Oil product alkane adsorption separation method

Abstract

The invention belongs to the field of oil product adsorption separation, and particularly relates to an adsorption separation method for alkane in oil products, which comprises the following steps: (1) stirring and mixing raw oil, an adsorbent and an auxiliary agent, adsorbing n-alkane and long-chain short-branch isoparaffin in the raw oil to form an inclusion compound, and settling; (2) separating the obtained clathrate from other unadsorbed components of the raw material oil in an adsorption system to obtain clathrate suspension and oil liquid; (3) heating and desorbing the obtained clathrate suspension to obtain an adsorbent and wax liquid; (4) recovering the adsorbent and the auxiliary agent from the oil liquid to obtain dewaxed oil; recovering the adsorbent and the auxiliary agent from the obtained wax liquid to obtain deoiled wax; and the adsorbent and the auxiliary agent return to the adsorption unit in the step (1). According to the method, n-alkanes in the oil product can be removed, most isoalkanes, especially long-chain short-branch isoalkanes can be removed, the freezing point of the oil product can be greatly reduced, and the used agent does not contain solvents with high toxicity such as aromatic hydrocarbon.

Description

Technical Field

[0001] The invention belongs to the field of oil product adsorption separation, and in particular relates to an adsorption separation method for alkanes in oil products. Background Art

[0002] Molecular refining technology is the current requirement of the times. Alkanes are the main components of various oil products. Normal alkanes have low octane numbers and high freezing points. Their mixtures are called petroleum waxes. If they exist in gasoline fractions, the gasoline octane number will be low; if they exist in kerosene and diesel, they will cause crystallization and block pipelines during use; if they exist in lubricating oils, crystallization and precipitation will destroy the lubricating film and cause mechanical damage. Isoalkanes have good lubricity and stability and can be used as environmentally friendly solvent oils and base lubricants. Separating normal alkanes and short side chain normal alkanes from oil products can be used as chemical raw materials and improve some properties of oil products.

[0003] At present, the technologies for separating normal alkanes from oil products include molecular sieve dewaxing of kerosene components, isopropanol urea dewaxing of diesel components, solvent dewaxing of wax oil components, and hydroisomerization dewaxing. These dewaxing technologies are either only applicable to the separation of normal alkanes in a certain type or class of distillate oil products, or convert normal alkanes into isoalkanes, which are not only consuming and costly, but also cannot achieve the separation of full-fraction normal alkanes and cannot separate isoalkanes.

[0004] CN115305112A discloses a mixed hydrocarbon fine separation device and method. The method comprises a first adsorption separation tower A and a second adsorption separation tower B connected in series, the top of the first adsorption separation tower A has an opening connected to the first fractionation tower, the top of the second adsorption separation tower B has an opening connected to the second fractionation tower, and the bottom of the second adsorption separation tower B has an opening connected to the third fractionation tower. The invention first separates straight-chain hydrocarbons, removes the straight-chain hydrocarbon residual liquid, and then separates monomethyl hydrocarbons, and the method of auxiliary fractionation or rectification realizes the fine separation of mixed hydrocarbons.

[0005] CN106433742A discloses a method for separating normal alkanes from distillate oil containing normal alkanes by absorption. The method comprises: (1) passing the distillate oil containing normal alkanes into a 5A molecular sieve adsorbent bed with a crystal size of 0.2 to 2.0 μm, wherein the adsorbent selectively adsorbs normal alkanes in the raw material; (2) passing a mixture of n-dodecane and n-pentadecane as a desorbent into the adsorbent bed to desorb the adsorbed normal alkanes to obtain an extract containing C5 to C11 normal alkanes and the desorbent, and the non-adsorbed components are discharged from the adsorbent bed together with the desorbent as a residual liquid; (3) sending the extract obtained in step (2) into an extract fractionation tower to obtain C5 to C11 normal alkanes at the top of the tower. 11normal alkanes, and a desorbent is obtained in the bottom of the tower; the raffinate is sent to a raffinate fractionation tower, raffinate oil is obtained at the top of the tower, and a desorbent is obtained in the bottom of the tower, and the obtained desorbents are mixed and recycled.

