Characterization of rice husk-based catalyst prepared via conventional and microwave carbonisation

Abstract

Carbon-based sulphonated catalysts (CBSCs) were made from rice husk for biodiesel production. The CBSCs were prepared by microwave (MW) and conventional heating processes from the same feedstock. In both heating systems, the preparation was a two-step process: carbonisation and sulphonation. The aim of this study was to use MW heating to reduce the conventional CBSC preparation time and enhance the -SO3H group attachment to the solid catalyst. The biomass based solid acid catalysts from the two systems were characterised and compared in terms of physicochemical properties including: sulphonation, morphology, surface area and structure. The reaction times for MW assisted carbonisation and for sulphonation were significantly reduced compared to the conventional heating system; these were 30 min vs 4 h and 20 min vs 12 h, respectively. The MW prepared catalyst showed higher sulphur content (4.91%) as compared to the conventional catalyst (2.10%). The FTIR analysis showed well distinguished peaks for -SO3H for the MW prepared catalyst suggesting the solid catalyst was successfully sulphonated, while these peaks were very weak for the conventional catalyst. SEM analysis revealed a highly porous structure in the MW prepared catalyst, whilst a denser solid resulted for its conventionally prepared analogue, owing to the higher temperatures applied and longer sulphonation time. The surface area for the MW was higher than the conventionally prepared catalysts (43.63 m 2 /g and 37.01 m 2 /g, respectively).The structure of the samples was identified as amorphous for both catalysts as confirmed by XRD. The prepared CBSC is expected to catalyse biodiesel production reaction as evidenced by its total acidity and surface area.

New composites based on low-density polyethylene and rice husk: Elemental and thermal characteristics

“…More than half of the electricity suppliers in Indonesia generate their electricity from coal [2]. Coal production in Indonesia is quite large, at around 2.751×10 8 tons in 2010 [3]. However, continuous mining and combustion of coal as fuel damages the natural environment.…”

Supermagnetic Nano-Bifunctional Catalyst from Rice Husk: Synthesis, Characterization and Application for Conversion of Used Cooking Oil to Biodiesel

“…The peaks at 1331.76 cm −1 and 837.37 cm −1 were assigned to the stretching vibration C-O and the deformation vibration of C-O-C, respectively [61]. The weak vibration of M+-O stretching adsorption bands at 544.80 cm −1 , and 463.04 cm −1 belonged to Fe-O and K-O bonding, respectively [62].The deformation bands of M + -OH converted to Si-O-M + located at 964.71 cm −1 and 912.26 cm −1 were assigned to Fe and K, respectively [63]. Upon the formation of Si-O-M + , the intensity of the siloxane absorption band was reduced and shifted to lower frequency due to the reduction of electron density [64].…”

“…Stretching vibrations of the C-O-C ester group were observed at 1158.64 cm −1 and 721.20 cm −1 , indicating that C-C-H was out of the plane of stretching vibration. The presence of two extra peaks in the biodiesel sample at 1437.64 cm −1 and 1195.76 cm −1 were determined as the asymmetric stretching vibration of methyl carbon-hydrogen bond and stretching vibration of -O-CH 3 group of mono-, di-, and triglyceride to indicate the formation of biodiesel [62,80,81].…”

Porous Fluorocarbon from Rice Husk for the Efficient Separation of Gases

“…The synthesized adsorbent was labeled as sulfonated rice husk (RHS). [17] 1 g of RHS was soaked with hydrofluoric acid (HF) (8-40%) in microwave Teflon vial and heated for 45 min at 100 °C. They produced fine powder was rinsed with double distilled water and dehydrated in the oven at 100 °C overnight.…”