Process for the deoxygenation of fischer-tropsch synthesis oils and deoxygenated adsorbents

Abstract

The application discloses a deoxygenation method and a deoxygenation adsorbent for Fischer-Tropsch synthesis oil, and relates to the field of Fischer-Tropsch synthesis oil processing.The deoxygenation method comprises the following steps: introducing Fischer-Tropsch synthesis oil into an adsorption tower filled with the deoxygenation adsorbent, and removing oxygen-containing compounds.The deoxygenation adsorbent is prepared by the following method: step S1, adding an aluminum source, a silicon source and a template agent into a lye, and performing first aging at room temperature; continuously adding the aluminum source and the silicon source, and performing second aging at room temperature; performing crystallization at a predetermined temperature; and filtering and washing the product to obtain a molecular sieve; and step S2, immersing the molecular sieve in a lye, adding a template agent into the lye, and then performing crystallization; and filtering, washing, drying and calcining the product after the crystallization to obtain the deoxygenation adsorbent.The deoxygenation method for Fischer-Tropsch synthesis oil provided by the application significantly improves the quality of Fischer-Tropsch synthesis oil and the economic benefits of subsequent processing by preparing a deoxygenation adsorbent with multiple levels of pores and combining the adsorption tower.

Description

[0001] This application claims priority to the Chinese patent application No. 2025119816147, filed on December 25, 2025, and entitled "Deoxygenation method of Fischer-Tropsch synthesis oil and deoxygenation adsorbent", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of petroleum chemical industry, in particular to a deoxygenation method of Fischer-Tropsch synthesis oil and a deoxygenation adsorbent. BACKGROUND

[0003] As a key component of coal-based liquid fuel, Fischer-Tropsch synthesis oil has a carbon number distribution concentrated in C5 to C19, in which the alkane component accounts for about 45% of the total amount, the olefin component accounts for more than 50%, and the oxygen-containing compounds including organic acids, alcohols, aldehydes, ketones, esters and other types account for about 5% in total. Since these oxygen-containing compounds are prone to complexation or substitution reaction with Lewis acid catalysts, the active centers of the catalyst system will be irreversibly occupied, causing the overall deactivation of the catalyst system; secondly, the presence of oxygen-containing compounds will also have different degrees of influence on the odor, color, oxidation stability and other properties of the oil product.

[0004] Therefore, efficient deoxygenation pretreatment of Fischer-Tropsch synthesis oil is a key link to ensure the smooth operation of the subsequent catalytic process and improve the product quality. SUMMARY

[0005] The present disclosure provides a deoxygenation method of Fischer-Tropsch synthesis oil and a deoxygenation adsorbent to solve the problems in the prior art.

[0006] According to a first aspect of the present disclosure, a deoxygenation method of Fischer-Tropsch synthesis oil is provided, comprising:

[0007] The Fischer-Tropsch synthesis oil is introduced into an adsorption tower filled with a deoxygenation adsorbent to remove the oxygen-containing compounds in the Fischer-Tropsch synthesis oil, wherein the deoxygenation adsorbent is prepared by the following method, comprising the following steps:

[0008] Step S1, an aluminum source, a silicon source and a template agent are added to an alkali solution, and a first aging is performed at room temperature; after the first aging is completed, the aluminum source and the silicon source are continuously added, and a second aging is performed at room temperature; after the second aging is completed, crystallization is performed at a predetermined temperature, and the product after crystallization is filtered, washed, and dried to obtain a molecular sieve;

[0009] Step S2, the molecular sieve obtained in step S1 is immersed in an alkali solution, and a template agent is added thereto, followed by crystallization; and the product after crystallization is filtered, washed, dried and calcined to obtain a deoxygenation adsorbent.

[0010] In one embodiment of the present disclosure, the step S1 further comprises: the first aging temperature is 20-30°C; the aging time is 4-8h; the second aging temperature is 30-50°C, and the aging time is 2-4h.

