Advancing sustainable biotechnology through protein engineering.

The push for industrial sustainability benefits from the use of enzymes as a replacement for traditional chemistry. Biological catalysts, especially those that have been engineered for increased activity, stability, or novel function, and are often greener than alternative chemical approaches. This Review highlights the role of engineered enzymes (and identifies directions for further engineering efforts) in the application areas of greenhouse gas sequestration, fuel production, bioremediation, and degradation of plastic wastes.

The Role of the Anion in Imidazolium-Based Ionic Liquids for Fuel and Terpenes Processing.

The potentialities of methylimidazolium-based ionic liquids (ILs) as solvents were evaluated for some relevant separation problems-terpene fractionation and fuel processing-studying selectivities, capacities, and solvent performance indices. The activity coefficients at infinite dilution of the solute (1) in the IL (3), γ13∞, of 52 organic solutes were measured by inverse gas chromatography over a temperature range of 333.2-453.2 K. The selected ILs are 1-butyl-3-methylimidazolium hexafluorophosphate, [C4mim][PF6], and the equimolar mixture of [C4mim][PF6] and 1-butyl-3-methylimidazolium chloride, [C4mim]Cl. Generally, low polar solutes follow γ1,C4mimCl∞ > γ1,C4mimPF6+C4mimCl∞ > γ1,C4mimPF6∞ while the opposite behavior is observed for alcohols and water. For citrus essential oil deterpenation, the results suggest that cations with long alkyl chains, such as C12mim+, promote capacity, while selectivity depends on the solute polarity. Promising results were obtained for the separation of several model mixtures relevant to fuel industries using the equimolar mixture of [C4mim][PF6] and [C4mim]Cl. This work demonstrates the importance of tailoring the polarity of the solvents, suggesting the use of ILs with mixed anions as alternative solvents for the removal of aliphatic hydrocarbons and contaminants from fuels.

Higher heating value estimation of wastes and fuels from ultimate and proximate analysis by using artificial neural networks.

Higher heating value (HHV) is one of the most important parameters in determining the quality of the fuels. In this study, comparatively large datasets of ultimate and proximate analysis are constructed to be used in HHV estimation of several classes of fuels, including char & fossil fuels, agricultural wastes, manure (chicken, cow, horse, sheep, llama, and pig), sludge (like paper, paper-mil, sewage, and pulp), micro/macro-algae's, wastes (RDF and MSW), treated woods, untreated woods, and others (non-fossil pyrolysis oils) between the HHV range of 4.22-55.55 MJ/kg. The relationships of carbon, hydrogen, and oxygen atomic ratios for fuel classes are illustrated by using ternary plots, and the effects of elemental composition on HHV was analyzed with the extensive dataset. Then, the ultimate (U) and ultimate & proximate (UP) datasets were utilized separately to estimate the HHV by using artificial neural networks (ANN). Hyperparameter optimization was carried out and the best performing ANNs were determined for each dataset, which yielded R2 values of 0.9719 and 0.9715, respectively. The results indicated that while ANNs trained by both datasets perform remarkably well, utilization of U dataset is sufficient for HHV estimation. Finally, the best performing ANN models for both U and UP datasets are given in a directly utilizable format enabling the accurate estimation of HHV of any fuel for optimization of fuel processing and waste management operations.

Recent Advances in Structured Catalytic Materials Development for Conversion of Liquid Hydrocarbons into Synthesis Gas for Fuel Cell Power Generators.

The paper considers the current state of research and development of composite structured catalysts for the oxidative conversion of liquid hydrocarbons into synthesis gas for fuel cell feeding and gives more detailed information about recent advances in the Boreskov Institute of Catalysis. The main factors affecting the progress of the target reaction and side reactions leading to catalyst deactivation are discussed. The properties of the Rh/Ce0.75Zr0.25O2/Al2O3/FeCrAl composite multifunctional catalyst for the conversion of diesel fuel into synthesis gas are described. The results of the catalyst testing and mathematical modeling of the process of diesel fuel steam-air conversion into synthesis gas are reported.

Experimental and theoretical study of deep oxidative desulfurization of Dibenzothiophene using Oxalate-Based catalyst.

The present study reports the experimental and theoretical investigation for production of ultra-low sulfur liquid fuels through estimation of various reactive species formed during the reaction with the help of simulation. All the experiments were performed using an ultrasound bath which operates at a frequency of 37 kHz and a theoretical power of 95 W. The presented oxalate-based technique is found to be more efficient with > 93% DBT oxidation within 15 min of reaction time at 25 °C due to formation of reactive species like FeIIC2O4 and [Formula: see text] which accelerate the reaction kinetics. Moreover, we have also investigated the influence of process parameters such as molar ratio of C2O42-/Fe2 +, oxidant concentration, volume ratio of organic to aqueous phase, sulfur concentration, and activation methods of oxidant. The results revealed that catalyst can be reused for several runs without decrease in catalytic activity. The experimental and simulation of cavitation bubble dynamics results revealed that sonochemical effect assists to accelerate the reaction kinetics through formation of free radicals (•O, •H, •OH and HO2∙) and other reactive species like O3 and H2O2 generated during transient cavitation. The sono-physical effects of cavitation help to create a fine emulsion in the liquid-liquid heterogeneous system leading to enhanced mass transfer rate by providing more interfacial surface area for occurring chemical reaction.