Scientific and practical aspects of development of ultrafine dispersions of modified petroleum oils

Abstract

The possibility of dispersing depressing additives in diesel oil using a static radiator for production of ultrafine emulsions having disperse-phase particles sized between 2.5 and 4 m is shown. Depressing additives such as olefinic hydrocarbon-based linear high-molecular compounds, which possess exceptional physico-chemical resistance to oxidation, thermoelasticity, and high mechanical properties, but do not exhibit a coagulating effect, are produced by nanophase catalysis technology. Compound (mixed) solvents are used as additive diluents. Laboratory tests of the additives in hydrofined diesel, furnace, and marine oils, and various crude-oil fractions showed a high depressing effect. K e y w o r d s : c o m p o u n d d e p r e s s i n g a d d i t i v e s , m a r i n e o i l , f u r n a c e o i l , u l t r a s o n i c a c t i o n , low-temperature properties, dispersity, pour point.Rational utilization of combustible petroleum materials (CPM), improvement of their quality, and expansion of reserves are critical problems of the oil-refining and petrochemical industry. The problem of improving the low-temperature properties of CPM is an urgent problem for Russia and other northern countries, since the cold climatic zone occupies 80% of the Russian landmass. This problem is acerbated by the fact that all the more paraffinic crudes are being extracted in Russia. High-molecular paraffins are responsible for degraded low-temperature properties of the crudes themselves, and also the products of their refinement. For this reason, the diesel fractions with a boiling point no higher than 290C must be separated to ensure an acceptable pour point. This gives rise to a significant reduction in refinement of diesel oil (DF), and, accordingly, the depth to which the crude is refined [1-5].Use of depressing additives is the most effective and economically expedient means of improving the low-temperature properties of the crudes. High-molecular compounds (HMC) with a capacity to mix rapidly with petroleum oils at an elevated temperature are employed in the production of depressing additives. The degree of dispersity of the additive will depend on its ability to mix with the oil. The process of combining DF with HMC takes place in two stages: emulsification and subsequent swelling, or complete solution 466 of the additive [6]. The procedure employed for the combination should completely eliminate fractionation of the oil and destruction of the HMC.Diesel oils modified with HMC, including block-copolymers are disperse nonuniform systems, and, consequently, are thermodynamically unstable, giving rise to their stratification (pentization) , especially at elevated temperatures under static conditions in the absence of agitation). The higher the physico-chemical affinity of BMC for DF, the higher the degree of dispersity of the additive in the oil and stratification stability of the composition petroleum product.Use of acoustic equipment to disperse additives in oils. Best results are achieved when the HMC and oils are combined usi...