阅读说明：本技术 一种测量天然气中芳香烃物质含量及析出量的装置及方法 (Device and method for measuring content and precipitation amount of aromatic hydrocarbon substances in natural gas ) 是由 刘建仪 陈奕兆 谢泱 刘治彬 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种测量天然气中芳香烃物质含量及析出量的装置及方法,所述测量天然气中芳香烃物质含量及析出量的装置包括增压恒温组件和测量组件,所述增压恒温组件包括高压驱替泵(1)、高低温交变实验箱(2)、平流泵Ⅰ(7)、平流泵Ⅱ(10)及真空泵(15),所述高低温交变实验箱(2)中设置有中间容器Ⅰ(3),所述高压驱替泵连接中间容器Ⅰ(3),所述中间容器Ⅰ(3)、平流泵Ⅰ(7)、平流泵Ⅱ(10)及真空泵(15)分别连接测量组件；所述测量组件用以测量芳香烃含量。通过使用发明提出了一种测量天然气中芳香烃物质含量及析出量的装置及方法,能够便捷地测定不同温度、压力条件下天然气中芳香烃种类及含量,同时也可以测量出芳香烃物质的析出量。(The invention discloses a device and a method for measuring the content and the precipitation quantity of aromatic hydrocarbon substances in natural gas, wherein the device for measuring the content and the precipitation quantity of the aromatic hydrocarbon substances in the natural gas comprises a pressurizing constant-temperature component and a measuring component, the pressurizing constant-temperature component comprises a high-pressure displacement pump (1), a high-low temperature alternating experiment box (2), a constant-flow pump I (7), a constant-flow pump II (10) and a vacuum pump (15), an intermediate container I (3) is arranged in the high-low temperature alternating experiment box (2), the high-pressure displacement pump is connected with the intermediate container I (3), and the intermediate container I (3), the constant-flow pump I (7), the constant-flow pump II (10) and the vacuum pump (15) are respectively connected with the measuring component; the measuring component is used for measuring the content of aromatic hydrocarbon. The invention provides a device and a method for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas, which can conveniently measure the types and the content of the aromatic hydrocarbon substances in the natural gas under different temperature and pressure conditions and can also measure the precipitation amount of the aromatic hydrocarbon substances.)

1. The device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas is characterized by comprising a pressurizing constant-temperature component and a measuring component, wherein:

the pressurization and constant temperature assembly comprises a high-pressure displacement pump (1), a high-low temperature alternation experiment box (2), a constant-temperature pump I (7), a constant-temperature pump II (10) and a vacuum pump (15), wherein an intermediate container I (3) is arranged in the high-low temperature alternation experiment box (2), the high-pressure displacement pump (1) is connected with the intermediate container I (3), and the intermediate container I (3), the constant-temperature pump I (7), the constant-temperature pump II (10) and the vacuum pump (15) are respectively connected with a measurement assembly;

the measuring assembly comprises an intermediate container II (8), an intermediate container III (9), an adsorption tank I (5), an adsorption tank II (13), a liquid collecting bottle I (23) and a liquid collecting bottle II (18), wherein the upper end of the intermediate container II (8) is connected with a constant flow pump I (7), the lower end of the intermediate container II (8) is connected with the upper end of the adsorption tank I (5), and the lower end of the adsorption tank I (5) is connected with the liquid collecting bottle I (23); the upper end of the intermediate container III (9) is connected with a constant flow pump II (10), the lower end of the intermediate container III (9) is connected with the upper end of an adsorption tank II (13), and the lower end of the adsorption tank II (13) is connected with a liquid collecting bottle II (18); and (4) determining the type and content of aromatic hydrocarbon substances in the sample by performing chromatographic analysis on the liquid in the liquid collecting bottle.

2. The device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas as claimed in claim 1, wherein the left side of the upper end of the adsorption tank I (5) is provided with a gas inlet stop valve I (6), and the gas inlet stop valve I (6) is connected with the intermediate container I (3); a liquid inlet stop valve I (20) is arranged on the right side of the upper end of the adsorption tank I (5), and the liquid inlet stop valve I (20) is connected with a middle container II (8); a liquid outlet stop valve I (4) is arranged on the left side of the tail end of the adsorption tank I (5), the liquid outlet stop valve I (4) is connected with a liquid collecting bottle I (23), and the liquid collecting bottle I (23) is placed in a balance I (22); the right side of the tail end of the adsorption tank I (5) is provided with an air outlet stop valve I (21), and the air inlet stop valve II (17) installed on the left side of the tail end of the adsorption tank II (13) is connected with the air outlet stop valve I (21).

