Method for determining characteristics of liquid oil products sublimation by means of express sublimation and device for realization of said method

FIELD: oil and gas extractive industry.

SUBSTANCE: method includes measuring in given sequence of appropriate parameters with following calculation of determined characteristics on basis of certain relation. Device for determining characteristics for sublimation of liquid oil products contains sublimation retort with dimensions, allowing to place 5-15 ml of analyzed probe therein, device for heating retort in its lower portion with constant and adjusted heating intensiveness, two inertia-less temperature sensors providing for continuous measurement of true value of temperature of sample in steam couple, device for continuous pressure measurement in stem phase of sample during sublimation, which includes pressure sensor as well as capillary and receiving and signals processing sensors, sent by temperature sensors and pressure sensor.

EFFECT: simplified construction, higher speed of operation.

2 cl, 4 ex, 10 tbl, 5 dwg

 

The present invention relates to a method for determining the distillation characteristics of liquid petroleum products using the mini-Express-distillation.

Volatility, or more precisely the ranges of boiling points of the various factions that make up the petroleum products represent a substantial characteristics, allowing to characterize these products, the latter is directly dependent on the molecular weight of these fractions.

Currently, the volatility of petroleum products, as a rule, determined by physical tests under conditions to be determined empirically by standard standards, including ASTM standards, which are recognized experts in all countries.

For example, the norm ASTM D 86 allows to determine the volatile light oil having a boiling point below 400°With, while standards ASTM D 1160 and ASTM D 2892 also allow to determine the volatility of heavy fuel oil having a higher boiling point. In the latter case, in order to lower the boiling point of the analyzed products and thus avoid their decomposition, it is sometimes necessary to resort to distillation in vacuum.

The known device for analysis that meets the above standards. These devices operate on the schema as follows:

The analyzed sample is injected into the distillation flask, equipped with a lead pipe, and close to the Boo tube with a thermometer.

Outlet tube connected to the tubular capacitor associated with the cooling system, the outlet of which is located above a graduated receiving tube.

Heat the flask in a pre-determined conditions to boil the sample and collect the resulting pair after their condensation into the receiving tube.

Note the temperature in the distillation flask vapor for a predetermined volume of condensate collected in the receiving tube.

Build the curve representing the dependence of the content of the collected sample volume percent of the temperature and use this characterizes the sample curve to match a sample to the required specifications.

It should be noted that the temperature in devices operating in accordance with the standard rules are not always correspond to the true boiling temperatures, but can match empirical temperature-dependent terms of experience, in particular, the use of thermometers.

Devices that are currently used for the characterization of liquid petroleum products, allow to obtain reliable and well-reproducible results, which is, therefore, to analyze representative samples, but have some disadvantages, i.e. they are too heavy and bulky. Also required is emy to test the volatility sample volume is relatively large (about 100 ml), and the duration of each test is at least 45 minutes.

To resolve these shortcomings, as evidenced by the researchers Polotsk State University (see the publication of the application Belarus 199880801), the proposed method and device for identifying characteristics of products of the distillation of liquid petroleum products using physical tests, each of which takes only about 10 minutes and requires only a very limited amount (about 5-15 ml).

Characteristics of the analyzed products determined directly from measurements of temperature and pressure and, thus, does not require any measurement of the volume of condensate collected in the receiving tube.

The specified device contains a heated distillation flask with the capillary at the level of the discharge tube, close the tube and equipped with a temperature sensor immersed in the boiling liquid, and a differential sensor which measures the pressure at the entrance to the capillary.

Carried out with the help of this device the method allows to calculate the temperature of the vapor sample at the temperature of liquid in the distillation flask and the rise of the pressure in the flask in the presence of the capillary.

This method of determining the distillation characteristics of petroleum products has some advantages.

Od is ako obtained in this way curves are not sufficiently reliable due to the fact, what, no account taken of changes in barometric pressure, as well as the remains in the distillation flask and loss of sample in the gas phase.

In addition, the temperature of the sample in the liquid phase distorted by heat.

This method is only suitable to determine distillation characteristics of light liquid petroleum products having a boiling point below 400°and may not be used to determine characteristics of the distillation of heavy hydrocarbon oils, because using this method for operation at atmospheric pressure is thermal decomposition of heavy products.

