OPTIMISATION OF THERMAL PLASMA TREATMENT OF PETROLEUM OILY SLUDGE USING RESPONSE SURFACE METHODOLOGY (RSM)

Abstract

The demand and the production of petroleum products have led to the accumulation of large volumes of petroleum oily sludge. This petroleum oily sludge is a notorious waste sludge that is harmful to humans, animals and the entire ecosystem. Traditional methods of treating the oily sludge do not provide the much-needed benign treatment. Thus, the application of thermal plasma technology in the treatment of petroleum oily sludge.  In this research, the treatment of petroleum oily sludge using the novel thermal plasma technique was optimized using Design Expert Software, employing response surface methodology (RSM) and Central composite design (CCD). Two quadratic models relating the two output responses, cold gas efficiency (CGE) and CO/CO₂ ratio, to the operating variable, plasma arc current, plasma gas flow rate and treatment time, were developed. The developed models showed a good fit with correlation coefficients of 99.32% and 99.66% for CGE and CO/CO₂ ratio, respectively. The optimum conditions of 52.59% and 1.80 for CCE and CO/CO₂ ratio, respectively, were obtained at a plasma arc current of 188.15 A, plasma gas flow rate of 31.54 l/min and a treatment time of 1.89 min.