Method for measuring content of petroleum in desulfurization solution

Abstract

The invention discloses a method for measuring the content of petroleum in a desulfurization solution. The method comprises the following steps: 1) collecting or preparing the desulfurization solution on site; 2) carrying out distillation treatment, dehydration, magnesium silicate adsorption and filtration on the desulfurization solution to obtain a petroleum standard oil sample; or field petroleum is used for dehydration, magnesium silicate adsorption and filtration treatment, and a standard oil sample is prepared; (3) preparing a standard sample series by using the standard samples, and making a standard working curve by using an infrared oil measuring instrument; 4) extracting petroleum in the desulfurized amine liquid by using environment-friendly carbon tetrachloride, and performing oscillation, demulsification, standing, separation, dehydration and magnesium silicate adsorption to obtain an extract; 5, the absorbance is measured and converted through an infrared oil measuring instrument, and the numerical value of the petroleum content in the desulfurization solution is workped.The method belongs to the technical field of component analysis, the implementation process is rapid, simple and convenient, used instruments and agents are stable and low in price, and the requirement for measuring the petroleum content in the desulfurization solution is met.

Description

Technical Field

[0001] This invention belongs to the field of petroleum content component analysis technology, and relates to a method for determining the petroleum content in desulfurization solutions. Background Technology

[0002] Natural gas typically contains a certain amount of carbon dioxide and hydrogen sulfide, requiring purification before use. The amine process is currently the primary technology for natural gas desulfurization and decarbonization. If condensate oil from the natural gas is not effectively separated in the separator before entering the desulfurization tower, it enters the desulfurization solution, affecting the foaming properties of the desulfurization amine solution and causing liquid blockage. This leads to unstable operation of the desulfurization tower and substandard desulfurization results, directly impacting the normal production and operation of the natural gas purification plant. The desulfurization solution is generally 40%–45% by weight of MDEA (N-methyldiethanolamine), with a pH range of 9–11. Due to long-term circulation, its composition is complex, mainly consisting of surfactants, condensate oil, hydrocarbons, solid impurities, amine degradation products, and thermally stable salts.

[0003] Currently, commonly used methods for determining petroleum content include ultraviolet spectrophotometry, infrared spectrophotometry, non-dispersive infrared absorption spectrophotometry, fluorescence spectrophotometry, gas chromatography, infrared spectroscopy, and gravimetric methods. Gravimetric methods are mainly suitable for measuring some non-volatile petroleum compounds, but the petroleum compounds in desulfurization solutions are primarily condensate oil, which is highly volatile; therefore, gravimetric methods are unsuitable for determining the petroleum content in desulfurization solutions. Other methods involve extracting and purifying the petroleum compounds from the sample with an extractant, establishing a standard curve, and then determining the petroleum content using Beer's Law. However, due to the large amount of surfactants in desulfurization solutions, severe emulsification occurs during the extraction process. Therefore, these methods cannot be directly applied to the determination of petroleum content in desulfurization solutions. Furthermore, non-dispersive infrared absorption spectrophotometry, fluorescence spectrophotometry, gas chromatography, and infrared spectroscopy require expensive equipment and have high sample requirements. Therefore, there is an urgent need to develop an effective method for determining the petroleum content in desulfurization solutions. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the petroleum content in desulfurization solutions, which solves the problems of severe emulsification and large errors in the determination of petroleum content in existing technologies.

[0005] The technical solution adopted in this invention is a method for determining the petroleum content in a desulfurization solution, implemented according to the following steps: Step 1: Collect desulfurization solution on site, or prepare desulfurization solution; Step 2: Distill the desulfurization solution, then dehydrate, adsorb magnesium silicate, and filter to obtain a standard oil sample of petroleum type. Alternatively, standard oil samples can be prepared by using on-site petroleum products for dehydration, magnesium silicate adsorption, and filtration. Step 3: Prepare a series of standard samples using standard samples, and use an infrared oil analyzer to create a standard working curve; Step 4: Extract petroleum compounds from the desulfurized amine solution using environmentally friendly carbon tetrachloride. After shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate, the extract is obtained. Step 5: Measure and convert the absorbance using an infrared oil analyzer, and calculate the petroleum content in the desulfurization solution based on the standard working curve and sampling volume.

