A process for producing a dewaxed oil and a wax product from a heavy hydrocarbon oil

Abstract

A method for producing dewaxed oil and wax product from heavy hydrocarbon oil, comprising: (1) mixing a dilution solvent with a heavy hydrocarbon oil feedstock under dewaxing conditions to perform solvent dewaxing, cooling to a filtration temperature, and separating a dewaxed filtrate and a wax paste from the waxy solution by solid-liquid separation, wherein the content of the dilution solvent in the wax paste is 30wt%-80wt%; the dilution solvent is a C3-C6 aliphatic ketone and / or a C6-C8 aromatic hydrocarbon; (2) removing the dilution solvent from the filtrate to obtain dewaxed oil with a reduced pour point; (3) introducing the wax paste into a sweating system to perform sweating under heating to obtain a deoiled wax paste; and (4) introducing the deoiled wax paste into a desolventizing system to remove the dilution solvent from the deoiled wax paste to obtain a wax product. The method provided by the present application directly performs sweating and deoiling on the wax paste containing the dilution solvent obtained by solvent dewaxing, and simultaneously obtains dewaxed oil and a wax product. The method adopts the wax paste containing the dilution solvent to perform sweating, thereby omitting the process of cooling and solidifying after melting the wax, and adopts a lower sweating temperature than conventional sweating, thereby saving heating energy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of petroleum wax production, and particularly relates to a method for producing paraffin wax by reducing the oil content in dewaxed wax paste using sweating and deoiling. BACKGROUND

[0002] Paraffin wax is a general term for wax products obtained after various processes of petroleum processing, including liquid paraffin, soap wax, semi-refined paraffin wax, fully refined paraffin wax and microcrystalline wax, and mainly composed of normal alkanes, a small amount of isomeric alkanes and naphthenes, etc. It is an important chemical raw material and can be widely used in rubber, plastic, fine chemical, daily chemical and other fields, and has stable market demand.

[0003] Dewaxing is a process of separating high condensation point components and low condensation point components in waxy oil components under dewaxing conditions. The low condensation point components have the characteristics of low normal alkane content and good low-temperature fluidity, and can be used as products or production raw materials with low-temperature fluidity requirements, such as production raw materials for lubricating oil base oil. The high condensation point components obtained by dewaxing have the characteristics of high normal alkane content and being solid at a relatively high temperature, but also contain oil and low-carbon normal alkane and isomeric alkane components, which affect the performance of paraffin wax, so it is necessary to remove them, which is called wax deoiling. The dewaxing and paraffin wax production methods mainly include cold pressing dewaxing and sweating deoiling process, solvent dewaxing and deoiling process, urea dewaxing process, molecular sieve dewaxing process and spray deoiling process.

[0004] The solvent dewaxing and deoiling process is to use vacuum distillate oil or light deasphalted oil as raw material, and a mixture of butanone and toluene as solvent, to separate the oil and wax in the raw material oil under dewaxing conditions due to the different solubilities of the two components in the mixed solvent, to obtain oil dissolved in the solvent and dewaxed wax paste not dissolved in the oil liquid, and to separate the mixture of oil and solvent to obtain dewaxed oil and solvent. Further, the wax and soluble components in the wax paste are separated under deoiling conditions due to the different solubilities of the wax and other components in the mixed solvent, to obtain soluble components dissolved in the solvent and deoiled wax paste not dissolved in the oil liquid, and to separate the mixture of soluble components and solvent to obtain wax oil, and to separate the deoiled wax paste from the solvent to obtain deoiled wax, which can be refined to obtain wax products. The solvent dewaxing has the characteristics of continuous production process, high wax yield and low oil content in wax, but the solvent dewaxing deoiling agent oil ratio is between 6 and 10, the solvent recovery evaporation energy consumption is large, and the comprehensive energy consumption is between 60 and 80 kgoe / t, which is a large energy consumer in petroleum refining.

