Biodiesel is conventionally produced by alkaline‐catalyzed transesterification, which requires high‐purity oils. However, low‐quality oils can be used as feedstocks for the production of biodiesel by enzyme‐catalyzed reactions. The use of enzymes has several advantages, such as the absence of saponification side reactions, production of high‐purity glycerol co‐product, and low‐cost downstream processing. In this work, biodiesel was produced from lipase‐catalyzed hydrolysis of waste cooking oil (WCO) followed by esterification of the hydrolyzed WCO (HWCO). The hydrolysis of acylglycerols was carried out at 30 °C in salt‐free water (WCO/water ratio of 1:4, v/v) and the esterification of HWCO was carried out at 40 °C with ethanol in a solvent‐free medium (HWCO/ethanol molar ratio of 1:7). The hydrolysis and esterification steps were carried out using immobilized Thermomyces lanuginosus lipase (TLL/WCO ratio of 1:5.6, w/w) and immobilized Candida antarctica lipase B (10 wt%, CALB/HWCO) as biocatalysts, respectively. The hydrolysis of acylglycerols was almost complete after 12 h (ca. 94 %), and in the esterification step, the conversion was around 90 % after 6 h. The purified biodiesel had 91.8 wt% of fatty acid ethyl esters, 0.53 wt% of acylglycerols, 0.003 wt% of free glycerol, viscosity of 4.59 cP, and acid value of 10.88 mg KOH/g. Reuse hydrolysis and esterification assays showed that the immobilized enzymes could be recycled five times in 10‐h batches, under the conditions described above. TLL was greatly inactivated under the assay conditions, whereas CALB remained fully active. The results showed that WCO is a promising feedstock for use in the production of biodiesel.

The aim of this work was to verify the effect of MFI aluminum content and crystal size on the selectivity for para-diethylbenzene during ethylbenzene disproportionation. It was observed that the para-diethylbenzene selectivity increased as MFI crystal size increased. The increase in aluminum content caused a decrease in the selectivity for para-diethylbenzene. However, for crystals larger than 8 m m, the decrease in aluminum content had little influence on the selectivity for para-diethylbenzene. The results can be explained by the number of active aluminum sites on the external surface of the crystals

Actively targeted drug loaded nanoparticles represent an exciting new form of therapeutics for cancer and other diseases. These formulations are complex and in order to realize their ultimate potential, optimization...