Iron-based deoxidizing catalyst, its preparation method and application

Abstract

The application relates to the technical field of catalyst preparation, and discloses an iron-based deoxidization catalyst, a preparation method and application thereof. The iron-based deoxidization catalyst comprises a carrier, an iron oxide compound active phase and an additive loaded on the surface of the carrier; the iron oxide compound is at least two of FeO, Fe2O3 and Fe3O4; and the additive is one or two or more of oxides of Ce, Mg, Na and Zr. The application provides a deoxidization catalyst taking non-noble metal iron oxide as a main active component, compared with other deoxidization technologies, the type of the active phase iron oxide compound on the surface of the deoxidization catalyst is controlled through efficient regulation of a reduction process, the adsorption and activation of oxygen are promoted, and the high oxygen adsorption and activation capacity promotes the deoxidization efficiency of the deoxidization catalyst. The catalyst has large treatment capacity and advantages of facilitating continuous long-period operation.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to an iron-based deoxidation catalyst, its preparation method, and its application. Background Technology

[0002] Catalytic oxidation is one of the most common chemical reactions in chemical production processes. Incomplete reactions between raw materials (low-carbon hydrocarbons) and oxidants (air, oxygen, ozone, etc.) lead to a significant accumulation of oxidants during the recycling of raw materials, resulting in a substantial risk of combustion and explosion in chemical production processes. The "Design Code for Combustible Gas Emission Systems in Petrochemical Industries" stipulates that combustible gases with an oxygen content greater than 2% (v%) should not be discharged into the plant's overall combustible gas emission system. Therefore, the efficient treatment of oxygen in oxygen-containing exhaust gases has become a critical issue that urgently needs to be addressed.

[0003] Currently, inert gas dilution and emission are the main methods for oxygen treatment. However, this method not only increases operating costs (due to large nitrogen consumption) but also causes environmental pollution due to VOC emissions. In recent years, catalytic oxidation has received extensive research due to its significant advantages in terms of economy, environmental protection, and energy conservation; however, the high price of precious metal catalysts and the low efficiency of deep deoxygenation remain problems. Therefore, the development of non-precious metal catalysts with high catalytic oxidation activity has attracted widespread attention from researchers.

[0004] Patent CN101165030B discloses a Mn-Ag dual-active-component deoxidizer for removing trace oxygen from ethylene and propylene. However, this deoxidizer catalyst requires repeated reduction and regeneration during use, and its processing capacity per unit time is low, with low deoxidation efficiency when the oxygen content is high. Patent CN100556533C discloses a low-valent oxide deoxidizer with Mn and Fe as active components, produced using domestically abundant manganese and iron ore as raw materials. Its cost is lower than existing manganese, copper, and nickel-type deoxidizers, giving it stronger market competitiveness. It deeply deoxidizes organic gases such as CH4, C2H4, and C3H6, reducing the residual oxygen content in the gas to ≤0.1×10-6V / V. Patent CN100513367C discloses a deoxidizer catalyst with MnO / Mn3O4 as the active component, incorporating alkaline earth metal oxides and alumina as activity promoters. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of low deoxidation efficiency of non-precious metal catalysts in the prior art, and to provide an iron-based deoxidation catalyst, its preparation method and application.

[0006] The first aspect of the present invention provides an iron-based deoxidation catalyst, the iron-based deoxidation catalyst comprising a support, an iron oxide active phase supported on the surface of the support, and an auxiliary agent;

[0007] The iron oxide compound is at least two of FeO, Fe2O3 and Fe3O4;

[0008] The auxiliary agent is one or more of the oxides of Ce, Mg, Na and Zr.

[0009] Preferably, when the iron oxide compound is FeO and Fe2O3, the molar ratio of the two is 1:1-2, more preferably 1:1.2-1.5.

[0010] Preferably, when the ferrooxide is FeO and Fe3O4, the molar ratio of the two is 1:1-2, more preferably 1:1.2-1.5.