The main disadvantage of this method is that conducted him through the tests do not meet the standard standards, in particular standards ASTM, which is a serious problem, because these standards is now widely accepted by experts for analysis of petroleum products.

The present invention is to overcome the above disadvantages by developing ways to determine the distillation characteristics as light liquid petroleum products, and heavy liquid petroleum products and their mixtures using the mini-Express-distillation thus, in order to obtain reliable and reproducible results corresponding to the results obtained using the dough is in accordance with standard norms and in particular, standards ASTM, universally accepted by experts.

According to the present invention the task can be achieved by use of the method, which consists in the following.

The analyzed sample of about 5-15 ml injected into the distillation flask, heated located below the element and provided with a pressure sensor, and two instantaneous temperature sensors that measure the true temperature of the sample in the liquid phase and the true value of the temperature of the sample in the vapor phase at a level located below the entrance of the outlet tube, which is equipped with distillation flask.

Heat the distillation flask at a constant rate of heating is determined by the nature of the analyzed sample, and maintain it in a state of constant boiling point.

Continuously measure the pressure of steam in the distillation flask at the level of the input into the output tube, and the true temperature of the sample in the liquid phase TLand in the vapor phase Tsand build the graph representing the dependence of this pressure and these temperatures from the time τ1.

Determine the first and second derivatives of the temperature change of the sample in the liquid phase and in the vapor phase

and deduce from them the initial boiling point liquid is AZE T

L
WR
that corresponds to the point for which

Determine the initial boiling point in the vapor phase T

S
WR
which corresponds to the time at which see the beginning of the pressure increase.

Determine the temperature T

L
End
in which is shown a temperature sensor that measures the true value of the temperature of the sample in the liquid phase, corresponds to the value indicated by the sensor, measuring the temperature of the sample in the vapor phase, and take the temperature T
L
End
equal to the temperature of the end of the boil in the vapor phase T
S
F
.

Determine the volume fraction distilled sample νVthe diagram representing the dependence of τ1changes in steam pressure P in the distillation flask and the true values of the temperatures of the sample in the vapor phase T Sexpressed by the equation

where Sf(TS, R) is the total area under the curve of pressure in the refining process, while Sf(TiSPi) is part of the area at the time τ1iand

V

res
i
denotes the volume of liquid in the distillation flask at the time τ1i.

Determine the dependence of the molar fraction of the distilled sample νmfrom the true temperature of the sample in the vapor phase TSaccording to the equation υMi=f(νvithat ρiTSi), in which ρidenotes the molar density of τ1i.

Determine the temperature of the end of the boil in the liquid phase T

L
F
by the method of successive approximations by the formula

where νenddenotes the molar fraction distilled at a temperature T

L
F
sample, and a and k are the coefficients of the mathematical model of the distillation, the corresponding empirical formula

calculated by the method of successive approximations by the equation

where

by calculating at each step the new value T

L
F
up until

Recalculate the dependence of the molar fraction of the distilled sample from the true temperature of the sample in the vapor phase with account balances and losses of the sample in the vapor phase according to the formula

νMi=ν’Mi+ΔLi+ΔSi

in which ΔSi denotes the share of the vapor phase in the process of distillation, ΔLi fraction of liquid phase at the moment of its formation by condensation νMidenotes the molar fraction distilled sample with account balances.

Determine the dependence of the volume fraction distilled sample νvifrom the true temperature of the sample in the liquid phase, described by the formula

νvi=f(νMithat ρiT

L
i
)

Build the appropriate chart.

It should be noted that the mathematical model of the distillation, the corresponding empirical formula

img src="https://img.russianpatents.com/811/8114384-s.jpg" height="12" width="32" >

presented in the publication Dimudu I.A., Jarkova O.N. and Abaev G.N. Mathematical model of fractional distillation of petroleum products and its identification by experimental data // Inzynieria Chemiczna i Procesowa, 1996, V.17, No. 4.

In addition, the experimental data obtained using the above method, correspond to the usual technique of distillation column with a single plate, bearing the name of distillation LBD (Laboratory Batch Distillation or distillation FD (Fractional Distillation).

According to another characteristic of the invention, the intensity of heating of the heating element is regulated depending on the nature of the analyzed sample so that the time required for distillation, was about 5-15 minutes

For sample whose characteristics are not completely known, the intensity of the heat may be at least determined at the preliminary stage of distillation.