[0006] CN103449949A discloses a method for separating normal alkanes from low-temperature coal tar oil products. The method comprises using irregular silica gel, spherical silica gel or alumina as a stationary phase, and loading into a chromatography column by dry method; adding the low-temperature coal tar containing normal alkanes to be separated into the chromatography column, eluting with a mobile phase, and collecting the elution fractions rich in normal alkanes at different time periods; detecting with an ultraviolet detector, removing the solvent from the collected elution fractions rich in normal alkanes, and obtaining normal alkanes with a purity of more than 95%.

[0007] CN102585887A discloses an adsorption separation method for naphtha. The method comprises passing naphtha into a simulated moving bed adsorption separation device filled with 5A molecular sieve under liquid phase conditions; obtaining a desorption effluent and a residual effluent through a continuous liquid-solid adsorption separation process; the desorption effluent and the residual effluent are respectively recovered by a desorbent to obtain a desorption oil rich in normal alkanes and a residual oil rich in non-normal alkanes; wherein the weight content of normal alkanes in the desorption oil is 90-100%; and the weight content of non-normal alkanes in the residual oil is 90-100%.

[0008] CN114836236A discloses a production process for military diesel, wherein the method comprises dewaxing and decondensing the second fraction oil obtained in the diesel stripping tower after fractionation in a diesel fractionating tower and stripping in a diesel stripping tower, and after dewaxing by the molecular sieve, the freezing point of the obtained military diesel can be controlled below -35°C or below -50°C, thereby increasing the yield of -35 and -50 military diesel.

[0009] CN107523344A discloses a method for producing soap wax and low-melting-point paraffin by sweating, wherein the method includes, on the basis of a common sweating and deoiling process, forming stable tiny bubbles in the wax layer with the sweating raw material under the action of a bubble stabilizer to facilitate the rapid discharge of oil, and at the same time, using air flow to carry out liquid oil through the wax layer during the sweating process to forcibly separate the wax and oil.

[0010] CN1117625235A discloses a solvent dewaxing method for Fischer-Tropsch synthetic oil products, wherein the method comprises stirring and mixing the Fischer-Tropsch synthetic oil product to be dewaxed with an ester solvent, filtering to obtain a filtrate, removing the ester solvent in the filtrate to obtain a dewaxed Fischer-Tropsch synthetic oil product; wherein the ester solvent is selected from one or more of methyl acetate, ethyl acetate, propyl acetate, and butyl acetate, preferably the ester solvent is methyl acetate and / or ethyl acetate, more preferably ethyl acetate.

[0011] CN115651700A discloses a lubricating oil solvent dewaxing method, wherein the method comprises the steps of diluting and mixing the raw oil with a first-stage wax lower oil once, diluting and mixing it twice, and diluting and mixing it with the filtrate three times, and then cooling it down and entering the filtering system to separate the oil and wax. The filtrate, oil-containing wax liquid, and wax lower liquid produced after the separation enter the filtrate recovery system, the wax liquid recovery system, and the wax lower oil recovery system respectively for solvent recovery. The filtrate, oil-containing wax liquid, and wax lower oil after removing the solvent produce product dewaxed oil, deoiled wax, and by-product wax lower oil respectively.

[0012] Liu Yusi and others used self-made binderless 5A molecular sieve adsorbent and investigated the effects of adsorption temperature, desorbent, adsorbent water content and Ca2+ exchange degree on the adsorption and separation process of n-alkanes with carbon numbers of 10 to 16 through pulse experiments. The experimental results show that increasing the temperature is beneficial to improving the adsorption and desorption rates of n-alkanes with carbon numbers of 12 to 16, and the most suitable adsorption temperature is 180°C; when n-heptane is used as the desorbent, n-alkanes with carbon numbers of 10 to 16 have a higher separation degree for isoalkanes, and n-heptane has a better desorption effect on n-alkanes with carbon numbers of 14 to 16 than n-pentane and n-hexane; when the water content (w) of the adsorbent changes in the range of 0.2% to 6.1%, the adsorption, desorption rate and separation degree of n-alkanes with carbon numbers of 10 to 16 change significantly, and the highest value is when the water content is 3.3%; the Ca2+ exchange degree of the adsorbent increases with the adsorption temperature. 2+ When the exchange degree changes in the range of 70.8% to 91.9%, it has little effect on the adsorption and separation effect of normal alkanes, but the Ca 2+ Excessive exchange rate will reduce the adsorption and desorption rates of normal alkanes with carbon numbers of 13 to 16.