[0011] Preferably, when the iron oxide compounds are Fe2O3 and Fe3O4, the molar ratio of the two is 1.5-2.5:1, more preferably 1.8-2:1.

[0012] Preferably, when the iron oxide compound is FeO, Fe2O3 and Fe3O4, the molar ratio of the three is 1:2-3:2-3; more preferably, it is 1:2.2-2.5:2.7-2.9.

[0013] A second aspect of the present invention provides a method for preparing the iron-based deoxidation catalyst described above, the method comprising the following steps;

[0014] (1) Mix iron salt, auxiliary agent precursor and solvent to obtain impregnation solution;

[0015] (2) The impregnation solution is impregnated onto the carrier, and then dried and calcined to obtain the calcined product;

[0016] (3) The calcined product is reduced to obtain an iron-based deoxidation catalyst;

[0017] The auxiliary precursor is selected from at least one of cerium salt, magnesium salt, zirconium salt and sodium salt;

[0018] The reduction conditions include: a reducing atmosphere of H2, CO, a mixture of CO and H2 or a mixture of H2 and N2, a temperature of 100-400℃, a time of 1-20h, a pressure of 0.1-1.5MPa, and a heating rate of 1-30℃ / min.

[0019] Preferably, the iron salt is selected from one or more of ferric nitrate, ferric chloride, and ferric ammonium citrate.

[0020] Preferably, the cerium salt is selected from cerium nitrate;

[0021] Preferably, the magnesium salt is selected from magnesium nitrate;

[0022] Preferably, the zirconium salt is selected from zirconium nitrate;

[0023] Preferably, the sodium salt is selected from sodium nitrate and / or sodium carbonate.

[0024] Preferably, the weight ratio of iron salt to carrier is 1-20:100;

[0025] Preferably, the weight ratio of the auxiliary precursor to the carrier is 0.1-5:100.

[0026] Preferably, the support is selected from SiO2, Al2O3 or molecular sieve.

[0027] Preferably, in step (2), the drying conditions include: a temperature of 100℃-200℃ and a drying atmosphere of air.

[0028] Preferably, in step (2), the calcination conditions include: a temperature of 300-600℃ and a calcination atmosphere of air;

[0029] Preferably, in the mixture of CO and H2, the volume ratio of CO to H2 is 2:1;

[0030] Preferably, in the H2 and N2 mixture, the H2 content is 5-15% by volume.

[0031] A third aspect of the present invention provides the application of the above-mentioned iron-based deoxygenation catalyst in olefin deoxygenation.

[0032] A fourth aspect of the present invention provides a method for deoxygenating olefins, the method comprising: contacting a feed gas containing propylene and oxygen with the iron-based deoxygenation catalyst described above to carry out a deoxygenation reaction.

[0033] Preferably, the oxygen content in the raw gas is not higher than 4.5% by volume.

[0034] Preferably, the reaction conditions include a reaction space velocity of 1000-7000 h⁻¹. -1 The temperature ranges from 60 to 350℃, and the pressure ranges from 0.1 to 1 MPa.

[0035] This invention provides a deoxygenation catalyst with non-precious metal iron oxide as the main active component. Compared with other deoxygenation technologies, it achieves this by efficiently regulating the reduction process and controlling the type of active phase iron oxide compounds on the catalyst surface, thus promoting oxygen adsorption and activation. The higher oxygen adsorption and activation capacity enhances the deoxygenation efficiency of the catalyst. This catalyst has a large processing capacity and is advantageous for continuous long-term operation. Detailed Implementation

[0036] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0037] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0038] In this invention, unless otherwise specified, "air velocity" refers to "volume air velocity" and "pressure" refers to "absolute pressure".

[0039] The first aspect of the present invention provides an iron-based deoxidation catalyst, the iron-based deoxidation catalyst comprising a support, an iron oxide active phase supported on the surface of the support, and an auxiliary agent;

[0040] The iron oxide compound is at least two of FeO, Fe2O3 and Fe3O4;

[0041] The auxiliary agent is one or more of the oxides of Ce, Mg, Na and Zr.

