Desenvolvimento experimental de um sistema de secagem solar para oleaginosas usadas na produção de biodiesel.

Abstract

This paper presents the development (design, construction and testing) o f a solar dryer used for drying the fruit of castor beans, popularly known as castor. Currently in Brazil the most used oilseed to produce biodiesel is soybean, while in the Northeast, the most used is the castor bean (Ricinus communis /,.). The traditional process of extracting oil from fruit for further processing into biodiesel starts with the pre-cleaning, and then goes to a cooker machine at a temperature up to 80 °C. In this process, the fruit loses humidity, its viscosity is reduced and facilitates pressing. It is still common a prior natural drying done outdoors in the yards of the farms, where the fruits are subjected to the action of animals and the weathertight (rain, wind, night humidity, dust, among others). This drying system does not meet hygiene and cleanliness recommended by national and international standards. The function of the solar drying system under development is to remove the humidity present in castor oil, reducing the use of the cooker machine and increasing efficiency in the production o f the oil. On the paper are presented the constructions and operating characteristics of the solar dryer and the drying curves from castor obtained experimentally, both in drying using solar dryer as the drying yard. Have been conducted several experimental tests, being presented and analyzed the results from four of these tests. It is possible to state that the drying process using the solar dryer has an average efficiency of 23.1% bigger compared with drying at the yard; and that the average air temperature obtained inside the solar dryer is 76% larger than the mean ambient temperature.