Candlenut oil (CNO) is a potentially new feedstock for biodiesel (BDF) production. In this paper, a two-step co-solvent method for BDF production from CNO was examined. Firstly, esterification of free fatty acids (FFAs) (7 wt%) present in CNO was carried out using a co-solvent of acetonitrile (30 wt%) and HSO as a catalyst. The content of FFAs was reduced to 0.8 wt% in 1 h at 65°C. Subsequent transesterification of the crude oil produced was carried out using a co-solvent of acetone (20 wt%) and 1 wt% potassium hydroxide (KOH). Ester content of 99.3% was obtained at 40°C in 45 min. The water content in BDF was 0.023% upon purification using vacuum distillation at 5 kPa. The components of CNO BDF were characterized using a Fourier-transform infrared spectrometry and gas chromatography-flame ionization detector. The physicochemical properties of BDF satisfied the ASTM D6751-02 standard. The gaseous exhaust emissions from the diesel engine upon combustion of the BDF blends (B0-B100) with petrodiesel were examined. The emissions of carbon monoxide and hydrocarbons were clearly lower, but that of nitrogen oxides was higher in comparison to those from petro-diesel.

Nonwoven mats made of a poly(lactic acid)/chitosan (PLA/CS) blend and a PLA/CS blend containing silver (Ag) nanoparticles (Ag/PLA/CS) were prepared using an electrospinning technique. The morphology of electrospun fibers was observed by field emission scanning electron microscopy. The addition of AgNO 3 to the PLA/CS blend solution improved the electrospinning ability of the PLA/CS blend. The average diameters of the electrospun PLA/CS and Ag/PLA/CS blend fibers decreased as CS content increased. The Ag particles were evenly distributed in PLA/CS ultrafine fibers observed under transmission electron microscopy. Ag nanoparticles were spontaneously generated during the electrospinning process. When the CS content in the blend increased, the size of the Ag nanoparticles on the surface of the electrospun fibers increased as well. The thermal and mechanical properties of the nonwoven mats were examined by differential scanning calorimetry and a tensile tester. Fourier transform infrared spectroscopy was used to characterize the molecular interactions among PLA, Ag, and CS in the blends. The antibacterial activity of the nonwoven mats against Escherichia coli and Staphylococcus aureus was studied using an optical density method.

Biodiesel fuels (BDFs) was successfully produced from Vietnamese Jatropha curcas oil with high content of free fatty acids (FFAs) in two stages. In the first stage, the esterification process was carried out with the optimal conditions as follows; a methanol-to-FFAs molar ratio of 6:1, 1 wt% H2SO4, at a temperature of 65 °C, and using 30% (wt/wt) acetonitrile as co-solvent. This step reduced the concentration of FFAs in the reaction mixture from 15.93 to 2 wt% in 60 min. In the second stage, the transesterification process generated fatty acid methyl esters (FAMEs) with 99% efficiency was performed in 30 min with the optimal conditions as follows; a methanol-to-oil molar ratio of 6:1, 1 wt% KOH, at a temperature of 40 °C, and 20% (wt/wt) acetone as co-solvent. The produced biodiesel quality meets the standards JIS K2390 and EN 14214 regarding FAME yield, FFAs and water contents.

In this study, we studied the production of biodiesel from waste cooking oil with co-solvent technology. A co-solvent technology with acetone has many advantage, but needs to remove solvents dissolved in the mixture. The optimum transesterification conditions to obtain the 98% purity of fatty acid methyl esters (FAMEs) are as follows: 1 wt.% potassium hydroxide catalyst, 20wt.% acetone and 5:1 methanol to oil molar ratio, reaction temperature of 40 0 C and reaction time of 30 minutes. The water content is 104 ppm, methanol content in the final product 95 ppm, and the concentration of acetone in the products 247 ppm.