Effects of empty fruit bunch storage duration on moisture content and higher heating value

Abstract

Empty fruit bunch (EFB) is part of the waste produced in the manufacturing of palm oil products. EFB is regarded to have the lowest economic value compared to palm kernel shell (PKS) and mesocarp fibre (MF) as it contains high amount of moisture. When dried to remove moisture, EFB quality and economic value can be increased. However, there is a lack of study that predicts the Higher Heating Value (HHV) of EFB based on the moisture content. This study aims to develop the correlation between the moisture content to the HHV and revenue generated by selling steam in order to clarify the problem. This study also aims to find the effects of storage duration on quality of EFB. The samples collected were divided into two stages; Stage 1 to study effects of moisture content on HHV while Stage 2 to study the effects of storage duration on moisture content and HHV. For Stage 2, 60g to 100g was taken from each sample daily to measure the moisture content and HHV. The result of this study is a linear correlation of the HHV and moisture content, y=-14.343x+17.601 with coefficient of determination, R2 value of 0.9858. It indicates a good fit linear regression. This correlation is useful in estimating the HHV of the EFB at known moisture content and to calculate the amount of steam and revenue that can be generated. The study of the storage duration effect shows the HHV increased when EFB is stored during the 7-day period. A financial mechanism in terms of price reduction was proposed based on the quality of EFB when used as fuel for boiler to produce a one tonne of steam. The EFB quality was categorised as High if moisture content less than 13 % and Low if the moisture content greater than 37 %. If the moisture content in between is regarded as medium quality. The proposed financial mechanism considered profit or losses and price reduction was suggested for lower quality of EFB according to the loss incurred. This financial mechanism can also be used in the related industry to standardise their EFB feedstock, predict the output of steam and revenue generated from selling steam, and estimate the price of EFB per tonne of steam according to the quality of EFB supplied.