[0011] In one embodiment of the present disclosure, the step S1 further comprises: washing the product after crystallization to a pH value of 7-8.

[0012] In one embodiment of the present disclosure, the crystallization temperature in the step S1 is 40-60°C, and the crystallization time is 8-15h; the crystallization temperature in the step S2 is 100-150°C, the crystallization time is 20-35h, and the calcination temperature is 510-600°C; the calcination time is 12-22h.

[0013] In one embodiment of the present disclosure, the mass ratio of the aluminum source to the silicon source added in the first aging and the second aging in the step S1 is 10:1-10:3; the mass ratio of the template agent to the aluminum source added in the step S1 is 1:8-1:12, and the mass ratio of the template agent to the molecular sieve added in the step S2 is 1:2-1:4.

[0014] In one embodiment of the present disclosure, the alkali liquor in the steps S1 and S2 is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and sodium carbonate solution.

[0015] In one embodiment of the present disclosure, the aluminum source in the step S1 is one or more of sodium metaaluminate, aluminum sulfate, and diaspore; and the silicon source is one or more of water glass, silicon dioxide, tetraethyl orthosilicate, and white carbon black.

[0016] In one embodiment of the present disclosure, the template agent added in the steps S1 and S2 is one or more of tetraethylammonium hydroxide, cetyltrimethylammonium bromide, tetrapropylammonium hydroxide, and sodium dodecyl sulfate.

[0017] In one embodiment of the present disclosure, the Fischer-Tropsch synthesis oil contains C5-C19 alkanes, alkenes, and oxygen-containing compounds.

[0018] According to a second aspect of the present disclosure, a deoxidized adsorbent is provided, which is prepared by any one of the above deoxidization methods.

[0019] The deoxidization method and deoxidized adsorbent of the Fischer-Tropsch synthesis oil provided by the present disclosure can effectively adsorb oxygen-containing compounds with different molecular sizes in the range of C5-C19 by passing the Fischer-Tropsch synthesis oil into an adsorption tower filled with the deoxidized adsorbent to remove the oxygen-containing compounds, thereby improving the deoxidization efficiency and preventing the subsequent catalyst from being deactivated.

[0020] Other features of the present application, its nature and advantages will become more apparent from the detailed description of exemplary embodiments of the application below. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, explain the principles of the disclosure.

[0022] Figure 1 is a flow chart of a method for preparing a deoxidizing adsorbent according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] In order to make the purposes, technical solutions and beneficial technical effects of the present application clearer, the present application will be described in detail below in combination with specific embodiments. It should be understood that the embodiments described in the specification are only for explaining the present application, and are not intended to limit the present application.

[0024] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form a range that is not explicitly recited; and any lower limit can be combined with other lower limits to form a range that is not explicitly recited, as can any upper limit with any other upper limit. In addition, although not explicitly recited, every point or individual number within a range is included in the range. Thus, every point or individual number can be combined as its own lower limit or upper limit with any other point or individual number or with other lower limits or upper limits to form a range that is not explicitly recited.

[0025] In the description of the present application, it should be noted that, unless otherwise specified, "above", "below" include the number itself, and "several" means two or more.

[0026] The above summary of the application does not intend to describe every disclosed embodiment or every implementation of the present application. The exemplary embodiments are illustrated in more detail in the following description. In various places in the application, guidance is provided by a series of embodiments, which can be used in various combinations. In each instance, the list is merely representative of a group, and should not be interpreted as exhaustive.

[0027] Fischer-Tropsch synthesis oil as a key component of coal-based liquid fuel, its carbon number distribution is concentrated in C5 to C19, in which the alkane component accounts for about 45% of the total, the olefin component accounts for more than 50%, and the oxygen-containing compounds including organic acids, alcohols, aldehydes, ketones, esters and other types, the overall proportion is about 5%. Because these oxygen-containing compounds are easy to complex or substitution reaction with Lewis acid catalyst, it will cause the irreversible occupation of the active center of the catalyst, resulting in the overall deactivation of the catalytic system; secondly, the presence of oxygen-containing compounds will also have different degrees of influence on the odor, color, oxidation stability and other properties of the lubricating oil base oil.

