Effect of Rice Husk Filler on the Structural and Dielectric Properties of Palm Oil as an Electrical Insulation Material

• Main Authors: Siti Sarah Junian, Mohamad Zul Hilmey Makmud, Zuhair Jamain, Khairatun Najwa Mohd Amin, Jedol Dayou, Hazlee Azil Illias
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Energies
• Subjects: dielectric properties; breakdown voltage; natural fibre; palm oil; electrical insulation; rice husk
• Online Access: https://www.mdpi.com/1996-1073/14/16/4921
• ISSN: 1996-1073

This study uses natural fibre, which is moisture absorbent, as an innovative and economical filler for insulating oil. Rice husk (RH) is a natural fibre known to have water-absorbing properties and used as a supplementary cementitious material. This research utilises the water-absorbing properties of RH to improve the physicochemical and dielectric properties of insulating oil. RH was refined into a fine powder at a diameter of less than 63 µm. Palm oil (PO) was synthesised with RH at concentrations of 0 g/L, 0.01 g/L, and 0.1 g/L. The moisture-absorbent properties of RH were analysed by using Fourier-transform infrared (FTIR) spectroscopy. The particle size and distribution of RH in PO were also obtained using a scanning electron microscope (SEM) and a Zeta particle analyser. The breakdown voltage (BDV) strength of PO with RH was measured according to IEC 60156, and the dielectric frequency response was investigated in the range of 10²–10⁵ Hz. RH is proven to absorb moisture from PO, as the O–H band intensity at the 3350 cm⁻¹ is increased from the experimental results. Therefore, the mean BDV and dielectric insulation properties of PO dispersed with RH also increased accordingly.