[0013] Li Jian et al. used Fischer-Tropsch straight-run diesel and isomerized diesel as raw materials, and separated normal alkanes and isomerized alkanes by urea / thiourea, thereby increasing the added value of the products. The experiment of separating normal / isoalkanes from straight-run diesel by urea or thiourea method shows that the content of normal alkanes in the product obtained by the first dewaxing by urea method reaches 97.0% (mass fraction, the same below), and the content of normal alkanes obtained by the second dewaxing reaches 98.0%; the content of normal / isoalkanes in the product is 96.5% by thiourea method, but the amount of thiourea used is reduced. Through the study of the separation of isomerized diesel by urea method, it can be seen that increasing the amount of urea is beneficial to reducing the freezing point of isomerized diesel. Comparing the separation results of urea method and thiourea method, it can be seen that urea and thiourea can react with normal / isoalkanes, but there are differences in stability. Relatively speaking, the complexes formed by urea and high-carbon isoalkanes or low-carbon normal alkanes are more stable, and the complexes formed by thiourea and high-carbon normal alkanes or low-carbon isoalkanes are more stable.

[0014] Zheng Lihui et al. used commercial paraffin as raw material and prepared paraffin with suitable phase transition temperature (melting range of 26-26.6℃) by urea inclusion method. Experiments show that the main and secondary factors affecting the reaction are inclusion temperature, mass ratio of urea to paraffin, reaction time, and mass ratio of ethanol to urea; when the reaction temperature is 70℃, the mass ratio of urea to paraffin is 3:1, the reaction time is 2.5h, and the mass ratio of ethanol to urea is 0.2, paraffin with an initial melting point of 26℃ and a final melting point of 26.6℃ is obtained.

[0015] Wang Shixin and others used MHUG tail oil to produce lubricant base oil and low-melting point food paraffin. They adopted the method of methyl ethyl ketone-toluene (MEK-TOL) dewaxing and deoiling and white clay refining. They could produce high-quality lubricant base oil and high-yield food paraffin from medium-pressure hydrogenation (MHUG) tail oil. The dewaxed oil can also be used as high-quality white oil raw material.

[0016] The above-mentioned prior art has the following technical problems:

[0017] 1. Existing dewaxing technologies have poor adaptability to raw materials, and each dewaxing technology is generally only applicable to one or one type of raw material.

[0018] 2. Existing dewaxing technology can often only separate normal alkanes, but it is difficult to separate long-chain short-branched isoalkanes, which affects product quality.

[0019] 3. Most of the agents used in existing dewaxing technologies contain highly toxic solvents such as aromatic hydrocarbons, and the production process consumes a lot of energy, making it difficult to achieve green, low-carbon and environmentally friendly requirements. Summary of the invention

[0020] The present invention aims to overcome the shortcomings of the prior art and provide a method for adsorbing and separating oil alkanes which is widely applicable to various raw oil products and can not only remove normal alkanes in the oil products, but also remove most of the isoalkanes, especially long-chain short-branch isoalkanes, and can greatly reduce the freezing point of the oil products. The agent used does not contain highly toxic solvents such as aromatic hydrocarbons.

[0021] To solve the above technical problems, the present invention is achieved as follows:

[0022] A method for separating alkanes from oil products by adsorption, comprising the following steps:

[0023] (1) The crude oil is stirred and mixed with the adsorbent and the auxiliary agent, and the normal alkanes and long-chain short-branch isoalkanes in the crude oil are adsorbed to form inclusion complexes and precipitate;

[0024] (2) separating the inclusion compound obtained in step (1) from the remaining components of the raw oil that have not been adsorbed in the adsorption system of step (1) to obtain an inclusion compound suspension and an oil liquid;

[0025] (3) heating and desorbing the inclusion compound suspension obtained in step (2) to obtain an adsorbent and a wax liquid;

[0026] (4) recovering the adsorbent and the auxiliary agent from the oil liquid obtained in step (2) to obtain dewaxed oil; recovering the adsorbent and the auxiliary agent from the wax liquid obtained in step (3) to obtain deoiled wax; and returning the adsorbent and the auxiliary agent to the adsorption unit in step (1).