3. The device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas as claimed in claim 1, wherein a liquid inlet stop valve II (11) is arranged at the left side of the upper end of the adsorption tank II (13), and the liquid inlet stop valve II (11) is connected with an intermediate container III (9); two stop valve II (12) of giving vent to anger are equipped with on adsorption tank II (13) upper end right side, what stop valve II (12) of giving vent to anger were connected has two branches, branch road one: the air outlet stop valve II (12) is connected with a vacuum pump (15), and the branch is two: the air outlet stop valve II (12) is connected with the volume flow meter (16); and a liquid outlet stop valve II (14) is arranged on the right side of the tail end of the adsorption tank II (13), the liquid outlet stop valve II (14) is connected with a liquid collecting bottle II (18), and the liquid collecting bottle II (18) is placed in a balance II (19).

4. The device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas as claimed in claim 1, wherein the adsorption tank I (5) and the adsorption tank II (13) are made of metal materials, can resist high temperature and high pressure, and are filled with adsorption medium activated carbon.

5. The device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas as claimed in claim 1, wherein the parts of the device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas are connected by pipelines.

6. A method for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas is characterized by comprising the following steps:

emptying the experimental device: respectively filling prepared activated carbon into an adsorption tank I (5) and an adsorption tank II (13), vacuumizing the whole device, and connecting a volume flow meter (16);

preparing a sample to be tested: adjusting the pressure and temperature of the sample in the intermediate container I (3) to test values, and keeping constant temperature and constant pressure;

sample adsorption: after a certain volume of sample gas is introduced, recording the reading in the volume flow meter (16);

sample desorption: pumping desorption liquid into an adsorption tank I (5) and an adsorption tank II (13), and respectively recording the pumping volumes as V1 and V2;

liquid drainage: discharging a small amount of desorption liquid to a liquid collecting bottle I (23) and a liquid collecting bottle II (18) for subsequent chromatographic analysis;

and (3) chromatographic analysis: and (4) carrying out chromatographic analysis on the liquid in the liquid collecting bottle I (23) and the liquid in the liquid collecting bottle II (18) to determine the types and the contents of the aromatic hydrocarbon substances in the samples.

7. The method of claim 6, wherein the amount of aromatic substances in the first (5) and second (13) adsorption tanks is calculated from the following formula:

in the formula, C_jiThe concentration of aromatic hydrocarbon substances is ug/ml; v_jThe volume of the desorption solution is ml; q is the volume L of the experimental sample;W_jiis the mass content of aromatic hydrocarbon substances g/m 3; the subscript i represents the number of aromatic species and the subscript j represents the numbers of adsorption tanks I (5) and II (13).

Technical Field

The invention relates to the technical field of natural gas physical property testing, in particular to a device and a method for measuring the content and precipitation amount of aromatic hydrocarbon substances in natural gas.

Background

Natural gas is a generic term for hydrocarbon-based gas mixtures present in subterranean rock reservoirs, the main component being alkanes. The methane is the majority, with small amounts of ethane, propane and butane, and generally also hydrogen sulfide, carbon dioxide, nitrogen, water and small amounts of carbon monoxide and other trace noble gases. Along with the increasing development of oil and gas fields at home and abroad in recent years, a natural gas field rich in aromatic hydrocarbon substances (mainly containing benzene, toluene, homologous compounds of benzene and the like) is gradually discovered. The substances have high condensation point, and the condensation point of benzene is near 5.5 ℃, so that solid phase separation is easily generated in a production separator of natural gas or a low-temperature dehydrator, and the blockage of a device and a pipeline is caused. Therefore, the method can accurately determine the types and the contents of the aromatic hydrocarbon substances in the natural gas, and is beneficial to providing technical support for the safety development of oil and gas fields.

