solar dryer was to 12%. The discounted cash flow results are positive and the recovery of the investment is achieved during a harvest period (approximately three months), which represents a high viability of use of this technology at the level of small producers.

Palavras-chave : drying time; moisture content; profitability; recovery period.