Fischer-Tropsch synthesis light oil self-reaction deep deoxidation method

Abstract

The invention discloses a Fischer-Tropsch synthesis light oil self-reaction deep deoxidation method, which comprises the following steps of: introducing a Fischer-Tropsch synthesis light distillate oil raw material into a crude deoxidation reaction tower filled with a catalyst, and generating an oxygen-enriched heavy substance with a distillation range of more than 160 DEG C after a light oxygen-containing compound in the tower is subjected to self-reaction; and introducing a product of the crude deoxidation reaction tower into a heavy-throwing rectifying tower, carrying out heavy-cutting treatment, discharging oxygen-enriched heavy oil from the bottom of the tower, introducing light distillate oil at the top of the tower into a deep deoxidation adsorption tower filled with an adsorbent, and carrying out deep deoxidation to obtain Fischer-Tropsch synthesis light distillate oil of which the oxide concentration is less than 0.1 mu g / g from the bottom of the adsorption tower. According to the method, the three towers are connected in series, so that the deep removal of the oxides in the Fischer-Tropsch synthesis light distillate oil is realized with low energy consumption and low cost.

Description

Technical Field

[0001] The invention relates to the field of chemical engineering and technology, and in particular to a self-reaction deep deoxygenation method for Fischer-Tropsch synthesis light oil. Background Art

[0002] The Fischer-Tropsch synthesis reaction is a synthesis reaction that uses synthesis gas as a raw material and produces a large amount of hydrocarbon organic matter under the action of a catalyst. Fischer-Tropsch synthetic oils can be used to produce diesel, Fischer-Tropsch wax, lubricating oil, solvent oil and other special oils and various olefin products and other chemical products. However, Fischer-Tropsch synthetic oils also contain organic oxygen-containing compounds with alcohols, aldehydes, acids, esters and ketones as the main components, accounting for 5% to 15% by weight. These oxygen-containing compounds will cause certain corrosion to the equipment and bring difficulties to the processing of downstream products. For example, in the process of linear α-olefin polymerization, they will reduce the activity of the catalyst, affect the performance of the catalyst and even cause the catalyst to be poisoned and deactivated; these oxygen-containing compounds will also affect the properties of the products, such as affecting the light stability of Fischer-Tropsch wax, making Fischer-Tropsch wax have a certain odor, reducing the product quality, and limiting the application of the product. The content of oxygen-containing compounds in naphtha will directly affect the quality of downstream chemical products; in addition, the presence of oxygen-containing compounds increases the viscosity of the oil, darkens the color, and easily generates colloids, which affects the oxidation stability of diesel and puts higher requirements on the storage and utilization of diesel. It is necessary to remove oxygenated compounds from Fischer-Tropsch synthetic oils.

[0003] At present, the methods for removing oxygenated compounds from Fischer-Tropsch oil mainly include hydrodeoxygenation, chemical removal, liquid-liquid extraction, distillation, physical adsorption, etc. For example, Chinese invention patent CN111718746A discloses a method for deoxygenation and refining of Fischer-Tropsch oil, wherein the Fischer-Tropsch oil is subjected to atmospheric and vacuum distillation to obtain a first fraction, a second fraction and a third fraction; (2) the first fraction is subjected to a first extraction with a methanol aqueous solution to obtain an extraction phase 1 and a raffinate phase 1; the second fraction is subjected to a second extraction with an ethanol aqueous solution to obtain an extraction phase 2 and a raffinate phase 2; the third fraction is subjected to a third extraction with an aqueous solution of glycol ethers to obtain an extraction phase 3 and a raffinate phase 3; (3) the raffinate phase 1, the raffinate phase 2 and the raffinate phase 3 are respectively washed with water to obtain deoxygenated and refined Fischer-Tropsch oil. The method not only maintains the content of α-olefins during the removal of oxygen-containing compounds, but also reduces the content of oxygen-containing compounds in the Fischer-Tropsch synthetic oil after deoxygenation and refining to below 100 ppm, and has a high oil recovery rate.

