Review on the various ash from palm oil waste as geopolymer material

Abstract

The solid waste from palm oil mill industry has been increasing annually where it has been reported that the palm oil waste was produced 4 million tons/years in Malaysia only. Hence, the solution to overcome the problems is to reuse the waste and produced new composites that are benefit. There are two types of palm ash waste which are palm oil fuel ash (POFA) and boiler ash. POFA is by product from power electricity generation plants that used palm oil shells and palm oil bunches as burn materials. Meanwhile boiler ash is the biomass known as mesocarp fiber and shell that consists of clinkers and ash that has been burnt in the boiler. Both of these ashes contain silica (Si) which has potential to develop as geopolymer composites. However, only POFA has been successfully produced ash geopolymer materials but it required other raw material that rich in alumina (Al) to produce geopolymer with suitable strength. In order to produce geopolymer, the POFA has been activated by alkaline activator consists of mixture of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH). On the other hand, the use of boiler ash as geopolymer materials was never been investigated.