[0028] Therefore, the efficient deoxygenation pretreatment of Fischer-Tropsch synthesis oil is the core link to ensure the smooth operation of the subsequent catalytic process and improve the product quality.

[0029] The present disclosure provides a deoxygenation method and deoxygenation adsorbent for Fischer-Tropsch synthesis oil to solve the problems in the prior art.

[0030] According to the first aspect of the present disclosure, the present disclosure provides a deoxygenation method for Fischer-Tropsch synthesis oil, comprising:

[0031] The Fischer-Tropsch synthesis oil is introduced into the adsorption tower filled with deoxygenation adsorbent to remove the oxygen-containing compounds in the Fischer-Tropsch synthesis oil, wherein the deoxygenation adsorbent is prepared by the following method, comprising the following steps, as shown in Figure 1

[0032] Step S1, aluminum source, silicon source and template agent are added to the alkali solution, and the first aging is carried out at room temperature; after the first aging is completed, aluminum source and silicon source are continuously added, and the second aging is carried out at room temperature; after the second aging is completed, crystallization is carried out at a predetermined temperature, and the product after crystallization is filtered, washed to obtain a molecular sieve;

[0033] Step S2, the molecular sieve obtained in step S1 is immersed in the alkali solution, and a template agent is added, and then crystallization is carried out, and the product after crystallization is filtered, washed, dried and calcined to obtain a deoxygenation adsorbent.

[0034] Specifically, the Fischer-Tropsch synthesis oil is introduced into the adsorption tower filled with deoxygenation adsorbent for removing oxygen-containing compounds, in the adsorption tower, the deoxygenation adsorbent is the stationary phase, and the Fischer-Tropsch synthesis oil is the liquid phase feed, because the polarity of the oxygen-containing compounds is strong, it can form hydrogen bond or dipole-dipole interaction with the hydroxyl group or acidic site on the surface of the deoxygenation adsorbent, thereby being selectively adsorbed; while non-polar hydrocarbons such as alkanes and alkenes are hardly adsorbed and will preferentially flow out with the liquid phase. When the deoxygenation adsorbent is gradually saturated and the deoxygenation efficiency decreases, the feed needs to be stopped and the deoxygenation adsorbent needs to be regenerated, for example, using solvent elution or other methods to desorb the oxygen-containing compounds adsorbed on the deoxygenation adsorbent, thereby restoring the activity of the deoxygenation adsorbent for recycling.​

[0035] The deoxygenated adsorbent used in the adsorption tower is prepared by the above method, wherein step S1 is the initial construction process of the molecular sieve framework, under alkaline conditions, the aluminum source and the silicon source first undergo hydrolysis and polycondensation reaction to form a silico-aluminate gel, and at the same time, the template agent begins to interact with the silicon-aluminum species to lay the foundation for subsequent structure guidance, then the aluminum source and the silicon source are added again and second room temperature aging is performed, wherein the first aging is used to promote the formation of primary colloidal particles, and the second aging can further adjust the silicon-aluminum ratio in the system, promote the perfection and homogenization of the gel network structure, and crystallize the solution after the second aging at a predetermined temperature to rearrange the amorphous gel into molecular sieve crystals with regular microporous structure. The product after crystallization is filtered, washed to obtain a molecular sieve with good crystallinity and developed micropores.

[0036] In step S2, the molecular sieve obtained in step S1 is placed in an alkali solution again, and a template agent is added for second crystallization. In this process, the alkali solution can perform controllable etching on the surface of the original molecular sieve, thereby partially dissolving the silicon-aluminum framework of the molecular sieve to produce a mesoporous structure; at the same time, the template agent can also induce the formation of an ordered mesoporous structure, and the second crystallization promotes the cooperative growth of the microporous framework and the mesoporous channel. After filtration, washing, drying and calcination, the template agent is removed, exposing abundant pore channels and surface active sites, and finally a deoxygenated adsorbent with high specific surface area and strong polar adsorption capacity is obtained.