[0042] In a preferred embodiment, when the ferrite compound is FeO and Fe2O3, the molar ratio of the two is 1:1-2, more preferably 1:1.2-1.5. Specifically, it can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2.

[0043] In one specific embodiment, the ferrite compound is FeO and Fe2O3, with a molar ratio of 13:17.

[0044] In a preferred embodiment, when the ferrite compound is FeO and Fe3O4, the molar ratio of the two is 1:1-2, more preferably 1:1.2-1.5. Specifically, it can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2.

[0045] In one specific embodiment, the ferrite compound is FeO and Fe3O4, with a molar ratio of 17:23.

[0046] In a preferred embodiment, when the ferrite compound is Fe2O3 and Fe3O4, the molar ratio of the two is 1.5-2.5:1, more preferably 1.8-2:1. Specifically, it can be 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, or 2.5:1.

[0047] In one specific embodiment, the ferrite compound is Fe2O3 and Fe3O4, with a molar ratio of 32:17.

[0048] In a preferred embodiment, when the ferrite compound is FeO, Fe2O3, and Fe3O4, the molar ratio of the three is 1:2-3:2-3; more preferably, it is 1:2.2-2.5:2.7-2.9. Specifically, when the ferrite compound is FeO, Fe2O3, and Fe3O4, the molar ratio of FeO to Fe2O3 can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, or 1:3; the molar ratio of FeO to Fe3O4 can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, or 1:3.

[0049] In one specific embodiment, when the iron oxide compound is FeO, Fe2O3 and Fe3O4, the molar ratio of the three is 8:18:23.

[0050] The non-precious metal iron-based deoxidation catalyst provided in this invention significantly reduces operating costs compared to other precious metal catalytic deoxidation technologies. The synergistic effect of the additives and active components effectively increases the oxygen vacancy content of the iron-based catalyst, promoting oxygen adsorption and activation.

[0051] A second aspect of the present invention provides a method for preparing the iron-based deoxidation catalyst described above, the method comprising the following steps;

[0052] (1) Mix iron salt, auxiliary agent precursor and solvent to obtain impregnation solution;

[0053] (2) The impregnation solution is impregnated onto the carrier, and then dried and calcined to obtain the calcined product;

[0054] (3) The calcined product is reduced to obtain an iron-based deoxidation catalyst;

[0055] The auxiliary precursor is selected from at least one of cerium salt, magnesium salt, zirconium salt and sodium salt;

[0056] The reduction conditions include: a reducing atmosphere of H2, CO, a mixture of CO and H2 or a mixture of H2 and N2, a temperature of 100-400℃, a time of 1-20h, a pressure of 0.1-1.5MPa, and a heating rate of 1-30℃ / min.

[0057] In this invention, the support can be any of the various supports commonly used in the art. In a preferred embodiment, the support is selected from SiO2, Al2O3, or molecular sieves.

[0058] More preferably, the carrier needs to be pretreated before use, then washed with deionized water to remove impurities, and then dried for later use.

[0059] In a preferred embodiment, the solvent in step (1) is selected from one or more of water, ethanol, ethylene glycol, methanol, glycerol and 1-2-ethylene glycol.

[0060] In a preferred embodiment, in step (2), the impregnation method is equal volume impregnation, excessive impregnation, distributed impregnation, or vacuum impregnation. More preferably, it is equal volume impregnation or distributed impregnation.

[0061] In a preferred embodiment, the iron salt is selected from one or more of ferric nitrate, ferric chloride, and ferric ammonium citrate.

[0062] In a preferred embodiment, the cerium salt is selected from cerium nitrate.

[0063] In a preferred embodiment, the magnesium salt is selected from magnesium nitrate.

[0064] In a preferred embodiment, the zirconium salt is selected from zirconium nitrate.

[0065] In a preferred embodiment, the sodium salt is selected from sodium nitrate and / or sodium carbonate.