According to another characteristic of the invention determine an empirical value of Tstandthe temperature of the sample in the vapor phase, corresponding to the standard norm on the basis of size TLthe temperature of the sample in the liquid phase calculated at the indicated stages by the formula

TiSTAnD=T

l
i
i

in which θ is a function representing the difference between said t what mperature.

The method according to the invention is particularly suitable to determine distillation characteristics of light liquid petroleum products in accordance with standard ASTM D 86.

In this case,

T

D86
stand

an empirical temperature corresponding to the norm ASTM D86, a θ

D86
i
calculated on the basis of the function

and determined either graphically or from the values of the parameters (a, k, T

L
WR
T
L
F
I calculated at stages 1-12.

The method can also be applied to characterize the distillation of heavy hydrocarbon oils having a boiling point above 400°C, at atmospheric pressure without reaching a temperature at which it occurs

the risk of thermal decomposition of the analyzed product.

To do this, pick up a light liquid petroleum product carrier having a boiling point below 300°that with westim analyzed sample, put this liquid carrier of the above operations, to obtain a graph showing the dependence of the molar fraction of the νmdistilled liquid carrier from the true temperature of the liquid in the liquid phase TL: νMi(medium)=f(T

L
i
),

prepare a mixture containing from about 85 to 95% of the liquid carrier and 5-15% of the analyzed sample so that at least 90% of this mixture had a boiling temperature below 360°C

subjecting the mixture to the specified operations to build a graph representing the dependence of the molar fraction of the νmdistilled mixture from the temperature of this mixture in the liquid phase TL: νmi(mixture)=f(T

L
i
),

assume that the temperature of the end of the boil T

HP
f
the analyzed sample is equal to the temperature of the end of the boiling mixture in the liquid phase:

T

HP
F
=T
L
FBP
(mix),

define T

L
F
(mixture) by the method of successive approximations,

calculate the initial boiling point in the liquid phase T

HP
iBp
the analyzed sample by the formula

where T1indicates the temperature of intersection of the curves νI1(medium)=f(T

L
1
and νM1(mixture)=f(T
L
1
), νM1denotes the molar fraction of the sample that corresponds to that temperature (T1and ΔT1=TFBP shallHP-T1,

define andHPand kHPwith the help of additional system of equations

∑ νMiSi(TL, ai, ki)=Smix(TLandmix, kmixand

∑ νMiSi(τ)=Smix(τ)

in which Si(τ) and Si(τ) are a function of the squares of the od charts distillation in coordinate systems ν MT νMthat τ, a ∑ is a function of the specific weight of the product carrier in the mixture, and build curves ν

HP
m
=f(T) by the formula

For simplicity, as a carrier, typically use a widely known product, such as kerosene and/or liquid petroleum with a boiling point below 300°C.

In addition to the normal ways distillation LBP and FD experts in the field of analysis of petroleum products sometimes use the methods of distillation columns with multiple theoretical plates, usually with at least fifteen theoretical plates, called the true distillation TBP (True Boiling Point), which is generally defined rules.

Thus, the present invention also allows you to build charts for the true boiling points TBP sample, in particular to determine its composition.

To this end charts normal distillation LBP νm=f(T), the corresponding column with a single plate, build charts the true boiling points TVR, the appropriate method from the column with at least fifteen theoretical plates, assuming that the temperature T

L
END
(LBP) and T
L
END
(TBP) is equal to that in the coordinate system νM, T the surface underneath charts normal distillation LBP equal surfaces located below charts the true boiling points TBP, and that TiBp(TBP)=f(Sl), where f(SlBp) depends on the square under normal chart distillation LBP in the coordinate system νMSo

The invention relates also to a device for implementing this method.

According to the present invention the device comprises a distillation flask with dimensions that allows you to put it from 5 to 15 ml of the analyzed sample and fitted in the upper part of the tube, and a side outlet tube connected to the condenser,

a device for heating the distillation flask in its lower part with a constant and variable intensity of the heat,

two instantaneous temperature sensor introduced in the distillation flask through a thin tube through the tube provides a continuous measurement of true temperature of the sample in the distillation process in the liquid phase and the true temperature of the sample in the vapor phase at a level located bore is only below the entrance of the outlet tube

device for the continuous measurement of the pressure in the vapor phase of the sample in the distillation process, which includes a pressure sensor connected with the interior of the distilling flask through a thin tube that passes through the tube, and the capillary is introduced into the inner portion of the outlet tube to the entry level in this tube,

the sensors for receiving and processing signals sent from the temperature sensors and pressure sensor.

