Engineering and Information Technology Collected Works - Research Publications
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ItemEngineering Principles of Ultrasound Technology(Elsevier, 2017-07-01)The book also contains how the technology could be launched in industry. Part I discusses ultrasound for food preservation, with topics like advances on thermo-sonication and nanothermosonication. This Chapter describes how ultrasonic waves are formed in ultrasonic baths, with horn transducers and in other acoustic devices. The range of acoustic frequencies and powers relevant to sonoprocessing are outlined. The concept of acoustic cavitation is explained as the formation of a field of small bubbles within a liquid exposed to ultrasound. It is the repetitive collapse of these bubbles under the influence of the acoustic field that is the dominant cause of most effects used in food processing, as it causes fluid turbulence and microjetting. The extent to which it is effective is a function of the system temperature and pressure, as well as fluid properties such as the surface tension, density and viscosity. The concept of acoustic nebulisation, which is the formation of a fine mist, is also explained.
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Item110th Anniversary: Process Developments in Carbon Dioxide Capture Using Membrane Technology(American Chemical Society, 2019-07-17)Carbon capture and storage has declined in prominence as a large scale response to climate change, but carbon dioxide capture will remain important into the future for the hydrogen economy, and for steel and cement as well as chemical production. Membrane technology can be a significant component of this industry if it is cost competitive. While most scientific research is focused on developing novel materials for this application, it is the process design of the membrane operations that is much more critical in reducing these costs. In postcombustion capture, this involves optimization of the pressure driving force across the membrane, either through feed compression or permeate vacuum pumping, integration of downstream cryogenic purification, and the use of combustion air sweeps. In precombustion capture, integration of the membrane into the steam reformer or water gas shift reactor is key. Membrane contactors can also play a role but must be carefully engineered to ensure pressure drop control and to minimize capillary condensation of water.
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ItemMembrane Separations in the Dairy Industry(Academic Press, 2019-03-15)Membrane filtration is widely used in the dairy industry. This chapter provides an overview of the various applications of reverse osmosis, nanofiltration, ultrafiltration, and microfiltration in the processing of milk, and dairy waste streams. A summary of milk composition and chemistry is provided in relation to membrane processing. Applications of membrane filtration in milk processing are then discussed, including on-farm concentration of milk, removal of microorganisms, and fractionation of protein and fat. Coverage also includes the use of membranes for standardizing the composition of cheese milk, processing and concentration of whey and whey proteins, and purification and treatment of dairy wastes. Recent progress in the understanding of flux decline and fouling in dairy membrane filtration is outlined, along with the potential application of ultrasound.
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ItemMEMBRANE TECHNOLOGY Embedded enzymes catalyse capture(NATURE PUBLISHING GROUP, 2018-05)
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ItemSolubility of Calcium Phosphate in Concentrated Dairy Effluent Brines(AMER CHEMICAL SOC, 2017-05-24)The solubility of calcium phosphate in concentrated dairy brine streams is important in understanding mineral scaling on equipment, such as membrane modules, evaporators, and heat exchangers, and in brine pond operation. In this study, the solubility of calcium phosphate has been assessed in the presence of up to 300 g/L sodium chloride as well as lactose, organic acids, and anions at 10, 30, and 50 °C. As a neutral molecule, lactose has a marginal but still detectable effect upon calcium solubility. However, additions of sodium chloride up to 100 g/L result in a much greater increase in calcium solubility. Beyond this point, the concentrations of ions in the solution decrease significantly. These changes in calcium solubility can readily be explained through changes in the activity coefficients. There is little difference in calcium phosphate speciation between 10 and 30 °C. However, at 50 °C, the ratio of calcium to phosphate in the solution is lower than at the other temperatures and varies less with ionic strength. While the addition of sodium lactate has less effect upon calcium solubility than sodium citrate, it still has a greater effect than sodium chloride at an equivalent ionic strength. Conversely, when these organic anions are present in the solution in the acid form, the effect of pH dominates and results in much higher solubility and a calcium/phosphate ratio close to one, indicative of dicalcium phosphate dihydrate as the dominant solid phase.
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