[0066] In a preferred embodiment, the weight ratio of iron salt to carrier is 1-20:100. Specifically, it can be 1:100, 2:100, 5:100, 7:100, 10:100, 15:100 or 20:100.

[0067] Preferably, the weight ratio of the auxiliary precursor to the carrier is 0.1-5:100. Specifically, it can be 0.1:100, 0.5:100, 1:100, 1.5:100, 2:100, 2.5:100, 3:100, 3.5:100, 4:100, 4.5:100 or 5:100.

[0068] Preferably, in step (2), the drying conditions include: a temperature of 100-200℃ and a drying atmosphere of air. Specifically, the drying temperature can be 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, or 200℃.

[0069] In a preferred embodiment, in step (2), the drying time is 5-20 hours, preferably 10-15 hours.

[0070] Preferably, in step (2), the calcination conditions include: a temperature of 300-600℃ and a calcination atmosphere of air. Specifically, the calcination temperature can be 300℃, 350℃, 400℃, 450℃, 500℃, or 600℃.

[0071] In a preferred embodiment, the roasting time in step (2) can be 2-8 hours. Specifically, it can be 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0072] In the method described in this invention, by controlling the reduction temperature, heating rate, reduction time, reduction pressure and other conditions during the reduction process, the composition of iron oxides in the iron-based deoxidation catalyst can be effectively adjusted, thereby efficiently constructing the effective content of the active phase on the surface of the iron-based deoxidation catalyst, promoting the adsorption and activation of O2 on the catalyst surface, and improving the deoxidation efficiency of the iron-based deoxidation catalyst.

[0073] In a preferred embodiment, the reduction conditions include: a reducing atmosphere of H2, CO, a mixture of CO and H2, or a mixture of H2 and N2; a temperature of 200-300℃; a time of 5-10 hours; a pressure of 0.1-0.25 MPa; and a heating rate of 2-15℃ / min. Specifically, the reduction temperature can be 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, or 300℃; the reduction time can be 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours; the heating rate can be 2℃ / min, 5℃ / min, 8℃ / min, 10℃ / min, or 13℃ / min; and the pressure can be 0.1 MPa, atmospheric pressure, 0.2 MPa, or 0.25 MPa.

[0074] More preferably, in the mixture of CO and H2, the volume ratio of CO to H2 is 2:1;

[0075] More preferably, in the H2 and N2 mixture, the H2 content is 5-15% by volume.

[0076] A third aspect of the present invention provides the application of the above-mentioned iron-based deoxygenation catalyst in olefin deoxygenation.

[0077] A fourth aspect of the present invention provides a method for deoxygenating olefins, the method comprising: contacting a feed gas containing propylene and oxygen with the iron-based deoxygenation catalyst described above to carry out a deoxygenation reaction.

[0078] In a preferred embodiment, the oxygen content in the raw gas is no higher than 4.5% by volume.

[0079] In a preferred embodiment, the reaction conditions include a reaction space velocity of 1000-7000 h⁻¹. -1 The temperature is 60-350℃, and the pressure is 0.1-1 MPa. More preferably, the reaction space velocity is 2500-5000 h⁻¹. -1 The temperature ranges from 120 to 260℃, and the pressure ranges from 0.1 to 0.5 MPa.

[0080] In a preferred embodiment, the olefin deoxygenation method of the present invention is carried out in a fixed-bed reactor.

[0081] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0082] Unless otherwise specified, all reagents used in the following examples are commercially available products.

[0083] Example 1

[0084] (1) Dissolve FeCl3 and Ce(NO3)3 in water to obtain an impregnation solution;

[0085] (2) The impregnation solution was impregnated onto the Al2O3 support by excessive impregnation, and then dried (100℃, 12h, air atmosphere) and calcined (500℃, 4h, air atmosphere) to obtain the calcined product.

[0086] The weight ratio of FeCl3, Ce(NO3)3 and the support is 3:2:100.

