STUDY OF BIOMASS BRIQUETTES AS CO-FIRING FUEL AT SUMBAWA THERMAL POWER PLANT

• Main Author: Dwi W, Yoga
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87180
• Institution: Institut Teknologi Bandung

According to the Indonesian Biomass Energy Society (MEBI), the potential biomass reserves in Indonesia are around 32.6 GW. The main obstacle to large scale biomass plants is the availability of biomass material supply and the initial design of coal fired power plants that are not for biomass. The Sumbawa thermal power plant with a capacity of 2 x 7 MW located in West Nusa Tenggara is one of PLN's power plants, managed by PT PLN (Persero) UPK Tambora which uses low calorie coal fuel / low rank coal with a calorific value of around 4000 kcal/kg. The Sumbawa Power Plant have carried out trial of 100% biomass use, namely wood chips as a substitute for coal in the Boiler Stoker, has conducted. The test results show that based on the steam pressure produced by the boiler, the steam turbine power produced is only 20% of the design power. This triggered the idea of processing biomass so that when used in coal fired power plants as a substitute for coal or co-firing with coal, it can produce turbine power that is close to when coal is used as fuel. The research methodology used is a literature study first. Then samples of biomass of woodchips and corn cobs collected and evaluated. Furthermore, the action taken on the sample is to make briquettes with 5 variations in the composition of the mass of woodchips and corn cobs, namely (50:50, 75:25, 25:75, 100:0, 0:100) and combustion characteristics because of changes in fuel both in terms of type, composition and geometry. The cause of the decrease in power can caused by the properties of biomass that are not in accordance with the boiler design, such as calorific value, moisture, and volatile matter. In addition, fuel feeder equipment and boilers not designed to use with biomass fuels. As a result, there is a decrease in the generation capacity (derating) because at the same load, a greater supply of biomass needed but cannot met due to the limited volume of the combustion chamber when used to burn biomass. From the results of the study, it found that good briquettes for use in the Sumbawa thermal power plant were 100% corncobs and 100% woodchips with a gross calorific value of 4754 kcal/kg and 4669 kcal/kg based on the analysis of the as receive basis. This research expected to be able to determine the right composition method to optimize the quality of biomass that supplied to the Sumbawa thermal power plant so that the plant can operate optimally.