Synthesis and Characterization of Metal Sulfates Loaded Palm Empty Fruit Bunch (PEFB) for Biodiesel Production

Biodiesel has been globally accepted as a green substitute for diesel fuel. However, the insecurity of food raised with the application of edible sources in biodiesel production has caused much debate. The feasible alternative technique is the use of inedible and low-grade sources such as palm fatty acid distillate (PFAD). In this work, the production of biodiesel (FAME) from PFAD using solid acid catalysts (SACs) derived from palm empty fruit bunch (PEFB) is investigated. The SACs were synthesized through impregnation of different metal sulfate precursors, i.e. ferrous sulfate heptahydrate (FeSO4.7H2O), copper sulfate pentahydrate (CuSO4.5H2O), and magnesium sulfate heptahydrate (MgSO4.7H2O) over PEFB. SEM-EDX observations found that impregnation and then calcination resulted in attachment of sulfur (S) and improved surface porosity. FT-IR analysis showed that there were distinct interactions between metal sulfates and PEFB. XRD characterization showed that the prepared catalysts have a crystalline structure. Besides, the catalytic activity of the SACs was closely associated with their acid densities measured by the titration method. Fe-PEFB catalyst showed the highest acid density (2.44 mmol/g) among the catalysts studied. To study the effect of process parameters on FFA conversion (%), optimization of methanol: PFAD molar ratio, catalyst dosage, reaction temperature, and reaction time was conducted. Maximum FFA conversion of 89.1% was obtained over Fe-PEFB while Cu-PEFB and Mg-PEFB achieved an FFA conversion of 63 and 56.5%, respectively, under the optimum reaction conditions. Thus, the present study offers a sustainable and environmentally benign method for biodiesel production.

Nanocellulose and nanoclay as reinforcement materials in polymer composites: A review

The advancement of nanotechnology has opened a new opportunity to develop nanocomposites using nanocellulose (NC) and nanoclay (NCl). Researchers have regarded these nanocomposites as promising substitutes for conventional polymers because of their characteristic and useful features, which include exceptional strength and stiffness, low weight, and low environmental impact. These features of NC and NCl explain their multifarious applications across many sectors. Here we review NC and NCl as well as various reinforced polymer composites that are made up of either of the two nanomaterials. The structural and physicochemical properties of NC and NCl are highlighted, along with the mechanical behavior and thermal properties of NC. Current nanomaterial hybrid biopolymers for the production of novel high-performance polymer nanocomposites are also discussed with respect to their mechanical properties.

Biocatalyst of Nanocomposite using Functionalized Low-Cost Activated Carbon from Zea mays L. (maize) Husk Leaf with Lipase for Hydrolysis of Olive Oil

The expansion of agricultural land and commercial food industries to meet rising global demands have imparted new challenges to the environment and human activities. Poor management of the generated waste by-products perpetually contributes to increased ecological burden. This study proposed the use of chemically-functionalized activated carbon sourced from Zea mays L. husk leave (FZHLAC) as support for the covalent immobilization of Candida rugosa lipase (CRL). This work aims to establish the protocol of preparing functionally satisfactory FZHLAC immobilized CRL (CRL-FZHLAC) and to assess its efficacy in hydrolyzing olive oil as the model reaction. Results of FT-IR spectroscopy, SEM, TGA, X-ray diffraction and BET confirmed that CRL-FZHLAC was successfully prepared with an enzyme loading of 13% (v/v). Maximum activity for hydrolysis (71.24 µmol/min/g) was achieved under an optimized condition of 50 °C, 200 rpm at pH 8 with reusability up to 5 cycles. Hydrolysis at 70 °C best fitted the first order reaction while the activation energies varies from 55.37 to -41.22 kJ/mol. The findings showed that CRL-FZHLAC is prospectively useful as biocatalysts to carry out a variety of aqueous-based biotransformation reactions

One-Dimensional-Like Titania/4'-Pentyl-4-Biphenylcarbonitrile Composite Synthesized Under Magnetic Field and its Structure-Photocatalytic Activity Relationship

The demonstration of the structure-properties relationship of shape-dependent photocatalysts remains a challenge today. Herein, one-dimensional (1-D)-like titania (TiO₂), as a model photocatalyst, has been synthesized under a strong magnetic field in the presence of a magnetically responsive liquid crystal as the structure-aligning agent to demonstrate the relationship between a well-aligned structure and its photocatalytic properties. The importance of the 1-D-like TiO₂ and its relationship with the electronic structures that affect the electron-hole recombination and the photocatalytic activity need to be clarified. The synthesis of 1-D-like TiO₂ with liquid crystal as the structure-aligning agent was carried out using the sol-gel method under a magnetic field (0.3 T). The mixture of liquid crystal, 4'-pentyl-4-biphenylcarbonitrile (5CB), tetra-n-butyl orthotitanate (TBOT), 2-propanol, and water, was subjected to slow hydrolysis under a magnetic field. The TiO₂-5CB took a well-aligned whiskerlike shape when the reaction mixture was placed under the magnetic field, while irregularly shaped TiO₂-5CB particles were formed when no magnetic field was applied. It shows that the strong interaction between 5CB and TBOT during the hydrolysis process under a magnetic field controls the shape of titania. The intensity of the emission peaks in the photoluminescence spectrum of 1-D-like TiO₂-5CB was lowered compared with the TiO₂-5CB synthesized without the magnetic field, suggesting the occurrence of electron transfer from 5CB to the 1-D-like TiO₂-5CB during ultraviolet irradiation. Apart from that, direct current electrical conductivity and Hall effect studies showed that the 1-D-like TiO₂ composite enhanced electron mobility. Thus, the recombination of electrons and holes was delayed due to the increase in electron mobility; hence, the photocatalytic activity of the 1-D-like TiO₂ composite in the oxidation of styrene in the presence of aqueous hydrogen peroxide under UV irradiation was enhanced. This suggests that the 1-D-like shape of TiO₂ composite plays an important role in its photocatalytic activity.