[0005] Cold-pressed dewaxing sweating oil-removing process is to separate oil and crude wax under cold-pressed condition by using the different solidification temperatures of oil and wax in the raw material oil. The crude wax contains hydrocarbons such as paraffin, naphthenes with side chains and aromatic hydrocarbons with side chains, and the melting temperature varies depending on the length of carbon chain, isomerization degree, ring structure and number. In the same molecular weight range, the higher the normality of paraffin, the higher the melting point, and the melting point decreases with the increase of isomerization degree and the connection of ring hydrocarbon. Sweating is to separate different hydrocarbons at different temperatures by using the melting point difference of different hydrocarbons in crude wax, so as to obtain products with different hydrocarbon structures, and further refined to obtain wax products with different melting points. Cold-pressed dewaxing sweating oil-removing has the characteristics of intermittent production process, no need to use organic solvent and low energy consumption. In the conventional sweating oil-removing process, with the gradual increase of sweating temperature, the low melting point components in the material melt into liquid and flow out through the pores between the wax crystals. In order to meet the separation precision requirements, the sweating time is generally prolonged, and the final sweating temperature is increased to close to the melting point of wax to obtain products meeting the product quality, which has the problems of low production efficiency, high temperature energy consumption and low yield of oil-removed wax.

[0006] CN105733679A discloses a sweating method for producing soap wax and paraffin wax, which adds low-boiling liquid to the raw material oil and uses gas flow to carry liquid oil through the wax layer to force the separation of wax and oil during the sweating process. However, there is a problem that the wax layer is compressed under pressure, and the channel of oil in the wax becomes smaller, which is not conducive to the separation of oil and wax. CN114437826A discloses a method for producing phase change energy storage wax, which adds a light solvent to the fischer-tropsch narrow fraction, which is beneficial to the discharge of isomeric hydrocarbons and light components, and improves the sweating efficiency and effect. However, there is a problem that the solvent has low solubility, and the sweat discharge is not sufficient. To solve the problem of dense wax layer and insufficient sweat discharge in the sweating process of the prior art, the present application provides an improved sweating method for producing paraffin wax. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a method for producing dewaxed oil and wax products from heavy hydrocarbon oil, reducing the oil content in the wax products and reducing energy consumption.

[0008] In order to achieve the above object, the present application provides a method for producing dewaxed oil and dewaxed oil and wax products from heavy hydrocarbon oil, comprising: (1) mixing a dilution solvent with heavy hydrocarbon oil feedstock under dewaxing conditions and performing solvent dewaxing, cooling to a filtration temperature, and separating a dewaxed filtrate and a wax paste from the waxy solution by solid-liquid separation, wherein the content of the dilution solvent in the wax paste is 30wt%-80wt%; the dilution solvent is C3-C6 aliphatic ketone and / or C6-C8 aromatic hydrocarbon; (2) introducing the dewaxed filtrate into a desolventizing system to remove the dilution solvent in the filtrate to obtain dewaxed oil with a reduced pour point; (3) introducing the wax paste into a sweating system to obtain dewaxed oil-free wax paste by warming and sweating; and (4) introducing the dewaxed oil-free wax paste into a desolventizing system to remove the dilution solvent in the dewaxed oil-free wax paste to obtain wax products.

[0009] Compared with the prior art, the method for producing dewaxed oil and wax products from heavy hydrocarbon oil provided by the present application has the following beneficial effects:

[0010] The method provided by the present application directly sweats and deoils the wax paste containing the dilution solvent obtained by solvent dewaxing, and simultaneously obtains dewaxed oil with a reduced pour point and wax products. The dilution solvent added in the heavy hydrocarbon oil feedstock as a crystallization improvement material reduces the viscosity of the solution between wax crystals, and helps the nucleation and growth of wax crystals during wax crystallization, thereby forming large crystalline particles. The separated wax paste is a loose wax cake formed by the accumulation of wax crystals, and has large intercrystalline voids and many channels. The dilution solvent wrapped in the wax crystals during wax crystallization acts as an oil dissolving agent during sweating, and can effectively reduce the viscosity of sweat, which is beneficial to the discharge of sweat. The sweating of the wax paste containing the dilution solvent saves the process of cooling and solidification after wax melting, and reduces the steps of sweating operation. A lower sweating temperature can be used than conventional sweating, for example, the melting point of the produced wax products is 55-65℃, and the final sweating temperature is 13-20℃ lower than the melting point of the wax products, thereby saving energy consumption. The dilution solvent can be recycled after being recovered, and no oil-containing waste is generated.