Compared with the prior device and method for measuring the content of the aromatic hydrocarbon in the natural gas. One method is a low-temperature freezing method, which mainly utilizes solid-phase substances in a natural gas sample condensed under low temperature conditions, and performs chromatographic analysis after absorption by absorption liquid, but the method is difficult to ensure that all the solid-phase substances are separated out under the low temperature conditions, and the measured value is easy to be smaller. The other method is a method for testing the content of benzene series in the air, which is a normal pressure test, cannot adapt to the phase change of natural gas and cannot meet the field working condition. Compared with the existing method for measuring the precipitation amount of aromatic hydrocarbon substances in natural gas, the method adopts a low-temperature weighing method in most cases, but the method cannot eliminate the influence of condensed water, so that the measured value is easy to be larger. Therefore, how to conveniently measure the types and the contents of the aromatic hydrocarbons in the natural gas under different temperature and pressure conditions is a technical problem which needs to be solved urgently.

Disclosure of Invention

In order to solve the problems, the invention provides a device for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas, which comprises a pressurizing constant temperature component and a measuring component, wherein:

the supercharging constant-temperature component comprises a high-pressure displacement pump, a high-low temperature alternating experiment box, a constant-flow pump I, a constant-flow pump II and a vacuum pump, wherein an intermediate container I is arranged in the high-low temperature alternating experiment box, the high-pressure displacement pump is connected with the intermediate container I, and the intermediate container I, the constant-flow pump II and the vacuum pump are respectively connected with a measuring component.

The measuring assembly comprises an intermediate container II, an intermediate container III, an adsorption tank I, an adsorption tank II, a liquid collecting bottle I and a liquid collecting bottle II, wherein the upper end of the intermediate container II is connected with a constant flow pump I, the lower end of the intermediate container II is connected with the upper end of the adsorption tank I, and the lower end of the adsorption tank I is connected with the liquid collecting bottle I; the upper end of the intermediate container III is connected with a constant flow pump II, the lower end of the intermediate container III is connected with the upper end of an adsorption tank II, and the lower end of the adsorption tank II is connected with a liquid collecting bottle II; and (4) determining the type and content of aromatic hydrocarbon substances in the sample by performing chromatographic analysis on the liquid in the liquid collecting bottle.

Preferably, an air inlet stop valve I is arranged on the left side of the upper end of the adsorption tank I and is connected with the intermediate container I; a liquid inlet stop valve I is arranged on the right side of the upper end of the adsorption tank I and is connected with an intermediate container II; a liquid outlet stop valve I is arranged on the left side of the tail end of the adsorption tank I and is connected with a liquid collecting bottle I, and the liquid collecting bottle I is placed in a balance I; i tail end right side of adsorption tank is equipped with stop valve I of giving vent to anger, stop valve I of giving vent to anger connects the stop valve II that admits air of II tail end left sides installations of adsorption tank.

Preferably, a liquid inlet stop valve II is arranged on the left side of the upper end of the adsorption tank II and is connected with a middle container III; II upper end right sides of adsorption tank are equipped with the stop valve II of giving vent to anger, what the stop valve II of giving vent to anger connected has two branches, branch road one: the air outlet stop valve II is connected with a vacuum pump, and the branch is two: the air outlet stop valve II is connected with the volume flow meter; and a liquid outlet stop valve II is arranged on the right side of the tail end of the adsorption tank II, the liquid outlet stop valve II is connected with a liquid collecting bottle II, and the liquid collecting bottle II is placed in a balance II.

Preferably, the adsorption tank I and the adsorption tank II are made of metal materials, can resist high temperature and high pressure, and are filled with adsorption medium active carbon for adsorbing aromatic hydrocarbon substances in natural gas; the ratio of the activated carbon contained in the adsorption tank I to the activated carbon contained in the adsorption tank II is 2:1, the adsorption tank I has an adsorption effect, and the adsorption tank II has a detection effect.

Preferably, the intermediate container I is filled with experimental sample gas, and the intermediate container II and the intermediate container III are filled with desorption liquid which is used for desorbing the activated carbon in the adsorption tank I and the adsorption tank II; the desorption liquid in the intermediate container II and the intermediate container III is one or a mixture of carbon disulfide, carbon tetrachloride, glacial acetic acid and ethanol.

Preferably, the adsorption tank I consists of an upper cover I and a tank body I; an air inlet stop valve I is arranged on the left side of an upper cover I, an air inlet stop valve I is arranged on the right side of the upper cover I, an air outlet stop valve I is arranged on the left side of the bottom of a tank body I, and an air outlet stop valve I is arranged on the left side of the bottom of the tank body I; the valve operates on a principle similar to a needle valve to control the flow of fluid.