[0004] For another example, Chinese invention patent CN114907878A discloses a method for removing oxygenated compounds from Fischer-Tropsch synthetic oil by coupling adsorption and distillation. The method allows the Fischer-Tropsch synthetic oil raw material to enter an adsorption and distillation separation unit, which is composed of one or more adsorption and distillation towers. The oxygenated compounds are deeply removed under the action of the deoxygenated adsorption and distillation filler inside the adsorption and distillation tower; the top of the tower obtains a light fraction with deep deoxygenation, and the bottom of the tower obtains a heavy fraction enriched with oxygenated compounds. The side line of the adsorption and distillation tower can produce the Fischer-Tropsch synthetic oil of the middle distillate section according to actual needs, and enter the subsequent adsorption and distillation tower to carry out deep removal of oxygenated compounds from other middle distillate oil products. The method of the present invention couples adsorption with distillation technology, does not require the use of desorbents, simplifies the process flow, reduces industrialization costs, and can simultaneously achieve deep removal of oxygenated compounds and fraction cutting in the Fischer-Tropsch synthetic oil. The deoxygenated adsorption and distillation filler in the present invention has a long service life, low distillation energy consumption, and high oxygenated compound removal efficiency.

[0005] For another example, Chinese invention patent CN114479914A discloses a method for removing oxygenated compounds from Fischer-Tropsch oil, which belongs to the technical field of Fischer-Tropsch oil processing. The method comprises: in a fixed bed reaction device, removing oxygenated compounds from the Fischer-Tropsch oil to be treated with sulfonic acid resin; the weight ratio of sulfonic acid resin to the Fischer-Tropsch oil to be treated is 1:100-200. By utilizing sulfonic acid resin to react with Fischer-Tropsch oil, oxygenated compounds in the Fischer-Tropsch oil can be removed by reaction while ensuring that straight-chain olefins are not lost, and additional straight-chain olefins are generated at the same time, thereby greatly increasing the olefin content in the oil product. In addition, the method is conducive to extending the service life of the sulfonic acid resin, generating fewer by-products, having little effect on the purity of olefins, low energy consumption, and high economic benefits.

[0006] It can be seen from the above existing technologies that the current deoxygenation process technologies are mainly based on extraction, adsorption and direct reaction of oxides, the degree of deoxygenation is limited, and there is no process technology to achieve the complete removal of oxides in the Fischer-Tropsch synthesis light distillate oil. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for deep deoxygenation of Fischer-Tropsch synthetic light oil through self-reaction.

[0008] The present invention is achieved by adopting the following technical solutions.

[0009] A method for deep deoxygenation of Fischer-Tropsch light oil by self-reaction, comprising the following steps:

[0010] The Fischer-Tropsch synthesis light distillate oil raw material is passed into a crude deoxygenation reaction tower equipped with a catalyst, and the light oxygen-containing compounds in the tower react to generate oxygen-rich heavy products with a distillation range greater than 160°C; the product of the crude deoxygenation reaction tower is passed into a weight-rejection distillation tower for heavy-cutting treatment, and the oxygen-rich heavy oil is discharged from the bottom of the tower. The light distillate oil at the top of the tower is passed into a deep deoxygenation adsorption tower equipped with an adsorbent, and after deep deoxygenation, a Fischer-Tropsch synthesis light distillate oil with an oxide concentration of less than 0.1 μg / g is obtained from the bottom of the adsorption tower.

[0011] By adopting the above technical scheme, the oxide content of the light distillate oil at the top of the weight-spinning distillation tower is reduced by more than 95% compared with the Fischer-Tropsch synthesis light distillate oil raw material, and the oxide content of the final product after being treated by the process of the present invention is less than 0.1 μg / g. The present invention realizes the deep removal of oxides in the Fischer-Tropsch synthesis light distillate oil with low energy consumption and low cost by connecting three towers in series.

[0012] Furthermore, the distillation range of the Fischer-Tropsch synthesis light distillate oil raw material is 30° C. to 160° C., and the oxygen-containing compound content of the raw material is controlled within 10%.

[0013] Furthermore, the mass content of the active component of the catalyst in the crude deoxygenation reaction tower is greater than 85%, and the active component is selected from Beta molecular sieve or Y molecular sieve.

[0014] Furthermore, the reaction temperature of the crude deoxygenation reaction tower is 80-250°C, the reaction pressure is 0.1-2.0 MPa, and the reaction volume space velocity is 0.05-1h -1 .

[0015] Furthermore, the weight rejection distillation tower is a vacuum tower with an absolute pressure of 5 to 100 kPa, a top temperature of 10 to 120° C., a bottom temperature of 100 to 140° C., a theoretical plate number of 40 to 60, and Raschig rings and / or Pall rings as fillers.

