Thermal Conversion Parameters of Composite Liquid Fuels on the Basis of Petroleum Sludge and Additions of Hydrocarbon Origin

With the aim to develop petroleum sludge thermal recycling technologies, the parameters characterizing the combustion of these sludges in mixtures with spent oils, diesel fuel, and methanol are studied. In combusting petroleum sludge without additions, sulfur and nitrogen oxide emissions are recorded in amounts four times higher than those produced in combusting diesel fuel. If petroleum waste is mixed with spent oils, the specific concentrations of SO2 and NO (recalculated for the heating value and mass of fuel combusted) decrease by 20–29 and 7–10%, respectively, and by 30 and 35–40%, respectively, when combined with diesel fuel. The study results testify that there are wide possibilities for reducing the burden on the environment by subjecting petroleum sludges to thermal recycling. Their thermal inertia at the evaporation and thermal decomposition stage decreased most efficiently when mixed with methanol and diesel fuel. Despite the difference in some individual characteristics of the additions studied, all of them had a commensurable effect on the change in the integral indicator of petroleum sludge thermal recycling efficiency—it increased by 12–16%. It is shown that diesel fuel is the most promising addition. The introduction of this component results not only in obtaining better environmental and power performance of the process, but also in that the petroleum sludge viscosity is reduced by four times, due to which the fuel atomization is improved, and its more complete combustion is achieved in power generating boilers of various types. The results of experiments carried out on two facilities of different scales can serve as substantiation of the need to develop the problem area of petroleum sludge thermal treatment with heat generation.