Effect of magnetic field on the synthesis of well-aligned TiO2-5CB by sol-gel method

This paper describes the approach by using a magnetic field as a technique in order to synthesize well-aligned materials. The magnetic field technique could be a potential method because it has advantage that all of the materials could be aligned by magnetic field as long as they have magnetic anisotropy. The aim of this research is to explore the effects of magnetic field and magnetic line in the synthesis of well-aligned material, namely titania (TiO2).  The synthesis of well-aligned titania with liquid crystal as the structure-aligning agent is demonstrated under magnetic field in the presence of liquid crystal, 4′-pentyl-4-biphenylcarbonitrile (5CB), tetra-n-butyl orthotitanate (TBOT), 2-propanol and water. The mixture underwent slow hydrolysis and drying process under magnetic field (0.3 T) in ambient condition. The use of magnetic field and 5CB liquid crystal as the structure aligning agent has led to the successful formation of well-aligned TiO2-5CB via sol-gel method. When no magnetic field was applied, the TiO2-5CB obtained was spherical in shape and no alignment can be observed. This study demonstrated that magnetic field can play an important role in the synthesis of well-aligned TiO2-5CB.

Insights into the physicochemical properties of the Malaysian oil palm leaves as an alternative source of industrial materials and bioenergy

This work was aimed at providing a comprehensive physicochemical characterization of the Malaysian oil palm leaves (OPL) that may be useful for industrial applications as well as providing new insights on minimizing the environmental impact of oil palm biomass wastes. The leaves of discarded oil palm fronds were collected, dried and ground. The leaves powder was subjected to acid and thermal treatments prior to physicochemical analyses. Physicochemical characterization included analyses of thermal gravimetry, ultimate analysis, Fourier-Transform infrared spectroscopy, X-ray fluorescence, X-ray diffraction and nitrogen sorption. Ultimate analysis revealed that the untreated OPL contained carbon (46.98 %), hydrogen (6.500 %), nitrogen (1.810 %) and sulfur (0.150 %) with a moderately high calorific value of 19.21 MJ/kg. Thermal gravimetric and derivative thermal gravimetric analyses indicated that OPL is a lignocellulosic material with little moisture and ash contents.   X-ray Florescence revealed Ca (39.20 %), K (22.10 %) and Si (19.20 %) as the three major elements in the ash of the untreated sample with Si (95.20%) being predominant for the treated ones. The ash of the acid treated sample was majorly amorphous silica which was slightly mesoporous with surface area of 160.59 m2g-1 as shown by X-ray diffraction and nitrogen sorption analyses respectively. These findings confirmed that the Malaysian OPL is a lignocellulosic biomass as well as a good source of amorphous silica, hence may prove useful as a potential renewable source of bioenergy and an alternative silica source for industrial applications.

A STATISTICAL APPROACH FOR OPTIMIZING THE HIGH YIELD GREEN PRODUCTION OF THE FLAVOR ESTER BUTYL BUTYRATE

Being the prevailing approach for producing esters such as butyl butyrate, the use of chemical route has been linked to numerous disadvantages. Hence, a green alternative method for higher yield production of butyl butyrate by esterification reaction utilizing Novozyme 435 as biocatalysts in a solvent-less system may prove useful. Such approach can be further improved by optimizing the relevant reaction parameters using the Response Surface Methodology by the Box-Benkhen Design attempted in this present study. The reaction parameters evaluated were: substrate molar ratio, time and temperature, and the response of each parameter was measured as percentage conversion yield. Using the Design Expert 7.1.6 optimization functions, the two sets of optimum conditions selected viz. [i] molar ratio butyric acid:butanol 1:3.93, 9.93 h at 56.09°C and [ii] molar ratio butyric acid:butanol 1:3.35, 9.79 h at 53.90°C had afforded the highest yield of butyl butyrate i.e. 99.62% and 99.55%, respectively. The ester product obtained from the reaction were confirmed as butyl butyrate by FTIR and GC. Therefore, the results substantiated the applicability of the RSM prediction technique as well as efficacy of Novozyme 435 as biocatalysts in the high yield solvent-less synthesis of butyl butyrate, adhering to the philosophy of Green Chemistry.