Handling of Micro-Organisms Growth and Sulfur Deposit in the Cooling Tower of Patuha Geothermal Power Plant (A Lesson Learned from Patuha Geothermal Power Plant, Indonesia)
Supriadinata MARZA, Murdoko Broto KUSUMO, Fajar Dhani WARDHANA; Rita Nur ANGGRAENI
[PT Geo Dipa Energi (Persero) Unit Patuha, Indonesia]
Geothermal fluids generally contain non condensable gas, especially H2S. It will undergo an oxidation reaction with the air in the cooling tower forming a solid sulfur compound. Impurities other than sulfur mineral deposits are microbiological deposits in the form of algae, moss and slime which are formed due to the cooling water basin conditions are exposed to the sun's heat, humidity condition, acidity levels and the other conditions which are supported the growth of micro-organisms. The formation of this deposit can occur along the water flow pipe, nozzle, filler, thus inhibiting the process of heat exchange between the cooling media and the cooled fluid. Chemical treatment on cooling water system is only focused on controlling the growth of microorganisms so that is not to exceed the required values. This biological treatment gives the results of the growth of low microorganism. Maintenance team cleaned them manually three times as long as operating period. A shutdown unit should be carried out which will cause derating and lost production. After experiment repeatedly, it was decided to carry out a combination of chemical treatments for cooling water. The first chemical treatment is routine dosing of non-oxidizing biocide to prevent the growth micro-organisms in the cooling water and the second is slug dozing of the sulfur dispersant, to reduce not only sulfur deposit but also reduce other suspended solid deposit. These methods prove optimal and effective that the heat transfer process runs more effectively and is able to reduce the cooling water temperature which made the pressure of condenser better than before.
|        Topic: Power Generation||Paper Number: 26056|