Volume 6, Issue 1

Alternate energy resources need to be developed to amend for depleting fossil fuel reserves. Lignocellulosic biomass is a globally available renewable feedstock that contains a rich sugar platform that can be converted into bioethanol through appropriate processing. The key steps of the process, pretreatment, enzymatic hydrolysis, and fermentation, have undergone considerable amount of research and development over the past decades nearing the process to commercialization. In order for the commercialization to be successful, the process needs to be operated at high dry matter content of biomass, especially in the enzymatic hydrolysis stage that influences ethanol concentration in the final fermentation broth. Biomass becomes a thick paste with challenging rheology for mixing to be effective. As the biomass consistency increases, yield stress increases which limits efficiency of mixing with conventional stirred tanks. The purpose of this review is to provide features and perspectives on processing of biomass into ethanol. Emphasis is placed on rheology and mixing of biomass in the enzymatic hydrolysis step as one of the forefront issues in the field.

This report describes a rapid, facile and an ecofriendly synthesis of silver nanoparticles (AgNps) using fruit extracts of Shora ( Capparis petiolaris ) and further as-synthesized AgNps were characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The effects of various other parameters such as pH, concentration of fruit extract, time, and change of light sources are studied. Analytical characterizations revealed that the sunlight-induced AgNps appeared at λ max =423 nm, had a spherical shape and varied in the range of 10–30 nm. Furthermore, AgNps showed moderate antioxidant activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH·) (38.98%, 0.125 m m ) and photocatalytic activity for the degradation of methylene blue (MB) (>58%, 240 min). The results indicated that as-synthesized AgNps could be used in future engineering and biomedical products.

Silver nanoparticles (AgNPs) were synthesized using Pelargonium/Geranium leaf extract via a hydrothermal method. The effects of the Pelargonium/Geranium leaf extract concentration (PLEC) and the amount of 1 m m AgNO 3 solution on the center of the broad emission peak (λ max ) and the color of the synthesized AgNP solution were investigated by using response surface methodology. The main reducing and stabilizing compounds of Pelargonium/Geranium leaf extract were identified by Fourier transform-infrared and gas chromatography. Spherical AgNPs with an average size of 29 nm were successfully fabricated at the optimal synthesis conditions using 9.8 ml of 1 m m AgNO 3 solution and 0.1 ml of 0.62 g/100 ml PLEC. AgNPs were determined to have a polydispersity index value of 0.413 and a ζ potential of +0.6 mV. The antifungal activity of fabricated AgNPs was tested against Aspergillus flavus and Aspergillus terreus , and found to posses a significant inhibitory effect against these microorganisms.

Nanotechnology is a growing area of research. For example, gold nanoparticles have a wide variety of applications, including optical, electronic, and medical; they are also used as catalysts in biosensor applications and can be used for scanning, carrier, heat source, and sensors. Therefore, nanoparticle synthesis is of great importance to the country’s economy and to scientific development. Nanoparticle synthesis involves using chemical methods, physical methods, or both chemical and physical methods. The synthesis is performed at high pressures or high temperatures and severe conditions, both of which have a high cost in terms of energy. In our investigation, we used a green synthesis method, which used quail eggs that required more moderate conditions and less energy. The yolk from quail eggs has a high protein and vitamin content. Using quail egg yolks, the reaction conditions were optimized in terms of pH, temperature, and concentration. The morphological properties of the obtained gold nanoparticles were characterized using an ultraviolet-visible spectrophotometer, a scanning electron microscope, and an X-ray diffraction analysis.

LaAlO 3 was synthesized using microcrystalline LaOCl and amorphous Al 2 O 3 precursors. The precursors were derived with single inorganic materials through spray pyrolysis. The precursors and derived oxide powders were characterized by differential thermal analysis, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. LaAlO 3 was found to crystallize directly from microcrystalline LaOCl and amorphous Al 2 O 3 precursors at 1073 K for 2 h in air, and the LaAlO 3 product purity is more than 99.9%.

This present study focuses on ultrasound assisted process intensification of hexyl acetate synthesis via lipozyme RMIM catalysed transesterification of hexanol with triacetin by using hexane as a solvent. Hexyl acetate, an ester with fruity odor and significant green note is mostly used as flavor and fragrance material in various areas. Effect of various parameters on conversion of hexyl acetate such as molar ratio, enzyme loading, temperature, power, agitation speed and duty cycle was studied systematically. With the molar ratio of 1:1 of hexanol to triacetin with 4% enzyme loading (w/v), at agitation speed of 100 rpm with application of sonication at 60 W power and 70% duty cycle resulted in to 83% conversion at 50°C temperature in 4 h when compared with conventional method which requires 9 h for 68% conversion.