[0006] The beneficial effects of this invention are that it determines the petroleum content in desulfurization solutions by measuring and converting absorbance using an infrared oil analyzer, and based on a standard working curve and sampling volume. The specific process involves standard sample preparation, standard working curve creation, extraction, demulsification, dehydration and drying, volume adjustment, and sample measurement. This method accurately measures the petroleum content in desulfurization solutions, overcoming the problem of severe emulsification during the determination of petroleum content in desulfurization solutions. This method is rapid and simple, and the equipment and reagents used are relatively stable and inexpensive. It can quickly determine the petroleum content in desulfurization solutions and has excellent application prospects and promotional value. Attached Figure Description

[0007] Figure 1 This is the standard working curve for the petroleum content in the desulfurization solution used in the method of this invention. Detailed Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0009] The method for determining the petroleum content in the desulfurization solution of the present invention is, in general, an infrared oil determination method, and is implemented according to the following steps: Step 1: Collect or prepare desulfurization solution on site; Step 2: Distill the desulfurization solution, then dehydrate, adsorb magnesium silicate, and filter to obtain a standard oil sample of petroleum type. Standard oil samples can also be prepared by on-site dehydration, magnesium silicate adsorption, and filtration of petroleum-based materials. The adsorption time is 30 minutes, and slow-speed filter paper is used for filtration.

[0010] Step 3: Prepare a series of standard samples using standard samples, and create a standard working curve using an infrared oil analyzer. The specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes, dilute to the mark with environmentally friendly carbon tetrachloride, and shake well to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the oil content was measured on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, a standard curve was plotted based on the measured absorbance and the corresponding oil content, see [reference needed]. Figure 1 This method is not only applicable to the various embodiments described below.

[0011] Step 4: Extract petroleum hydrocarbons from the desulfurized amine solution using environmentally friendly carbon tetrachloride. The extract is obtained after shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate. The specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution and pour it into a 125 mL separatory funnel. Add 25 mL of environmentally friendly carbon tetrachloride and 0.1 g to 0.5 g of demulsifier. Shake for 4-6 min and let stand for 30-45 min. Release the carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 4-6 min and let stand for 30-45 min. Release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel. 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate into a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

[0012] Step 5: Measure and convert the absorbance using an infrared oil analyzer. Based on the standard working curve and sampling volume, calculate the petroleum content in the desulfurization solution. The specific process is as follows: Using environmentally friendly carbon tetrachloride as a blank, the wavelength on the infrared oil analyzer was 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the A content of the extract was measured.3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converted to absorbance, the system automatically calculates the petroleum content in the desulfurization solution based on the standard working curve and sampling volume. The calculation formula is: , In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

[0013] It should be noted that if the oil content exceeds 80% of the standard working curve, the extract needs to be diluted before measurement; when calculating the oil content in the sample, it needs to be multiplied by the dilution factor.

[0014] Example 1 According to the aforementioned method steps of this invention, the MDEA solution (produced fluid) of an oil well was measured.

[0015] Step 1: Preparation of desulfurization solution: Prepare a 40% (mass fraction) desulfurization solution by mixing MDEA solution with distilled water. Then add an antifoaming agent at a concentration of 600 mg / L to the desulfurization solution to simulate the surface-active substances in the desulfurization solution. Add different amounts of condensate oil to prepare desulfurization solutions with different condensate oil contents, as shown in Table 1 below.

[0016] Step 2: Distill the desulfurization solution prepared in Step 1, then dehydrate, adsorb magnesium silicate, and filter to obtain a petroleum standard sample; the adsorption time is 30 minutes, and slow-speed filter paper is used for filtration.