Given these characteristics of the user for the test enters into the distillation flask 5-15 ml of the analyzed sample, for example with a syringe, and then closes the flask and installs the necessary intensity of the heat.

The sensors for receiving and processing signals then automatically switch circuit connected with the temperature sensors and differential pressure, and carry out the heating and distillation of the sample.

In the distillation of various sensors continuously transmit the sensors for receiving and processing the signals that allow you to automatically build charts distillation, display, and print these charts, in less than 15 minutes

Depending on the intended use distillation flask can be (without leaving the scope of the invention) or stationary flask, in particular of glass or stainless steel, or cap flask. In the latter case, Kapil is Yar consists of a stationary element, mainly stainless steel.

According to another characteristic of the invention the device is a portable monoblock.

In the latter case we are talking about a particularly preferred feature, because it allows you to have a very small weight and volume, which is suitable for rapid testing of petroleum products in any place, in particular in the areas of hostilities in the army.

Method and device that constitutes the subject matter of the invention. will be described in more detail with reference to the accompanying drawings, in which

Figure 1 depicts the diagram of a device for determining the distillation characteristics of liquid petroleum products according to the invention;

Figure 2 depicts the graph of the normal distillation of liquid oil composition hexane-isooctane-Dean according to the invention;

Figure 3 depicts the graph of the normal distillation of the mixture composition hexane-isooctane-Dean and distillation of a mixture of hexane-toluene-Dean according to the invention;

Figure 4 depicts a diagram of a normal distillation of the mixture composition hexane-isooctane-Dean and distillation of a mixture of hexane-toluene-Dean according to the invention;

Figure 5 depicts a diagram of the distillation of a liquid medium and analyzed a sample of heavy oil according to the invention.

The device comprises a distillation flask 1 (1) spherical form is, equipped with a lateral pin 4, the dimensions of which allow you to enter 5-15 ml of the analyzed sample.

The flask 1 is heated in the lower part with constant and variable intensity of heating of the heating resistance 2. The bulb 1 is sealed in the upper portion of the removable tube 3, through which you can enter the analyzed sample, in particular with a syringe.

Two instantaneous sensor 5 and 6 temperature introduced into the distillation flask 1 by means of thin tubes 5′ and 6′passing through the tube 3.

The first sensor 5 temperature immersed in the analyzed fluid for continuous measurement of true temperature of the sample in the distillation process in the liquid phase.

Regarding the second temperature sensor 6, the latter is installed in the upper part of the distillation flask 1 at a level which is slightly below the entrance 40 of the outlet tube 4 thus, in order to allow continuous measurement of true temperature of the sample in the distillation process in the vapor phase.

The device also contains a device for the continuous measurement of the pressure in the upper part of the distillation flask 1.

The device contains a sensor 7 (Fig 1) pressure difference, which is connected with the interior of the distillation flask 1 using a thin flexible tube 7′, which passes through the tube 3.

The sensor 7. is agnosti pressure works in conjunction with a metal capillary 8, introduced into the inner portion of the outlet tube 4 distillation flask 1, when the vapor outlet of the sample out in the refining process through the capillary 8.

The capillary 8 is mounted so that it comes out in a distillation flask to the entry level 40 exhaust duct 4 and is connected by its opposite end with an air condenser 9, providing for condensation of vapours from the distillation flask 1, with their subsequent transfer to the national team capacity(not shown).

The design of the outlet tube 4 distillation flask 1, the capillary 8 and condenser 9 is such that the capacitor screw up when assembling the device, presses the capillary and seals in place of the exit vapors from the distillation flask 1.

A thin tube 7′connecting the sensor 7 to the differential pressure and the interior of the distillation flask 1, provided with T-shaped coupling 10 enclosing a flow limiter (not shown). Away from the coupling 10 departs additional thin tube 11 attached to the microcompressor 12 for discharge into this tube a weak current of air, to avoid distortion of the signals sent by the sensor 7 to the differential pressure.

The fan 13 allows you to cool the distillation flask 1 after each test.

As schematically depicted by the dashed lines, the signals sent by the sensor 7 to the differential pressure, and sensors 5, 6 temperature, Reduta sensors 14 for receiving and processing these signals, which type and display charts distillation as answer.

