COFFEE DRYING SYSTEM DESIGN FOR GEOTHERMAL DIRECT USE APPLICATION IN FLORES ISLAND

Abstract

Mataloko is one of the areas in Ngada District, East Nusa Tenggara Province where there is a geothermal power plant operating with 2.5 MW capacity. The type of reservoir is brine-dominated. In addition to geothermal sources from the powerplant, there is a
geothermal resource that is coming from surface manifestation around the powerplant. Moreover, Mataloko is not only a geothermal area but also an agricultural and plantation area where coffee is the biggest plantation commodity with the cumulative harvest in every year reaching 3,000 tonne. Current practice for drying the coffee fruit or cherry on the open air (conventional) is a challenge for farmers. This practice cost and requires significant time for producing high quality green beans. A geothermal direct use of drying system has been designed for coffee commodity in Mataloko. The drying system scheme utilizes a Shell and Tube type of Heat Exchanger to produce 50oC for the final air temperature. Meanwhile, this system will use Tray Dryer with capacity of 500 kg. At this capacity, the energy required by the dryer is 240 kWh per 500 kg batch (8 hours). The amount of energy from the dryer will save 0.18 metric tons CO2 emission per 500 kg batch that equivalent to CO2 emissions from the same drying process when compared to diesel fuel.