[0017] Step 3: Prepare a series of standard samples using standard samples, and create a standard working curve using an infrared oil analyzer. The specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes, dilute to the mark with environmentally friendly carbon tetrachloride, and shake well to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the oil content was measured on an infrared oil analyzer at a wavelength of 3030 cm⁻¹.-1 2960cm -1 2930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, a standard curve was plotted based on the measured absorbance and the corresponding oil content, see [reference needed]. Figure 1 .

[0018] Step 4: Extract petroleum hydrocarbons from the desulfurized amine solution using environmentally friendly carbon tetrachloride. The extract is obtained after shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate. The specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution, pour it into a 125 mL separatory funnel, add 25 mL of environmentally friendly carbon tetrachloride, then add 0.4 g of demulsifier, shake for 5 min, let stand for 30 min, and release carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 5 min, let stand for 30 min, and release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel.

[0019] 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate in a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

[0020] Step 5: Using environmentally friendly carbon tetrachloride as a blank, measure the oil content on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the A content of the extract was measured. 3030 A 2960 A 2930 ; The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, the system automatically calculates the petroleum content in the desulfurization solution based on the standard working curve and sampling volume. The calculation formula is as follows: , In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

[0021] When measuring the content of petroleum hydrocarbons, wavenumbers of 2930 cm⁻¹ were used. -1 (Stretching vibration of the CH bond in the CH2 group), 2960 cm⁻¹ -1 (Stretching vibration of the CH bond in the CH3 group) and 3030cm -1 The absorbance A at the point of (stretching vibration of the CH bond in the aromatic ring) 2930 A 2960 and A 3030 The system calculates a total absorbance based on the correction coefficient.

[0022] If the oil content exceeds 80% of the standard working curve, the extract needs to be diluted before measurement; when calculating the oil content in the sample, it needs to be multiplied by the dilution factor.

[0023] The measurement results are shown in Table 1. The average relative error is 0.93%, which meets the technical requirements for field testing in oil fields.

[0024] Table 1. Determination results of desulfurization solutions with different condensate oil contents

[0025] Example 2 The produced fluid of a natural gas purification plant was measured according to the aforementioned method steps of the present invention.

[0026] Step 1: Collect desulfurization solution from a natural gas purification plant. The sample is a black liquid.

[0027] Step 2: Distill the desulfurization solution, then dehydrate, adsorb magnesium silicate, and filter to obtain petroleum standard samples; The adsorption time was 30 minutes, and slow-speed filter paper was used for filtration.

[0028] Step 3: Prepare a series of standard samples using standard samples, and create a standard working curve using an infrared oil analyzer. The specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Use a pipette to pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the oil content was measured on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -12930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, a standard curve was plotted based on the measured absorbance and the corresponding oil content, see [reference needed]. Figure 1 .

[0029] Step 4: Extract petroleum hydrocarbons from the desulfurized amine solution using environmentally friendly carbon tetrachloride. The extract is obtained after shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate. The specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution, pour it into a 125 mL separatory funnel, add 25 mL of environmentally friendly carbon tetrachloride, then add 0.3 g of demulsifier, shake for 4 min, let stand for 45 min, and release carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 6 min, let stand for 45 min, and release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel. 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate in a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

[0030] Step 5: Using environmentally friendly carbon tetrachloride as a blank, measure the oil content on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the A content of the extract was measured. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A. 3030 A 2960 A 2930 Converting to absorbance, the system automatically calculates the petroleum content in the desulfurization solution based on the standard working curve and sampling volume. The calculation formula is: , In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

[0031] In Example 2, a total of four measurements were performed, and the results are shown in Table 2. The relative standard deviation was 0.006%, which meets the requirements for on-site testing.

[0032] Table 2. Results of oil content determination in Example 2

[0033] Example 3 The produced fluid of a natural gas purification plant was measured according to the aforementioned method steps of the present invention.

[0034] Step 1: Collect a desulfurization solution sample from a natural gas purification plant. The sample is pea-green in color.