The reliability of the method and device according to the invention was checked by means of tests, the results of which are given below.

Example 1 characterization of normal distillation LBD mixture of hexane-isooctane-Dean

And test using the method according to the invention

Analyzed the mixture having the following volumetric composition: hexane 40%isooctane 55%, Dean 5%.

Ten ml of this mixture was injected into the distillation flask device according to the invention.

The flask was placed in the device and supplied by its capillary and air condenser.

After that, he launched a program of distillation and continuously measured the temperature of the sample in the liquid phase TLand in the vapor phase TS, and the pressure P inside the flask.

The sensors for receiving and processing signals allowed us to continuously monitor the program distillation and calculate the normal characteristics of distillation LBD mixture in accordance with the method according to the invention.

The results obtained are presented in Table 1 and figure 2.

Table 1
νvIBP0,050,10,20,30,40,50,60,7 0,80,90,95FBP
tS78,579,280,481,3of 83.485,587,990,69499,5111,5155, 2mm173,6
TL81,782,5of 83.4is 83.88688,591,595100,1107,2130, 8mmof 174.4covers 175.6
Tstand75to 78.37980,481,7of 83.485,3at 88.1to 91.696,6105,2128,7168,7

In Table 1 and in figure 2 the values of tstandcorrespond to the temperature values, recalculated in accordance with standard ASTM D 86.

At the end of the distillation automatically disables the device to heat up and the fan turns on to cool the distillation flask.

Conducted test allowed us to obtain for the mixture temperature TF=173,6°S, which is close to the temperature of the pure distillation of the Dean and the value of T

S
iBp
=78,5°C and T
S
iBp
=81,7°C.

After distillation distillation flask device was drained and prepared a new sample for analysis.

In a test using a known method, the corresponding well-known publication Belarus 1980801.

Was carried out distillation of the same mix as in the test And, in the same way except that we measured only the temperature of the mixture TLin the liquid phase.

According to this method was calculated volume fraction distilled sample νvas a function of time τ1using the following formula:

After that, calculates the temperature Tstandsince the temperature TLaccording to the formula tstand=TL-And where And

where A1, A2, A3And4, A5and a6are the estimated coefficients, while TCFdenotes the average boiling point.

Was determined the temperature of the end of the boil TFby the method of least squares according to equation

and, it was assumed that the temperature TFcorresponds to the temperature at which the observed mi is imally variance or the maximum correlation coefficient.

Obtained during the test the results are presented in Table 2

Table 2
υvIBP0,050,10,20,30,40,50,60,70,80,90,95FBP
tL83,6of 83.485,786,88890,394,9102107,2to 112.2144,7175,8180,6
Tstand77,1to 78.378,879,580,782,887,786,392,498,4109,2125,3172,6

Defined in this test, the temperature TFis different from the temperature of the end of the boil clean Dean 6.5°C.

Example 2

Characterization of normal distillation LBD diesel fuel

A sample of diesel fuel was subjected to the same tests as in example 1, using the method according to the invention (A) and the above-mentioned known method ().

The results obtained in the tests according to izopet the tion, given in table 3.

Table 3
νVIBP0,050,10,20,30,40,50,60,70,80,90,95FBP
TS217,8239,7254,8270,6290,6to 307.1322,5334,9347,2362,0380,5389,0397,9
TL226,6249,7264,3279,0299,6317,9335,7351,2369,8390,0408,1415,8412,5
Tstand208,1237250,4267,7284,7299,6313325,7338,4351,5368,5380,7386,7

The results obtained in tests carried out in a known manner, are shown in Table 4.

td align="center"> IBP
Table 4
νv0,050,10,20,30,40,50,60,70,80,90,95FBP
tL232,3254,7268,3281,8308,7325,9342,4356,5364,6373,5378,2386,3398,5
Tstand213,3241,7254,1270,3293,2to 307.1spreads for about 319.2330,6341,8353,2368,5378,8382,8

After that we compared the convergence obtained, on the one hand, according to the invention and, on the other hand, by a known method.

The results are shown in Table 5.

Table 5
AnalyzedMethodνV
samples IBP10%20%50%90%FBP
Diesel fuelInvention0,70,2 0,50,40,71,2
 Known1,661,541,01,41,71,88

Thus, we can conclude that the convergence obtained according to the invention (0,4°C), twice convergence obtained in accordance with the known method (1°).

