Fei Ling Pua

Sulfur hexafluoride (SF₆) gas is one of the high global warming potential (GWP) gases regulated under the Kyoto Protocol. In Malaysia’s Biennial Update Report 3, the Revised 1996 Intergovernmental Panel on Climate Change Guidelines were followed to estimate the SF₆ emissions in the country, including the time series from 1990 to 2016. The majority of SF₆ emissions originate from the use of this gas in electrical equipment, where it is predominantly used in transmission switch gears, which have increased rapidly because of increasing electricity demand. SF₆ gas plays a significant role in greenhouse gas emissions in Malaysia because this gas has a higher GWP than carbon dioxide. Hence, this SF₆ gas needs to be estimated using newer guidelines such as the 2006 IPCC Guidelines. Detailed activity data in the new methodology require stakeholders’ engagement with utility providers and government agencies. This paper describes the GHG inventory improvement plan, focusing on SF₆ emissions for Industrial Processes and Product Use for Malaysia through this transition of methodology.

The development of heterogenous catalysts using renewable materials has received wide attention. A heterogenous catalyst has been a preferred choice as it evades the disadvantages of homogeneous catalysts, nevertheless, heterogenous catalysts has limited activity and a longer separation process. The current study emphasises the preparation of a new magnetic catalyst using oil palm empty fruit bunch (EFB) fibre as a carbon-based support material. The effect of different alkaline pre-treatments over the methyl ester conversion rate were investigated. The catalyst preparation parameters were studied by using the single factor optimisation approach, including the fibre loading, impregnation time, calcination temperature, and calcination time. Their effects in the esterification of oleic acid were investigated in this study. The optimisation study shows that the Na₂CO₃-treated(T)-EFBC magnetic catalyst had the highest esterification rate of 93.5% with 7 g EFB fibre loading, a 2 h impregnation time and a calcination temperature of 500 °C for 2 h. The catalyst possessed a good acidity of 3.5 mmol/g with excellent magnetism properties. This study showed that the catalysts are magnetically separable and exhibited good stability with 82.1% after five cycles. The oil palm EFB supported magnetic acid catalyst indicates it as a potential option to the existing solid catalysts that is economical and environmentally friendly for the esterification process.

In this paper, solid base catalyst KF/CLW-Fe3O4 was prepared from carbide lime waste, primarily calcium hydroxide with tiny amounts of carbonate and; the catalyst was used in the optimization study on the methyl ester production. The new strong base catalyst was synthesized by chemical impregnation. This catalyst was characterized by Hammett indicator analysis, Brunauer, Emmett, and Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD) and temperature-programmed desorption (TPD) of carbon dioxide. The catalyst was further used to catalyzed the transesterification reaction to produce methyl ester. Taguchi method was used to assess the impact of catalyst at different intervals of reaction parameters, including reaction time, methanol to oil ratio, and catalyst loading. A mixed level of orthogonal array design with L9, analysis of variance (ANOVA) and signal to noise ratio were used to determine parameters that significantly impact the palm oil transesterification reaction. High methyl ester conversion was attained, and the catalyst can be easily separated and reused. KF/CLW-Fe3O4 has great potential to be used to produce methyl ester because of its high catalytic activity and environmental friendliness. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Industrial waste is produced in large amounts annually; without proper planning, the waste might cause a serious threat to the environment. Hence, an industrial waste-based heterogeneous magnetic catalyst was synthesized using carbide lime waste (CLW) as raw material for biodiesel production via transesterification of palm oil. The catalyst was successfully synthesized by the one-step impregnation method and calcination at 600 °C. The synthesized catalyst, C-CLW/g-Fe2O3, was characterized by temperature-programmed desorption of carbon dioxide (CO2-TPD), scanning electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FT-IR). The catalyst has a specific surface area of 18.54 m2/g and high basicity of 3,637.20 µmol/g. The catalytic performance shows that the optimum reaction conditions are 6 wt% catalyst loading, 12:1 methanol to oil molar ratio with the reaction time of 3 h at 60 °C to produce 90.5% biodiesel yield. The catalyst exhibits good catalytic activity and magnetism, indicating that the CLW can be a potential raw material for catalyst preparation and application in the biodiesel industry. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).