CN-121994741-A - Method for measuring petroleum content in desulfurization solution

CN121994741ACN 121994741 ACN121994741 ACN 121994741ACN-121994741-A

Abstract

The invention discloses a method for measuring petroleum content in a desulfurization solution, which comprises the steps of 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 standard petroleum sample of petroleum, or carrying out dehydration, magnesium silicate adsorption and filtration treatment on the petroleum on site to obtain the standard petroleum sample, 3) preparing a standard sample series by using the standard sample, preparing a standard working curve by using an infrared oil measuring instrument, 4) extracting petroleum in the desulfurization amine liquid by using environment-friendly carbon tetrachloride, obtaining an extraction liquid after oscillation, demulsification, standing, separation, dehydration and magnesium silicate adsorption, 5) measuring and converting absorbance by using the infrared oil measuring instrument, and calculating to obtain the numerical value of the petroleum content in the desulfurization solution according to the standard working curve and the sampling volume. The invention belongs to the technical field of component analysis, has quick and simple implementation process, uses stable instruments and medicaments and has low price, thereby satisfying the measurement of petroleum content in desulfurization solution.

Inventors

WANG BING
YE PENGPENG
CAO JINGMIN
LI XIN
WENG JUNLI
CHEN XING
WEN XIN
CHEN XIAOFEI
LIU YANG
YANG QINGSONG
YAN HANG
SUN YUQIAN

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (7)

1. The method for measuring the petroleum content in the desulfurization solution is characterized by comprising the following steps: step 1, collecting a desulfurization solution on site, or preparing the desulfurization solution; Step 2, distilling the desulfurization solution, and then dehydrating, adsorbing by magnesium silicate and filtering to obtain a standard oil sample of petroleum; Or the on-site petroleum is used for dehydration, magnesium silicate adsorption and filtration treatment to prepare a standard oil sample; step 3, preparing a standard sample series by using a standard sample, and manufacturing a standard working curve by using an infrared oil meter; Step 4, extracting petroleum in the desulphurizing amine liquid by using environment-friendly carbon tetrachloride, and obtaining an extract after oscillation, demulsification, standing, separation, dehydration and magnesium silicate adsorption; And 5, measuring and converting absorbance by an infrared oil meter, and calculating to obtain the numerical value of the petroleum content in the desulfurization solution according to a standard working curve and a sampling volume.
2. The method for measuring petroleum content in a desulfurization solution according to claim 1, wherein in step 1, the desulfurization solution is prepared by a method comprising the steps of, Preparing a desulfurization solution with the mass fraction of 40% by using an MDEA solution and distilled water, adding a defoaming agent into the desulfurization solution according to 600mg/L, and respectively adding condensate oil with different amounts to prepare the desulfurization solution with different condensate oil contents.
3. The method for measuring petroleum content in a desulfurization solution according to claim 1, wherein in step 2, the adsorption time is 30min, and the filtration is performed by using a slow filter paper.
4. The method for determining the petroleum content in the desulfurization solution according to claim 1, wherein in step 3, the specific process is as follows: weighing 0.1000g of standard sample, dissolving the standard sample in a 100mL volumetric flask with environment-friendly carbon tetrachloride, fixing the volume to a scale mark, shaking uniformly to prepare a standard oil solution with the oil concentration of 1.0mg/mL, respectively sucking 0.00mL, 0.10mL, 0.25mL, 1.00mL, 2.50mL and 5.00mL of standard oil solution by using a pipette, placing the standard oil solution in 650 mL colorimetric tubes, diluting the standard oil solution to the scale mark with environment-friendly carbon tetrachloride, and shaking uniformly to prepare a standard sample series; Then, taking environment-friendly carbon tetrachloride as a blank, respectively measuring the absorbance of a standard sample series at the position with the wavelength of 3030cm -1 、2960cm -1 、2930cm -1 on an infrared oil meter, measuring A 3030 、A 2960 、A 2930 , automatically converting A 3030 、A 2960 、A 2930 into absorbance by the infrared oil meter, and drawing a standard curve according to the measured absorbance and the corresponding oil content.
5. The method for determining the petroleum content in the desulfurization solution according to claim 1, wherein in step 4, the specific process is as follows: 4.1 Taking 50.00mL of the desulphurizing amine liquid, pouring the desulphurizing amine liquid into a 125mL separating funnel, adding 25mL of environment-friendly carbon tetrachloride, adding 0.1 g-0.5 g of demulsifier, oscillating for 4-6min, standing for 30-45min, discharging carbon tetrachloride from the lower end of the separating funnel, continuously adding 25mL of environment-friendly carbon tetrachloride into the separating funnel to perform secondary extraction on the desulphurizing amine liquid, oscillating for 4-6min, standing for 30-45min, and discharging environment-friendly carbon tetrachloride from the lower end of the separating funnel; 4.2 Collecting the secondary extract, dehydrating with 5g anhydrous sodium sulfate for 5min, filtering with slow filter paper, removing anhydrous sodium sulfate, collecting filtrate into a 50mL colorimetric tube, diluting with environment-friendly carbon tetrachloride to scale, sealing the bottle stopper, and shaking to obtain extract.
6. The method for determining the petroleum content in the desulfurization solution according to claim 1, wherein in step 5, the specific process is: Taking environment-friendly carbon tetrachloride as a blank, respectively measuring A 3030 、A 2960 、A 2930 of an extract liquid at the position of 3030cm -1 、2960cm -1 、2930cm -1 on an infrared oil meter, automatically converting A 3030 、A 2960 、A 2930 into absorbance by the infrared oil meter, and calculating to obtain the numerical value of petroleum content in the desulfurization solution according to a standard working curve and a sampling volume, wherein the calculation formula is as follows: , wherein rho is the oil content in mg/L; 50-the volume of the cuvette in mL; m-the oil content found on the standard curve in mg/L; V-amine liquid volume in mL.
7. The method for measuring the petroleum content in the desulfurization solution according to claim 6, wherein in step 5, if the measured oil content exceeds 80% of the standard working curve, the extract is diluted, the measurement is performed after the dilution, and finally, the result of measuring the oil content in the sample is calculated by multiplying the dilution factor.

