Using Solar Heat for Drying Coffee, Herbs and Spices
JM Estrada, Columbia, S.A.
Many agricultural products require the removal of a great deal of their moisture content before they can be processed into finished products and/or shipped to market. This dehydration process requires a large volume of warm air. To achieve this end, farmers in many parts of the world use high-priced propane for heating fuel which drives production costs and erodes margins. Improvement in energy efficiency is needed across a wide range of the agricultural production and processing sector.
In the case of coffee, the moisture content of the freshly harvested coffee bean is typically between 60% and 80%. In order to send the beans to the roasting operation they first need to be dried to only 8% to12% moisture.
JM Estrada, Colombia, S.A. is a manufacturer of drying equipment for coffee, sugarcane and other agricultural products since 1865. Upon learning of solar air heating technology the company’s president, Jorge Estrada, began to consider how his machinery might be fitted with a transpired solar collector to provide the heated air needed for drying.
After some initial experimentation, he submitted his herb dryer with lnSpire® solar air heater in the National Science Awards Competition sponsored by the Department of Antioquia to dry herbs and medicinal plants.
Estrada entered the competition with submissions to three categories of technical challenges: a) Solar Dryer for Dehydration of Medicinal Herbs and Spices, b) Propane Dryer for Cocoa Beans, and c) Design of a Roaster for Optimizing Chemical Reactions in Specialty Coffee.
The use of electric power in the dryer was limited to a¾ horsepower engine and in Estrada’s case the solar energy used to heat the air was free.
The modular unit pulls solar-heated air through its perforated panel and delivers it to the dryer.
JM Estrada was awarded first-place in all three categories! As per JM Estrada’s analysis, one modular lnSpire® unit can dry an average of 6,000 coffee trees.
Through his experiments and contest submissions, Estrada has established that the lnSpire® solar air heating panel produces enough heat to dry products throughout most of the year. Further, ATAS’ modular units greatly reduce energy consumption while providing a safe and homogeneous source of heat for drying agricultural products.