[0016] Furthermore, the mass content of active components of the adsorbent in the deep deoxygenation adsorption tower is greater than 90%, and the active component is 13X molecular sieve.

[0017] Furthermore, the adsorption temperature of the deep deoxygenation adsorption tower is 30-100°C, the height-to-diameter ratio of the adsorption tower is 2-10, and the adsorption volume space velocity is 0.2-4h -1 , adsorption pressure 0.1~2.0MPa.

[0018] This application has the following beneficial effects.

[0019] Compared with the extraction and adsorption methods, the present invention has the advantages of low energy consumption, low adsorbent consumption and low cost, can achieve the deep removal of oxides in the Fischer-Tropsch synthesis light distillate oil, and reduce the industrial cost of deoxygenation of the Fischer-Tropsch synthesis light distillate oil. In addition, the catalyst and adsorbent in the present invention have a long service life and high deoxygenation efficiency, providing a more economical and simple method for the processing and utilization of the Fischer-Tropsch synthesis light distillate oil and the development of downstream comprehensive utilization of olefins. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a process flow chart of the present invention;

[0021] Among them, 1. Crude deoxygenation reaction tower; 2. Weight rejection distillation tower; 3. Deep deoxygenation adsorption tower. DETAILED DESCRIPTION

[0022] The present patent application is further described below in conjunction with embodiments.

[0023] Unless otherwise specified, the experimental methods used in the following preparation examples and embodiments are conventional methods.

[0024] A method for deep deoxygenation of Fischer-Tropsch light oil by self-reaction, comprising the following steps:

[0025] The distillation range of the Fischer-Tropsch synthesis light distillate oil raw material is 30°C to 160°C. First, the Fischer-Tropsch synthesis light distillate oil is passed into a crude deoxygenation reaction tower 1 equipped with a catalyst, in which the alcohols, aldehydes, acids, esters, ketones and other oxides contained in the Fischer-Tropsch synthesis light distillate oil undergo acetalization, aldol condensation and etherification and other series of reactions between oxides to generate oxygen-rich heavy products with a distillation range greater than 160°C, the crude deoxygenation reaction tower product is passed into a weight-rejection distillation tower 2 for weight-removal treatment, the oxygen-rich heavy oil is discharged from the bottom of the tower, the oxide content of the light distillate oil at the top of the tower is reduced by more than 95% compared with the Fischer-Tropsch synthesis light distillate oil raw material, and then the light distillate oil at the top of the tower is passed into a deep deoxygenation adsorption tower 3 equipped with an adsorbent, and after deep deoxygenation, a Fischer-Tropsch synthesis light distillate oil with an oxide concentration of less than 0.1μg / g is obtained from the bottom of the adsorption tower.

[0026] Example 1

[0027] The experiment was carried out using raw materials from a certain enterprise. The raw material data are shown in Tables 1.1 and 1.2.

[0028] Table 1.1 Hydrocarbon composition of Fischer-Tropsch synthesis light distillate oil feedstock

[0029] Carbon number Alkanes Olefins Oxide Subtotal C3 0.82％ 0.82％ C4 1.47％ 1.47％ C5 3.18％ 6.61％ 1.35％ 11.14％ C6 4.79％ 12.96％ 1.86％ 19.61％ C7 5.27％ 16.38％ 21.65％ C8 5.28％ 17.45％ 22.73％ C9 5.20％ 17.39％ 22.59％ total 23.72％ 70.78％ 5.50％ 100.00％

[0030] Table 1.2 Distillation range of Fischer-Tropsch synthesis light distillate oil raw materials

[0031] Distillation range, ℃ Initial distillation point / ℃ 30 5% recovery temperature / ℃ 45 10% recovery temperature / ℃ 54 30% recovery temperature / ℃ 79 50% recovery temperature / ℃ 95 70% recovery temperature / ℃ 111 90% recovery temperature / ℃ 132 95% recovery temperature / ℃ 143 Final distillation point / ℃ 153

[0032] The Fischer-Tropsch synthesis light distillate oil enters the crude deoxygenation reaction tower, which is loaded with commercially available catalyst A1, with a reaction temperature of 120°C, a reaction pressure of 0.5 MPa, and a reaction volume space velocity of 0.5 h -1 The physical properties of catalyst A1 are shown in Table 1.3.

