Palm kernel shell is the process of palm oil extraction from the pulp of the fruit core, and then the shell of the core will be removed, some of which is the palm shell (English name: Palm Kernel Shell (PKS). Its characteristic is that the heat generated during combustion is higher than that of general biomass fuels, and its unique chemical characteristics can reduce the emission of low-temperature chamber gas. Palm shell itself is not very valuable and has been abandoned for a long time. In 2016, a cement factory in Malaysia used palm shell as biofuel to generate heat by combustion with coal. Today, manufacturers in many European countries, including Britain, the Netherlands and Italy, are trying to provide energy by burning palm-shell blended coal to ease rising fuel costs and reduce carbon emissions.
Because of the fuel feature, a palm kernel shell boiler is requested to design based on its feature. It is different from the coal. For a palm kernel shell boiler, we need to redesign its furnace shape and structure to ensure the boiler efficiency and stop it from coking. Once the boiler cokes, it is difficult to clean. So choosing a palm kernel shell boiler is necessary when using the palm kernel shell as the fuel.
In Malaysia, biomass boiler is becoming popular due to design, maintenance and cost. Palm kernel shell is their first choice of biomass fuel then come after EFB pellet, wood chip, saw dust pellet, shredded EFB. We are not saying palm kernel shell is become scarcity however the supply really becomes a constraint as of current situation.
Several boilers such as chain grate boiler, fluidized bed boiler have been used to enable oil palm mill to generate enough energy for its consumption and sometimes export excess. chain grate boilers are characterized with low sensitivity to fuel bed agglomeration and this is of advantage when applied to biomass combustion, since biomass fuels often have low ash melting temperatures. The fluidized bed boiler avoids or solves the problems of ash accumulation and slagging in biomass combustion and heat exchange process, and can stably operate for a long time. The ash content of carbon ash is low, and the comprehensive utilization of fly ash can be realized, and the combustion efficiency can reach 90% the above.