[0011] Other features and advantages of the present application will be described in detail in the following specific embodiments. DETAILED DESCRIPTION

[0012] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0013] The present application provides a method for producing dewaxed oil and wax product from heavy hydrocarbon oil, comprising: (1) mixing and solvent dewaxing dilute solvent with heavy hydrocarbon oil raw material under dewaxing conditions, cooling to filtration temperature, and separating dewaxed filtrate and wax paste from the waxy solution by solid-liquid separation, wherein the content of dilute solvent in the wax paste is 30wt%-80wt%; the dilute solvent is C3-C6 aliphatic ketone and / or C6-C8 aromatic hydrocarbon; (2) introducing the dewaxed filtrate into a desolventizing system to remove the dilute solvent in the filtrate to obtain dewaxed oil with reduced pour point; (3) introducing the wax paste into a sweating system to obtain deoiled wax paste by warming and sweating; and (4) introducing the deoiled wax paste into a desolventizing system to remove the dilute solvent in the deoiled wax paste to obtain wax product.

[0014] In the present application, the heavy hydrocarbon oil raw material has a distillation range of 350-500°C and a freezing point of >25°C, and is selected from vacuum distillate oil or solvent refined oil.

[0015] Optionally, the dilute solvent is selected from one or more of acetone, butanone, benzene and toluene.

[0016] Preferably, the dilute solvent is a mixture of butanone and toluene, wherein the volume content of butanone is 45v%-70v%; preferably, the volume content of butanone is 50v%-65v%.

[0017] Optionally, in step (1), the dilute solvent is added to the heavy hydrocarbon oil at one time or in several times, and a mixed oil solution is obtained after mixing; the mixed oil solution is cooled to the filtration temperature at a rate of 0.5-4°C / min, and the high freezing point components are separated out at low temperature, and the dewaxed filtrate and wax paste are obtained after solid-liquid separation; the temperature of the mixed oil solution to which the dilute solvent is added for the first time is 25-70°C, the filtration temperature is -30--5°C, and the temperature of the wax paste is -30--5°C.

[0018] Preferably, the temperature of the mixed oil solution to which the dilute solvent is added for the first time is 30-65°C.

[0019] Preferably, the cooling rate is 1-3°C / min.

[0020] Preferably, the filtration temperature is -25--10°C.

[0021] Optionally, in step (1), the mass ratio of the dilute solvent to the heavy hydrocarbon oil raw material is 1-4.5:1.

[0022] Preferably, the mass ratio of the dilute solvent to the heavy hydrocarbon oil raw material is 1.5-4:1.

[0023] Optionally, the solvent dewaxing step is carried out in a crystallization stirred tank, and the scraping stirring speed of the crystallization stirred tank during the cooling process of the mixed oil solution of the dilute solvent and the heavy hydrocarbon oil raw material is 20-300 revolutions / min.

[0024] Preferably, the stirring speed of the crystallization stirred tank is 30-200 rpm.

[0025] In step (2), the dilution solvent in the dewatered filtrate is removed by evaporation.

[0026] In the method provided by the present application, the oil content in the wax paste obtained in step (1) is not less than 4%.

[0027] Alternatively, in step (3), the wax paste is heated from the sweating starting temperature to the sweating ending temperature in a sweating dish, and then kept at the sweating ending temperature for 2-3 h, the sweating starting temperature is 5°C higher than the temperature of the wax paste, the heating rate is 0.5-4°C / h, and the sweating ending temperature is 10-25°C lower than the melting point of the wax product; the sweating is ended to obtain a deoiled wax paste; the oil content in the obtained deoiled wax paste is 1.0-1.9 wt%, and the deoiled wax paste is further subjected to solvent removal to obtain a wax product with a melting point of 50-70°C.

[0028] When the heavy hydrocarbon oil raw material is used to produce a wax product with a melting point of 50-70°C, the sweating ending temperature is 10-25°C, preferably 16-20°C, lower than the melting point of the wax product.

[0029] Preferably, the heating rate is 1-3°C / h.

[0030] Alternatively, the dilution solvent content in the deoiled wax paste obtained by sweating is 1-6%.

[0031] Preferably, the sweating ending temperature is 13-20°C lower than the melting point of the deoiled wax paste, the oil content in the obtained deoiled wax paste is 1.1-1.6 wt%, and the deoiled wax paste is further subjected to solvent removal to obtain a wax product with a melting point of 55-65°C.

[0032] When the heavy hydrocarbon oil raw material is used to produce a wax product with a melting point of 55-65°C, the sweating ending temperature is 13-20°C, preferably 14-16°C, lower than the melting point of the wax product.

