Nur Aainaa Syahirah Ramli

Comparison of response surface methodology and artificial neural network for optimum levulinic acid production from glucose, empty fruit bunch and kenaf

Levulinic acid (LA) is one of the versatile chemicals that can be produced from lignocellulosic biomass. In this study, response surface methodology (RSM) and artificial neural network (ANN) were applied to optimise LA yield from glucose, empty fruit bunch (EFB) and kenaf. The effect of process variables namely reaction temperature, reaction time and acid concentration on LA production was investigated. Application of ANN for modelling technique was more reliable since better data fitting and prediction capabilities were obtained. Next, both biomass were pre-treated with 1-ethyl-3-methylimidazolium chloride ionic liquid, (EMIM)(Cl) to degrade the biomass and to observe its effect on the hydrolysis process. Thermal gravimetric analysis results revealed kenaf degraded to cellulose and hemicellulose more easily than EFB. Higher LA yield was obtained from both pre-treated samples, but the yield from kenaf (39.5 wt%) was more prevalent than EFB (31.6 wt%).

Catalytic Conversion of Oil Palm Fronds to Levulinic Acid in Ionic Liquid

Conversion of oil palm fronds (OPF) to levulinic acid (LA) over Fe/HY zeolite catalyst in BMIM[Br] ionic liquid has been investigated in this study. The optimization of OPF conversion reported 24.7% levulinic acid yield at 153 °C, 5.9 h, 0.96 g and 1.1 g of reaction temperature, reaction time, OPF loading and catalyst loading, respectively. The results indicated that BMIM[Br] could disrupt the covalent linkages in the OPF structures and dissolved the hollocellulose. This allowed the hollocellulose chains, accessible to the chemical transformation, to react and produce LA in presence of the Fe/HY catalyst. This study demonstrated that the combination of Fe/HY catalyst and BMIM[Br] has the potential to be applied for biomass conversion to LA under adequate process conditions.

Ionic Solid Nanomaterials: Synthesis, Characterization and Catalytic Properties Investigation

A series of ionic solid nanomaterials denoted as IS1, IS2 and IS3 have been prepared using butylmethylimidazolium bromide ([BMIM][Br]) ionic liquid as cation, and three types of heteropolyacid; phosphotungstic acid (H3PW12O40), phosphomolybdic acid (H3PMo12O40), and silicotungstic acid (H4SiW12O40) as anion. The nanomaterials were characterized by FTIR, XRD, SEM, TGA, NH3-TPD and BET. Its catalytic performance was investigated by catalyzing glucose conversion to levulinic acid and hydroxymethylfurfural. It was observed that the ionic solids have higher acidity with semi amorphous structure, higher thermal stability and insignificant water content compared to the parent compound. Among the three prepared ionic solids, phosphomolybdic based ionic solid (IS2) exhibited the best catalytic performance due to its highest total acidity.