Potentials of palm kernel shell derivatives: a critical review on waste recovery for environmental sustainability
Ifeanyi Uchegbulam, Emmanuel Owoichoechi Momoh, Solomon A. Agan
Abstract
Huge quantities of Palm Kernel Shell (PKS) are produced as wastes annually due to increase in demand for palm oil. Regardless of the numerous potential derivatives from the waste PKS such as activated carbon, pulverized shells, liquified fumes etc., there still exists the problem of its indiscriminate disposal or incineration without energy recovery thereby creating both economic and environmental concerns. This review is therefore aimed at presenting the state of the art on the numerous applications of PKS as a carbon–neutral, biodegradable, affordable and available residual component of oil palm processing, which if properly maximized will be a value-added precursor to solving the associated disposal and environmental challenges. Findings from most studies demonstrate that PKS has great potentials as a bioabsorbent, abrasive, detoxifier, antibacteria, antifungi and antioxidant material as well as a biofuel for syngas and biodiesel production. Other applications of PKS include reinforcement for polymer and metallic composites and aggregates in construction and ceramics. Industrial uses of PKS in agriculture, oilrefining, healthcare, fashion, glass, drugs and rubber vulcanizate production were also discussed. The suitability of PKS for other engineering applications were also highlighted with recommendation for further exploitation suggested. This review is expected to provide technical data for both scientists and policy makers in environmental sustainability.