[0035] Step 2: Use on-site petroleum-based materials for dehydration, magnesium silicate adsorption, and filtration to obtain standard samples. The adsorption time is 30 minutes, and the samples are filtered using slow-speed filter paper.

[0036] Step 3: Prepare a series of standard samples using standard samples, and create a standard working curve using an infrared oil analyzer. The specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes, dilute to the mark with environmentally friendly carbon tetrachloride, and shake well to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the wavelength of the infrared oil analyzer was 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 ; The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, a standard curve was plotted based on the measured absorbance and the corresponding oil content, see [reference needed]. Figure 1 .

[0037] Step 4: Extract petroleum hydrocarbons from the desulfurized amine solution using environmentally friendly carbon tetrachloride. The extract is obtained after shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate. The specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution and pour it into a 125 mL separatory funnel. Add 25 mL of environmentally friendly carbon tetrachloride and 0.1 g of demulsifier. Shake for 6 min and let stand for 35 min. Release the carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 4 min and let stand for 35 min. Release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel. 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate in a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

[0038] Step 5: Using environmentally friendly carbon tetrachloride as a blank, measure the oil content on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the A content of the extract was measured. 3030 A 2960 A 2930 ; The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, the system automatically calculates the petroleum content in the desulfurization solution based on the standard working curve and sampling volume. The calculation formula is: , In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

[0039] In Example 3, a total of four measurements were performed, and the results are shown in Table 3. The relative standard deviation was 0.011%, which meets the requirements for on-site testing.

[0040] Table 3. Results of oil content determination in Example 3

[0041] Example 4 The produced fluid of a natural gas purification plant was measured according to the aforementioned method steps of the present invention.

[0042] Step 1: Collect a desulfurization solution sample from a natural gas purification plant. The sample is light greenish-brown.

[0043] Step 2: Use on-site petroleum-based materials for dehydration, magnesium silicate adsorption, and filtration to obtain standard samples. The adsorption time is 30 minutes, and the samples are filtered using slow-speed filter paper.

[0044] Step 3: Prepare a series of standard samples using standard samples, and create a standard working curve using an infrared oil analyzer. The specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Use a pipette to pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the wavelength of the infrared oil analyzer was 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, a standard curve was plotted based on the measured absorbance and the corresponding oil content, see [reference needed]. Figure 1 .

[0045] Step 4: Extract petroleum hydrocarbons from the desulfurized amine solution using environmentally friendly carbon tetrachloride. The extract is obtained after shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate. The specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution, pour it into a 125 mL separatory funnel, add 25 mL of environmentally friendly carbon tetrachloride, then add 0.2 g of demulsifier, shake for 5 min, let stand for 30 min, and release carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 5 min, let stand for 30 min, and release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel. 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate in a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

[0046] Step 5: Using environmentally friendly carbon tetrachloride as a blank, measure the oil content on an infrared oil analyzer at a wavelength of 3030 cm⁻¹. -1 2960cm -1 2930cm-1 At each location, the A content of the extract was measured. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A. 3030 A 2960 A 2930 Converting to absorbance, the system automatically calculates the petroleum content in the desulfurization solution based on the standard working curve and sampling volume. The calculation formula is: , In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

[0047] In Example 4, a total of four measurements were performed, and the results are shown in Table 4. The relative standard deviation was 0.006%, which meets the requirements for on-site testing.

[0048] Table 4. Results of oil content determination in Example 4

[0049] It is evident that the method of the present invention has simple and easy-to-implement steps, small measurement error, and fully meets the requirements of on-site testing.

Claims

1. A method for determining the petroleum content in a desulfurization solution, characterized in that, Follow these steps: Step 1: Collect desulfurization solution on site, or prepare desulfurization solution; Step 2: Distill the desulfurization solution, then dehydrate, adsorb magnesium silicate, and filter to obtain a standard oil sample of petroleum type. Alternatively, standard oil samples can be prepared by using on-site petroleum products for dehydration, magnesium silicate adsorption, and filtration. Step 3: Prepare a series of standard samples using standard samples, and use an infrared oil analyzer to create a standard working curve; Step 4: Extract petroleum compounds from the desulfurized amine solution using environmentally friendly carbon tetrachloride. After shaking, demulsification, settling, separation, dehydration, and adsorption with magnesium silicate, the extract is obtained. Step 5: Measure and convert the absorbance using an infrared oil analyzer, and calculate the petroleum content in the desulfurization solution based on the standard working curve and sampling volume.