[0033] The method provided by the present application comprises the following steps: adding a dilution solvent into heavy oil raw material, mixing the oil liquid with the dilution solvent uniformly at a dilution temperature to form a solution of the raw oil and the dilution solvent, cooling the solution under a cooling condition to a filtration separation temperature, separating the solution to obtain dewaxed filtrate and wax paste, and removing the solvent from the dewaxed filtrate to obtain dewaxed oil. The wax paste is introduced into a sweating system, and is heated and sweated to collect wax liquid obtained at different sweating temperatures, and the solvent is removed to obtain products with different oil contents. The addition of the dilution solvent into the raw oil in the dewaxing process reduces the viscosity of the dewaxed oil liquid, and is beneficial to the attachment of the precipitated wax crystals to the crystal nucleus to grow into large wax crystals. The dewaxed oil liquid is continuously stirred during the cooling of the dewaxed oil liquid by the coolant, and the wax crystals formed on the cold wall are scraped off to enter the oil liquid, and are attached to the crystal nucleus to grow after being partially dissolved, so that the wax crystals with low oil content and high strength are formed, the loose wax cake layer is formed after the oil liquid is filtered and removed, the space between the wax crystal layers is large, which is beneficial to the flow of sweat in the sweating process, and the purpose of reducing the oil content in the wax by sweating is achieved.

[0034] In the method provided by the present application, in step (1), the dilution temperature is the temperature at which the first added dilution solvent is mixed with the raw oil liquid uniformly, and the mixed solution contains the dilution solvent. The temperature at which the first dilution solvent is added into the raw oil liquid is 25-70°C, preferably 30-65°C.

[0035] Alternatively, the dilution solvent can be added at one time or in multiple times, preferably in two or three times.

[0036] The solvent dewaxing device is preferably a crystallization stirred tank, and the wall scraping stirring refers to the continuous scraping of the wax crystals condensed and precipitated on the cold wall of the oil solution during the cooling and crystallization of the dewaxed oil liquid in the crystallization stirred tank, so that the wax crystals falling off are redissolved in the oil solution and recrystallized, and the wax crystals with low oil content and large particles are formed. The wall scraping stirring speed of the oil solution during the cooling and temperature reduction of the oil solution with the coolant is 20-300 rpm, preferably 30-200 rpm.

[0037] In step (1), the wax-containing oil liquid is separated into dewaxed filtrate and wax paste. The solid-liquid separation can be performed by using a conventional solid-liquid separation method in the art, for example, natural sedimentation and filtration separation. The separation method can be used in the prior art, and will not be described here. The wax paste is the unfiltered material obtained by the solid-liquid separation of the wax-containing oil solution at the filtration temperature. The mass fraction of the solvent in the wax paste is 30wt%-80wt%, preferably 35wt%-75wt%, and the temperature of the wax paste is-30--10°C.

[0038] In the method, in step (2), the dewaxed filtrate is introduced into a solvent removal system to remove the dilution solvent in the filtrate to obtain dewaxed oil. The solvent removal can be performed by using the existing technology, and the evaporation vaporization method can be used to remove the dilution solvent in the filtrate.

[0039] In the method, in step (3), the wax paste obtained in step (1) is introduced into a sweating system, and sweating is performed under controlled conditions, and the heating rate is 0.5-4 ℃ / h, preferably 1-3 ℃ / h.

[0040] In the method, the heating rate of the solvent dewaxing and the cooling rate of the wax layer sweating can be controlled by using a gas bath, a water bath, and an oil bath, and a jacket or a coil pipe can be arranged to heat the heat medium and the material. The cooling is performed when the temperature is lowered. The heat exchange and the cooling are the existing technology, and a person skilled in the art can perform the temperature control according to the requirements, and thus, no further description is given herein.

[0041] The method further includes step (4), in which the dewaxed oil is removed from the sweating dewaxed oil paste to obtain a wax product with low oil content.

[0042] The method for removing the solvent from the dewaxed filtrate and the dewaxed oil paste is known in the art, for example, the material flow is respectively introduced into a solvent recovery tower to remove the solvent to obtain dewaxed oil and a wax product, and the recovered dilution agent is recycled.

[0043] The above describes the preferred embodiments of the present application, but the present application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0044] The present application will be described in detail below through examples.