Description

Method for measuring petroleum content in desulfurization solution Technical Field The invention belongs to the technical field of component analysis of petroleum content, and relates to a method for measuring petroleum content in a desulfurization solution. Background Natural gas generally contains a certain amount of carbon dioxide and hydrogen sulfide, and the natural gas can be used after being purified, and an alcohol amine method is a main process for desulfurizing and decarbonizing the natural gas at present. Condensate oil in natural gas does not effectively separate from a liquid separating tank before entering a desulfurizing tower and enters a desulfurizing solution, so that the foaming performance of the desulfurizing amine liquid is affected, the liquid blocking phenomenon is caused, the desulfurizing tower cannot stably operate, the desulfurizing effect does not reach the standard, and the normal production operation of a natural gas purifying plant is directly affected. The desulfurization solution is generally 40% -45% by mass of MDEA (N-methyldiethanolamine), and the pH range is 9-11. The composition is complex due to long-term circulation operation, and mainly comprises surfactant, condensate oil, hydrocarbon substances, solid impurities, amine degradation products, heat-stable salts and the like. At present, the commonly used methods for measuring the content of petroleum include ultraviolet spectrophotometry, infrared spectrophotometry, non-dispersive infrared absorption spectrophotometry, fluorescence spectrophotometry, gas chromatography, infrared spectrometry, weight method and the like, the weight method is mainly suitable for measuring some non-volatile petroleum, petroleum in desulfurization solution is mainly condensate oil, and the volatility is strong, so the weight method is not suitable for measuring the content of petroleum in desulfurization solution. Other determination methods are to extract and purify petroleum in the sample by using an extractant, then establish a standard curve, and then determine the petroleum content in the sample by using beer's law. Because the desulfurization solution contains a large amount of surface active substances, serious emulsification occurs in the extraction process, the petroleum content measurement methods cannot be directly applied to measurement of petroleum content in the desulfurization solution, and equipment used by a non-dispersive infrared absorption photometry, a fluorescence spectrophotometry, a gas chromatography and an infrared spectrometry is relatively expensive and has high requirements on samples. Therefore, there is an urgent need to develop an effective method for determining petroleum content in desulfurization solutions. Disclosure of Invention The invention aims to provide a method for measuring petroleum content in a desulfurization solution, which solves the problems of serious emulsification and large error of measurement results in the petroleum content measurement process in the prior art. The invention adopts the technical scheme that the method for measuring the petroleum content in the desulfurization solution is implemented according to the following steps: step 1, collecting a desulfurization solution on site, or preparing the desulfurization solution; Step 2, distilling the desulfurization solution, and then dehydrating, adsorbing by magnesium silicate and filtering to obtain a standard oil sample of petroleum; Or the on-site petroleum is used for dehydration, magnesium silicate adsorption and filtration treatment to prepare a standard oil sample; step 3, preparing a standard sample series by using a standard sample, and manufacturing a standard working curve by using an infrared oil meter; Step 4, extracting petroleum in the desulphurizing amine liquid by using environment-friendly carbon tetrachloride, and obtaining an extract after oscillation, demulsification, standing, separation, dehydration and magnesium silicate adsorption; And 5, measuring and converting absorbance by an infrared oil meter, and calculating to obtain the numerical value of the petroleum content in the desulfurization solution according to a standard working curve and a sampling volume. The invention has the advantages that the measurement of petroleum content in the desulfurization solution is carried out according to the standard working curve and the sampling volume by measuring and converting the absorbance through the infrared oil meter, the specific process is that, the petroleum content in the desulfurization solution is accurately measured through the steps of standard sample preparation, standard working curve preparation, extraction, demulsification, dehydration and drying, constant volume, sample measurement and the like, and the problem of serious emulsification in the process of measuring the petroleum content in the desulfurization solution is solved. The method is quick and simple, the used equipment and medicament a