[0037] The present disclosure provides a high-efficiency, continuous solution for removing oxygen-containing compounds in Fischer-Tropsch synthesis oil by preparing a deoxygenated adsorbent with a specific multi-level pore structure and combining an adsorption tower, which significantly improves the quality of Fischer-Tropsch synthesis oil and the economic benefits of subsequent processing.

[0038] In an embodiment of the present disclosure, step S1 further includes: the first aging temperature is 20-30°C; the aging time is 4-8h; the second aging temperature is 30-50°C, and the aging time is 2-4h.

[0039] Specifically, by controlling the temperature and time of the first aging and the second aging, the nucleation and growth process of the molecular sieve can be effectively regulated. In the first aging stage, the aging temperature is 20-30°C, and the aging time is 4-8h, which is conducive to the formation of a moderate number of uniform crystal nuclei to provide a good foundation for subsequent crystal growth. Subsequently, in the second aging stage, by adjusting the aging temperature to 30-40°C and the aging time to 2-4h, the directional growth and structural rearrangement of these crystal nuclei can be further promoted, thereby obtaining a molecular sieve with high crystallinity, regular crystal morphology and specific pore structure. The control of such aging conditions makes the prepared molecular sieve more stable and uniform in structure, avoiding product differences caused by uncertain conditions.

[0040] In one embodiment of the present disclosure, the step S1 further comprises: washing the product after crystallization to a pH value of 7-8. It means that the product after crystallization is treated by water washing or other appropriate detergents to remove the adsorbed or residual alkaline substances on the surface and in the pores thereof until the pH value of the washing liquid reaches neutral or the range close to neutral (7-8). This step is to ensure the purity of the molecular sieve and avoid the negative impact of residual alkaline substances on the stability of the molecular sieve structure, the pore characteristics and the subsequent adsorption performance.

[0041] In another embodiment of the present disclosure, the crystallization temperature in step S1 is 40-60°C, and the crystallization time is 8-15h; the crystallization temperature in step S2 is 100-150°C, the crystallization time is 20-35h, and the calcination temperature is 510-600°C; the calcination time is 12-22h.

[0042] Specifically, by controlling the crystallization temperature in step S1 to be 40-60°C and the crystallization time to be 8-15h, it can ensure that the initial crystallization process of the molecular sieve is fully carried out, forming a regular and stable molecular sieve skeleton structure, avoiding the generation of incomplete crystallization or crystal defects, and laying a good foundation for the subsequent secondary crystallization. On this basis, in step S2, the molecular sieve is immersed in the alkaline solution and the template agent is added, and then the crystallization temperature is further controlled to be 100-150°C and the crystallization time is controlled to be 20-35h. The crystallization in this stage, under the guidance of the template agent, further optimizes and perfects the pore structure of the molecular sieve, forming an adsorbent with specific pore size distribution and high specific surface area. Finally, by controlling the calcination temperature to be 510-600°C and the calcination time to be 12-22h, it can ensure that the template agent can be completely removed from the pores of the molecular sieve, while avoiding the collapse of the molecular sieve skeleton structure due to high temperature or the sintering of active sites.

[0043] Therefore, by synergistically optimizing and controlling the temperature and time parameters in the crystallization and calcination processes, the present disclosure can prepare a deoxygenation adsorbent with ideal crystal structure, pore distribution and high activity, thereby significantly improving the removal efficiency of oxygen-containing compounds in the Fischer-Tropsch synthetic oil and the service life of the adsorbent.