[0033] Table 1.3 Physical properties of catalyst A1

[0034] <![CDATA[Catalyst A1]]> Morphology Butterfly Quality composition 88% Y molecular sieve + 12% attapulgite <![CDATA[Specific surface area, m 2 / g]]> 487 Bulk ratio, g / mL 0.67

[0035] The product obtained by the reaction of the Fischer-Tropsch light distillate oil through the crude deoxygenation reaction tower has the hydrocarbon composition data shown in Table 1.4:

[0036] Table 1.4 Hydrocarbon composition of crude deoxygenation reaction tower product

[0037]

[0038]

[0039] The crude deoxygenation reaction tower product enters the weight rejection distillation tower for heavy component cutting. The distillation tower is filled with Raschig rings and has 45 plates. The absolute pressure of the distillation tower is controlled at 15 kPa, the tower bottom temperature is controlled at 140 °C, and the tower top temperature changes from 10 to 120 °C during the distillation process to achieve the cutting of light and heavy components of the oil product. The hydrocarbon composition of the top product of the distillation tower is shown in Table 1.5 and the hydrocarbon composition of the bottom product is shown in Table 1.6. The yield of the top product of the distillation tower is 94.5%, and the yield of the bottom product of the distillation tower is 5.5%. The oxide content of the top product of the distillation tower is 95.77% lower than that of the Fischer-Tropsch synthesis light distillate oil raw material.

[0040] Table 1.5 Hydrocarbon composition of the top product of the distillation tower

[0041] Carbon number Alkanes Olefins Oxide Subtotal C3 0.03％ 0.03％ C4 0.06％ 0.06％ C5 3.36％ 6.99％ 0.06％ 10.41％ C6 5.06％ 13.70％ 0.08％ 18.84％ C7 5.57％ 17.32％ 22.89％ C8 5.58％ 18.45％ 24.03％ C9 5.45％ 18.29％ 23.74％ Heavy components 0.00％ total 25.03％ 74.75％ 0.23％ 100.00％

[0042] Table 1.6 Hydrocarbon composition of distillation tower bottom product

[0043] Carbon number Alkanes Olefins Oxide Subtotal C9 0.86％ 1.55％ 2.41％ Heavy components 97.59％ 97.59％ total 0.86％ 1.55％ 97.59％ 100.00％

[0044] The top product of the distillation tower is sent to the deep deoxygenation adsorption tower for deep deoxygenation treatment. The adsorption temperature is 35°C and the adsorption volume space velocity is 0.5h -1 , adsorption pressure 0.9MPa, adsorption tower height-diameter ratio 3, commercial adsorbent A2 properties are shown in Table 1.7, and the hydrocarbon composition of the adsorption tower bottom product is shown in Table 1.8. After passing through the deep deoxygenation adsorption tower, the oxide content of the Fischer-Tropsch synthesis light distillate oil is reduced to less than 0.1ug / g.

[0045] Table 1.7 Physical properties of adsorbent A2

[0046] <![CDATA[Adsorbent A2]]> Morphology 0.4~0.8mm microsphere Quality composition 95% 13X molecular sieve + 5% kaolin <![CDATA[Specific surface area, m 2 / g]]> 555 Bulk ratio, g / mL 0.72

[0047] Table 1.8 Hydrocarbon composition of the top product of the distillation tower

[0048]

[0049]

[0050] Example 2

[0051] The experiment was carried out using raw materials from a certain enterprise. The raw material data are shown in Tables 2.1 and 2.2.

[0052] Table 2.1 Hydrocarbon composition of Fischer-Tropsch synthesis light distillate oil feedstock

[0053] Carbon number Alkanes Olefins Oxide Subtotal C3 0.82％ 0.82％ C4 1.47％ 1.47％ C5 3.18％ 6.61％ 1.35％ 11.14％ C6 4.79％ 12.96％ 1.86％ 19.61％ C7 5.27％ 16.38％ 21.65％ C8 5.28％ 17.45％ 22.73％ C9 5.20％ 17.39％ 22.59％ total 23.72％ 70.78％ 5.50％ 100.00％

[0054] Table 2.2 Distillation range of Fischer-Tropsch synthesis light distillate oil raw materials

[0055] Distillation range, ℃ Initial distillation point / ℃ 30 5% recovery temperature / ℃ 45 10% recovery temperature / ℃ 54 30% recovery temperature / ℃ 79 50% recovery temperature / ℃ 95 70% recovery temperature / ℃ 111 90% recovery temperature / ℃ 132 95% recovery temperature / ℃ 143 Final distillation point / ℃ 153

[0056] The Fischer-Tropsch synthesis light distillate oil enters the crude deoxygenation reaction tower, which is loaded with commercially available catalyst B1. The reaction temperature is 170°C, the reaction pressure is 0.6 MPa, and the reaction volume space velocity is 0.8 h -1 The physical properties of catalyst B1 are shown in Table 2.3.