Example 3

Charting the TBP distillation of a mixture of hexane-toluene-Dean

Prepared mixture of hexane-toluene-Dean, has the following volumetric composition: 45%-45%-10%.

Built diagrams of the normal distillation LBD and charts TBP distillation of this mixture, which are presented in figure 3. To obtain these graphs, it was assumed that

- T

HP
F
(LBD)=TFBP(TBP)

- Tibp(TVR)=f(SLBD)

surface located above the chart νM=f(T) (LBD) and νM=f(T) (TBP) are equal.

Thus, were able to determine according to the invention the molar ratio between the different components of the mixture.

The results are shown in table 6.

Carried out a similar test on a mixture of hexane-toluene-Dean, has the following volumetric composition: 45%-45%-10%.

Built diag is Amma normal distillation LBD and charts TBP distillation of this mixture (figure 4).

The following table 7 shows the molar fraction of the different components of the mixture, which could be designed according to the invention.

Tables 6 and 7 show that the invention has allowed to obtain a satisfactory correlation between the calculated volume fractions and true experimental volume fractions of the original mixture.

Example 4

Characterization of a heavy liquid distillation of petroleum with a boiling point above 400°

The quality of the product carrier was selected petrol having the following characteristics normal distillation LBP: a=0,462; k=1,834; TiBp=88,3°C; TF=164,4°C.

Received and constructed according to the invention chart distillation ν=F(T) of a liquid medium.

Thus obtained results are shown in Table 8 and presented in figure 5.

Table 8
vIBP0,072is 0.1020,1370,1780,2230,2730,3270,3860,4510,5180,5910,6670,7470,8310,90,961FBP
T88,3107,5 110,9114117,2120,1122,9125,7128,5131,3134136,9140,1143,5147,5151,4156, 3mm164,4

After that, the liquid media was added 10% of the analyzed sample of heavy oil.

This mixture is also processed by the method according to the invention.

Thus, using the calculation were able to determine the following parameters normal distillation LBD this mixture: a=EUR 7.57; k=1,285; TiBp=81°C; Tf=534,2°C.

Characteristics distillation of this mixture are shown in Table 9 and presented in figure 5.

Table 9
vIBP0,0780,110,1480,1910,240,2940,3510,4140,4820,5540,6310,7110,7950,8740,9290,973FBP
T81,495,5100106,4112,5119,2a 126.7135144,5155,5168,7184,6 205,2233,8273,9320387,7534,2

After this was determined T

HP
WR
by the formula

Determined T

HP
F
by the method of successive approximations with

using algorithm

After that determined the parameters of the distillation of a sample and theHPand kHP" additional equations

∑νMiSi(TL, ai, ki)=Smix(TL, amix, kmixand ∑νMISi(τ)=Smix(τ)

The parameters of the distillation mixture is determined by calculation, are as follows: "andHP"=of 10.21; kHP"=1,54; T

HP
WR
=76,4°S; and T
HP
f
=534,2°C.

The distillation characteristics of the sample of heavy oil obtained by this test are given in Table 10 and presents the and 5.

Table 10
vWR0,0780,110,1480,190,2390,2920,350,4120,480,550,620,7070,7910,870,920,97FBP
T77,194,3398,78to 103.8109,6to 116.2123,8to 132.6of 142.8155, 2mm170,2189,7214,4249,9299,8355,2429,9534,2

1. The method for determining the distillation characteristics of liquid petroleum products using the mini-Express-distillation, comprising the following steps: analyze a sample of about 5-15 ml injected into the distillation flask, heated located below the element and provided with a pressure sensor, and two instantaneous temperature sensors that measure the true temperature of the sample in the liquid phase and the true value of the temperature of the sample in the vapor phase at a level located below the entrance of the outlet tube, which is equipped with distillation flask, heat the indicate the distillation flask at a constant rate of heating, defined by the nature of the analyzed sample, and maintain it in a state of constant boiling continuously measure the pressure of steam in the distillation flask at the level of the input into the output tube, and the true temperature of the sample in the liquid phase TLand in the vapor phase TSand build the graph representing the dependence of changes in pressure and temperature from the time τ1determine the first and second derivatives of the temperature change of the sample in the liquid phase and in the vapor phase:

and deduce from them the initial boiling point in the liquid phase T

L
WR
that corresponds to the point for which

determine the initial boiling point in the vapor phase T

S
WR
which corresponds to the time at which see the beginning of pressure increase, determine the temperature T
L
END
in which is shown a temperature sensor that measures the true value of the tempo of the atmospheric temperature of the sample in the liquid phase, corresponds to the value indicated by the sensor, measuring the temperature of the sample in the vapor phase, and take the temperature T
L
END
equal to the temperature of the end of the boil in the vapor phase T
S
F
determine the volume fraction distilled sample Vvthe diagram representing the dependence of τ1changes in steam pressure P in the distillation flask and the true temperature of the sample in the vapor phase TSexpressed by the equation

where Sf(TS, R) is the area under the curve of pressure in the refining process, while Sf(TiSPi) depends on the part of this surface at the time τ1iand

V

res
i
denotes the volume of liquid in the distillation flask at the time τ1i,

determine the dependence of the molar fraction of the distilled sample VMfrom the true temperature of the sample in the vapor phase TSaccording to the equation VMi=f(νvithat ρiTSidenotes the molar density at time τ1idetermine the temperature of the end of the boil in the liquid phase T

L
F
by the method of successive approximations by the formula

where νENDdenotes the molar fraction distilled at a temperature T

L
FBP
sample

a and k are the coefficients of the mathematical model of the distillation, the corresponding empirical formula

moreover, as a measure of the symmetry of the curve distillation fractional composition of oil in the coordinate system of the temperature - mole fraction of distillate” relative to the average boiling temperature of the product

k represents an index of the intensity of boiling product at an average temperature of boiling of the product

τ - dimensionless temperature parameter mathematical model of the fractional composition of petroleum, the coefficients a and k are calculated by the method of successive approximations by the equation

where

by calculating at each step the new value T

L
f
up until

T

L(n)
FBP
-T
L(n-l)
F
1° C

where n is the number of the iteration step,

recalculate the dependence of the molar fraction of the distilled sample from the true temperature of the sample in the vapor phase with account balances and losses of the sample in the vapor phase according to the formula

νMi=ν ′Mi+Δ Li+Δ Si,

where ν ′Miis the mole fraction of the distilled sample excluding residues and loss of sample in the vapor phase,

Δ Si denotes the share of the vapor phase in the process of distillation,

Δ Li fraction of liquid phase at the moment of its formation by condensation,

νMidenotes the molar fraction distilled sample with account balances

determine the dependence of the volume fraction distilled sample νvifrom the true temperature of the sample in the liquid phase of the agreement is but the formula

νvi=f(νMithat ρiT

L
i
),

where T

L
i
the true value of the temperature of the sample in the liquid phase,

ρiis the molar density of the product, wikipaedia in time τ1i,

and build the appropriate chart.

2. The method according to claim 1, characterized in that regulate the activity of the heating of the heating element so that the time required for the distillation of the sample, accounted for approximately 5-15 minutes

3. The method according to any one of claims 1 and 2, characterized in that to determine the empirical value of Tstandthe temperature of the sample in the vapor phase, corresponding to the standard norm on the basis of size TLthe temperature of the sample in the liquid phase calculated by the formula

Tistand=T

L
i
i,

where θ is a function representing the difference between these temperatures.

4. The method according to claim 3, characterized in that T

D86
stand
an empirical temperature corresponding to the norm ASTM D86, a θ
D86
i
indicates the difference between the temperature of the liquid phase wikipaedia product and the temperature measured by the temperature sensor used in a known standard method, in relation to a particular volume fraction of distillate Vvicalculated according to equation

and determined either graphically or from the values of the parameters (a, k, T

L
WR
T
L
F
)defined previously.