[0027] Furthermore, the auxiliary agent includes an adsorption aid and an auxiliary agent.

[0028] Furthermore, in the step (1), the temperature range of the stirring mixing of the raw oil, the adsorbent and the auxiliary agent is 10 to 35° C. and the mixing pressure is normal pressure.

[0029] Furthermore, the adsorption aid is an alcohol ketone compound; and the auxiliary agent is a hydrocarbon compound.

[0030] Furthermore, the adsorbent is a urea compound; specifically, the adsorbent can be urea, thiourea, etc.; the adsorption aid is an alcohol compound and a ketone compound, and the mass proportion of the ketone compound is 0-100%; the auxiliary agent is n-hexane or cyclohexane.

[0031] Furthermore, in step (4), the deoiled wax is normal alkanes and long-chain short-branch isoalkanes.

[0032] Furthermore, in the step (1), the mass ratio of the adsorbent to the crude oil is 0.1 to 10:1; the mass ratio of the adsorbent aid to the crude oil is 0.1 to 50:1; and the mass ratio of the auxiliary agent to the crude oil is 0.1 to 40:1.

[0033] Furthermore, in the step (3), the temperature range of heating desorption is 50 to 200°C.

[0034] Furthermore, in the step (4), the wax liquid is recovered from the adsorbent and the auxiliary agent, and the wax liquid is heated, washed with water, and dried to obtain deoiled wax; wherein the washing temperature is 50 to 99°C, and the drying temperature is 100 to 300°C.

[0035] Furthermore, in the step (4), the oil is recovered from the adsorbent and auxiliary agent, and the dewaxed oil is obtained by heating, washing and drying the oil; wherein the heating temperature is 50-200°C, the washing temperature is 50-99°C, and the drying temperature is 100-300°C.

[0036] The present invention can be used for various raw oil products, and can not only separate normal alkanes from oil products, but also separate most isoalkanes, especially long-chain short-branch isoalkanes, which can greatly reduce the freezing point of oil products. The agent used does not contain highly toxic solvents such as aromatic hydrocarbons. It has the following technical features:

[0037] 1. Wide range of raw materials and strong adaptability. In principle, the present invention can be applied to various raw oils, solving the problem that the application scope of previous dewaxing technology is relatively single.

[0038] 2. Deep dewaxing and low product solidification point. The presence of wax components in crude oil products causes a high solidification point, which does not meet quality requirements. Since the wax components are mainly normal alkanes and long-chain short-branched isoalkanes, compared with traditional dewaxing technology, the present invention can not only remove all normal alkanes in the raw material, but also remove long-chain short-branched isoalkanes through green and efficient adsorption separation technology. After the normal alkanes and long-chain short-branched isoalkanes in the crude oil products are deeply removed by the present invention, the solidification point of the product is significantly reduced, which can significantly improve the low-temperature performance of the product.

[0039] 2. Simple process and mild conditions. The entire process of the present invention has only three steps: adsorption, desorption and auxiliary agent recovery. There is no high temperature and high pressure process, which is a green chemical processing technology.

[0040] 3. Low consumption and environmentally friendly. Compared with traditional technologies, the adsorbents, adsorption aids and auxiliary agents used in the present invention do not contain aromatic hydrocarbons. The process is green, environmentally friendly, low-toxic and low-carbon. The agents are all recycled. No waste gas or waste residue is generated in the whole process, and only a small amount of wastewater is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The figure is a principle block diagram of the oil alkane adsorption separation method of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below through specific examples. These examples are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be subject to the definition of the attached claims. Unless otherwise specified, the various reagents and materials used in the present invention can be purchased from the market.

[0043] Example 1

[0044] Taking a certain raw oil product as raw material, the experiment was carried out according to the attached flow chart. The raw material properties are shown in Table 1, the process parameters are shown in Table 2, and the product properties are shown in Table 3. The adsorbent is a mixture of urea and thiourea, with thiourea accounting for 40% by mass; the adsorbent is acetone, and the auxiliary agent is cyclohexane.