A plasma microreactor dedicated to chemical synthesis has been conceived and developed using soft-lithography techniques. In this study, we propose to use highly reactive species created by the plasma discharge to replace traditionally used chemical initiators. A dielectric barrier discharge plasma was generated under atmospheric pressure and then dispersed into a continuous liquid phase with a T-junction geometry. Injected metal electrodes made it possible for in situ optical observations with an intensified charge-coupled device camera. No signal was detected when analyzing the exhaust liquid by electron spin resonance (ESR) spectroscopy. Numerical simulations confirmed that only low quantities of hydroxyl radicals could diffuse into the liquid phase, giving a concentration of DMPO-OH of 10 −6 mol/l, below the detection limit of ESR.

A highly efficient, eco-friendly and one-pot synthesis of benzofuran substituted thiazolo[3,2-b][1,2,4]triazoles was developed involving the reaction of 2-acetyl benzofurans and 5-mercapto-3-(4-chlorophenyl)-1,2,4triazole in the presence of molecular iodine under ultrasonic conditions to give 5-(benzofuran-2-yl)-acylthio-3-(4-chlorophenyl)-1,2,4triazoles, which was further cyclised using Eaton’s reagent under microwave conditions to give 5-(benzofuran-2-yl)-2-(4-chlorophenyl)thiazolo[3,2-b][1,2,4]triazoles.

As a means to valorize glycerol, the synthesis of solketal through a ketalization reaction with acetone was performed. Mild solventless conditions were applied to test the activity of different commercially available sulfonic ion exchange resins that had already been used for other applications, namely: Amberlyst 35dry, Amberlyst 36dry, Purolite CT275DR, Purolite CT276 and Lewatit GF101. Thorough characterization of the resins is herein provided and discussed, including acidity, elemental analysis, thermogravimetric, 13C-NMR, surface area and pore size distribution measurements. Lewatit GF101 showed the best performance reaching a yield to solketal of 47% after 6 h of operation at 313 K using a molar excess of acetone to glycerol of 4.5 to 1, owing to a greater availability of active centers as well as the ease of access to them than in the rest of the resins. Additionally, reutilization with and without regeneration was performed in up to five cycles, showing that Purolite CT276 had the lowest relative drop of its maximum activity, despite being the least active in each of the cycles.

This article presents an environmentally friendly approach for the conversion of rapeseed oil via supercritical ethanol condition, with and without the presence of a solid catalyst, to produce biodiesel. The experiment was conducted in a batch reactor at various temperatures, reaction times, and ethanol to oil molar ratios. The evolution of process was followed by high performance liquid chromatography to determine accurately and quickly the content of final reaction mixture in a single analysis. The results show that the highest biodiesel yields of 93% (with ZnO) and 88% (with CaO) were obtained after the reaction time of 60 min at a temperature of 270°C. This process has high potential in minimizing the production cost of biodiesel due to its simplicity and technical advantage.

In the present study, the moisture of high titanium slag was chosen as the research object. Taking advantage of selective heating of microwave and the specific inductive capacity of water, the drying experiment of high titanium slag using microwave heating have been carried out. The results revealed that the presence of moisture in the form of high titanium slag was adsorbed water, and the wet sample possesses excellent wave-adsorbing performance; the bed depth preferred was no larger than 10 mm, with moisture content at around 3%. The microwave drying process was divided into two stages: the constant-stage and the deceleration-stage. The optimum conditions were identified to be microwave power of 700 W, sample mass of 200 g, bed depth of 10 mm and drying time of 50 s. The dehydration extent can reach 90% and moisture content remains at 0.3% under the optimum conditions. The demonstration of microwave drying techniques can be applied effectively and efficiently into the treatment processing of drying of the raw materials of metallurgy and chemical industry with the theoretical and scientific basis.

The mechanical behavior, physical behavior, microstructural characteristics, and corrosion behavior of AA2014/silicon carbide (SiC)/carbonized eggshell hybrid green metal matrix composites (MMCs) were investigated. Twenty-five samples of hybrid composite with different combinations of SiC and carbonized eggshell particles in AA2014 matrix alloy were prepared. Microstructure presents that the reinforcement particles (SiC and eggshells) are uniformly distributed in the matrix AA2014 alloy. Transmission electron microscope image shows proper wettability between SiC, carbonized eggshell, and AA2014 aluminum alloy. The tensile strength and the fatigue strength for the composites containing 2.5 wt.% SiC up to 7.5 wt.% carbonized eggshell were observed to be higher than that of the other selected composites. The hardness values for the composites containing 12.5 wt.% SiC and 2.5 wt.% carbonized eggshell were in all cases higher than that of the other composites. The results show that toughness decreases with the increase in the weight ratio of SiC and carbonized eggshell in the composites. The results reveal that the sample of AA2014/2.5% SiC/12.5% carbonized eggshell shows minimum corrosion rate among all the selected samples. Density, porosity, and overall cost of hybrid metal matrix composites were also calculated to see the effects of carbonized eggshell and SiC addition in AA2014 matrix alloy.