RU2730473C1 - Method of viscous oil products density determination - Google Patents

Abstract

FIELD: measurement; oil industry.

SUBSTANCE: invention relates to a method of determining density of dark and viscous petroleum products. Method involves preparing the sample and heating it in a drying cabinet. According to the invention, the heated sample is poured onto an ice cube, the sample cooled down on ice is transferred into a glass with cooled water to +10…+15 °C after at least a minute, thereafter, calcium chloride brine is poured into the shell in a thin stream, the liquid is periodically mixed in the barrel, after which the sample floating in the barrel is observed. In case the sample drops to the bottom, pickles are continued to be poured in a thin stream. If the sample breaks off from the bottom and begins to rise, then the measurements are completed. Then liquid is poured into cylinder and its density is determined with help of hydrometer and thermometer. Density is re-calculated according to GOST 3900-85 tables.

EFFECT: high accuracy of analysis, reduced amount of sample, shorter time for analysis and cleaning of working room after analysis.

1 cl, 1 ex

Description

The invention relates to methods for determining the density of dark and viscous oil products with a density of 1 g / cm3, in particular, for determining the density of such oil products as asphalt, bitumen, tar and other heavy oil residues.

Known areometric method for determining density, described in GOST 3900-85 and ASTM D1298-12b (2017), to determine the density, relative density (specific gravity) or density in API degrees of low-viscosity liquids. When analyzing viscous opaque petroleum products, which are solids at room temperature, difficulties arise that lead to an increase in the analysis time and a decrease in its accuracy. To reduce the error when using this method in connection with measurements of the characteristics of large volumes of oil, readings of the hydrometer should be taken at a temperature close to the temperature of the main volume of oil. But to bring such petroleum products as tar, asphalt, etc., into a low-viscosity liquid state, it is necessary to heat them to a temperature of 100 ° C and above, which will inevitably lead to large errors when recalculating to the value of the relative density at temperatures of 20 ° C and 15 ° C. In addition, when determining the density in a cylinder located on a laboratory bench at room temperature, the temperature of the oil product will drop rapidly, and the thermometers proposed in the standards have room temperature before immersion in the oil product, and after immersion, it is necessary to wait until the column of mercury stops. All this leads to a delay in the analysis time. When the thermometer is stirring the oil, the ball of the thermometer touches the steel wall, causing the temperature to drop rapidly, leading to another possible error. To reduce the time to reach equilibrium between the hydrometer and the mercury column of the thermometer, it is necessary to lower the thermometer and the hydrometer into the cylinder with the oil product at the same time, but this can also contaminate the scale, both the hydrometer and the thermometer, which will lead to difficulty in determining the density.

After the analysis, a significant amount of time is spent on cleaning the working room and washing the dirty dishes. To wash dishes from tar or asphalt, special steaming devices and a large amount of solvent are required.

The objective of the present invention is to eliminate the above disadvantages with the achievement of the following technical result: increasing the accuracy of the analysis, reducing the amount of the sample and the time for conducting and cleaning the working room after the analysis.

This problem is solved by the fact that in the method for determining the density of dark and viscous oil products, including preparing a sample, heating it in an oven, recalculating the density according to the tables of GOST 3900-85, according to the invention, the heated sample is poured onto an ice cube that has cooled down for at least a minute. on ice, the sample is transferred into a glass with chilled water up to +10 - + 15 ° С, then calcium chloride brine is poured into the glass in a thin stream, the liquid is periodically stirred in the glass, after which the sample is observed floating in the glass if the sample falls to the bottom, continue to pour brine in a thin stream, in another case, if the sample breaks off from the bottom and begins to rise slowly, the measurements are completed at this, and the liquid is poured into the cylinder and its density is determined using a hydrometer and a thermometer. If the sample floats to the top, in case of overflow of brine, water is poured into it and wait until the sample begins to slowly descend.

The proposed method can be used for serial analyzes.

In a high beaker with a height of 250 mm and above, begin the determination of the density of the sample with the lowest density, and then remove a piece of the sample and place the next higher density. To increase the accuracy of the method, the density is determined in a high vessel where the hydrometer floats, and its reading and temperature are measured.

The method based on equalizing the density of the oil in a salt solution is carried out as follows.

- Equipment utensils and reagents:

Technical calcium chloride;

- Ice generator;

Chemical glass, 250 ml;

Glass stick;

Conical flask;

Measuring cylinder for 100 ml;

Areometer aon-1;

Thermometer tl2.

The sample is preheated in an oven to reduce its viscosity, but not higher than 180 ° C. To speed up the analysis it is allowed to break off a piece of the sample. The heated sample is poured onto an ice cube. After a minute, the sample cooled down on ice is transferred into a glass with water cooled to +10 and + 15 ° C. The water is cooled so that the sample does not stick to the walls and to the bottom of the beaker. After that, brine of calcium chloride is poured into the glass in a thin stream. The liquid in the glass is periodically mixed. After that, watch the breakdown floating in the glass. If the sample falls to the bottom, continue to pour the brine in a thin stream. If the sample detaches from the bottom and begins to rise, the measurement is completed at this point, and the liquid is poured into the cylinder, and then its density (ρ) is determined using a hydrometer and a thermometer.

For example, ρ = 1.028 at t = 14 ° C, we find in the GOST 3900-85 table ρ = 1.0243 at t = 20 ° C.

Example.

In a tall beaker, filled with chilled water so that the hydrometer (1000-106) does not touch the bottom of the beaker, place the sample with the supposedly lowest density. The sample piece sinks to the bottom, which means that its density is higher than that of water. After that, calcium chloride brine is poured into the glass in a thin stream, the liquid in the glass is periodically stirred, observing the sample floating in the glass. If the sample falls to the bottom, continue to pour brine in a thin stream, otherwise, if the sample breaks off from the bottom and begins to rise, the density (ρ1) on the hydrometer scale and the temperature (t1) of the water in the glass are recorded. Then clean water is poured into the glass in a thin stream, the liquid in the glass is periodically stirred until the sample sinks to the bottom, after which the temperature (t2) and density (ρ2) of the brine are again recorded.

The result of the analysis is to determine the arithmetic mean of two measurements. To convert density at the measurement temperature to density at 20 ° C, you can use standard tables from GOST 3900-85.

A sample with a certain density is removed from the beaker and the next sample in increasing density is placed in the beaker according to the algorithm described above,

ρ1 = 1.020 at t1 = 12 ° С

ρ2 = 1.019 at t2 = 13 ° C,

converting the density to a temperature of 20 ° C according to the table:

ρ1 ²⁰ = 1.015

ρ2 ²⁰ = 1.0146

consider the arithmetic mean;

ρ = (1.015 + 1.0146) / 2 = 1.0148, after which the density determination is completed.

Claims (1)

A method for determining the density of dark and viscous oil products, including preparing a sample, heating it in an oven, recalculating the density according to the tables of GOST 3900-85, characterized in that the heated sample is poured onto an ice cube, the sample cooled on ice is transferred to a glass at least a minute later with chilled water up to +10 - + 15 ° С, after that the brine of calcium chloride is poured into the glass in a thin stream, the liquid is periodically stirred, after which the sample is observed in the glass, if the sample falls to the bottom, the brine is continued to be poured in a thin stream, in the other case, if the sample breaks off from the bottom and begins to rise, the measurements are completed, the liquid is poured into the cylinder and its density is determined using a hydrometer and a thermometer.