阅读说明：本技术 一种磺化改性槐糖脂或其盐以及它们的制备方法 (Sulfonated modified sophorolipid or salt thereof and preparation method thereof ) 是由 乔富林 秦冰 江建林 高敏 侯研博 于 2019-09-03 设计创作，主要内容包括：提供一种磺化改性槐糖脂或其盐及它们的制备方法,其中该磺化改性槐糖脂具有下面的结构式(I),并且是通过磺化试剂对内酯型槐糖脂进行磺化而制得。相比之下,该磺化改性槐糖脂或其盐具有更强的抗盐能力和更好的润湿性,而且油水界面活性和除油能力更强,是一种性能优良、绿色低毒的油田化学品。此外,所述制备方法具有工艺简单、反应条件温和、产率高的优点,因而特别适于工业化生产。(A sulfonated modified sophorolipid or a salt thereof, wherein the sulfonated modified sophorolipid has the following structural formula (I) and is prepared by sulfonating an lactone-type sophorolipid with a sulfonating agent, and a method for preparing the same are provided. In contrast, the sulfonated modified sophorolipid or the salt thereof has stronger salt resistance and better wettability, and stronger oil-water interfacial activity and oil removal capability, and is an oil field chemical with excellent performance, green and low toxicity. Furthermore, the preparation methodHas the advantages of simple process, mild reaction condition and high yield, thereby being particularly suitable for industrial production.)

1. A sulfonated modified sophorolipid having the following structural formula (I):

or a salt thereof.

2. The sulfonated modified sophorolipid according to claim 1, wherein said salt has the following structural formula (II):

in the formula, M⁺Is a cation.

3. The sulfonate-modified sophorolipid according to claim 2, wherein said M⁺Is selected from Li⁺、Na⁺、K⁺、NH₄ ⁺One or more of (a).

4. A method of preparing the sulfonated modified sophorolipid of claim 1, comprising the steps of:

(1) adding lactonic sophorolipid into organic solvent, heating and stirring to obtain lactonic sophorolipid solution; and

(2) and adding a sulfonating agent into the solution of the lactone type sophorolipid to carry out sulfonation reaction to obtain the sulfonated modified sophorolipid.

5. The method according to claim 4, wherein the organic solvent is one or more selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, tetrahydrofuran, tetrahydropyran, 1, 2-dichloroethane, pyridine; and

the heating in the step (1) is carried out at a temperature of 35 to 100 ℃, preferably 45 to 75 ℃.

6. The method of claim 4, wherein the sulfonating agent is one or more selected from chlorosulfonic acid, sulfamic acid, sulfur trioxide pyridine complex, concentrated sulfuric acid, sulfur trioxide.

7. The method according to claim 4, wherein the molar ratio of the sulfonating agent to the lactone-type sophorolipid is (1-10): 1, preferably (1-4): 1.

8. The process according to claim 4, wherein the sulfonation is carried out at a temperature of 45 to 100 ℃ for 0.5 to 12 hours, preferably 2 to 5 hours.

9. The method according to any one of claims 4 to 8, further comprising a step (3) of adding a base to the obtained sulfonated modified sophorolipid after the step (2), thereby obtaining a sulfonated modified sophorolipid salt, wherein the base is one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonia water.

10. Use of the sulfonated modified sophorolipid or salt thereof according to any one of claims 1 to 3 or the sulfonated modified sophorolipid or salt thereof produced by the method according to any one of claims 4 to 9 in the field of oil recovery.

Technical Field

The invention relates to an oil field chemical and a preparation method thereof, in particular to sulfonated modified sophorolipid or salt thereof and a preparation method thereof.

Background

The biosurfactant is a substance with surface activity secreted in the metabolic process of microorganisms when the microorganisms are cultured under certain conditions, such as glycolipid, lipopeptide or neutral lipid derivative. Similar to the traditional industrial synthesized surfactants, the biosurfactants also have the functions of solubilization, emulsification, foaming, wetting and the like. Compared with the traditional industrially synthesized surfactants, the biosurfactants, particularly the glycolipid surfactants, have the advantages of large and complex molecular structures, good biocompatibility, no toxicity, biodegradability, no pollution, specificity, good selectivity and the like. The characteristics lead the biosurfactant to have great application potential in a plurality of fields of oil extraction, daily chemicals, medicines and the like, and the biosurfactant is natural, green and excellent in property.