Preferably, the adsorption tank II consists of an upper cover II and a tank body II; a liquid inlet stop valve II is arranged on the left side of the upper cover II, a liquid inlet stop valve II is arranged on the right side of the upper cover II, a liquid outlet stop valve II is arranged on the left side of the bottom of the tank body II, and a gas outlet stop valve II is arranged on the left side of the bottom of the tank body II; the valve operates on a principle similar to a needle valve to control the flow of fluid.

Preferably, the parts of the device for measuring the content and the precipitated amount of the aromatic hydrocarbon substances in the natural gas are connected by pipelines.

Another aspect of the present invention provides a method for measuring the content and the amount of aromatic hydrocarbon substances in natural gas, including the following steps:

emptying the experimental device: and respectively filling the prepared activated carbon into an adsorption tank I and an adsorption tank II. Close inlet stop valve I, feed liquor stop valve I, go out liquid stop valve I, feed liquor stop valve II and go out liquid stop valve II, open outlet stop valve I, inlet stop valve II and outlet stop valve II, the temperature of adjustment high low temperature alternation proof box is the setting value, after constant temperature a period, opens the vacuum pump, with whole device evacuation. And after finishing, closing the air outlet stop valve II, dismantling the vacuum pump and connecting the volume flow meter.

Preparing a sample to be tested: and (3) pressurizing the sample pressure in the intermediate container I to an experimental test pressure Pi by using a high-pressure displacement pump I, keeping the pressure constant, starting a high-low temperature alternating test box simultaneously, adjusting the temperature of the sample in the intermediate container I to a test temperature Ti, and keeping the temperature constant.

Sample adsorption: open inlet stop valve I, outlet stop valve I, inlet stop valve II and outlet stop valve II. After a certain volume of sample gas was introduced, the reading in the volumetric flowmeter was recorded as Q. And closing the four valves.

Sample desorption: and respectively opening a liquid inlet stop valve I and a liquid inlet stop valve II, pushing an intermediate container II and an intermediate container III at a constant speed by using a constant flow pump I and a constant flow pump II, pumping desorption liquid into the adsorption tank I and the adsorption tank II, and respectively recording the pumping volumes as V1 and V2. After the pump is pumped to finish, the liquid inlet stop valve I and the liquid inlet stop valve II 11 are closed to wait for desorption.

Liquid drainage: and respectively opening the liquid outlet stop valve I and the liquid outlet stop valve II, discharging a small amount of desorption liquid into the liquid collection bottle I and the liquid collection bottle II, and sealing and storing. For subsequent chromatographic analysis.

And (3) chromatographic analysis: and (4) carrying out chromatographic analysis on the liquid in the liquid collecting bottle I and the liquid in the liquid collecting bottle II to determine the types and the contents of aromatic hydrocarbon substances in the samples.

The invention has the beneficial effects that: the device and the method for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas can effectively measure the types and the content of the aromatic hydrocarbon substances in the natural gas, can also measure the precipitation amount of the aromatic hydrocarbon substances under different temperature and pressure, provide a convenient device and an effective method for the fine measurement of gas reservoir components, and provide experimental data for preventing the aromatic hydrocarbon substances in the natural gas from being precipitated by the measured result.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for measuring the content and the amount of aromatic substances in natural gas according to the present invention;

FIG. 2 is a schematic structural diagram of an adsorption tank I;

FIG. 3 is a schematic structural view of adsorption tank II.

Wherein: 1-high-pressure displacement pump, 2-high-low temperature alternating test box, 3-intermediate container I, 4-liquid outlet stop valve I, 5-adsorption tank I, 6-air inlet stop valve I, 7-advection pump I, 8-intermediate container II, 9-intermediate container III, 10-advection pump II, 11-liquid inlet stop valve II, 12-air outlet stop valve II, 13-adsorption tank II, 14-liquid outlet stop valve II, 15-vacuum pump, 16-volume flow meter, 17-air inlet stop valve II, 18-liquid collecting bottle II, 19-balance II, 20-liquid inlet stop valve I, 21-air outlet stop valve I, 22-balance I, 23-liquid collecting bottle I, 24-upper cover I, 25-tank body I, 26-upper cover II and 27-tank body II.