2. The method for determining the petroleum content in the desulfurization solution according to claim 1, characterized in that: In step 1, the desulfurization solution is prepared as follows: A desulfurization solution with a mass fraction of 40% was prepared by mixing MDEA solution with distilled water. Then, an antifoaming agent was added to the desulfurization solution at a concentration of 600 mg / L. Different amounts of condensate oil were added to prepare desulfurization solutions with different condensate oil contents.

3. The method for determining the petroleum content in the desulfurization solution according to claim 1, characterized in that: In step 2, the adsorption time is 30 minutes, and slow-speed filter paper is used for filtration.

4. The method for determining the petroleum content in the desulfurization solution according to claim 1, characterized in that, Step 3, the specific process is as follows: Weigh 0.1000g of standard sample, dissolve it in 100mL volumetric flask with environmentally friendly carbon tetrachloride, and dilute to the mark. Shake well to prepare a standard oil solution with an oil concentration of 1.0mg / mL. Pipette 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL, and 5.00mL of the standard oil solution into six 50mL colorimetric tubes, dilute to the mark with environmentally friendly carbon tetrachloride, and shake well to prepare a series of standard samples. Then, using environmentally friendly carbon tetrachloride as a blank, the wavelength of the infrared oil analyzer was 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the absorbance of the standard sample series was measured, and A was obtained. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Convert the absorbance to absorbance and plot a standard curve based on the measured absorbance and the corresponding oil content.

5. The method for determining the petroleum content in the desulfurization solution according to claim 1, characterized in that, Step 4, the specific process is as follows: 4.1) Take 50.00 mL of desulfurized amine solution and pour it into a 125 mL separatory funnel. Add 25 mL of environmentally friendly carbon tetrachloride and 0.1 g to 0.5 g of demulsifier. Shake for 4-6 min and let stand for 30-45 min. Release the carbon tetrachloride from the bottom of the separatory funnel. Continue to add 25 mL of environmentally friendly carbon tetrachloride to the separatory funnel for a second extraction of the desulfurized amine solution. Shake for 4-6 min and let stand for 30-45 min. Release the environmentally friendly carbon tetrachloride from the bottom of the separatory funnel. 4.2) Collect all the secondary extracts together, dehydrate with 5g of anhydrous sodium sulfate for 5min, then filter with slow filter paper to remove anhydrous sodium sulfate. Collect the filtrate into a 50mL colorimetric tube, dilute to the mark with environmentally friendly carbon tetrachloride, tighten the stopper and shake well to obtain the extract.

6. The method for determining the petroleum content in the desulfurization solution according to claim 1, characterized in that, Step 5, the specific process is as follows: Using environmentally friendly carbon tetrachloride as a blank, the wavelength on the infrared oil analyzer was 3030 cm⁻¹. -1 2960cm -1 2930cm -1 At each location, the A content of the extract was measured. 3030 A 2960 A 2930 The infrared oil analyzer will automatically detect A 3030 A 2960 A 2930 Converting to absorbance, and based on the standard working curve and sampling volume, the petroleum content in the desulfurization solution is calculated using the following formula: ， In the formula, ρ represents oil content, expressed in mg / L. 50 — Volume of the colorimetric tube, in mL; M—Oil content obtained from the standard curve, in mg / L; V – Volume of amine solution, in mL.

7. The method for determining the petroleum content in the desulfurization solution according to claim 6, characterized in that: In step 5, if the measured oil content exceeds 80% of the standard working curve, the extract needs to be diluted before measurement. Finally, when calculating the oil content in the sample, the result needs to be multiplied by the dilution factor.

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