WO2011072468A1

WO2011072468A1 - Method for separating and enriching lower diamonoid compounds from petroleum and source rock

Info

Publication number: WO2011072468A1
Application number: PCT/CN2010/000419
Authority: WO
Inventors: 黄凌; 王汇彤; 张水昌; 魏彩云; 张文龙
Original assignee: 中国石油天然气股份有限公司
Priority date: 2009-12-18
Filing date: 2010-03-31
Publication date: 2011-06-23
Also published as: CN102101817A; CN102101817B

Abstract

Disclosed is a method for separating and enriching lower diamondoid compounds from petroleum and source rock, which includes: extracting the source rock sample with a solution of dichloromethane and methanol to give a source rock extract; removing normal saturated hydrocarbons and asphaltic components from the source rock extract or a crude oil sample with ZSM-5 molecular sieve, obtaining isomeric saturated hydrocarbons components through silica-gel column; adding a solution of β-cyclodextrin into the solution of the isomeric saturated hydrocarbons, separating the mixed suspension to obtain a deposit, adding the deposit into a solution of hydrochloric acid, maintaining the temperature from 40 to 95℃ in an oven, cooling to room temperature after the hydrolysis of β-cyclodextrin catalyzed by an acid is completed, and extracting with a saturated hydrocarbon solvent to obtain lower diamondoid compounds. In this method, the rate of recovery of mono-diamondoid compounds is up to 18%, the rate of recovery of di-diamondoid compounds is up to 35%, and the rate of recovery of tri-diamondoid compounds is up to 1.5%.

Description

Separation and enrichment methods of low-grade adamantides in petroleum and source rocks

Technical field

The present invention relates to a process for separating and enriching low-grade adamantane compounds (single adamantane, bisadamantane and triamantane and their alkyl side chain-containing derivatives) from petroleum and source rocks.

Background technique

Adamantane compounds have a special lattice structure and are not susceptible to organic matter types and depositional environments under most geological conditions. They have strong resistance to corrosion, biodegradability and thermal stability. The field of oil and gas geochemistry research is an ideal hydrocarbon isotope marker, which can be used as a source of oil and gas exploration and a basis for comparison of natural gas with related crude oil and condensate. However, there have been few studies on the application of adamantane compounds as stable isotope markers, mainly because of the large variety of compounds in petroleum and source rock extracts, and the adamantane compounds are similar in nature and concentration to many components. Generally low, it is very difficult to separate and enrich adamantane compounds from petroleum and source rocks.

The enrichment methods that have been reported so far mainly utilize the properties of lower adamantane having a high melting point and a high boiling point relative to other hydrocarbons to separate such compounds. For example, Mair et al. ¹ used crude oil with perfluorotributylamine at 190. The amphoteric hydrocarbon is concentrated by azeotropic distillation under azeotropic distillation, and the crude crystal of the adamantium is collected at the junction of the condensation tube and the steaming head, and the single adamantane is separated from the distillate by the process of crystallization after sublimation. Hala et al. ² ' ³ , after extracting monoamantane and diadamantane from petroleum by distillation, adding appropriate amount of thiourea to extract crystals, and finally separating them by gas chromatography to obtain single diamond 双 and double Donkey Kong 垸. Chen et al. ⁴ distilled the raw materials containing the diamond-like compound into five top-capturing components, including unsubstituted monoamantane, substituted mono-adamantan, unsubstituted. Double vajra, substituted double vajra and unsubstituted triamantane. In order to solve the precipitation of low-grade diamond quinone compounds in production equipment in natural gas production Problems caused by the operation, Alexander et al., ⁵ _ ⁸ discloses adamantyl lower embankment extracted with the solvent from the gas stream and to further lower the adamantane compound extracted by adsorption on silica gel, by using a heat exchanger to extract Compounds and various methods such as extraction of lower adamantane compounds from a gas stream by using a porous solid such as zeolite. Swanson et al. ⁹ discloses a process for recovering lower adamantane compounds from a gas stream; and Partridge et al., ^1Q , discloses a process for recovering lower adamantane compounds from a liquid stream. However, the lower adamantane species obtained by the above method are relatively simple and suitable for higher concentration systems, and cannot effectively enrich various low-grade adamantane compounds from lower-content petroleum and source rocks.

Summary of the invention

The object of the present invention is to establish a simple and effective method for separating and enriching low-grade adamantane compounds by utilizing the cooperation between β-cyclodextrin and lower adamantane compounds, so as to obtain the purity and content of the enriched products. Can meet the requirements of isotope mass spectrometry.

