Leaching Characteristics of Inorganic Constituents from Oil Palm Residues by Water

Abstract

Oil palm residues are not currently suitable as feedstock for thermal energy generation because their high ash content can cause slagging, corrosion, and fouling. A water leaching treatment is a potential strategy to reduce the ash content in these residues. This study evaluates the effects of the duration and temperature of water leaching on two types of oil palm residues, namely, empty fruit bunches (EFBs) and palm kernel shells (PKSs). The optimum process duration for ash removal from EFBs was found to be 5 min, as the effect of convection on scrubbing was observed to remove substantial ash from the substrate during this period. A cross-flow model with estimated kinetic parameters of water leaching for EFB and PKS was developed and showed that three leaching stages of EFB achieved the greatest ash reduction from 5.47% to 2.63%. A low ash content of PKS showed no value for ash removal in any leaching process. Although there was no significance in the total ash reduction due to temperature effects, the leaching treatment was found to be most effective in reducing potassium, from 2.42% to 0.69% and 0.36% at 25 and 55 °C, respectively.

Steam explosion of oil palm residues for the production of durable pellets

“…This was a reasonable result as there was a loss of volatiles during steam treatment. In order to reduce the ash content of EFB, water leaching is deemed as a possible pre-treatment process in removing the soluble ash from the surface of the EFB particles prior to steam explosion [13].…”

“…This may impose a significant ash handling, slagging and fouling problems during combustion. Applying water leaching prior to pellet production for metal and ash removal would be recommended to prepare a good quality feedstock to the power plant [7,13].…”

Production and Characterization of Low-ash Empty Fruit Bunches (EFB) Pellets as a Solid Biofuel

“…These approaches have been found technically e cient in removing inorganic matters, ash and Cl from the feedstock, and improving mechanical durability, strength and combustion characteristics of the derived pellets [35,36,33]. Water leaching study on EFB is able to reduce ash content from 5.47 wt.% to 2.63 wt.%, and K content from 2.42 wt.% to 0.36 -0.69 wt.% [29]. Hydrothermal treatment applied on EFB has resulted in 55% reduction of ash content and lowered K and Cl contents to 0.84 wt.% and 0.18 wt.%, respectively [34].…”

“…Ash and inorganic elements such as alkali metals e.g. potassium (K), sulphur (S) and chlorine (Cl) generated from biomass combustion contribute to corrosion, slagging and fouling of boiler furnaces and stoves [15,29]. As a result, heat transfer e ciency and boiler performance are greatly reduced while maintenance and boiler operation cost increased.…”

Leaching as a Pretreatment Process to Complement Torrefaction in Improving Co-firing Characteristics of Jatropha curcas Seed Cake

“…However, most laboratory-based investigations employ soaking, i.e. submerging the biomass in water for a specific period of time [3,[10][11][12][13][14][15]. This method is favoured in laboratory-scale studies since it is simple to implement and allows variables such as the leaching time and/or water temperature to be controlled and hence their effect on the leaching efficacy investigated.…”