Additional additives to reduce ash related operation problems of solid biofuel from oil palm biomass upon combustion

Ash related operational problem is one of the most prominent issues in using lignocellulosic biomass as solid biofuel. This study evaluates the effect of kaolin and calcite addition as fuel additives on the ash melting characteristic and heating value of the oil palm biomass (empty fruit bunch and oil palm trunk). Both additives significantly improved the ash melting characteristic of the oil palm biomass. While the concentrations of additives act as a variable to increase the sintering temperature, it also had strong impacts on higher heating value reduction and ash content increment. Kaolin reduced the sintering degree of the ashes with the formation of inorganic elements mixtures mostly detained in the ash sediments. In compare, the presence of calcite helped to increase the ash melting temperature but at the same time induce higher concentration of fly ash in the flue gas. Overall, kaolin is more efficient than calcite to decrease the sintering degree of the ashes from molten to loose with the measure of 0.5 g/g ash while calcite require higher dose (at the dose higher than 0.7 g/g ash) when combusted at 1000 °C.