The method for separating and enriching low-grade adamantane compounds in petroleum and source rocks according to the present invention is divided into three steps: sample pretreatment, inclusion process and hydrolysis process:

1) Pretreatment of the sample:

The source rock sample is pulverized to a particle size of less than 100 μππ, and then ultrasonically extracted in methylene chloride and methanol solution for 24 hours. The volume ratio of dichloromethane to methanol is 1:1, methylene chloride and methanol solution and hydrocarbon. The source rock sample dosage ratio is 10~30 mL/g; the extract is filtered and poured into a separatory funnel containing deionized water, and the bottom aqueous phase is extracted three times with n-pentane and dichloromethane solution, n-pentamidine and The volume ratio of the aqueous solution to the n-pentamidine and methylene chloride solution is 0. 5~2, and the combined extracts are added with sodium sulfate to remove water and nitrogen is blown off to obtain a hydrocarbon. Source rock extract;

The above source rock extract or crude oil sample is dissolved in cyclohexanide or isooctane and used as an eluent to remove the normal saturated hydrocarbon and asphaltene components in the sample with ZSM-5 molecular sieve. Before use of ZSM-5 molecular sieve Bake at 450 ° C for 12 hours, the mass ratio of sample to ZSM-5 molecular sieve is 1:60~: L20; Then, a saturated hydrocarbon component is obtained through a silica gel column using a saturated hydrocarbon solvent as an eluent.

100~200 mesh, baked at 250 °C for 12 hours, the mass ratio of sample to silica gel is 1:60~120;

2) Inclusion of β-cyclodextrin for low-grade aglycone

The β-cyclodextrin is prepared into a solution having a concentration of 1 to 6 mg/mL with deionized water, and the isomeric saturated hydrocarbon solution obtained in the above step is added, and then rapidly stirred by a magnetic stirrer for 1 to 8 hours, and the β-cyclodextrin aqueous solution is The volume ratio of the isomeric saturated hydrocarbon solution is from 1 to 10; the obtained milky white suspension is filtered with an organic microporous membrane of 45 μm, or centrifuged at 3000 rpm for 20 minutes to obtain a β-cyclodextrin containing a low-grade diamond. Precipitation of alkane compounds;

3) Hydrolysis of β-cyclodextrin

Transfer the obtained precipitate to a glass bottle containing a concentration of 0. 1~5 mol/L hydrochloric acid solution. The ratio of hydrochloric acid solution to precipitation is 20~: 100 mL/g, and sealed at 40~95 °C. The oven is kept at a constant temperature for 4 to 50 hours. After the acid-catalyzed hydrolysis reaction of β-cyclodextrin is completed, it is cooled to room temperature. The lower adamantane compound is extracted with a saturated hydrocarbon solvent, and the acid-catalyzed hydrolysis of the saturated hydrocarbon solvent and β-cyclodextrin is carried out. The volume ratio of the liquid was 0.5 to 2, and the obtained saturated hydrocarbon solution was separated and washed three times with deionized water. After removing water with dry sodium sulfate powder, the organic phase was concentrated by nitrogen blowing at room temperature.

The saturated hydrocarbon solvent used in the dissolution, column chromatography and extraction of the sample may be: n-pentamidine, n-hexane, cyclohexane, isooctane or a mixed solution thereof.

DRAWINGS

Figure 1: Flow chart for the separation and enrichment of lower-grade adamantane compounds in petroleum and source rocks. detailed description

The invention is further illustrated by the following examples.

Example 1

Take 1 g of source rock sample pulverized to 100 μm in 25 mL of dichloromethane: methanol (1 1 v/v) Ultrasonic extraction in solution for 24 hours. The extract was filtered and poured into 100 mL of a sep. funnel containing 25 mL of deionized water. The bottom aqueous phase was extracted three times with 10 mL of n-pentane:dichloromethane (2:1 v/v) solution, and the combined extracts were added to remove water. After drying the sample at room temperature, dissolve the sample with a small amount of isooctane, use isooctane as the eluent, remove the normal saturated hydrocarbon and asphaltene with 6 g ZSM-5 molecular sieve column, and then use n-hexane as the eluent. The isooctane solution of the sample was passed through a 12 g silica gel column to give an isomeric saturated hydrocarbon component. The resulting solution was poured into 50 mL of a 5 mg/mL aqueous solution of β-cyclodextrin and stirred rapidly for 4 hours. The obtained milky white suspension was filtered through a 0.45 pm organic microfiltration membrane, and the resulting precipitate was washed with 20 mL of n-hexane. The obtained precipitate was transferred to a glass bottle containing 30 mL of a 0.5 mol L hydrochloric acid solution, sealed, and placed in an oven at 90 ° C for 12 hours. After the sample was cooled to room temperature, 20 mL of n-hexane was added to extract the lower adamantane compound. The separated n-hexane layer was washed three times with 20 mL of deionized water, and the appropriate amount of sodium sulfate was added to remove water, and then concentrated at room temperature under nitrogen. The organic phase is placed in a vial and stored in a suitable volume. The analysis results of the enriched products showed that the recovery rates of single diamond, diamantane and triammonium were: 2.43%, 25.1% and 1.73%, respectively.

