TRANSFORMATION OF SHORT-CHAIN n-ALKANES UNDER TREATMENT OF HYDRODYNAMIC CAVITATION

Abstract

The structure and properties of oil disperse systems (ODS) are mainly determined by the presence of paraffin hydrocarbons (n-alkanes) in the crude oil and natural gas liquid. Short-chain n-alkanes (С8-С17) are part of ODS dispersion medium. Under oil refining treatment, they concentrate in the distillate fractions and influence the operation characteristics of product liquid fuels and natural gas liquid.We studied the influence of hydrodynamic cavitation on the short-chain n-alkanes. Cavitation was produced by a high pressure disintegrator DA-1. A plunger pump produced compression pressure 50 MPa. Cavitation treatment was applied three times in a row. The research object was liquid oil paraffin containing 96.5% wt. n-alkanes С9-С21 (including 95% wt. С9-С17) and 2.5% wt. isoalkanes С10-С20; the balance was a mixture of other hydrocarbons. The results of GLC demonstrated that the total conversion of initial n-alkanes С14-С17 was not high, but it grew growing constantly: after the 1st cavitation cycle - 1.4%, after the 2nd cavitation cycle - 2.7%, after the 3rd one - 3.6%. At the highest conversion, the concentration of n-alkanes C8-C13 in liquid oil paraffin increased by 28% rel., and the concentration of n-alkanes C18-C22 - by 36% rel. The information obtained allows predicting the influence of the short-chain n-alkanes present in the oil feed on alterations of its hydrocarbon and fraction composition after cavitation.

Cavitation as a method of improving the energy efficiency of oil industry enterprises

“…The results obtained in the work [12] confirmed the character of the main directions of conversion of short-chain alkanes under the influence of hydrodynamic cavitation. The presence of such hydrocarbons in the composition of oil and gas condensate allows, due to hydrodynamic cavitation, to slightly increase the content of alkanes S18-S22 (boiling limits of 310-370 ° C) and, to a greater extent, C8 -C13 (boiling in the range of 125-235 ° C).…”

Oxidation of Sulphur pollutants in model and real fuels using hydrodynamic cavitation

“…The composition and polarity of diesel, coupled with a potentially higher number of cavitational events may contribute to the improved formation and stability of the fuel-water emulsion [23] , [24] . Processing of real fuels may also benefit from an upgrading effect reducing their viscosity when exposed to cavitating conditions [29] , [30] allowing for easier processing and mixing [31] . The viscosity of diesel is typically 1.9 to 3.7 mPa-s at 40 °C, and dodecane (used to simulate diesel) is 0.8498 mPa-s at 25 °C [32] .…”