Detailed Description

For the purpose of describing the embodiments of the present invention in detail, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Aiming at the defect that the deviation of the measured value is large in the conventional device and method for measuring the content of aromatic hydrocarbon in natural gas, the invention provides a device and method design scheme for measuring the content and precipitation amount of aromatic hydrocarbon in natural gas.

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The invention mainly aims to provide a device and a method for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas, and aims to provide a technical scheme for conveniently measuring the types and the contents of the aromatic hydrocarbon substances in the natural gas under different temperature and pressure conditions.

In order to achieve the above object, the present invention provides an embodiment, as shown in fig. 1, fig. 1 is a schematic structural diagram of an apparatus for measuring content and precipitation amount of aromatic hydrocarbon substances in natural gas according to the present invention.

Further, a device for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas comprises a pressurizing constant-temperature component and a measuring component, wherein:

the pressurizing constant-temperature component comprises a high-pressure displacement pump 1, a high-low temperature alternating experiment box 2, a constant-flow pump I7, a constant-flow pump II 10 and a vacuum pump 15, wherein an intermediate container I3 is arranged in the high-low temperature alternating experiment box, the high-pressure displacement pump is connected with the intermediate container I3, and the intermediate container I3, the constant-flow pump I7, the constant-flow pump II 10 and the vacuum pump 15 are respectively connected with a measuring component;

the measuring assembly comprises an intermediate container II 8, an intermediate container III 9, an adsorption tank I5, an adsorption tank II 13, a liquid collecting bottle I23 and a liquid collecting bottle II 18, wherein the upper end of the intermediate container II 8 is connected with a constant flow pump I7, the lower end of the intermediate container II 8 is connected with the upper end of the adsorption tank I5, and the lower end of the adsorption tank I5 is connected with the liquid collecting bottle I23; the upper end of the intermediate container III 9 is connected with a constant flow pump II 10, the lower end of the intermediate container III 9 is connected with the upper end of an adsorption tank II 13, and the lower end of the adsorption tank II 13 is connected with a liquid collecting bottle II 23; and (4) determining the type and content of aromatic hydrocarbon substances in the sample by performing chromatographic analysis on the liquid in the liquid collecting bottle.

Further, an air inlet stop valve I6 is arranged on the left side of the upper end of the adsorption tank I5, and the air inlet stop valve I6 is connected with the intermediate container I3; a liquid inlet stop valve I20 is arranged on the right side of the upper end of the adsorption tank I5, and the liquid inlet stop valve I20 is connected with the intermediate container II 8; a liquid outlet stop valve I4 is arranged on the left side of the tail end of the adsorption tank I5, the liquid outlet stop valve I4 is connected with a liquid collecting bottle I23, and the liquid collecting bottle I23 is placed in a balance I22; the I5 tail end right sides of adsorption tank are equipped with stop valve I21 of giving vent to anger, stop valve I21 of giving vent to anger connects II 13 tail end left sides of adsorption tank and installs stop valve II 17 that admits air.

Further, a liquid inlet stop valve II 11 is arranged on the left side of the upper end of the adsorption tank II 13, and the liquid inlet stop valve II 11 is connected with an intermediate container III 9; II 11 upper end right sides of adsorption tank are equipped with stop valve II 12 of giving vent to anger, what stop valve II 12 of giving vent to anger connected has two branches, branch road one: the air outlet stop valve II 12 is connected with a vacuum pump 15, and the branch is two: the air outlet stop valve II 12 is connected with a volume flow meter 16; and a liquid outlet stop valve II 14 is arranged on the right side of the tail end of the adsorption tank II 13, the liquid outlet stop valve II 14 is connected with a liquid collecting bottle II 18, and the liquid collecting bottle II 18 is placed in a balance II 19.

Furthermore, the adsorption tank I5 and the adsorption tank II 13 are made of metal materials, can resist high temperature and high pressure, and are filled with adsorption medium active carbon for adsorbing aromatic hydrocarbon substances in natural gas; the ratio of the activated carbon contained in the adsorption tank I5 to the activated carbon contained in the adsorption tank II 13 is 2:1, the adsorption tank I5 is used for adsorption, and the adsorption tank II 13 is used for detection.

Further, the intermediate container I3 is filled with experimental sample gas, and the intermediate container II 8 and the intermediate container III 9 are filled with desorption liquid which are used for desorbing the activated carbon in the adsorption tank I5 and the adsorption tank II 13; the desorption liquid in the intermediate container II 8 and the intermediate container III 9 is one or a mixture of carbon disulfide, carbon tetrachloride, glacial acetic acid and ethanol.