Example 2

A 1 g source rock sample pulverized to 100 μm was subjected to ultrasonic extraction in a 25 mL dichloromethane:methanol (1:1 v/v) solution for 24 hours. The extract was filtered and poured into 100 mL of a sep. funnel containing 25 mL of deionized water. The bottom aqueous phase was extracted three times with 10 mL of n-pentane:dichloromethane (2:1 v/v) solution. After combining the extracts, an appropriate amount of sodium sulfate was added to remove water. The sample was dried by nitrogen at room temperature, dissolved in a small amount of cyclohexane, and the cycloheximide was used as an eluent. The normal saturated hydrocarbon and asphaltene were removed by a 6 g ZSM-5 molecular sieve column, and then n-pentamidine was used as an eluent. A sample of n-hexane was passed through a 12 g silica gel column to give an isomeric saturated hydrocarbon component. The resulting solution was poured into 50 mL of a 2 mg/mL aqueous solution of β-cyclodextrin and stirred rapidly for 4 hours. The resulting milky white suspension was centrifuged for 20 minutes (3000 rpm) to obtain a precipitate, and the resulting precipitate was washed three times with 10 mL of n-pentane. The resulting precipitate was transferred to a glass bottle containing 30 mL of a 2 mol/L hydrochloric acid solution, sealed and placed. The oven was kept at 40 ° C for 50 hours. After the sample is cooled to room temperature, 20 mL of n-pentamidine is added to extract the lower-grade adamantant compound, and the separated n-pentane layer is washed three times with 20 mL of deionized water. After adding appropriate amount of sodium sulfate to remove water, nitrogen is added at room temperature. The organic phase is concentrated by blowing to a suitable volume and stored in a sample vial. The analysis results of the enriched products showed that the recovery rates of monoamantane, bis-adamant and triamantane were 0.52%, 15.1% and 0.29%, respectively.

Example 3

A sample of 100 mg of crude oil was taken and dissolved with a small amount of cyclohexane. Using cyclohexanone as eluent, 6 g ZSM-5 molecular sieve column was used to remove normal saturated hydrocarbons and asphaltenes, and then the solution of cyclohexylamine was passed through a 12 g silica gel column with n-pentamidine as eluent. Isomerized saturated hydrocarbon component. The resulting solution was poured into 50 mL of a 1 mg/mL aqueous solution of β-cyclodextrin and stirred rapidly for 1 hour. The resulting milky white suspension was centrifuged for 20 minutes (3000 rpm) to obtain a precipitate, and the resulting precipitate was washed three times with 10 mL of n-pentane. The resulting precipitate was transferred to a glass bottle containing 30 mL of a 0.1 mol/L hydrochloric acid solution, sealed, and placed in an oven at 80 ° C for 24 hours. After the sample is cooled to room temperature, 20 mL of n-pentane is added to extract the lower adamantane compound. The separated n-pentamidine layer is washed three times with 20 mL of deionized water, and the appropriate amount of sodium sulfate is added to remove water, and nitrogen is allowed at room temperature. The organic phase is concentrated by blowing to a suitable volume and stored in a sample vial. The analysis results of the enriched products showed that the recovery rates of single diamond, double diamond and triple diamond were: 0.44%, 11.1% and 0.28%, respectively.

Example 4

A 100 mg crude oil sample was taken and dissolved with a small amount of isooctane. Using isopropane as eluent, 6 g ZSM-5 molecular sieve column was used to remove normal saturated hydrocarbons and asphaltenes, and then the iso-indole solution of the sample was passed through a 12 g silica gel column with n-hexane as an eluent. A saturated hydrocarbon component. The resulting solution was poured into 50 mL of a 6 mg/mL aqueous solution of β-cyclodextrin and stirred rapidly for 8 hours. The obtained milky white suspension was filtered through a 0.45 μM organic microfiltration membrane, and the resulting precipitate was washed with 20 mL of hexane. The resulting precipitate was transferred to a glass containing 30 mL of a 1 mol/L hydrochloric acid solution. Inside the glass bottle, it was sealed and placed in an oven at 90 °C for 4 hours. After the sample was cooled to room temperature, 20 mL of n-hexane was added to extract the lower adamantane compound. The separated n-hexane layer was washed three times with 20 mL of deionized water, and the appropriate amount of sodium sulfate was added to remove water, and then concentrated at room temperature under nitrogen. The organic phase is placed in a vial and stored in a suitable volume. The analysis results of the enriched products showed that the recovery rates of single diamond, double diamond and triamantane were: 2.45%, 28.1% and 1.19%, respectively. Industrial applicability