[0087] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 200℃, time 6 hours, heating rate 5℃ / min, pressure atmospheric pressure, and reduction under pure H2 atmosphere. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be FeO and Fe2O3, and the molar ratio of the two was 13:17, by XPS and Mössbauer spectroscopy quantitative analysis.

[0088] (4) A gaseous gas containing propylene and oxygen (96% vol% propylene and 4% vol% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 2000 h⁻¹. -1The reaction pressure was 0.3 MPa and the reaction temperature was 235 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.1%.

[0089] Example 2

[0090] (1) Dissolve FeCl3 and Ce(NO3)3 in water to obtain an impregnation solution;

[0091] (2) The impregnation solution was impregnated onto the carrier SiO2 by a stepwise impregnation method, and then dried (100℃, 12h, air atmosphere) and calcined (500℃, 4h, air atmosphere) to obtain the calcined product.

[0092] The weight ratio of FeCl3, Ce(NO3)3 and the support is 3:2:100.

[0093] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 300℃, time 8 hours, heating rate 2℃ / min, pressure atmospheric pressure, and reduction under pure H2 atmosphere. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be FeO and Fe3O, and the molar ratio of the two was 17:23.

[0094] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1 The reaction pressure was 0.3 MPa and the reaction temperature was 265 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.2%.

[0095] Example 3

[0096] (1) Dissolve Fe(NO3)3 and Mg(NO3)2 in ethanol to obtain an impregnation solution;

[0097] (2) The impregnation solution was impregnated onto the carrier SiO2 by a stepwise impregnation method, and then dried (120℃, 12h, air atmosphere) and calcined (450℃, 4h, air atmosphere) to obtain the calcined product.

[0098] The weight ratio of Fe(NO3)3, Mg(NO3)2 and the support is 3:1:100.

[0099] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 350℃, time 10 hours, heating rate 6℃ / min, pressure atmospheric pressure, and reduction under pure H2 atmosphere. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be Fe2O3 and Fe3O4, and the molar ratio of the two was 32:17.

[0100] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1 The reaction pressure was 0.5 MPa and the reaction temperature was 255 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.25%.

[0101] Example 4

[0102] (1) Dissolve Fe(NO3)3 and Mg(NO3)2 in ethanol to obtain an impregnation solution;

[0103] (2) The impregnation solution was impregnated onto the carrier SiO2 by excessive impregnation, and then dried (120℃, 12h, air atmosphere) and calcined (500℃, 4h, air atmosphere) to obtain the calcined product.

[0104] The weight ratio of Fe(NO3)3, Mg(NO3)2 and the support is 3:1.5:100.

[0105] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 350℃, time 10 hours, heating rate 6℃ / min, pressure atmospheric pressure, and reduction under CO atmosphere. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be FeO and Fe2O3, and the molar ratio of the two was 14:19, by XPS and Mössbauer spectroscopy quantitative analysis.

[0106] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1 The reaction pressure was 0.2 MPa and the reaction temperature was 265 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.05%.

[0107] Example 5

[0108] (1) Dissolve ferric ammonium citrate and NaNO3 in ethylene glycol to obtain an impregnation solution;

[0109] (2) The impregnation solution was impregnated onto the Al2O3 support by excessive impregnation, and then dried (150℃, 12h, air atmosphere) and calcined (400℃, 4h, air atmosphere) to obtain the calcined product.

[0110] The weight ratio of ferric ammonium citrate, NaNO3, and the carrier is 3:1:100.

[0111] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 300℃, time 8 hours, heating rate 2℃ / min, pressure atmospheric pressure, and reduction under an atmosphere of H2 / CO = 1:2. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be FeO, Fe2O3 and Fe3O4, and the molar ratio of the three was 8:18:23.

[0112] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 2000 h⁻¹. -1 The reaction pressure was 0.4 MPa and the reaction temperature was 265 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.002%.