[0045] The calculation formula of the solvent content in the wax paste is: solvent content = ((wax paste mass - wax paste mass after removal of the solvent) ÷ wax paste mass) × 100%;

[0046] The calculation formula of the mass yield of the dewaxed oil is: mass yield of the dewaxed oil = (dewaxed oil mass ÷ mass of the dewaxed raw oil) × 100%;

[0047] The calculation formula of the mass yield of the wax product is: mass yield of the wax product = (wax product mass ÷ mass of the dewaxed raw oil) × 100%.

[0048] In the examples,

[0049] The heavy hydrocarbon oil raw material A and the heavy hydrocarbon oil raw material B are taken from Sinopec Co., Ltd. Maoming Branch, and the properties are shown in Table 1, and the analysis method is shown in Table 2.

[0050] Table 1

[0051] Item Heavy hydrocarbon oil feedstock A Heavy hydrocarbon oil feedstock B Kinematic viscosity (100°C) / (mm 2 / s) 9.364 4.588 Freezing point / °C / 27 Pour point / °C 45 / Distillation range / °C 5 / ％ 437 371 50 / ％ 493 419 95％ 542 455

[0052] Example 1

[0053] (1) The dilution solvent is a mixture of butanone and toluene, and the volume fraction of butanone is 50%.

[0054] The dilution solvent is added to the heavy hydrocarbon oil feedstock A in two times, the first time of dilution solvent addition is at 65°C, the dilution ratio is 1, the second time of dilution solvent addition is at 30°C, the dilution ratio is 3, and the mass ratio of dilution solvent to heavy hydrocarbon oil feedstock is 4:1.

[0055] The solvent dewaxing device adopts a jacketed crystallization stirred tank, the cooling rate of the solution from the first time of dilution solvent addition to the filtration temperature is 1°C / min, the scraping wall stirring speed is 200 rpm, the temperature is cooled to the filtration temperature of -10°C, and the filter cake is separated and washed with a flushing agent at the filtration temperature to obtain a filtrate and a wax paste, the flushing agent is a mixture of butanone and toluene, the volume fraction of butanone is 50%, the mass ratio of flushing agent to heavy hydrocarbon oil feedstock A is 0.5, and the flushing temperature is -10°C. The solvent content in the wax paste is 40% by weight, and the oil content is 7.9% by weight.

[0056] (2) The dewaxed oil is obtained after the filtrate is removed of the solvent, and the mass yield of the dewaxed oil is calculated to be 64.8% by weight.

[0057] (3) The temperature of the wax paste for sweating is -10°C, the wax paste is placed in a sweating dish, the sweating starting temperature is -5°C, the temperature rising rate is 1°C / h, the sweating termination temperature is 45°C, the constant temperature time is 2 h, and the oil-removed wax paste is obtained after the melted oil is removed by filtration after the sweating is completed, and the melting temperature of the oil-removed wax paste is 48°C. (4) The dilution solvent in the oil-removed wax paste is removed to obtain a wax product, the mass yield of the wax product is 15.9%, the melting point is 64.3°C, the oil content is 1.55%, and the kinematic viscosity at 100°C is 5.929 mm 2 / s, the oil content and the melting point of which can meet the technical requirements of the melting point and the oil content of the No. 64 semi-refined wax.

[0058] Comparative Example 1

[0059] Comparative Example 1 adopts a conventional solvent dewaxing and sweating method to remove the oil in the wax, and the heavy hydrocarbon oil feedstock A is the same as that in Example 1, and the step (1) is the same as that in Example 1.

[0060] (2) The obtained wax paste is removed of the dilution solvent to obtain a wax paste after the solvent removal, the mass yield of the wax paste is 35.2% by weight, the oil content in the wax paste is 7.9% by weight, and the wax paste does not contain the solvent.

[0061] (3) The dewaxed wax paste is added with 5% butanone, and melted at 60°C to be used as sweating raw material. The sweating raw material is put into a sweating kettle to be melted by heating, and cooled at a rate of 1.5°C / h to 35°C. The wax paste is cooled for 5h, and then sweating starts at an initial temperature of 35°C and a heating rate of 1°C / h. The sweating ends at a temperature of 62°C, and the temperature is kept constant for 2h. After the sweating, the deoiled wax paste is obtained.

[0062] (4) The butanone in the deoiled wax paste is removed to obtain a wax product. The mass yield of the wax product is 14.8%, the melting point is 63.8°C, the oil content is 2.59%, and the kinematic viscosity at 100°C is 5.283mm 2 / s. The oil content cannot meet the technical requirement of the oil content of the semi-refined wax No. 62, although the melting point of the wax is basically the same.

