Granular activated carbon (GAC) has been used for purification of air, flue gas treatment and many other applications. The exhaust gases from high power diesel engines require high volume of GAC (hundreds of kg) to adsorb the pollutants such as NOx and VoCs as the volume flow rate is relatively high (thousands of l/s). In such cases, it would be highly economical to reuse the GAC many times through regeneration (i.e. desorption of NOx and VoCs).
Regeneration can be effectively and efficiently performed using microwave energy. The regeneration can be done in two ways; inline during adsorption or offline after adsorption. Offline is applicable when the space requirement is not an issue. When space is a limiting factor, inline regeneration is an advantage in two ways; no need for a separate regenerating chamber other than adsorption chamber and requires lower quantity of GAC.
The underpinning science of the regeneration mechanism using microwave is not well understood. The aim of the PhD research will be to investigate the scientific details of the regeneration process and the associated chemistry. Since the diesel exhaust gas contains moisture, some parts of the NOx content will be converted into HNO3 and possible other by-products.
The research will also investigate the constituents of the by-products using GCC and Mass spectrometry. The student will investigate the chemistry associated with the regeneration process and by-product formation using experimental techniques.