[0113] Example 6

[0114] (1) Dissolve ferric ammonium citrate and Na2CO3 in water to obtain an impregnation solution;

[0115] (2) The impregnation liquid was impregnated onto the carrier molecular sieve by an equal volume impregnation method, and then dried (120℃, 12h, air atmosphere) and calcined (400℃, 4h, air atmosphere) to obtain the calcined product.

[0116] The weight ratio of ferric ammonium citrate, Na2CO3, and the carrier is 2:1:100.

[0117] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 200℃, time 6 hours, heating rate 2℃ / min, pressure atmospheric pressure, and reduction under CO atmosphere. The composition of the iron oxides in the iron-based deoxidation catalyst was found to be FeO, Fe2O3 and Fe3O4, and the molar ratio of the three was 7:17:20.

[0118] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1The reaction pressure was 0.34 MPa and the reaction temperature was 255 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 0.2%.

[0119] Comparative Example 1

[0120] (1) Dissolve ferric nitrate in water to obtain an impregnation solution;

[0121] (2) The impregnation solution was impregnated onto the carrier molecular sieve by excessive impregnation, and then dried (120℃, 12h, air atmosphere) and calcined (400℃, 4h, air atmosphere) to obtain the calcined product.

[0122] The weight ratio of ferric nitrate to carrier is 3:100.

[0123] (3) The calcined product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 250℃, time 8 hours, heating rate 6℃ / min, pressure atmospheric pressure, and reduction under pure H2 atmosphere. The composition of the iron oxide compound of the iron-based deoxidation catalyst was found to be Fe2O3 by XPS and Mössbauer spectroscopy quantitative analysis.

[0124] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1 The reaction pressure was 0.3 MPa and the reaction temperature was 225 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 1.0%.

[0125] Comparative Example 2

[0126] (1) Dissolve ferric chloride in water to obtain an impregnation solution;

[0127] (2) The impregnation solution was impregnated onto the carrier SiO2 by excessive impregnation, and then dried (120℃, 12h, air atmosphere) and calcined (400℃, 4h, air atmosphere) to obtain the calcined product.

[0128] The weight ratio of ferric chloride to carrier is 3:100.

[0129] (3) The roasted product was loaded into a fixed bed reactor for reduction. The reduction conditions were: temperature 200℃, time 8 hours, heating rate 2℃ / min, pressure atmospheric pressure, and reduction under pure H2 atmosphere. The composition of the iron oxide compound of the iron-based deoxidation catalyst was found to be Fe3O4 by XPS and Mössbauer spectroscopy quantitative analysis.

[0130] (4) A gaseous gas containing propylene and oxygen (96% propylene and 4% oxygen) is introduced into a fixed-bed reactor for gas-phase deoxygenation reaction; the reaction space velocity is 3000 h⁻¹. -1 The reaction pressure was 0.3 MPa and the reaction temperature was 205 °C. The oxygen content was monitored in real time using gas chromatography online detection, and the oxygen content was 1.25%.

[0131] Test case

[0132] The deoxygenation rates in the examples and comparative examples were calculated, and the results are shown in Table 1. The calculation method is as follows:

[0133]

[0134] Table 1

[0135] Example 1 4 0.1 97.5 Example 2 4 0.2 95 Example 3 4 0.25 93.75 Example 4 4 0.05 98.75 Example 5 4 0.002 99.95 Example 6 4 0.3 92.5 Comparative Example 1 4 1.0 75.0 Comparative Example 2 4 1.25 68.75

[0136] As shown in Table 1, the olefin deoxygenation method described in this invention can effectively remove oxygen contained in olefins.

