Search

The use of depressant additives is the most common method for producing diesel fuels with improved low-temperature properties. However, the depressants effectiveness largely depends on the composition of the diesel fuel, in particular on the content of n-paraffinic hydrocarbons, which to the greatest extent determine the low-temperature properties of the fuel. The work revealed the regularities of the n-paraffins addition influence on the depressant additives effectiveness. It was found that the addition of n-paraffins to blends of diesel fuels with depressants in low concentrations (0.05–0.50% wt.) enhances the depressants effectiveness in relation to the cold filter plugging point: maximum at 6–16 °C depending on the diesel fuel sample. It is shown that the effect is observed for DF of various compositions, various depressants, and also n-paraffins of various compositions. It was established that the positive effect of adding n-paraffins increases with the heavier added n-paraffins. Recommendations have been developed for obtaining diesel fuels with improved low-temperature properties and enhancing the depressant additives effectiveness: for a sample of straight-run diesel fuel F1, it is recommended to use a blend of fuel, depressant A1 and 0.50% wt. n-paraffins, separated from heavy gasoil; for a sample of straight-run diesel fuel F2, it is recommended to use a blend of fuel, depressant A2 and 0.50% wt. n-paraffins, separated from heavy gasoil or a blend of fuel, depressant A1 and 0.05% wt. n-paraffins, separated from highly paraffinic oil fraction. The revealed patterns and the developed recommendations will allow increasing the production of low-freezing DF brands, and also offer a resource-efficient option for using heavy gas oil fractions. The results obtained in the work contribute to expanding the understanding of the mechanism of interaction between diesel fuel hydrocarbons and the active ingredients of depressant additives. [ABSTRACT FROM AUTHOR]

The use of depressant additives is the most common method for producing diesel fuels with improved low-temperature properties. However, the depressants effectiveness largely depends on the composition of the diesel fuel, in particular on the content of n-paraffinic hydrocarbons, which to the greatest extent determine the low-temperature properties of the fuel. The work revealed the regularities of the n-paraffins addition influence on the depressant additives effectiveness. It was found that the addition of n-paraffins to blends of diesel fuels with depressants in low concentrations (0.05–0.50% wt.) enhances the depressants effectiveness in relation to the cold filter plugging point: maximum at 6–16 °C depending on the diesel fuel sample. It is shown that the effect is observed for DF of various compositions, various depressants, and also n-paraffins of various compositions. It was established that the positive effect of adding n-paraffins increases with the heavier added n-paraffins. Recommendations have been developed for obtaining diesel fuels with improved low-temperature properties and enhancing the depressant additives effectiveness: for a sample of straight-run diesel fuel F1, it is recommended to use a blend of fuel, depressant A1 and 0.50% wt. n-paraffins, separated from heavy gasoil; for a sample of straight-run diesel fuel F2, it is recommended to use a blend of fuel, depressant A2 and 0.50% wt. n-paraffins, separated from heavy gasoil or a blend of fuel, depressant A1 and 0.05% wt. n-paraffins, separated from highly paraffinic oil fraction. The revealed patterns and the developed recommendations will allow increasing the production of low-freezing DF brands, and also offer a resource-efficient option for using heavy gas oil fractions. The results obtained in the work contribute to expanding the understanding of the mechanism of interaction between diesel fuel hydrocarbons and the active ingredients of depressant additives.

The process of hydrogen-free upgrading of diesel fraction on ZSM-5 type zeolite catalyst was implemented at the laboratory catalytic unit under the conditions of varying the process temperature. The composition and characteristics of the feedstock diesel fraction and the obtained upgrading products were investigated. The obtained diesel fraction upgrading products were tested for compliance with the standards. The directions of hydrocarbon transformations in the process of upgrading on a zeolite catalyst were considered. The influence of the upgrading process temperature on the composition and characteristics of the obtained products was estimated. For the first time, the optimal technological parameters for the implementation of the upgrading process on a zeolite catalyst from the perspective of the production of arctic diesel fuel were determined.

