No abstract

No abstract

The purpose of this work was to understand the effect of the acoustic cavitation on the alkaline hydrolysis of wool and compare it with a conventional method of steam based alkaline hydrolysis. In acoustic cavitation assisted alkaline hydrolysis, the effect of concentration of solid (wool) and alkali on the properties of wool were also investigated. In conventional alkaline hydrolysis, the experiments were carried in a laboratory scale autoclave at temperature of 120 °C and pressure of 2 bar for 15 min. While acoustic cavitation assisted hydrolysis was carried out using the untreated and treated wool, hydrolyzed samples were characterized using FTIR, TGA and DSC to find out the extent of structural degradation occurring as a result of the treatment. It was observed that both the processes resulted in to a cleavage of disulfide bonds in wool, which cross-link the protein chains and are responsible for the higher stability and lower solubility of wool. However, the acoustic assisted alkaline hydrolysis is an environmentally friendly and less energy intensive process as it was performed at room temperature. The wool hydrolysates produced using acoustic assisted alkaline hydrolysis could find a potential application in agricultural fields such as fertilizer, soil improvement additive, etc.

The process intensification (PI) can significantly improve energy and process efficiency by enhancing mixing, mass, and heat transfer as well as driving forces. There are several benefits of such improvements, which include energy and cost savings, enhanced safety, smaller reactor size, less waste generation, and higher product quality. This review article focuses on the PI, discussion about its dimensions and structure, what it involves, and recent developments in PI which can be achieved using the technique of cavitation. Recommendations for optimum operating parameters needed for process intensification using cavitation phenomena which has been reported in the literature have been presented along with some of our own work in the area. Some experimental case studies have been presented which highlight the degree of intensification achieved when cavitation is used for different physicochemical transformations. These physicochemical transformations include crystallization, emulsification, extraction, wastewater treatment, depolymerization, and water disinfection.

This work reports on the process optimization of ultrasound-assisted, paraffin wax in water nanoemulsions, stabilized by modified sodium dodecyl sulfate (SDS). This work focuses on the optimization of major emulsification process variables including sonication time, applied power and surfactant concentration. The effects of these variables were investigated on the basis of mean droplet diameter and stability of the prepared emulsion. It was found that the stable emulsion with droplet diameters about 160.9 nm could be formed with the surfactant concentration of 10 mg/ml and treated at 40% of applied power (power density: 0.61 W/ml) for 15 min. Scanning electron microscopy (SEM) was used to study the morphology of the emulsion droplets. The droplets were solid at room temperature, showing bright spots under polarized light and a spherical shape under SEM. The electrophoretic properties of emulsion droplets showed a negative zeta potential due to the adsorption of head sulfate groups of the SDS surfactant. For the sake of comparison, paraffin wax emulsion was prepared via emulsion inversion point method and was checked its intrinsic stability. Visually, it was found that the emulsion get separated/creamed within 30 min. while the emulsion prepared via ultrasonically is stable for more than 3 months. From this study, it was found that the ultrasound-assisted emulsification process could be successfully used for the preparation of stable paraffin wax nanoemulsions.