[0137] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An iron-based deoxygenation catalyst for olefin deoxygenation, characterized in that, The iron-based deoxidation catalyst includes a support, an active phase of iron oxides supported on the surface of the support, and an auxiliary agent. The iron oxide compound is at least two of FeO, Fe2O3 and Fe3O4; The auxiliary agent is one or more of the oxides of Ce, Mg, Na and Zr; When the iron oxide compound is FeO and Fe2O3, the molar ratio of the two is 1:1-2; When the iron oxide compound is FeO and Fe3O4, the molar ratio of the two is 1:1-2; When the iron oxide compound is Fe2O3 and Fe3O4, the molar ratio of the two is 1.5-2.5:1; When the iron oxide compound is FeO, Fe2O3 and Fe3O4, the molar ratio of the three is 1:2-3:2-3; The preparation method of the iron-based deoxidation catalyst includes the following steps; (1) Mix iron salt, auxiliary precursor and solvent to obtain impregnation solution; (2) The impregnation solution is impregnated onto the carrier, and then dried and calcined to obtain the calcined product; (3) The calcined product is reduced to obtain an iron-based deoxidation catalyst; The precursor of the auxiliary agent is selected from at least one of cerium salt, magnesium salt, zirconium salt and sodium salt; The calcination conditions include: a temperature of 300-600℃ and a calcination atmosphere of air; The reduction conditions include: the reducing atmosphere is a mixture of H2, CO, CO and H2 or a mixture of H2 and N2, the temperature is 100-400℃, the time is 1-20h, the pressure is 0.1-1.5MPa, and the heating rate is 1-30℃ / min. The weight ratio of the auxiliary precursor to the carrier is 0.1-5:100, and the weight ratio of the iron salt to the carrier is 1-20:

100.

2. The iron-based deoxidation catalyst according to claim 1, characterized in that, When the iron oxide compound is FeO and Fe2O3, the molar ratio of the two is 1:1.2-1.

5.

3. The iron-based deoxidation catalyst according to claim 1, characterized in that, When the iron oxide compound is FeO and Fe3O4, the molar ratio of the two is 1:1.2-1.

5.

4. The iron-based deoxidation catalyst according to claim 1, characterized in that, When the iron oxide compounds are Fe2O3 and Fe3O4, their molar ratio is 1.8-2:

1.

5. The iron-based deoxidation catalyst according to claim 1, characterized in that, When the iron oxide compound is FeO, Fe2O3 and Fe3O4, the molar ratio of the three is 1:2.2-2.5:2.7-2.

9.

6. The iron-based deoxidation catalyst according to claim 1, characterized in that, The iron salt is selected from one or more of ferric nitrate, ferric chloride, and ferric ammonium citrate.

7. The iron-based deoxidation catalyst according to claim 1, characterized in that, The cerium salt is selected from cerium nitrate.

8. The iron-based deoxidation catalyst according to claim 7, characterized in that, The magnesium salt is selected from magnesium nitrate.

9. The iron-based deoxidation catalyst according to claim 7, characterized in that, The zirconium salt is selected from zirconium nitrate.

10. The iron-based deoxidation catalyst according to claim 7, characterized in that, The sodium salt is selected from sodium nitrate and / or sodium carbonate.

11. The iron-based deoxidation catalyst according to claim 1, characterized in that, The support is selected from SiO2, Al2O3 or molecular sieve.

12. The iron-based deoxidation catalyst according to claim 1, characterized in that, In step (2), the drying conditions include: a temperature of 100-200℃ and a drying atmosphere of air.

13. The iron-based deoxidation catalyst according to claim 1, characterized in that, In the mixture of CO and H2, the volume ratio of CO to H2 is 2:

1.

14. The iron-based deoxidation catalyst according to claim 13, characterized in that, In the mixture of H2 and N2, the H2 content is 5-15% by volume.

15. A method for deoxygenating olefins, characterized in that, The method includes: contacting a feed gas containing propylene and oxygen with the iron-based deoxygenation catalyst for olefin deoxygenation as described in claim 1 to carry out a deoxygenation reaction.

16. The method according to claim 15, characterized in that, The oxygen content in the raw gas is no higher than 4.5% by volume.

17. The method according to claim 15 or 16, characterized in that, The reaction conditions include a reaction space velocity of 1000-7000 h⁻¹. -1 The temperature ranges from 60 to 350℃, and the pressure ranges from 0.1 to 1 MPa.

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