[0063] Example 2

[0064] (1) Butanone and toluene mixture is used as dilution solvent, and the volume fraction of butanone is 65%. The mass ratio of the dilution solvent to the raw oil is 1.5:1. In a crystallization stirred tank, the dilution solvent is added to the heavy hydrocarbon oil raw material B twice. The first time, the dilution solvent is added at a temperature of 30°C, and the dilution ratio is 0.5. The second time, the dilution solvent is added at a temperature of 0°C, and the dilution ratio is 1. The filtration temperature is -23°C. The temperature of the solution is reduced from the temperature of the first time of adding the dilution solvent to the filtration temperature at a rate of 3°C / min. The scraping stirring speed of the crystallization stirred tank is 30r / min. The solution is filtered at the filtration temperature to obtain a filtrate and a wax paste, respectively. The flushing agent is a mixture of butanone and toluene, and the volume fraction of butanone is 65v%. The mass ratio of the flushing agent to the raw oil is 0.5. The flushing temperature is -23°C. The solvent content in the obtained wax paste is 75wt%, and the oil content is 7.1wt%.

[0065] (2) The de-waxed oil is obtained by removing the dilution solvent from the filtrate. The mass yield of the de-waxed oil is 82.5wt%.

[0066] (3) The temperature of the wax paste used for sweating is -23°C, and the solvent content in the wax paste is 75wt%. The wax paste is put into a sweating pan. The initial temperature of the sweating is -18°C, the heating rate is 3°C / h, and the final temperature of the sweating is 42°C. The temperature is kept constant for 2h to obtain the deoiled wax paste. The melting temperature of the deoiled wax paste is 45°C.

[0067] (4) After the sweating, the dilution solvent in the deoiled wax paste is removed to obtain a low-oil-content wax product. The mass yield of the wax product is 7.5%, the melting point is 55.4°C, the oil content is 1.14%, and the kinematic viscosity at 100°C is 3.417mm 2 / s. The oil content and the melting point can meet the technical requirements of the melting point and the oil content of the semi-refined wax No. 54.

[0068] Comparative Example 2

[0069] Comparative Example 2 used the conventional solvent dewaxing and sweating to remove oil from the wax to remove oil from the wax. Heavy hydrocarbon oil feedstock B was used in the same manner as in Example 2.

[0070] (1) The same method as in Example 2, step (1) was used to obtain the wax paste. The wax paste was removed from the diluent solvent to obtain the dewaxed wax paste after the removal of the diluent solvent. The oil content of the dewaxed wax paste was 4.11 wt%, and the dewaxed wax paste was free of diluent solvent. The mass yield of the dewaxed wax paste was 17.5 wt%.

[0071] (2) The dewaxed wax paste was added to 10% butanone as the sweating raw material. The sweating pan was placed in a heating device and melted at 55°C. The temperature was lowered at a rate of 1.5°C / h to 35°C. The wax paste was cooled for 5 h, and then sweating began. The initial sweating temperature was 38°C, the temperature increasing rate was 3°C / h, the final sweating temperature was 54°C, and the constant temperature time was 2 h. The dewaxed wax paste was obtained, and the melting point of the dewaxed wax paste was 57°C. After the sweating was completed, the diluent solvent was removed from the dewaxed wax paste to obtain the low-oil-content wax product. The mass yield of the low-oil-content wax product was 6.7%, the melting point was 54.9°C, the oil content was 2.01%, and the kinematic viscosity at 100°C was 3.500 mm 2 / s. At the same melting point, the oil content of the wax product did not meet the technical requirements of the oil content of the semi-refined wax No. 54.

[0072] Table 2

[0073] Item Analytical method Kinematic viscosity (100°C) / (mm 2 / s) GB / T 265 Freezing point / °C GB / T 510 Pour point / °C GB / T 3535 Distillation range / °C ASTM D6352 Melting point GB / T 2539 Oil content GB / T 3554

[0074] As can be seen from the results of Examples 1 and 2, the sweating of the dewaxed wax paste containing the diluent solvent directly can obtain the product meeting the oil content requirements of the semi-refined wax at a lower sweating temperature. Compared with the dewaxed wax paste without the diluent solvent, the sweating temperature is lower, and the oil content of the wax is lower.

