The influence of a polymer waste pyrolysis product on rheological properties of high viscosity oil

Abstract

Highly viscous (heavy) oil shows low mobility, which affects the efficiency of its pipeline transportation. The delivery of oil from wells to refineries has long been the cause of energy expenditures during pipeline transportation. Various methods are employed to reduce these expenditures: heating, dilution, ultrasonic exposure and emulsification in water. We have studied the influence of rubber waste pyrolysis product on rheological and physical characteristics of high-viscosity oil in order to reduce its viscosity and, as a consequence, to reduce the system resistance during pipeline transportation. The results have shown that addition of 5% pyrolysis product significantly reduces viscosity and thixotropy of high-viscosity oil at temperature as low as 20 °C. The greatest effect of viscosity reduction was observed at the temperature of 30 ⁰C, while this effect was leveled out at 40 ⁰C. However, when increase in shear stress surpassed 10 Pa, an almost linear dependence was observed in viscosity reduction in the range from 5% to 20% both for oil and for oil systems with the pyrolysis product. At the same time, when shear stress and temperatures changed, the nature of flow of oil systems with the pyrolysis product almost completely corresponded to the behavior of oil. In general, given the lower viscosity of the pyrolysis product, behavior of the systems is regular, with the exception of the oil system plus 5% pyrolysis product at the temperature of 40 ⁰C, when the dynamic viscosity is higher than the oil viscosity across the entire range of shear rates. However, results of the study show that the systems are unlikely to form eutectics because the chilling temperature of the test oil was 29.8 ⁰C, the chilling temperature of the pyrolysis product was below 5 ⁰C, and the chilling temperature of oil : pyrolysis product system (80 : 20) was 27.2 ⁰C. The resulting systems remain thixotropic and have a non-Newtonian nature of the flow, that is, paraffins and resinous substances do not form solutions and eutectics with the pyrolysis product.