Oxidation of CH3CHO by O3 and H2O2 Mixtures in Supercritical CO2 in a Perfectly Stirred Reactor

Organic waste streams must be handled in an environmentally benign manner. We present an alternative to incineration for such waste streams. The process involves the dissolution of the organic byproducts into supercritical carbon dioxide and the subsequent oxidation of these compounds by ozone and hydrogen peroxide. The feasibility of the process is examined through numerical calculations on a surrogate organic species, CH3CHO. A parametric matrix of the optimal conditions that allow for complete destruction of acetaldehyde (into CO2 and H2O) and the reaction pathways are evaluated. The oxidation process is exothermic, with as little as 2% acetaldehyde and 4% ozone (in a bath containing 94% supercritical CO2) reacting to produce an almost 600 K rise in temperature. The calculations indicate that the use of nonideal equations of state provides results that are negligibly different from those obtained using the ideal gas relationship.