The present invention provides a method for separating and enriching adamantane compounds from petroleum and source rocks, using a highly selective binder (β-cyclodextrin) and utilizing them with lower adamantane compounds The characteristics of inclusion and hydrolysis in an acidic aqueous solution occur, so that various low-grade adamantene compounds contained in the initial sample can be separated and enriched at one time, and the purity is required for isotope mass spectrometry. The experimental results show that the recovery rate of the single adamantane compound can reach more than 18%, the recovery rate of the bis-adamantane compound can reach more than 35%, and the recovery rate of the compound of the Sanjinang compound can be up to 1. More than 5%.

The invention is applicable to the separation and enrichment of lower adamantane compounds in samples such as source rock, petroleum and natural gas condensate. Since the method has simple operation steps, no special requirements for reagents and equipment, and good enrichment effect, the low-grade adamant compound can be used as a marker for measuring carbon and hydrogen isotopes. This is a good guide for determining the generation and parental sources of reservoirs (especially high-mature crude oils and cracked gases) as well as source-source comparisons and oil-source comparisons.

Claims

Rights request

A method for separating and enriching a lower adamantane compound in petroleum and source rocks, characterized in that the method is divided into three steps of sample pretreatment, inclusion process and hydrolysis process,

1) Pretreatment of the sample:

The source rock sample was pulverized to a particle size of less than 100 μππ, and then subjected to ultrasonic extraction in dichloromethane and methanol for 24 hours, dichloromethane and methanol in a volume ratio of 1: 1, dichloromethane and methanol solution and hydrocarbon source. The rock sample is used in an amount of 10 to 30 mL/g. The extract is filtered and poured into a separatory funnel containing deionized water. The bottom aqueous phase is extracted three times with n-pentane and dichloromethane solution, n-pentane and two. The volume ratio of the chloromethane to the volume ratio of 2:1, the bottom aqueous phase and the n-pentane and methylene chloride solution is 0. 5~2, and the combined extracts are added with sodium sulfate to remove water and the solvent is blown off by nitrogen to obtain a hydrocarbon source. Rock extract

Dissolve the above source rock extract or crude oil sample with cyclohexane or isooctane as an eluent, and remove the normal saturated hydrocarbon and asphaltene components in the sample with ZSM-5 molecular sieve. Before ZSM-5 molecular sieve Bake at 450 ° C for 12 hours, the mass ratio of sample to ZSM-5 molecular sieve is 1: 60~: 120; then use a saturated hydrocarbon solvent as eluent to pass through the silica gel column to obtain an isomerized saturated hydrocarbon solution, the silica gel particle size is 100~ 200 mesh, baked at 250 ° C for 12 hours, the mass ratio of sample to silica gel is 1: 60~120;

2) Inclusion of β-cyclodextrin for lower adamantane compounds

The β-cyclodextrin is prepared into a solution having a concentration of 1 to 6 mg/mL with deionized water, and the isomeric saturated hydrocarbon solution obtained in the above step is added, and then rapidly stirred by a magnetic stirrer for 1 to 8 hours, and the β-cyclodextrin aqueous solution is The volume ratio of the isomeric saturated hydrocarbon solution is 1 to 10 _; the obtained milky white suspension is filtered with an organic microporous membrane of 0.55 μm or centrifuged at 3000 rpm for 20 minutes to obtain a β-cyclodextrin inclusion low level. Precipitation of adamantane compounds;

3) Hydrolysis of β-cyclodextrin The obtained precipitate was transferred to a glass bottle containing a concentration of 0.1 to 5 mol/L hydrochloric acid solution, and the ratio of the hydrochloric acid solution to the precipitate was 20~; L00 mL/ _g , and sealed at 40 to 95 ° C. The oven is kept at a constant temperature for 4 to 50 hours. After the acid-catalyzed hydrolysis reaction of β-cyclodextrin is completed, it is cooled to room temperature, and the lower hydrocarbon aglycone is extracted with a saturated hydrocarbon solvent. The acid-catalyzed hydrolysis of the saturated hydrocarbon solvent and β-cyclodextrin is carried out. The volume ratio of the liquid is 0. 5~2, and the obtained saturated hydrocarbon solution is separated and washed three times with deionized water. After removing the water with dry sodium sulfate powder, the organic phase is concentrated by nitrogen blowing at room temperature to obtain a low-grade diamond plant. Compound.