[0044] In one embodiment of the present disclosure, the mass ratio of the aluminum source to the silicon source added in the second aging in step S1 is 10:1-10:3, the mass ratio of the template agent to the aluminum source added in step S1 is 1:8-1:12, and the mass ratio of the template agent to the molecular sieve added in step S2 is 1:2-1:4. The above-mentioned ratios have been verified by experiments to be able to significantly optimize the composition uniformity and stability of the molecular sieve precursor gel, which makes the prepared molecular sieve have a more regular crystal structure, a more uniform pore distribution and more stable active sites, thereby effectively improving the catalytic performance and service life of the deoxygenation adsorbent.

[0045] In one embodiment of the present disclosure, the alkali liquor in steps S1 and S2 is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide and sodium carbonate solution.

[0046] Specifically, in the synthesis process of the molecular sieve, the alkali liquor is crucial to the dissolution of the silicon source and the aluminum source, the polymerization and the formation of the molecular sieve framework. Sodium hydroxide and potassium hydroxide are common strong bases, which can provide a high pH value, promote the formation and crystallization of the silica-alumina gel, and have a high degree of ionization in aqueous solution, making it easy to control the alkalinity of the reaction system. Calcium hydroxide is a medium-strong base, which has a relatively low solubility, but can provide calcium ions and play a role as a structure directing agent in some molecular sieve systems. Sodium carbonate solution is a weak base, which provides hydroxide ions through hydrolysis, and has a relatively mild alkalinity, which can control the crystallization rate and avoid uneven products caused by too fast crystallization. Selecting one or a combination of them can flexibly adjust the alkalinity, ionic strength and possible cation effect of the reaction system according to the type of the target molecular sieve and the required crystallization conditions, thereby optimizing the structure and performance of the molecular sieve.

[0047] In one embodiment of the present disclosure, the aluminum source in step S1 is one or more of sodium metaaluminate, aluminum sulfate and diaspore, and the silicon source is one or more of water glass, silicon dioxide, tetraethyl orthosilicate and white carbon black. Since different aluminum sources and silicon sources differ in solubility, reactivity and ion release rate, reasonable selection and combination can accurately control the silica-alumina ratio, crystallization rate, crystal size and morphology of the molecular sieve, thereby optimizing the pore structure and surface acid sites of the molecular sieve.

[0048] In one embodiment of the present disclosure, the template agent added in steps S1 and S2 is one or more of tetraethylammonium hydroxide, cetyltrimethylammonium bromide, tetrapropylammonium hydroxide and sodium dodecyl sulfate. The template agent can control the pore structure, pore size distribution and surface acid sites of the prepared molecular sieve, so that the deoxygenation adsorbent can better match the molecular size and chemical properties of the oxygen-containing compounds in the Fischer-Tropsch synthetic oil, thereby significantly improving the adsorption capacity and removal efficiency of the adsorbent for the oxygen-containing compounds.

[0049] In one embodiment of this disclosure, the Fischer-Tropsch synthetic oil contains C5-C19 alkanes, alkenes, and oxygen-containing compounds.

[0050] Specifically, Fischer-Tropsch synthetic oils are mainly C5-C19, with alkanes accounting for approximately 45%, olefins for over 50%, and oxygenated compounds for about 5%. These oxygenated compounds primarily consist of organic acids, alcohols, aldehydes, ketones, and esters of various carbon numbers. Because oxygenated compounds such as alcohols, aldehydes, and ketones can undergo complexation or substitution reactions with Lewis acid catalysts, some catalysts can be poisoned and deactivated. Furthermore, the presence of oxygenated compounds can affect the odor, color, and oxidation stability of the lubricating oil base oil to varying degrees. Therefore, necessary pretreatment of Fischer-Tropsch synthetic oils is required to remove oxygenated compounds that are harmful to catalyst and product stability, thereby improving the product's economic efficiency and quality.

[0051] According to a second aspect of this disclosure, a deoxygenating adsorbent is provided, which is prepared by the above-described deoxygenation method.

