Design of a Geothermal Energy Dryer for Tea Withering and Drying in Wayang Windu Geothermal Field

Abstract

The Wayang Windu power plant in West Jawa, Indonesia, has been producing power since June 2000 and is currently delivering 220 MW of electricity into the national grid. The plant is operated by Magma Nusantara Limited (MNL), which has a Joint Operating Contract (JOC) with Pertamina Geothermal Energy (PGE), and uses flash steam technology, in which steam is used to generate electricity by directly driving a large turbine. At present, 100% of the brine is injected into injection wells located 14 km south of the plant. The Wayang Windu power plant is surronded by tea plantations and villages. There are also three tea factories in this area. The Malabar tea factory is the largest among them and is located within 500 m of the brine pipeline. The maximum product capacity of the Malabar is 63 tonnes per day. Those tea plantation and factories are managed by PTP Nusantara VIII. Currently, the heat source for withering and drying tea leaves in Malabar tea plantation is Industrial Diesel Oil (IDO). Malabar burns about 1.25 millions liters per year of IDO. The hot brine can be used as a replacement for IDO.
Three parties (BPPT, MNL/PGE and PTP Nusantara VIII) proposed to utilize the brine to replace IDO. The engineering design for replacing IDO is presented here. Also, the thermodynamics and the main components (heat exchangers) for withering and drying are discussed.