In this study, the optimization of microwave-assisted alkaline (MAA) pretreatment is performed to attain the optimal operating parameters for the delignification of cocoa pod husk (CPH). The MAA performance was examined by heating the CPH solid with different particle sizes (60–120 mesh) and NaOH solution with a different sample to a solvent (SS) ratio (0.02–0.05 g/L), for short irradiation time (1–4 min). Box-Behnken Design (BBD) was utilized to optimize the percentage of lignocellulose composition changes. The results show that by enlarging particle size, the content of lignin and cellulose decreased while hemicellulose increased. By prolong irradiation time, the content of lignin and hemicellulose decreased while cellulose elevated. On the other hand, increasing the SS ratio was not significant for hemicellulose content changes. From FTIR and SEM characterization, the MAA drove the removal of lignin and hemicellulose of CPH and increased cellulose slightly. Supported by kinetic study which conducted in this work, it was exhibited that MAA pretreatment technology is an effective delignification method of CPH which can tackle the bottleneck of its commercial biofuel production. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0).

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Biobutanol is a renewable fuel that can be used as a gasoline substitute and a chemical feedstock. Its production using the Clostridial bacterial strain involves three steps: refreshment from a stock, a preculture for bacterial propagation, and primary fermentation for butanol production. Refreshment is an important process to activate the bacteria and multiply the stock. This process uses potato glucose media for C. saccharoperbutylacetonicum N1-4, while the use of starch from other sources has not been studied. This study aimed to understand various carbon sources' effects on this refreshment process as part of ABE (acetone-butanol-ethanol) fermentation. Starch was substituted in refreshment media with several types of potato, rice, sweet corn, and sweet potato at 15% w/v. After 24 hours of refreshment at an ambient temperature, fermentation was run for 48 hours in TYA (tryptone-yeast-acetate) glucose media. All the starch sources could be used in the refreshment process, resulting in butanol and total solvent concentration ranging from 7.58 to 8.76 g/L and 12.5 to 14.6 g/L, respectively. Among the samples, sweet corn provided the highest fermentation performance, with butanol of 8.76 g/L, total solvents of 14.6 g/L, average butanol productivity of 0.182 g/L/h, and a butanol yield per substrate of 0.481 C-mol/C-mol. All the starchy materials used in this experiment offered potential for ABE fermentation, while sweet corn performed remarkably-producing the highest final butanol concentration, productivity, and yield.

The effect of meta versus para substitution on the aggregation of bischolesteryl appended 2,6-disubstituted pyridine-based gelatorsThe structurally isomeric, bent core, 2,6-disubstituted pyridine derivatives (PyPC and PyMC) were synthesized, and their gelation ability and aggregation behavior in different solvents were studied using various techniques including electron microscopy (TEM and SEM) and X-ray diffraction analysis (XRD). The PyPC was found to be soluble in most of the organic solvents studied, which may be due to the possible existence of intramolecular hydrogen bonding in PyPC (low angle) that enhanced its solubility. In contrast, 10 the PyMC was less soluble, making it a more efficient gelator than PyPC. The results from the morphological studies showed that the xerogel of PyPC in dodecanol exhibited a nanotube morphology (diameter ~70 nm), whereas PyMC in dodecanol exhibited a fibrous morphology, indicating that the existence of positional isomerism had a profound effect on the aggregation of the molecules in solution.Both right-and left-handed helical structures were observed in all gelators; however, left-handed structures were more predominant.Intermolecular hydrogen bonding as well as π-π stacking cooperatively played an important role in the aggregation of the gelators as 15 evidenced by XRD and temperature-dependent 1 H-NMR spectroscopy analyses. Based on these results, aggregation mechanisms were proposed.