The Ministry of Defense of the Russian Federation have developed a unique standard for Arctic diesel fuel, which implies attainment of low-temperature indices of diesel fuel below -65°C without additives. Because of its high commercial production, over the time from 2017 through 2020 PAO Slavneft-YaNOS (Slavneft-YaNOS PJSC) prepared experimental and semi-industrial batches of Arctic diesel fuel during several pilot-scale runs for the Ministry of Defense of the Russian Federation. This fuel has now been put into production. [ABSTRACT FROM AUTHOR]

The paper presents the results of determining the characteristics and composition of straight-run diesel fuels. In addition, low-temperature properties (cloud point, cold filter plugging point, pour point) the diesel fuels and low-temperature additives blends are studied. The regularities of influence the nparaffins and aromatic hydrocarbons content in the diesel fuel composition on the effectiveness of the low-temperature additive is identified. [ABSTRACT FROM AUTHOR]

The article considers the feasibility of using jet fuel as a low-temperature additive for diesel fuels. The main physicochemical properties and operational characteristics of straight-run diesel fuel sample, jet fuel sample, and their blends have been experimentally determined. It has been established that the use of jet fuel as a low-temperature additive allows producing summer diesel fuel brands. Moreover, it has been established that the use of jet fuel in combination with a depressant- dispersant additive allows producing interseasonal diesel fuel. [ABSTRACT FROM AUTHOR]

The problems of utilizing diesel fuel produced from oil from Talakan oil field (Sakha Republic, Yakutia) have been considered. The analysis of applying depressor additives has been conducted with the objective of improving low-temperature properties of the produced fuel. [ABSTRACT FROM AUTHOR]

Dewaxing of a diesel fuel (DF) of heavy fractional composition (HFC) in an electric field using Dodiflow-4971 depressants and higher fatty alcohols (HFAs) as process activators is studied. It is shown that dewaxing of DF of HFC allows production of DF with improved low-temperature properties. The yield of dewaxed diesel fuel (DDF) at -15°C reaches 75.8 wt% with cloud-point depression of 17°C; at -5°C, the DDF is 77.8 wt% with 11°C depression. The electric charge of alcohols generated during crystallization and the temperature range of thermoelectric effects where the charge persists have a combined effect on the DF dewaxing indices. The dewaxing and quality indices of the DDF are greater for higher values of these characteristics. It is shown that the effectiveness of HFAs as dewaxing activators increases in the order tetradecanol < hexadecanol < octadecanol < C HFA fraction < C HFA fraction. [ABSTRACT FROM AUTHOR]

The influence of different groups of diesel hydrocarbons on the physicochemical properties and performance characteristics of diesel fuels has been considered. The parameters to be evaluated have been cetane number, cetane index, diesel index, pour point, and cold filter plugging point. It has been shown that the hydrocarbon group composition, which reflects only the amount of arenes and paraffinic-naphthenic hydrocarbons, gives insufficient information for prediction of the performance properties of fuels. A more detailed study of the hydrocarbon composition of each group of compounds-the ratio of mono-, bi-, polycyclic arenes, the concentration and the ratio of high- and low-melting-point n-alkanes and isoalkanes-has made it possible to reveal the influence of each group on individual fuel characteristics. [ABSTRACT FROM AUTHOR]

Abstract: Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats is, has undergone rapid development and acceptance as an alternative diesel fuel. Kinematic viscosity is one of the fuel properties specified in biodiesel standards, with 40°C being the temperature at which this property is to be determined and ranges of acceptable kinematic viscosity given. While data on kinematic viscosity of biodiesel and related materials at higher temperatures are available in the literature, this work reports on the kinematic viscosity of biodiesel and a variety of fatty acid alkyl esters at temperatures from 40°C down to −10°C in increments of 5°C using the appropriately modified standard reference method ASTM D445. Investigating the low-temperature properties of biodiesel, including viscosity, of biodiesel and its components is important because of the problems associated with the use of biodiesel under these conditions. Such data may aid in developing biodiesel fuels optimized for fatty ester composition. An index termed here the low-temperature viscosity ratio (LTVR) using data at 0°C and 40°C (divide viscosity value at 0°C by viscosity value at 40°C) was used to evaluate individual compounds but also mixtures by their low-temperature viscosity behavior. Compounds tested included a variety of saturated, monounsaturated, diunsaturated and triunsaturated fatty esters, methyl ricinoleate, in which the OH group leads to a significant increase in viscosity as well as triolein, as well as some fatty alcohols and alkanes. Esters of oleic acid have the highest viscosity of all biodiesel components that are liquids at low temperatures. The behavior of blends of biodiesel and some fatty esters with a low-sulfur diesel fuel was also investigated. [Copyright &y& Elsevier]