[0057] Table 2.3 Physical properties of catalyst B1

[0058] <![CDATA[Catalyst B1]]> Morphology Butterfly Quality composition 90%Beta+10%Kaolin <![CDATA[Specific surface area, m 2 / g]]> 445 Bulk ratio, g / mL 0.60

[0059] The product obtained by the reaction of the Fischer-Tropsch light distillate oil through the crude deoxygenation reaction tower has the hydrocarbon composition data shown in Table 2.4:

[0060] Table 2.4 Hydrocarbon composition of crude deoxygenation reaction tower product

[0061] Carbon number Alkanes Olefins Oxide Subtotal C3 0.03％ 0.03％ C4 0.05％ 0.05％ C5 3.17％ 6.59％ 0.05％ 9.81％ C6 4.78％ 12.92％ 0.07％ 17.76％ C7 5.25％ 16.33％ 21.59％ C8 5.26％ 17.40％ 22.66％ C9 5.18％ 17.34％ 22.52％ Heavy components 5.58％ 5.58％ total 23.65％ 70.58％ 5.77％ 100.00％

[0062] The crude deoxygenation reaction tower product enters the weight rejection distillation tower for heavy component cutting. The distillation tower is filled with ball rings and has 53 plates. The absolute pressure of the distillation tower is controlled at 12 kPa, the bottom temperature is controlled at 135 °C, and the top temperature changes from 10 to 100 °C during the distillation process to achieve the cutting of light and heavy components of the oil product. The hydrocarbon composition of the top product of the distillation tower is shown in Table 2.5 and the hydrocarbon composition of the bottom product is shown in Table 2.6. The yield of the top product of the distillation tower is 94.4%, and the yield of the bottom product of the distillation tower is 5.6%. The oxide content of the top product of the distillation tower is 96.29% lower than that of the Fischer-Tropsch synthesis light distillate oil raw material.

[0063] Table 2.5 Hydrocarbon composition of the top product of the distillation tower

[0064] Carbon number Alkanes Olefins Oxide Subtotal C3 0.03％ 0.03％ C4 0.05％ 0.05％ C5 3.36％ 6.98％ 0.05％ 10.39％ C6 5.06％ 13.69％ 0.07％ 18.82％ C7 5.57％ 17.30％ 22.87％ C8 5.58％ 18.43％ 24.01％ C9 5.48％ 18.35％ 23.84％ Heavy components 0.00％ total 25.04％ 74.75％ 0.20％ 100.00％

[0065] Table 2.6 Hydrocarbon composition of distillation tower bottom product

[0066] Carbon number Alkanes Olefins Oxide Subtotal C9 0.12％ 0.22％ 0.34％ Heavy components 99.66％ 99.66％ total 0.12％ 0.22％ 99.66％ 100.00％

[0067] The top product of the distillation tower enters the deep deoxygenation adsorption tower for deep deoxygenation treatment. The adsorption temperature is 50°C and the volume space velocity is 0.9h -1 , adsorption pressure 0.4MPa, adsorption tower height-diameter ratio 5, commercial adsorbent B2 properties are shown in Table 2.7, and the hydrocarbon composition of the adsorption tower bottom product is shown in Table 2.8. After passing through the deep deoxygenation adsorption tower, the oxide content of the Fischer-Tropsch synthesis light distillate oil is reduced to less than 0.1ug / g.