[0052] The embodiments of the present invention will be described in detail below with reference to the examples. The deoxygenating adsorbents used in the following examples are all... Figure 1 The method shown is for obtaining the product; however, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified, specific conditions in the examples were performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0053] Example 1

[0054] Add 40g of sodium aluminate solution (10wt%), 6g of silica, and 4g of cetyltrimethylammonium bromide (CTAB) to 200mL of 5wt% sodium hydroxide solution, and stir continuously. Aging is carried out at 25℃ for 4 hours. After the first aging, add another 40g of sodium aluminate (10wt%) and 6g of silica, and stir continuously. A second aging is carried out at 35℃ for 2 hours. The solution after the second aging is crystallized at 50℃. The crystallized product is filtered and washed until the pH reaches 7-8 to obtain a molecular sieve. 20g of the obtained molecular sieve is immersed in a 10%wt% sodium hydroxide solution, and 10g of cetyltrimethylammonium bromide (CTAB) is added while stirring continuously. The solution is then transferred to a hydrothermal reactor and crystallized at 120℃ for 24 hours. The crystallized product is filtered, washed, dried, and calcined to obtain a microporous deoxygenating adsorbent.

[0055] Example 2

[0056] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica and 4 g of sodium dodecyl sulfate (SDS) were added and continuously stirred, and aged at 25 °C for 4 h; after the first aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added and stirred, and secondly aged at 35 °C for 2 h. The solution after the second aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10% wt sodium hydroxide solution, and 10 g of sodium dodecyl sulfate (SDS) was added and continuously stirred, and then transferred into an autoclave for crystallization at 120 °C for 24 h. The product after crystallization was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0057] Example 3

[0058] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica and 4 g of tetraethylammonium hydroxide (TEAOH) were added and continuously stirred, and aged at 25 °C for 4 h; after the first aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added and stirred, and secondly aged at 35 °C for 2 h. The solution after the second aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10% wt sodium hydroxide solution, and 10 g of tetraethylammonium hydroxide (TEAOH) was added and continuously stirred, and then transferred into an autoclave for crystallization at 120 °C for 24 h. The product after crystallization was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0059] Example 4

[0060] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica and 4 g of tetraethylammonium hydroxide (TEAOH) were added and continuously stirred, and aged at 25 °C for 4 h; after the first aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added and stirred, and secondly aged at 35 °C for 2 h. The solution after the second aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10% wt sodium hydroxide solution, and 10 g of tetraethylammonium hydroxide (TEAOH) was added and continuously stirred, and then transferred into an autoclave for crystallization at 120 °C for 24 h. The product after crystallization was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0061] Comparative Example 1

[0062] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica, and 4 g of cetyltrimethylammonium bromide (CTAB) were added, and continuously stirred, and aged at 25 °C for 4 h. The aged solution was crystallized at 50 °C, and the crystallized product was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10 wt% sodium hydroxide solution, and 10 g of cetyltrimethylammonium bromide (CTAB) was added thereto, and continuously stirred, and then transferred to an autoclave and crystallized at 120 °C for 24 h. The crystallized product was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0063] Comparative Example 2

[0064] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica, and 4 g of cetyltrimethylammonium bromide (CTAB) were added, and continuously stirred, and aged at 25 °C for 4 h. The aged solution was crystallized at 50 °C, and the crystallized product was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10 wt% sodium hydroxide solution, and 10 g of cetyltrimethylammonium bromide (CTAB) was added thereto, and continuously stirred, and then transferred to an autoclave and crystallized at 120 °C for 24 h. The crystallized product was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0065] Comparative Example 3

[0066] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica, and 4 g of cetyltrimethylammonium bromide (CTAB) were added, and continuously stirred, and aged at 25 °C for 4 h. The aged solution was crystallized at 50 °C, and the crystallized product was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10 wt% sodium hydroxide solution, and 10 g of cetyltrimethylammonium bromide (CTAB) was added thereto, and continuously stirred, and then transferred to an autoclave and crystallized at 120 °C for 24 h. The crystallized product was filtered, washed, dried, and calcined to obtain a micro-mesoporous deoxidizing adsorbent.