At present, many traditional oil field chemical agents can not satisfy the requirement of oil recovery field to green because toxicity and irritability are higher, and the novel oil-displacing agent of green low toxicity is urgently needed. This facilitates the use of biosurfactants for tertiary oil recovery and oil transportation. Currently, the three most widely used biosurfactants with the highest yield are sophorolipids, rhamnolipids and lipopeptides. Patent CN 107794018A discloses a biological glycolipid oil-displacing agent and application thereofThe oil displacement agent has the characteristics of good water solubility, safety, no toxicity, convenient construction, simple process, wide application range and performance superior to that of a chemical agent, and can effectively reduce the viscosity of thickened oil and improve the recovery ratio of crude oil. The patent CN 107556993A discloses a high temperature and high salt resistant biological emulsifying viscosity-reducing agent and a preparation method thereof, the biological emulsifying viscosity-reducing agent is prepared by rhamnolipid fermentation liquor (10-30%), sophorolipid fermentation liquor (0.1-0.3%) and auxiliary agent (0.01-0.02%) according to a proportion, the highest temperature resistance reaches 120 ℃, and the highest temperature resistance can tolerate 1.2 multiplied by 10⁵And (5) the salinity of the saline water is mg/L.

Although the oil displacement agent composite formula system based on the biosurfactant has excellent properties, the properties of a single biosurfactant are still required to be improved. For example, the stability of industrial sophorolipids is insufficient, and the salt resistance and interfacial activity are relatively low. In addition, the biosurfactant has the defect of insufficient adaptability in the application process, such as large difference of effects when crude oil is extracted in different blocks. Aiming at the problem, the biosurfactant is chemically modified to increase the structural diversity, so that the method is a good solution.

However, the methods reported in the literature for chemical modification of biosurfactants are complex. Peng, Yifong et al reported in the literature (Sophorrolipids: Expanding structural differentiation by ring-opening cross-catalysis. Eur. J. lipid Sci. Technol. 2015,117,217-228) that Ru catalysts catalytically modified sophorolipid, but Ru catalysts are expensive, and the reaction route needs hydrogenation reaction, and the conditions are harsh. A method for obtaining a cationic quaternary ammonium salt surfactant by modifying sophorolipid through multi-step reaction is reported in a document (A new class of antibacterial biological surfactants, Green chem.,2015,17,3373-3377) by Delbeke, E.I.P., and the like, but the modification method has the defects of large reaction steps, low overall yield and unsuitability for application in the field of oilfield chemistry. Therefore, it is necessary to develop a low-cost, simple and easy modification method to improve the performance of biosurfactant and further promote its application.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides novel sulfonated modified sophorolipid and a preparation method thereof. The invention prepares a novel sulfonated modified sophorolipid by taking lactone sophorolipid as a raw material and carrying out sulfonation reaction. The invention aims to improve the adaptability of sophorolipid to crude oil in different blocks, improve the salt resistance of sophorolipid, increase the oil/water interface activity and oil washing capacity of sophorolipid and enrich the structural diversity of biosurfactant after simple chemical modification, thereby widening the application of environment-friendly bio-based oil displacement agents in oil field exploitation.

To achieve the above objects, the present invention provides a novel sulfonated modified sophorolipid or a salt thereof and a method for producing the same.

In one aspect, the present invention provides a sulfonated modified sophorolipid having the following structural formula (I):

or a salt thereof.

In one embodiment, the salt has the following structural formula (II):

in the formula, M⁺Is a cation.

In another embodiment, said M⁺Is selected from Li⁺、Na⁺、K⁺、NH₄ ⁺One or more of (a).

In another aspect, the present invention provides a method for preparing a sulfonated modified sophorolipid represented by formula (I), comprising the steps of:

(1) adding lactonic sophorolipid into organic solvent, heating and stirring to obtain lactonic sophorolipid solution; and

(2) and adding a sulfonating agent into the solution of the lactone type sophorolipid to carry out sulfonation reaction to obtain the sulfonated modified sophorolipid.

In one embodiment, the organic solvent is one or more selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, tetrahydrofuran, tetrahydropyran, 1, 2-dichloroethane, pyridine; and

the heating in the step (1) is carried out at a temperature of 35 to 100 ℃, preferably 45 to 75 ℃.

In another embodiment, the sulfonating agent is one or more selected from chlorosulfonic acid, sulfamic acid, sulfur trioxide pyridine complex, concentrated sulfuric acid, sulfur trioxide.

In another embodiment, the molar ratio of the sulfonating agent to the lactone-type sophorolipid is (1-10): 1, preferably (1-4): 1.

In another embodiment, the sulfonation reaction is carried out at a temperature of 45 to 100 ℃ for 0.5 to 12 hours, preferably 2 to 5 hours.

In still another embodiment, the preparation method further comprises a step (3) of adding a base to the obtained sulfonated modified sophorolipid after the step (2), thereby obtaining the sulfonated modified sophorolipid salt represented by the formula (II), wherein the base is one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonia water.

