Optimum Excess Air for the Utilization of Palm Biodiesel Blends in Fire Tube Boiler

Abstract

Biodiesel has great potential to be applied in a variety of combustion engines, such as boiler. The excess air control in the combustion process plays an important role to produce an ideal combustion performance. The changes in the physical properties of the fuel due to the use of palm biodiesel or its blends affect the amount of required air to the combustion chamber. This study was conducted in a package type fire tube boiler with a design pressure of 3 bars and heat capacity of 60,000 kCal/hour. Palm biodiesel blends were set as boiler fuel with composition of 10%, 20%, 30% and 50% in diesel oil. Fan damper scale is part of the burner system that in charge to regulate the air flow into the combustion chamber. The fan damper scale was set in the range of 4.0-4.9. For higher blends of biodiesel, the fan damper was optimum in lower scale (4.0 or less). More biodiesel in blends, less combustion air was needed to enter. Hence, the excess air of palm biodiesel combustion in fire tube boiler was in range of 57-67%.