[0067] Comparative Example 4

[0068] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica and 4 g of cetyltrimethylammonium bromide (CTAB) were added, and continuously stirred, and aged at 25 °C for 4 h. After the first aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added, and continuously stirred, and second aged at 35 °C for 2 h. After the second aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added, and continuously stirred, and third aged at 35 °C for 2 h. The solution after the third aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10 wt% sodium hydroxide solution, and 10 g of cetyltrimethylammonium bromide (CTAB) was added thereto, and continuously stirred, and then transferred to an autoclave and crystallized at 120 °C for 24 h. The product after crystallization was filtered, washed, dried, and calcined to obtain a deoxidizing adsorbent having micro-mesopores.

[0069] Comparative Example 5

[0070] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%), 6 g of silica and 4 g of cetyltrimethylammonium bromide (CTAB) were added, and continuously stirred, and aged at 25 °C for 4 h. After the first aging, 40 g of sodium aluminate (10 wt%) and 6 g of silica were continuously added, and continuously stirred, and second aged at 35 °C for 2 h. The solution after the aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a microporous molecular sieve.

[0071] Comparative Example 6

[0072] To 200 mL of 5 wt% sodium hydroxide solution, 40 g of sodium aluminate solution (10 wt%) and 6 g of silica were added, and continuously stirred, and aged at 25 °C for 4 h. The solution after the aging was crystallized at 50 °C, and the product after crystallization was filtered, washed to pH 7-8, to obtain a molecular sieve. 20 g of the obtained molecular sieve was immersed in a 10 wt% sodium hydroxide solution, and 10 g of cetyltrimethylammonium bromide (CTAB) was added thereto, and continuously stirred, and then transferred to an autoclave and crystallized at 120 °C for 24 h. The product after crystallization was filtered, washed, dried, and calcined to obtain a deoxidizing adsorbent having micro-mesopores.

[0073] The deoxygenated adsorbent obtained above was subjected to specific surface area analysis and adsorption capacity determination, and the analysis results are shown in Table 1. The adsorption capacity determination was determined using a fixed bed reactor, and the raw material was a C4-C19 Fischer-Tropsch synthesis light fraction oil, and the carbonyl value (measured by carbonyl value adsorption capacity) of the raw material was 1800 μg / mL, and the carbonyl value detection was performed according to the GB / T6324.5-2008 standard.

[0074] Table 1 Adsorbent specific surface area results

[0075]

[0076] Analysis of the data in Table 1 shows that during the preparation of the molecular sieve in step S1, after adding the aluminum source, silicon source and template agent into the alkali solution at the same time, and then performing secondary aging and crystallization, the specific surface area of the deoxygenated adsorbent can be significantly increased, and the adsorption capacity of the adsorbent can be improved; and through the experimental data of Comparative Examples 2-4, it can be seen that compared with once aging and thrice aging, the deoxygenated adsorbent obtained by twice aging according to the present disclosure is relatively optimal.

[0077] The deoxygenation method of Fischer-Tropsch synthesis oil and deoxygenated adsorbent provided by the present disclosure pass Fischer-Tropsch synthesis oil into an adsorption tower filled with deoxygenated adsorbent, for removing oxygen-containing compounds, wherein the deoxygenated adsorbent is formed by two aging and crystallization steps, etc., to form a multi-stage pore structure, increase the specific surface area, effectively adsorb oxygen-containing compounds of different molecular sizes in the range of C5-C19, thereby improving the deoxygenation efficiency and preventing the subsequent catalyst from being deactivated.

[0078] The above has described various embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications, or technical improvements in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein. The scope of the present disclosure is defined by the appended claims.