5. The method for determining the distillation characteristics of liquid petroleum products using the mini-Express-distillation according to any one of claims 1 to 4, characterized in that for determining the characteristics of the distillation of heavy hydrocarbon oils with boiling points above 400° With, pick a light liquid petroleum product carrier having a boiling point below 300° S, which is compatible with the analyzed sample is subjected to this liquid oil-nose is tel operations, specified in claim 1, and get a graph showing the dependence of the molar fraction of the νmdistilled liquid carrier from the true temperature of the liquid in the liquid phase TL: νMi(medium)=f(T

L
i
), prepare a mixture containing from 85 to 95% of the liquid carrier and about 5-15% of the analyzed sample to at least 90% of this mixture had a boiling temperature below 360° To expose the mixture to the operations specified in claim 1, and get a graph showing the dependence of the molar fraction of the νMdistilled mixture from the temperature of this mixture in the liquid phase TL: νMi(mixture)=f(T
L
i
), assume that the temperature of the end of the boil T
HP
F
the analyzed sample is equal to the temperature of the end of the boiling mixture in the liquid phase

T

HP
F
=T
L
F
(mix)

define T

L
F
(mixture) by the method of successive approximations, calculate the initial boiling point in the liquid phase T
HP
F
the analyzed sample by the formula

where T1indicates the temperature of intersection of the graphs νMi(medium)=f(T

L
i
and νMi(mixture)=f(T
L
i
),

νM1denotes the molar fraction of the sample that corresponds to that temperature (T1),

Δ T1=

HP
FBP
-T1,

where T

HP
F
- temperature end of the boil in the liquid phase of the sample of heavy oil,

HPand kHPthe parameters of the mathematical model curve distillation of a sample of heavy oil, wikipaedia at temperatures above 400° in the coordinate system of the temperature - mole fraction of distillate, which is defined with the help of additional system of equations

∑ νMiSi(TL, ai, ki)=Smix(TL, amix, kmixand

∑ νMiSi(τ )=Smix(τ )

where Siis a function of the area under the graphs distillation in the coordinate system νmTLfor each of the components of a mixture (product medium and heavy analyzed product),

Smixa similar function is the area under the graph of distillation in the coordinate system νmT for the mixture of the product of the medium and heavy analyzed product

amix, kmixthe parameters of the mathematical model curve distillation of the analyzed mixture of the product of the carrier and sample heavy oil in the coordinate system of the temperature - mole fraction of distillate”,

Si(T) and Si(τ ) are a function of the area under the graphs distillation in coordinate systems VMT and VMthat τ for each of the components of a mixture (product-medium and heavy analyzed product),

Smix(τ ) is the same function PLO the ADI under the chart distillation in the coordinate system of V Mthat τ for the mixture of the product carrier and heavy analyzed product

Σ is a function of the specific weight of the product carrier in the mixture,

and build charts V

HP
M
=f(t) by the formula

where ν

HP
M
is the mole fraction of the analyzed sample, wikipaedia at temperatures above 400° C.

6. The method according to claim 5, characterized in that the light oil product carrier consists of kerosene and/or liquid petroleum with a boiling point below 300° C.

7. The method according to any one of claims 1 to 6, characterized in that the charts normal distillation LBD νm=f(t), the corresponding column with a single plate, build charts the true boiling points TVR, the appropriate method from the column with at least fifteen theoretical plates, assuming that the temperature T

L
END
(LBP) and t
L
END
(TBP) is equal to y is in the coordinate system ν mT the area under the normal charts distillation LBP is equal to the areas under the graphs of the true boiling points TBP and that TIBP(TBP)-f(sLBP), where f(SL) depends on the area under the graph of the normal distillation LBP in the coordinate system νm, T, where LBD - Laboratory Batch Distillation (laboratory gradual distillation) and TBP True Boiling Point (true boiling point).

8. The device for implementing the method, as claimed in any one of claims 1 to 7, containing distillation flask sizes, allowing you to put it from 5 to 15 ml of the analyzed sample and fitted in the upper part of the tube and a lateral outlet tube connected to the condenser, device for heating the distillation flask in its lower part with a constant and variable intensity of heat, characterized in that it contains two instantaneous temperature sensor introduced in the distillation flask through a thin tube through the tube provides a continuous measurement of true temperature of the sample in the distillation process in the liquid phase and the true temperature values this sample in the vapor phase at a level located slightly above the entrance of the outlet tube, a device for continuous measurement of the pressure in the vapor phase of the sample in the distillation process, which includes a pressure sensor connected to the internal h is d distillation flask through a thin tube, passing through the tube, and the capillary is introduced into the inner portion of the outlet tube to the entry level in this tube, and the sensors for receiving and processing signals sent from the temperature sensors and pressure sensor.

9. The device according to claim 8, characterized in that the distillation flask is cap bulb and capillary consists of a stationary element, preferably of stainless steel.

10. Device according to any one of p and 9, characterized in that the device is a portable monoblock.



 

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