Preparation of activated carbon derived from Jatropha curcas fruit shell by simple thermo-chemical activation and characterization of their physico-chemical properties

High surface area activated carbons were prepared by simple thermo-chemical activation of Jatropha curcas fruit shell with NaOH as a chemical activating agent. The effects of the preparation variables, which were impregnation ratio (NaOH:char), activation temperature and activation time, on the adsorption capacity of iodine and methylene blue solution were investigated. The activated carbon which had the highest iodine and methylene blue numbers was obtained by these conditions as follows: 4:1 (w/w) NaOH to char ratio, 800 °C activation temperature and 120 min activation time. Characterization of the activated carbon obtained was performed by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and nitrogen adsorption isotherm as BET. The results present that the activated carbon possesses a large apparent surface area (S_BET = 1873 m²/g) and high total pore volume (1.312 cm³/g) with average pore size diameter of 28.0 Å.     

Enhanced liquid biofuel production from crude palm oil over synthesized NiMoW-ZSM-5/MCM-41 catalyst

Micro-mesoporous ZSM-5/MCM-41 composites were prepared and then loaded with varied contents of NiMoW by the wet impregnation method. The hydrocracking conversion of crude palm oil to liquid biofuels with the prepared catalysts was carried out in a batch reactor at 400°C for 2 h. ZSM-5/MCM-41 composite exhibited 51.00% conversion with a yield of 9.23% gasoline, 20.60% kerosene, and 21.17% diesel. Upon loading of NiMoW, the catalysts exhibited an improved conversion (≥ 62.60%) and a reduced formation of coke, which resulted from combined properties of ZSM-5 with MCM-41 and the presence of dispersed NiMoW. The contents of impregnated metals also affected the performance of catalysts. Using ANOVA analysis (p < 0.05), we found that 8:8:8 wt.% NiMoW-ZSM-5/MCM-41 catalyst was suitable for the production of biofuels, when considering the efficiency and cost-effectiveness.     

Evaluation of antioxidant activities and phenolic subtype contents of ethanolic bran extracts of Thai pigmented rice varieties through chemical and cellular assays

This study revealed that the ethanolic bran extracts of 11 Thai pigmented (red and purple) and 2 nonpigmented rice varieties exerted scavenging activity against DPPH and ABTS radicals and ROS in HL‐60 cells in the following order: red > purple > nonpigmented rice. These rice extracts also showed the same order of phenolic and flavonoid contents, which were strongly correlated with their scavenging activity. Phenolic subtype analysis further indicated that proanthocyanidins as well as anthocyanins and protocatechuic acid contributed directly to antioxidant capacity in red and purple rice bran, respectively. In contrast, these pigmented rice bran extracts possessed moderate chelating activity partly attributed to their contents of phenolics and flavonoids, especially proanthocyanidins in red rice bran. Moreover, rice bran extracts significantly restored SOD and CAT activities in oxidative stress‐induced A549 cells. This study provides new insights on the intracellular potent antioxidant capacity of pigmented rice bran extracts in the cell‐based systems.