In a further aspect, the present invention provides the use of the sulfonated modified sophorolipid or a salt thereof as described above, or the sulfonated modified sophorolipid or a salt thereof prepared according to the above method, in the field of oil recovery.

The sulfonated modified sophorolipid or salt thereof has stronger salt resistance and more excellent interfacial activity compared with the unmodified sophorolipid.

The invention takes lactone sophorolipid obtained by microbial fermentation as a raw material, and prepares a novel sulfonated modified sophorolipid through sulfonation reaction. The preparation process of the invention is simple, the reaction condition is mild, the yield is high, and the invention is especially suitable for industrial production. The obtained product is green and environment-friendly, has excellent salt resistance, interface activity, wettability and oil washing capacity, and has wide application prospect.

Drawings

FIG. 1 is an ESI mass spectrum of the novel sulfonated and modified sophorolipid prepared in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the following examples, all reagents used were commercially available chemical reagents unless otherwise specified, and there are no particular limitations thereon.

The application provides a sulfonated modified sophorolipid, which has the following structural formula (I):

or a salt thereof.

In one embodiment, the salt has the following structural formula (II):

in the formula, M⁺Is a cation. Preferably, M is⁺Is Li⁺、Na⁺、K⁺、NH₄ ⁺。

In the present application, M is⁺In addition to the above monovalent cations, it may also be a divalent cation such as Mg²⁺、Ca²⁺Etc. or trivalent cation Al³⁺And the like. This is not particularly limited.

The method for preparing the sulfonated and modified sophorolipid shown in the formula (I) comprises the following steps:

(1) adding lactonic sophorolipid into organic solvent, heating and stirring to obtain lactonic sophorolipid solution; and

(2) and adding a sulfonating agent into the solution of the lactone type sophorolipid to carry out sulfonation reaction to obtain the sulfonated modified sophorolipid.

Among them, the lactone-type sophorolipid used in the present invention has a structure represented by the following formula (III):

and the reaction formula of the sulfonation reaction is as follows:

it is presumed that the above sulfonation reaction occurs only at the hydroxymethyl position of the lactone-type sophorolipid, mainly due to steric hindrance effects.

The lactone-type sophorolipid, sulfonating agent, base and solvent used in the present invention may be commercially available chemical reagents or may be prepared by methods known in the art.

In the production method according to the present invention, the organic solvent described in step (1) is preferably one or more of N, N-dimethylformamide, N-dimethylacetamide, tetrahydrofuran, tetrahydropyran, 1, 2-dichloroethane, and pyridine, and more preferably one or more of N, N-dimethylformamide and 1, 2-dichloroethane. In addition, the volume ratio of the lactone sophorolipid to the organic solvent is preferably 1: 1-1: 20.

In the preparation method according to the present invention, the heating in the step (1) is preferably performed at a temperature of 35 to 100 ℃, more preferably 45 to 75 ℃.

In the preparation method according to the present invention, the sulfonating agent in step (2) is preferably one or more of chlorosulfonic acid, sulfamic acid, sulfur trioxide pyridine complex, concentrated sulfuric acid; and the molar ratio of the sulfonation reagent to the lactone-type sophorolipid can be (1-10): 1, preferably (1-4): 1, and more preferably (2-4): 1. The molar ratio can be selected according to the desired degree of sulfonation of the lactone-type sophorolipid. In fact, in order to increase the utilization rate of lactone-type sophorolipid, an excess of sulfonating agent may be selected.

In the preparation method according to the invention, the sulfonation reaction in the step (2) is preferably carried out at a temperature of 45-100 ℃; the reaction time is preferably 0.5 to 12 hours, and more preferably 2 to 5 hours.

The preparation method further comprises the step (3) after the step (2), namely, a proper amount of alkali is added, and the pH value of the solution is adjusted to be neutral or weakly alkaline (the pH value is 7.0-9.0). The alkali is preferably one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonia water. Bases of divalent or trivalent metal cations may also be used, and there is no particular limitation thereto. In practical oil recovery applications, said step (3) can also be performed at the time of field use.

Example 1

Preparation of sulfonated modified sophorolipid:

68.88g (100.0 mmol) of lactonic sophorolipid (purchased from Qilu Biotech group Co., Ltd., Shandong) was dissolved in 500 ml of N, N-dimethylformamide and stirred at 50 ℃ until completely dissolved. Then, 0.2 mol of sulfur trioxide pyridine complex was added and reacted at 80 ℃ for 4 hours. After the reaction is finished, removing the solvent by using a rotary evaporator to obtain the sulfonated modified sophorolipid with the yield of 99 percent.

ESI-MS characterization of the product: 381([ (M-2H)/2)]^2-) As shown in fig. 1. The mass spectrum result shows that the compound prepared in the embodiment is the sulfonated and modified sophorolipid product.