Claims

1. A process for the deoxygenation of Fischer-Tropsch synthesis oils, characterized in that, The application relates to a method for removing oxygen-containing compounds in Fischer-Tropsch synthesis oil, comprising the following steps: Step S1: adding an aluminum source, a silicon source and a template agent into a lye, and carrying out first aging at room temperature; after the first aging, continuously adding the aluminum source and the silicon source, and carrying out second aging at room temperature; after the second aging, carrying out crystallization at a predetermined temperature; and filtering, washing and drying the product after the crystallization to obtain a molecular sieve; Step S2: immersing the molecular sieve obtained in step S1 in a lye, adding a template agent into the lye, and then carrying out crystallization; and filtering, washing, drying and calcining the product after the crystallization to obtain a deoxygenation adsorbent; The mass ratio of the aluminum source to the silicon source added in the first and second aging in step S1 is 10:1-10:3; the mass ratio of the template agent to the aluminum source added in step S1 is 1:8-1:12; and the mass ratio of the template agent to the molecular sieve added in step S2 is 1:2-1:4; The template agent added in steps S1 and S2 is one or more of tetraethylammonium hydroxide, cetyltrimethylammonium bromide, tetrapropylammonium hydroxide and sodium dodecyl sulfate; The first aging temperature in step S1 is 20-30 DEG C; the aging time is 4-8 h; the second aging temperature is 30-50 DEG C; and the aging time is 2-4 h; The product after the crystallization is washed to a pH value of 7-8 in step S1; The crystallization temperature in step S1 is 40-60 DEG C; the crystallization time is 8-15 h; the crystallization temperature in step S2 is 100-150 DEG C; the crystallization time is 20-35 h; the calcination temperature is 510-600 DEG C; and the calcination time is 12-22 h. The lye in steps S1 and S2 is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide and sodium carbonate solution.

2. The deoxidation method according to claim 1, characterized by, The aluminum source in step S1 is one or more of sodium metaaluminate, aluminum sulfate and diaspore; and the silicon source is one or more of water glass, silicon dioxide, tetraethyl orthosilicate and white carbon black.

3. The deoxidation method according to claim 1, characterized by, The Fischer-Tropsch synthesis oil contains C5-C19 alkanes, alkenes and oxygen-containing compounds.

4. The deoxidation method according to claim 1, characterized by, The deoxygenation adsorbent is prepared by the method in any one of claims 1-4, comprising the following steps:

5. A deoxygenated adsorbent, characterized in that, Step S1: adding an aluminum source, a silicon source and a template agent into a lye, and carrying out first aging at room temperature; after the first aging, continuously adding the aluminum source and the silicon source, and carrying out second aging at room temperature; after the second aging, carrying out crystallization at a predetermined temperature; and filtering, washing and drying the product after the crystallization to obtain a molecular sieve; Step S2: immersing the molecular sieve obtained in step S1 in a lye, adding a template agent into the lye, and then carrying out crystallization; and filtering, washing, drying and calcining the product after the crystallization to obtain a deoxygenation adsorbent; ​ The mass ratio of the aluminum source and the silicon source added in the first aging and the second aging in the step S1 is 10:1-10:3; the mass ratio of the template agent and the aluminum source added in the step S1 is 1:8-1:12, and the mass ratio of the template agent and the molecular sieve added in the step S2 is 1:2-1:4; The template agent added in the step S1 and the step S2 is one or more of tetraethylammonium hydroxide, cetyltrimethylammonium bromide, tetrapropylammonium hydroxide, and sodium dodecyl sulfate; The step S1 further comprises: the first aging temperature is 20-30°C; the aging time is 4-8h; the second aging temperature is 30-50°C, and the aging time is 2-4h; The step S1 further comprises: washing the product after crystallization to a pH value of 7-8; The crystallization temperature in the step S1 is 40-60°C, and the crystallization time is 8-15h; the crystallization temperature in the step S2 is 100-150°C, the crystallization time is 20-35h, the calcination temperature is 510-600°C; and the calcination time is 12-22h.

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