[0075] As can be seen from the results of Examples 1-2, whether the raw material oil A or the raw material oil B is used, the method of the present application can be used to sweat the dewaxed wax paste containing the diluent solvent to remove oil and prepare the dewaxed wax with reduced oil content.

Claims

1. A method for producing dewaxed oil and wax products from heavy hydrocarbon oil, characterized in that, include: (1) Under dewaxing conditions, the diluent is mixed with the heavy hydrocarbon oil raw material and solvent dewaxing is carried out. The mixture is cooled to the filtration temperature and the wax-containing solution is separated into solid and liquid to obtain dewaxed filtrate and wax paste. The content of the diluent in the wax paste is 30wt%-80wt%; the diluent is C3-C6 fatty ketone and / or C6-C8 aromatic hydrocarbon. (2) The dewaxing filtrate is introduced into the desolventizing system to remove the diluent from the filtrate and obtain a dewaxing oil with a lower pour point; (3) The wax paste is introduced into a sweating system to raise the temperature and induce sweating, thereby obtaining a deoiled wax paste; (4) The deoiled wax paste is introduced into the descaling system to remove the diluent from the deoiled wax paste and obtain the wax product.

2. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 1, characterized in that, The heavy hydrocarbon oil feedstock has a distillation range of 350~500℃ and a freezing point >25℃, and is selected from vacuum distillate oil or solvent-refined oil.

3. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 1, characterized in that, The diluting solvent is selected from one or more of acetone, butanone, benzene, and toluene.

4. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 3, characterized in that, The diluent is a mixture of butanone and toluene, wherein the volume content of butanone is 45 v% to 70 v%.

5. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 4, characterized in that, The volume content of methyl ethyl ketone (MEK) is 50 v% to 65 v%.

6. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, In step (1), the diluent is added to the heavy hydrocarbon oil once or in several batches, and after mixing, a mixed oil solution is obtained. The mixed oil solution is cooled to the filtration temperature at a rate of 0.5~4℃ / min. The high pour point group is separated at low temperature. After solid-liquid separation, dewaxed filtrate and wax paste are obtained. The temperature of the mixed oil solution to which the diluent is added for the first time is 25~70℃, the filtration temperature is -30~-5℃, and the temperature of the wax paste is -30~-5℃.

7. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 6, characterized in that, The temperature of the mixed oil solution when the diluent is first added is 30~65℃.

8. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 6, characterized in that, The cooling rate of the mixed oil solution is 1~3℃ / min, and the filtration temperature is -25~-10℃.

9. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, In step (1), the mass ratio of the diluent to the heavy hydrocarbon oil feedstock is 1~4.5:

1.

10. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, The mass ratio of the diluent to the heavy hydrocarbon oil feedstock is 1.5 to 4:

1.

11. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, Step (1) is carried out in a solvent crystallization stirred tank. During the cooling process of the mixed oil solution of dilution solvent and heavy hydrocarbon oil raw material, the stirring speed of the crystallization stirred tank is 20~300 rpm.

12. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 11, characterized in that, The stirring speed of the crystallization stirring tank is 30~200 rpm.

13. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, In step (2), the diluent in the filtrate is removed by evaporation and vaporization.

14. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, In step (3), the wax paste is heated from the sweating start temperature to the sweating end temperature in the sweating dish and kept at the temperature for 2-3 hours to obtain the deoiled wax paste; the sweating start temperature is 5°C higher than the temperature of the wax paste, the heating rate is 0.5-4°C / h, and the sweating end temperature is 10-25°C lower than the melting point of the wax product.

15. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 14, characterized in that, In step (3), the heating rate is 1~3℃ / h.

16. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 14, characterized in that, The sweating termination temperature is 16-20°C lower than the melting point of the wax product. The oil content in the obtained deoiled wax paste is 1.0-1.9 wt%, and the diluent content in the deoiled wax paste is 1-6 wt%. The melting point of the wax product obtained after removing the solvent is 50-70°C.

17. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to claim 14, characterized in that, The sweating termination temperature is 13-20°C lower than the melting point of the wax product. The oil content in the obtained deoiled wax paste is 1.1-1.6 wt%, and the diluent content in the deoiled wax paste is 2-5 wt%. The melting point of the wax product obtained after removing the diluent is 55-65°C.

18. The method for producing dewaxed oil and wax products from heavy hydrocarbon oil according to any one of claims 1-5, characterized in that, In step (4), the diluent in the degreasing wax paste is removed by evaporation and vaporization.