Fatty acid distillate as an alternative boiler fuel

Abstract

This paper investigated the use of fatty acid distillate (FAD) produced as a by-product of edible oil refining as a fuel source for boilers. Using a diesel heater to model the combustion chamber of a fire tube boiler showed that diesel blends with FAD up to 60% could be used with different levels of preheating. A small to medium sized edible oil refinery was used to generate an economic model. It was estimated that an edible oil refinery of this size required a boiler able to supply 3 GJ/h of energy. In this situation, the FAD produced could provide approximately 57% of the yearly energy requirements for the boiler. An economic analysis revealed that using FAD (42 MJ/kg) as fuel will increase its value from New Zealand Dollar ($) 0.425/kg to approximately $1.30–1.55/kg depending on the cost of standard boiler fuel. Running the boiler on LPG ($30/GJ) or diesel ($37.7/GJ) was estimated to cost $960,000 and $1,200,000 respectively per year. If all the FAD was used as alternative fuel to provide 57% of the yearly energy, then up to $700,000 could be saved each year.

Keywords

• Edible oil refining
• Alternative boiler fuels
• Fatty acid distillate
• Energy
• Cost estimation