[0068] Table 2.7 Physical properties of adsorbent B2

[0069] <![CDATA[Adsorbent B2]]> Morphology 0.4~0.8mm microsphere Quality composition 94% 13X molecular sieve + 6% diatomaceous earth <![CDATA[Specific surface area, m 2 / g]]> 560 Bulk ratio, g / mL 0.70

[0070] Table 2.8 Hydrocarbon composition of the top product of the distillation tower

[0071] Carbon number Alkanes Olefins Oxide Subtotal C3 0.00％ C4 0.00％ C5 3.37％ 7.00％ 10.36％ C6 5.07％ 13.72％ 18.78％ C7 5.58％ 17.33％ 22.91％ C8 5.59％ 18.47％ 24.06％ C9 5.50％ 18.39％ 23.89％ Heavy components 0.00％ total 25.10％ 74.90％ 0.00％ 100.00％

[0072] Example 3

[0073] The experiment was carried out using raw materials from a certain enterprise. The raw material data are shown in Tables 3.1 and 3.2.

[0074] Table 3.1 Hydrocarbon composition of Fischer-Tropsch synthesis light distillate oil feedstock

[0075] Carbon number Alkanes Olefins Oxide Subtotal C3 0.82％ 0.82％ C4 1.47％ 1.47％ C5 3.18％ 6.61％ 1.35％ 11.14％ C6 4.79％ 12.96％ 1.86％ 19.61％ C7 5.27％ 16.38％ 21.65％ C8 5.28％ 17.45％ 22.73％ C9 5.20％ 17.39％ 22.59％ total 23.72％ 70.78％ 5.50％ 100.00％

[0076] Table 3.2 Distillation range of Fischer-Tropsch synthesis light distillate oil raw materials

[0077] Distillation range, ℃ Initial distillation point / ℃ 30 5% recovery temperature / ℃ 45 10% recovery temperature / ℃ 54 30% recovery temperature / ℃ 79 50% recovery temperature / ℃ 95 70% recovery temperature / ℃ 111 90% recovery temperature / ℃ 132 95% recovery temperature / ℃ 143 Final distillation point / ℃ 153

[0078] The Fischer-Tropsch synthesis light distillate oil enters the crude deoxygenation reaction tower, which is loaded with commercially available catalyst C1, with a reaction temperature of 210°C, a reaction pressure of 1.2 MPa, and a reaction volume space velocity of 1.0 h -1 The physical properties of catalyst C1 are shown in Table 3.3.

[0079] Table 3.3 Physical properties of catalyst C1

[0080] <![CDATA[Catalyst C1]]> Morphology Clover Quality composition 98% Beta Zeolite + 2% Diatomaceous Earth <![CDATA[Specific surface area, m 2 / g]]> 421 Bulk ratio, g / mL 0.78

[0081] The product obtained by the reaction of the Fischer-Tropsch light distillate oil through the crude deoxygenation reaction tower has the hydrocarbon composition data shown in Table 3.4:

[0082] Table 3.4 Hydrocarbon composition of crude deoxygenation reaction tower product

[0083] Carbon number Alkanes Olefins Oxide Subtotal C3 0.04％ 0.04％ C4 0.07％ 0.07％ C5 3.17％ 6.60％ 0.06％ 9.83％ C6 4.78％ 12.93％ 0.08％ 17.80％ C7 5.26％ 16.35％ 21.61％ C8 5.27％ 17.42％ 22.68％ C9 5.19％ 17.36％ 22.54％ Heavy components 5.43％ 5.43％ total 23.67％ 70.65％ 5.68％ 100.00％

[0084] The crude deoxygenation reaction tower product enters the weight rejection distillation tower for heavy component cutting. The distillation tower packing is a 1:1 mixture of ball rings and Raschig rings. The number of distillation tower plates is 57. By controlling the absolute pressure of the distillation tower to 15kPa and the bottom temperature to 140°C, the top temperature of the tower changes from 30 to 120°C during the distillation process to achieve the cutting of light and heavy components of the oil products. The hydrocarbon composition of the top product of the distillation tower is shown in Table 3.5 and the hydrocarbon composition of the bottom product is shown in Table 3.6. The yield of the top product of the distillation tower is 94.5%, and the yield of the bottom product of the distillation tower is 5.5%. The oxide content of the top product of the distillation tower is 95.24% lower than that of the Fischer-Tropsch synthesis light distillate oil raw material.

