Electrokinetic Processes in Chemical Engineering

There is continuing strong interest in the use of electrical energy for driving chemical and physical processes which are of interest to chemical engineers. Electrokinetic processes in chemical engineering are concerned with a potentially wide range of electrically driven phenomena. These range from electrode processes for chemical conversions and metal recovery; electrically enhanced ion transport exploited in separation processes; deposition techniques; enhanced spraying processes; electrospinning,; and enhanced physical separations involving solid-liquid mixtures (e.g. electrofiltration), gas-solid mixtures (e.g. electrostatic precipitation), and liquid-liquid mixtures (e.g. coalescence). Applications can range from well established processes such as electrowinning for base metals production, through to novel electrochemical oxidation processes for waste-water treatment. There are significant roles for electrochemical processes in biotechnology, and in the development of more efficient transportation energy systems. One of the main drivers for the wider use of electrically driven processes is the requirement for more intensive production methods, and the on-going push for stricter emission standards, especially for atmospheric and water-borne liquid discharges. Reduction in carbon dioxide and other greenhouse gas emissions is another very important driver. Electrokinetic techniques have an important role in the adoption of more intensive process technologies, for distributed manufacturing techniques, and the desire to reduce process plant footprint and material inventories. A further consideration is the development of biological systems and products, which exploit differences in electrical properties for improved processes such as downstream-separations. The current preoccupation with the search for cheaper alternative sources of energy is another major driving force behind future developments in electrical technologies. Applications include solar electricity production, fuel cell technology, enhanced electrically based water splitting, and the use of electrostatics for the improvement of biodiesel production.