Further, as shown in fig. 2, fig. 2 is a schematic structural diagram of an adsorption tank i 5, wherein the adsorption tank i 5 is composed of an upper cover i 24 and a tank body i 25; an air inlet stop valve I6 is arranged on the left side of an upper cover I24, an liquid inlet stop valve I20 is arranged on the right side of the upper cover I24, a liquid outlet stop valve I14 is arranged on the left side of the bottom of a tank body I, and an air outlet stop valve I12 is arranged on the left side of the bottom of the tank body I; the valve operates on a principle similar to a needle valve to control the flow of fluid.

Further, as shown in fig. 3, fig. 3 is a schematic structural diagram of an adsorption tank ii 13, wherein the adsorption tank ii 13 is composed of an upper cover ii 26 and a tank body ii 27; a liquid inlet stop valve II 20 is arranged on the left side of the upper cover II 26, a liquid inlet stop valve II 20 is arranged on the right side of the upper cover II 26, a liquid outlet stop valve II 14 is arranged on the left side of the bottom of the tank body II, and a gas outlet stop valve II 12 is arranged on the left side of the bottom of the tank body II; the valve operates on a principle similar to a needle valve to control the flow of fluid.

Furthermore, all parts of the device for measuring the content and the precipitation amount of the aromatic hydrocarbon substances in the natural gas are connected by pipelines.

Another embodiment of the present invention provides a method for measuring the content and the precipitation amount of aromatic hydrocarbon substances in natural gas, including the following steps:

another aspect of the present invention provides a method for measuring the content and the amount of aromatic hydrocarbon substances in natural gas, including the following steps:

emptying the experimental device: and respectively filling the prepared activated carbon into an adsorption tank I5 and an adsorption tank II 13. Close inlet stop valve I6, feed liquor stop valve I20, play liquid stop valve I4, feed liquor stop valve II 11 and play liquid stop valve II 14, open outlet stop valve I21, inlet stop valve II 17 and outlet stop valve II 12, the temperature of adjustment high low temperature alternation test case is the setting value, after a constant temperature period, opens vacuum pump 15, with whole device evacuation. And after finishing, closing the air outlet stop valve II 12, removing the vacuum pump 15 and connecting the volume flow meter 16.

Preparing a sample to be tested: the sample pressure in the intermediate container I3 is pressurized to the experimental test pressure Pi by the high-pressure displacement pump I1, the pressure is constant, the high-low temperature alternating test box 2 is started simultaneously, the sample temperature in the intermediate container I3 is adjusted to the test temperature Ti, and the temperature is constant.

Sample adsorption: and opening an air inlet stop valve I6, an air outlet stop valve I21, an air inlet stop valve II 17 and an air outlet stop valve II 12. After a certain volume of sample gas was introduced, the reading in the volumetric flowmeter was recorded as Q. And closing the four valves.

Sample desorption: and respectively opening a liquid inlet stop valve I20 and a liquid inlet stop valve II 11, pushing an intermediate container II 8 and an intermediate container III 9 at a constant speed by using a constant flow pump I7 and a constant flow pump II 10, pumping desorption liquid into an adsorption tank I5 and an adsorption tank II 13, and respectively recording the pumping volumes as V1 and V2. And after the pump is pumped, closing the liquid inlet stop valve I20 and the liquid inlet stop valve II 11 to wait for desorption.

Liquid drainage: and respectively opening the liquid outlet stop valve I4 and the liquid outlet stop valve II 14, discharging a small amount of desorption liquid into the liquid collecting bottle I23 and the liquid collecting bottle II 18, and sealing and storing. For subsequent chromatographic analysis.

And (3) chromatographic analysis: and (4) carrying out chromatographic analysis on the liquid in the liquid collecting bottle I23 and the liquid in the liquid collecting bottle II 18 to determine the type and the content of the aromatic hydrocarbon substances in the sample.

Further, the chromatographic analysis further comprises:

specifically, through a standard chromatogram of the aromatic hydrocarbon substance, the relation between the chromatographic peak area and the concentration under the chromatographic conditions can be obtained as follows:

C_i＝k_ix_i (1)

in the formula, C_iThe concentration of aromatic hydrocarbon substances is ug/ml; k is a radical of_iThe proportionality coefficient ug/(ml mV) of aromatic hydrocarbon substances; x is the number of_iThe chromatographic peak area mV; the subscript i represents the number of aromatic species.

