Production of Rigid Polyurethane Foams Using Polyol from Liquefied Oil Palm Biomass: Variation of Isocyanate Indexes.

Development of polyurethane foam (PUF) containing bio-based components is a complex process that requires extensive studies. This work reports on the production of rigid PUFs from polyol obtained via liquefaction of oil palm empty fruit bunch (EFB) biomass with different isocyanate (NCO) indexes. The effect of the NCO index on the physical, chemical and compressive properties of the liquefied EFB-based PUF (EFBPUF) was evaluated. The EFBPUFs showed a unique set of properties at each NCO index. Foaming properties had affected the apparent density and cellular morphology of the EFBPUFs. Increasing NCO index had increased the crosslink density and dimensional stability of the EFBPUFs via formation of isocyanurates, which had also increased their thermal stability. Combination of both foaming properties and crosslink density of the EFBPUFs had influenced their respective compressive properties. The EFBPUF produced at the NCO index of 120 showed the optimum compressive strength and released the least toxic hydrogen cyanide (HCN) gas under thermal degradation. The normalized compressive strength of the EFBPUF at the NCO index of 120 is also comparable with the strength of the PUF produced using petrochemical polyol.

Highly stable binder free CNTs/rGO aerogel electrode for decolouration of methylene blue & palm oil mill effluent via electro-Fenton oxidation process.

In this study, single wall carbon nanotubes (CNTs)/reduced graphene oxides (rGO) aerogels were prepared by a one-pot hydrothermal process without using a binder. The produced CNTs/rGO aerogel was used as cathode in electro-Fenton system for the decolouration of methylene blue (MB) and palm oil mill effluent (POME). The addition of CNTs increased the surface area, pore volume and conductivity of the rGO aerogel, which further enhanced their performance as cathode towards the decolouration of MB and POME via electro-Fenton reaction. Complete decolouration of MB using rGO aerogel without CNTs could not be achieved. The effect of electro-Fenton reaction parameters conducted using the aerogel samples including, current, electrolyte concentrations and pH, were investigated accordingly. The CNTs/rGO aerogel electrode also showed high stability and reusability for up to six consecutive treatment cycles for MB. Besides, the CNTs/rGO aerogel also showed good performance in treating POME with 69.8%, 47.6% and 58.1% of reduction in true colour, total organic carbon (TOC) and chemical oxygen demand (COD), respectively, via 60 minutes electro-Fenton reaction. This study showed that CNTs/rGO aerogels with high porosity and stability can be prepared using simple procedure without adding binder. This fully carbon-based aerogel can serve as effective cathode for decolouration of organic dye and effluent.

Exceedingly biocompatible and thin-layered reduced graphene oxide nanosheets using an eco-friendly mushroom extract strategy.

PURPOSE: A simple, one-pot strategy was used to synthesize reduced graphene oxide (RGO) nanosheets by utilizing an easily available over-the-counter medicinal and edible mushroom, Ganoderma lucidum. METHODS: The mushroom was boiled in hot water to liberate the polysaccharides, the extract of which was then used directly for the reduction of graphene oxide. The abundance of polysaccharides present in the mushroom serves as a good reducing agent. The proposed strategy evades the use of harmful and expensive chemicals and avoids the typical tedious reaction methods. RESULTS: More importantly, the mushroom extract can be easily separated from the product without generating any residual byproducts and can be reused at least three times with good conversion efficiency (75%). It was readily dispersible in water without the need of ultrasonication or any surfactants; whereas 5 minutes of ultrasonication with various solvents produced RGO which was stable for the tested period of 1 year. Based on electrochemical measurements, the followed method did not jeopardize RGO's electrical conductivity. Moreover, the obtained RGO was highly biocompatible to not only colon (HT-29) and brain (U87MG) cancer cells, but was also viable towards normal cells (MRC-5). CONCLUSION: Besides being eco-friendly, this mushroom based approach is easily scalable and demonstrates remarkable RGO stability and biocompatibility, even without any form of functionalization.

Cationic and anionic modifications of oil palm empty fruit bunch fibers for the removal of dyes from aqueous solutions.

Oil palm empty fruit bunch (EFB) fibers were employed to remove dyes from aqueous solutions via adsorption approaches. The EFB fibers were modified using citric acid (CA) and polyethylenimine (PEI) to produce anionic and cationic adsorbents, respectively. The CA modified EFB fibers (CA-EFB) and PEI-modified EFB fibers (PEI-EFB) were used to study the efficiency in removing cationic methylene blue (MB) and anionic phenol red (PR) from aqueous solutions, respectively, at different pHs, temperatures and initial dye concentrations. The adsorption data for MB on the CA-EFB fitted the Langmuir isotherm, while the adsorption of PR on the PEI-EFB fitted the Freundlich isotherm, suggesting a monolayer and heterogeneous adsorption behavior of the adsorption processes, respectively. Both modified fibers can be regenerated up to seven adsorption/desorption cycles while still providing as least 70% of the initial adsorption capacity.

Direct production of biodiesel from high-acid value Jatropha oil with solid acid catalyst derived from lignin.

BACKGROUND: Solid acid catalyst was prepared from Kraft lignin by chemical activation with phosphoric acid, pyrolysis and sulfuric acid. This catalyst had high acid density as characterized by scanning electron microscope (SEM), energy-dispersive x-ray spectrometry (EDX) and Brunauer, Emmett, and Teller (BET) method analyses. It was further used to catalyze the esterification of oleic acid and one-step conversion of non-pretreated Jatropha oil to biodiesel. The effects of catalyst loading, reaction temperature and oil-to-methanol molar ratio, on the catalytic activity of the esterification were investigated. RESULTS: The highest catalytic activity was achieved with a 96.1% esterification rate, and the catalyst can be reused three times with little deactivation under optimized conditions. Biodiesel production from Jatropha oil was studied under such conditions. It was found that 96.3% biodiesel yield from non-pretreated Jatropha oil with high-acid value (12.7 mg KOH/g) could be achieved. CONCLUSIONS: The catalyst can be easily separated for reuse. This single-step process could be a potential route for biodiesel production from high-acid value oil by simplifying the procedure and reducing costs.

Comparative studies of products obtained from solvolysis liquefaction of oil palm empty fruit bunch fibres using different solvents.

Solvolysis of oil palm empty fruit bunches (EFB) fibres using different solvents (acetone, ethylene glycol (EG), ethanol, water and toluene) were carried out using an autoclave at 275°C for 60 min. The solvent efficiency in term of conversion yield was found to be: EG>water>ethanol>acetone>toluene. The liquid products and residue obtained were analyzed using Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass selectivity. The obtained results showed that the chemical properties of the oil product were significantly affected by the type of solvent used for the solvolysis process. The higher heating value (HHV) of oil products obtained using ethanol is ∼29.42 MJ/kg, which is the highest among the oil products produced using different solvents. Water, ethanol and toluene yield major phenolic compounds. While EG favors the formation of alcohol compounds and acetone yields ketone and aldehyde compounds.