[0045] Table 1

[0046] nature unit Numeric Viscosity, 100℃ <![CDATA[mm 2 s -1 ]]> 6.178 Viscosity Index 150 Pour Point ℃ -30 Flash point ℃ 244 Dynamic viscosity, -35℃ mpa·s 2560

[0047] Table 2

[0048]

[0049]

[0050] Table 3

[0051] nature unit Numeric Viscosity, 100℃ <![CDATA[mm 2 s -1 ]]> 6.542 Viscosity Index 143 Pour Point ℃ -61 Flash point ℃ 237 Dynamic viscosity, -35℃ mpa·s 2730

[0052] like Figure 1 As shown, a method for separating alkanes from oil products by adsorption comprises the following steps:

[0053] (1) The crude oil is stirred and mixed with a mixture of urea and thiourea, acetone and cyclohexane, wherein the mass proportion of thiourea in the mixture of urea and thiourea is 40%; the stirring speed is 200 rpm, the stirring time is 2 hours, the stirring and mixing temperature is 15°C; and the stirring and mixing pressure is normal pressure. Under the adsorption temperature of 30°C, the normal alkanes and long-chain short-branch isoalkanes in the crude oil are adsorbed to form inclusion complexes and precipitate; the mass ratio of the adsorbent to the crude oil is 1.2:1; the mass ratio of the adsorbent to the crude oil is 2.1:1; and the mass ratio of the auxiliary agent to the crude oil is 1.8:1;

[0054] (2) separating the inclusion compound obtained in step (1) from the remaining components of the raw oil that have not been adsorbed in the adsorption system of step (1) to obtain an inclusion compound suspension and an oil liquid;

[0055] (3) heating and desorbing the inclusion compound suspension obtained in step (2) at a temperature of 95° C. to obtain an adsorbent and a wax liquid;

[0056] (4) recovering adsorbents and additives from the oil obtained in step (2) to obtain dewaxed oil; recovering adsorbents and additives from the oil obtained, heating, washing and drying the oil to obtain dewaxed oil; wherein the heating temperature is 50°C, the washing temperature is 50°C, and the drying temperature is 100°C; recovering adsorbents and additives from the wax liquid obtained in step (3) to obtain deoiled wax normal alkanes and long-chain short-branch isoalkanes; recovering adsorbents and additives from the wax liquid, heating, washing and drying the wax liquid to obtain deoiled wax; wherein the washing temperature is 50°C, and the drying temperature is 100°C; the adsorbents and additives are returned to the adsorption unit described in step (1) again.

[0057] Example 2

[0058] Taking a certain oil product as raw material, the experiment was carried out according to the attached flow chart. The raw material properties are shown in Table 1, the process parameters are shown in Table 2, and the product properties are shown in Table 3. The adsorbent is a mixture of urea and thiourea, in which thiourea accounts for 25% by mass; the adsorbent is a mixture of acetone and propanol, in which acetone accounts for 50% by mass; and the auxiliary agent is cyclohexane.

[0059] Table 1

[0060] nature unit Numeric Viscosity, 100℃ <![CDATA[mm 2 s -1 ]]> 4.2 Viscosity Index 136 Freezing point ℃ 25 Distillation, HK ℃ 380 KK ℃ 480

[0061] Table 2

[0062]

[0063]

[0064] Table 3

[0065] nature unit Numeric Viscosity, 100℃ <![CDATA[mm 2 s -1 ]]> 4.56 Viscosity Index 121 Freezing point ℃ ＜-24 Distillation, HK ℃ 375 KK ℃ 482

[0066] like Figure 1 As shown, a method for separating alkanes from oil products by adsorption comprises the following steps:

[0067] (1) The crude oil is stirred and mixed with a mixture of urea and thiourea, a mixture of acetone and propanol, and cyclohexane, wherein the mass proportion of thiourea in the mixture of urea and thiourea is 25%; the mass proportion of propanol in the mixture of acetone and propanol is 50%; the stirring and mixing temperature is 25°C, the stirring and mixing pressure is normal pressure, the stirring speed is 200rpm, the stirring time is 2h, and the stirring and mixing pressure is normal pressure. Under the adsorption temperature of 20°C, the normal alkanes and long-chain short-branch isoalkanes in the crude oil are adsorbed to form inclusion complexes and precipitate; the mass ratio of the adsorbent to the crude oil is 2.5:1; the mass ratio of the adsorbent to the crude oil is 2.0:1; the mass ratio of the auxiliary agent to the crude oil is 0.5:1;