Specifically, the types of the aromatic hydrocarbon substances in the adsorption tank I5 and the adsorption tank II 13 can be respectively determined by performing chromatographic analysis on the liquid in the liquid collecting bottle I23 and the liquid in the liquid collecting bottle II 18 and comparing with a standard sample chromatogram of the aromatic hydrocarbon substances, and the aromatic hydrocarbon substance concentrations in the adsorption tank I5 and the adsorption tank II 13 can be obtained by using the formula (1) and are respectively marked as C_1iAnd C_2i。

Specifically, the aromatic hydrocarbon substance contents in the adsorption tanks i 5 and ii 13 can be calculated from the experimentally recorded gas flow meter reading Q and pumping volumes V1 and V2 of the pumping pump i 7 and the pumping pump ii 10 by the following formulas:

in the formula, C_jiThe concentration of aromatic hydrocarbon substances is ug/ml; v_jThe volume of the desorption solution is ml; q is the volume L of the experimental sample; w_jiIs the mass content of aromatic hydrocarbon substances g/m 3; the subscript i represents the number of aromatic species and the subscript j represents the numbers of canister I5 and canister II 13.

Specifically, after the experiment is completed, the overall calculation of the adsorption efficiency is required, the adsorption efficiency is above 80%, otherwise, the flow or sampling time is adjusted, and the sampling is performed again. The adsorption efficiency was calculated from the following formula:

in the formula, W_1iThe mass content of aromatic hydrocarbon substances in the adsorption tank I5 is g/m 3; w_2iThe mass content of the aromatic hydrocarbon substances in the adsorption tank II 13 is g/m 3; k is the adsorption efficiency% of the experiment.

Specifically, the total aromatic hydrocarbon content should be the sum of the contents of adsorption tank I5 and adsorption tank II 13:

W_i＝W_1i+W_2i (4)

in the formula, W_1iThe mass content of aromatic hydrocarbon substances in the adsorption tank I5 is g/m 3; w_2iThe mass content of the aromatic hydrocarbon substances in the adsorption tank II 13 is g/m 3; w_iThe total aromatic content g/m3 was determined for this experiment.

Specifically, the experimental temperature is reduced to T_iRepeating the above steps to obtain the temperature T_iThe content of aromatic hydrocarbon substances in the natural gas can be obtained by the content difference of each time_iPrecipitation amount of the following aromatic hydrocarbon substances:

m_si＝W_i-W_i-1 (5)

in the formula, W_iIs the content of aromatic hydrocarbon substances in the natural gas under the ith pressure condition g/m 3; w_i-1Is the content g/m3 of aromatic hydrocarbon substances in the natural gas under the pressure condition of i-1 st; m is_siThe amount of aromatic hydrocarbon substances precipitated under the ith pressure condition was g/m 3.

Specifically, the above steps are repeated until the temperature T is reached_iTo the minimum temperature at which the aromatic hydrocarbons precipitate. According to the experimental results, the pressure P is plotted_iUnder the condition, the precipitation amount m of aromatic hydrocarbon substances_siAs a function of temperature T_iThe change curve of (2).

Specifically, changing the experimental test pressure, and repeating the steps to obtain the precipitation amount m of the aromatic hydrocarbon substances under different pressures P_siAs a function of temperature T_iThe change curve of (2).

The method adopts the principle of activated carbon adsorption/carbon disulfide desorption to measure the types and the contents of aromatic hydrocarbon substances in the natural gas, is simple and convenient to operate, and has higher test result precision; the invention develops an adsorption tank with a needle valve, and aims to avoid errors of desorption liquid retained in a pipeline in content calculation; the method can accurately determine the types and the contents of the aromatic hydrocarbon substances in the natural gas, and provides a good technical means for refining natural gas components; the invention can carry out aromatic hydrocarbon content test experiments under different temperature and pressure, can obtain the precipitation amount of aromatic hydrocarbon substances under different temperature and pressure, and provides experimental data for the safety production of oil and gas fields.

In the above embodiments, the basic principle and the main features of the present invention and the advantages of the present invention are described. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, and that modifications and variations can be made by one skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.