Effect of the Dewaxol 7801 depressant-dispersant additive on summer diesel fuel

Obtaining winter diesel fuel is an expensive and complex process, in which paraffinic hydrocarbons are removed from the fuel. Today, the consumption of winter diesel fuel in Russia has reached its maximum, and the volume produced is not enough to meet the needs of the Russian market. Therefore, obtaining winter diesel fuel from summer grades, by adding a depressant additive, remains relevant. The most common depressants are ethylene vinyl acetate copolymers. The effectiveness of depressant-dispersant additives depends on the fractional and group hydrocarbon composition of diesel fuel. Also, the physicochemical characteristics of the paraffins contained in the fuel play an important roleDuring long-term storage of fuel, depressants do not prevent fuel stratification. Therefore, together with a depressant additive, a paraffin dispersant is used, the composition of such additives includes mainly amides and imides of mono- and dicarboxylic acids. Dewaxol 7801 depressant and dispersant additive is a specially selected composition based on surfactants and copolymers in a hydrocarbon solvent. The use of this additive makes it possible to improve the low-temperature performance of diesel fuel without affecting other properties. From the low-temperature properties of diesel fuel, we have chosen the limiting filterability temperature, since it is this temperature that characterizes the real working conditions. When the maximum filterability temperature is reached, the n-paraffin crystals reach sizes exceeding the pore diameters of the filters, the fuel is not pumped through the fine filters of the high-pressure fuel pump, and the fluidity of the fuel deteriorates. The article shows the effect of Dewaxol 7801, a depressant-dispersant additive, on summer diesel fuel, in various concentrations and when the fuel is heated from 40 to 60 degrees in steps of 10 degrees.

Development of pour point depressants for crude oil and study of their properties

A pour point depressant additive has been developed to reduce the pour point of paraffinic oils. The depressant contains a (non-ionic) surfactant, a depressant component and a solvent. The depressor properties of the developed compositions have been studied. It has been established that while adding the compositions to the oil mixture, at a concentration of 0.02% wt. the pour point decreases from +31 oC to -3 - +7 оС, and at a concentration of 0.04% wt. up to -5- + 4 оС. Under the effect of the developed compositions the oil viscosity at + 35 оС decreases from 46.3 mPa·s to 22.1-27.7 mPa·s, and at + 40 °C - from 38.2 mPa·s to 16.6-21.6 mPa·s. Viscosity reduction performance at the indicated temperatures are 40.2-51.6% and 43.5-56.5%, respectively. Compositions 8, 14 and 17 exhibit higher depressor properties.

USE OF POLYETHYLENE WASTE AS DEPRESSIVE ADDITIVES

Was investigated effect of low molecular weight polyethylene (LMPE) as a depressant additive to low-viscosity marine fuel and diesel fuel. It is confirmed that using LMPE in diesel fuel, the requirements of GOST 19006-73 in terms of the “filterability coefficient” are not provided. Has been found a method for producing a depressant additive based on LMPE for diesel fuel, which ensures full compliance of the fuel with the requirements of technical documentation. The method of thermal destruction of polyethylene expand the raw material base for additives.

Improving the cold flow properties of marine diesel fuel using centrifugation

The possibility of improving the low-temperature properties of marine diesel fuel of the Antipinsky Refinery by dewaxing was studied. Paraffin was isolated from the fuel in a centrifuge in the presence of a depressant additive. The depressant additive is selected from a series of synthesized additives for depressant effectiveness. The influence of the centrifuge rotor speed, the additive content and the initial cooling temperature of the sample on the dewaxing parameters of the fuel was studied. The possibility of isolating the additive from the obtained paraffin concentrates is shown. The dewaxing products obtained under optimal conditions were studied. A paraffin concentrate product containing 40.03% solid paraffins was isolated from fuel. Paraffin was isolated from paraffin concentrate by dewaxing with a selective solvent. The cloud point and freezing point of paraffin were 30 and 29 ° C, respectively. When converted to the original fuel, the amount of released paraffins was 7.3% of the 21% by weight contained in the original fuel. The fuel obtained at optimal parameters for low temperature properties corresponds to grade D of diesel fuel according to EN 590: 2009.