Example 2

Preparation of sulfonated modified sophorolipid:

68.88g (100.0 mmol) of lactonic sophorolipid (available from Qilu Biotech group Co., Ltd., Shandong) was dissolved in 600 ml of 1, 2-dichloroethane, and the mixture was stirred at 75 ℃ until completely dissolved. Then, 0.3 mol of chlorosulfonic acid was added and reacted at 45 ℃ for 6 hours. After the reaction is finished, removing the solvent by using a rotary evaporator to obtain the sulfonated modified sophorolipid with the yield of 99 percent.

In the following test examples, the salt resistance, interfacial tension, wettability and oil washing effect of the sulfonated modified sophorolipid and the unmodified lactone-type sophorolipid were compared.

Wherein the sulfonated modified sophorolipid used is obtained from the above example 1, and before use, the sulfonated modified sophorolipid is dissolved in an aqueous solution, and a proper amount of alkali is added to adjust the pH of the solution to be neutral or weakly alkaline (pH 7-9); the unmodified lactonic sophorolipid used was a lactonic sophorolipid obtained from Qilu Biotech group, Inc., Shandong.

Test example 1

And (3) measuring the salt resistance: a certain amount of lactone-type sophorolipid and the sulfonated modified sophorolipid obtained in example 1 were accurately weighed in a triangular flask, 100 ml of a saline solution (i.e., an aqueous sodium chloride solution) having a concentration of 80000ppm was added thereto to prepare a lactone-type sophorolipid solution and a sulfonated modified sophorolipid solution each having a concentration of 500, 1000, 3000ppm, respectively, a small amount of sodium hydroxide was added to each solution to adjust the pH to 8.0, magnetic stirring was simultaneously performed at the same rotation speed and temperature (3000r/min, 25 ℃), and the dissolution conditions of the lactone-type sophorolipid and the sulfonated modified sophorolipid obtained in example 1 in the saline solution were observed.

The observation result shows that the sulfonated modified sophorolipid can be fully dissolved in 80000ppm of saline solution under the concentration of 500ppm, 1000ppm and 3000 ppm; the unmodified sophorolipid can not be completely dissolved at the concentrations of 500ppm, 1000ppm and 3000ppm, and an oily substance is separated out at the bottom of the bottle. Therefore, after sulfonation modification, the salt resistance of the sophorolipid is obviously improved, and the requirement of oil reservoir conditions on the salt resistance of oilfield chemicals can be met.

Test example 2

Measurement of interfacial tension: the oil/water interfacial tension between crude oil and the surfactant solution was measured by the spinning drop method using a model TX-500C interfacial tension meter of American CNG corporation (SY/T5370-1999 standard). The testing temperature is 70 ℃, the rotating speed is 6000r/min, the used oil phases are five crude oils of tower and river thick oil, spring bright thick oil, victory and old 25 thick oil, permanent 8 thick oil and victory and offshore thick oil, and the mineralization degree of water is 80000 ppm. The results of interfacial tension are shown in Table 1 (interfacial tension unit: mN/m):

TABLE 1

The oil/water interfacial tension result shows that the sulfonated modified sophorolipid provided by the invention has stronger oil-water interfacial activity, and the oil-water interfacial tension of the sulfonated modified sophorolipid is reduced by 1-2 orders of magnitude compared with that of the unmodified sophorolipid.

Test example 3

And (3) wettability determination: firstly, respectively and uniformly coating the thick oil on the surface of a clean glass slide at high temperature, and naturally cooling the glass slide. The contact angles of droplets of 0.5mM and 5.0mM aqueous surfactant solutions on the surface of the slide were then determined by the sitting drop method. The experimental temperature was controlled at 25 ℃. The contact angle (/ degree) results are given in table 2:

TABLE 2

The contact angle result in table 2 shows that the wettability of sophorolipid is improved after sulfonation modification, and the contact angle of liquid drops on the surface of crude oil is reduced by 4-8 degrees.

Test example 4

The sulfonated modified sophorolipid prepared in example 1 and the unmodified sophorolipid were subjected to static oil-wash rate performance evaluation by the method in the national petrochemical group corporation standard Q/SHCG11-2011, and the results are shown in table 3 (oil-wash rate unit:%):

TABLE 3

The results in table 3 show that the sulfonated modified sophorolipid provided by the invention has stronger oil washing capability than unmodified sophorolipid, and the static oil washing rate is improved by 20-30%.

In conclusion, compared with the lactone type sophorolipid prepared by industrial fermentation, the sulfonated modified sophorolipid prepared by the invention has stronger salt resistance, oil-water interfacial activity and wettability and better oil washing capability, is an oil field chemical agent with excellent performance, green and low toxicity, can be used as a surfactant, and even can be used as the surfactant in the oil extraction field.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.