[0068] (2) separating the inclusion compound obtained in step (1) from the remaining components of the raw oil that have not been adsorbed in the adsorption system of step (1) to obtain an inclusion compound suspension and an oil liquid;

[0069] (3) heating and desorbing the inclusion compound suspension obtained in step (2) at a temperature of 80° C. to obtain an adsorbent and a wax liquid;

[0070] (4) recovering adsorbents and additives from the oil obtained in step (2) to obtain dewaxed oil; recovering adsorbents and additives from the oil obtained, heating, washing and drying the oil to obtain dewaxed oil; wherein the heating temperature is 150°C, the washing temperature is 76°C, and the drying temperature is 200°C; recovering adsorbents and additives from the wax liquid obtained in step (3) to obtain deoiled wax normal alkanes and long-chain short-branch isoalkanes; recovering adsorbents and additives from the wax liquid, heating, washing and drying the wax liquid to obtain deoiled wax; wherein the washing temperature is 76°C, and the drying temperature is 200°C; the adsorbents and additives are returned to the adsorption unit described in step (1) again.

[0071] The above embodiments are used to illustrate the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for separating alkanes from oil products by adsorption, characterized in that: The steps include: (1) The crude oil is stirred and mixed with the adsorbent and the auxiliary agent, and the normal alkanes and long-chain short-branch isoalkanes in the crude oil are adsorbed to form inclusion complexes and precipitate; (2) separating the inclusion compound obtained in step (1) from the remaining components of the raw oil that have not been adsorbed in the adsorption system of step (1) to obtain an inclusion compound suspension and an oil liquid; (3) heating and desorbing the inclusion compound suspension obtained in step (2) to obtain an adsorbent and wax liquid; (4) recovering the adsorbent and the auxiliary agent from the oil liquid obtained in step (2) to obtain dewaxed oil; recovering the adsorbent and the auxiliary agent from the wax liquid obtained in step (3) to obtain deoiled wax; and returning the adsorbent and the auxiliary agent to the adsorption unit of step (1).

2. The method for separation of alkanes from oil products by adsorption according to claim 1, characterized in that: The auxiliary agents include adsorption aids and auxiliary agents.

3. The method for separation of alkanes from oil products by adsorption according to claim 2, characterized in that: In the step (1), the raw oil, the adsorbent and the auxiliary agent are stirred and mixed at a temperature ranging from 10 to 35° C. and at a mixing pressure of normal pressure.

4. The method for separation of alkanes from oil products by adsorption according to claim 3, characterized in that: The adsorption aid is an alcohol ketone compound; the auxiliary agent is a hydrocarbon compound.

5. The method for separation of alkanes from oil products by adsorption according to claim 4, characterized in that: The adsorbent is a urea compound; the adsorption aid is an alcohol compound and a ketone compound, and the mass proportion of the ketone compound is 0-100%; and the auxiliary agent is n-hexane or cyclohexane.

6. The method for separation of alkanes from oil products by adsorption according to claim 5, characterized in that: In the step (4), the deoiled wax is normal alkanes and long-chain short-branch isoalkanes.

7. The method for separation of alkanes from oil products by adsorption according to claim 2, characterized in that: In the step (1), the mass ratio of the adsorbent to the raw oil is 0.1 to 10:1; the mass ratio of the adsorbent aid to the raw oil is 0.1 to 50:1; and the mass ratio of the auxiliary agent to the raw oil is 0.1 to 40:

1.

8. The method for separation of alkanes from oil products by adsorption according to any one of claims 2 to 7, characterized in that: In the step (3), the temperature range of heating desorption is 50 to 200°C.

9. The method for separation of alkanes from oil products by adsorption according to claim 8, characterized in that: In the step (4), the wax liquid is recovered from the adsorbent and the auxiliary agent, and the wax liquid is heated, washed with water, and dried to obtain deoiled wax; wherein the washing temperature is 50 to 99°C, and the drying temperature is 100 to 300°C.

10. The method for separation of alkanes from oil products by adsorption according to claim 9, characterized in that: In the step (4), the oil is recovered from the adsorbent and the auxiliary agent, and the dewaxed oil is obtained by heating, washing and drying the oil; wherein the heating temperature is 50 to 200°C, the washing temperature is 50 to 99°C, and the drying temperature is 100 to 300°C.

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