[0085] Table 3.5 Hydrocarbon composition of the top product of the distillation tower

[0086] Carbon number Alkanes Olefins Oxide Subtotal C3 0.04％ 0.04％ C4 0.07％ 0.07％ C5 3.36％ 6.98％ 0.06％ 10.40％ C6 5.06％ 13.69％ 0.09％ 18.83％ C7 5.57％ 17.30％ 22.86％ C8 5.58％ 18.43％ 24.00％ C9 5.47％ 18.32％ 23.79％ Heavy components 0.00％ total 25.03％ 74.71％ 0.26％ 100.00％

[0087] Table 3.6 Hydrocarbon composition of distillation tower bottom product

[0088] Carbon number Alkanes Olefins Oxide Subtotal C9 0.34％ 0.86％ 1.20％ Heavy components 98.80％ 98.80％ total 0.34％ 0.86％ 98.80％ 100.00％

[0089] The top product of the distillation tower enters the deep deoxygenation adsorption tower for deep deoxygenation treatment. The adsorption temperature is 70°C, the adsorption pressure is 0.6MPa, and the adsorption volume space velocity is 1.1h -1 The height-to-diameter ratio of the adsorption tower is 8, the physical properties of adsorbent C2 are shown in Table 3.7, and the hydrocarbon composition of the bottom product of the adsorption tower is shown in Table 3.8. After passing through the deep deoxygenation adsorption tower, the oxide content of the Fischer-Tropsch synthesis light distillate oil is reduced to less than 0.1ug / g.

[0090] Table 3.7 Physical properties of adsorbent C2

[0091] <![CDATA[Adsorbent C2]]> Morphology 0.4~0.8mm microsphere Quality composition 93% 13X molecular sieve + 7% attapulgite <![CDATA[Specific surface area, m 2 / g]]> 650 Bulk ratio, g / mL 0.63

[0092] Table 3.8 Hydrocarbon composition of the top product of the distillation tower

[0093] Carbon number Alkanes Olefins Oxide Subtotal C3 0.00％ C4 0.00％ C5 3.37％ 7.00％ 10.37％ C6 5.07％ 13.72％ 18.79％ C7 5.58％ 17.34％ 22.92％ C8 5.59％ 18.48％ 24.07％ C9 5.49％ 18.36％ 23.85％ Heavy components 0.00％ total 25.10％ 74.90％ 0.00％ 100.00％

[0094] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for deep deoxygenation of Fischer-Tropsch light oil by self-reaction, characterized in that: The following steps are involved: The Fischer-Tropsch synthesis light distillate oil raw material is passed into a crude deoxygenation reaction tower (1) equipped with a catalyst, and the light oxygen-containing compounds in the tower react to generate oxygen-rich heavy products with a distillation range greater than 160°C; the product of the crude deoxygenation reaction tower is passed into a weight rejection distillation tower (2) for weight removal treatment, and the oxygen-rich heavy oil is discharged from the bottom of the tower. The light distillate oil at the top of the tower is passed into a deep deoxygenation adsorption tower (3) equipped with an adsorbent, and after deep deoxygenation, a Fischer-Tropsch synthesis light distillate oil with an oxide concentration of less than 0.1 μg / g is obtained from the bottom of the adsorption tower.

2. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The distillation range of the Fischer-Tropsch synthesis light distillate oil raw material is 30° C. to 160° C., and the oxygen-containing compound content of the raw material is controlled within 10%.

3. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The mass content of the active component of the catalyst in the crude deoxygenation reaction tower (1) is greater than 85%, and the active component is selected from Beta molecular sieve or Y molecular sieve.

4. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The reaction temperature of the crude deoxygenation reaction tower (1) is 80-250°C, the reaction pressure is 0.1-2.0 MPa, and the reaction volume space velocity is 0.05-1h -1 .

5. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The weight rejection distillation tower (2) is a vacuum tower with an absolute pressure of 5-100 kPa, a top temperature of 10-120° C., a bottom temperature of 100° C.-140° C., a theoretical plate number of 40-60, and Raschig rings and / or Pall rings as fillers.

6. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The mass content of active components of the adsorbent in the deep deoxygenation adsorption tower (3) is greater than 90%, and the active component is 13X molecular sieve.

7. The method for deep deoxygenation of Fischer-Tropsch light oil self-reaction according to claim 1, characterized in that: The adsorption temperature of the deep deoxygenation adsorption tower (3) is 30-100°C, the height-to-diameter ratio of the adsorption tower is 2-10, and the adsorption volume space velocity is 0.2-4h -1 , adsorption pressure 0.1~2.0MPa.

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