Catalyst for regulating and controlling catalytic pyrolysis product of oil-rich coal as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst for regulating and controlling catalytic pyrolysis products of oil-rich coal and a preparation method and application thereof.The catalyst comprises a 5A molecular sieve, an auxiliary and active metal, the auxiliary and the active metal are loaded on the 5A molecular sieve, the auxiliary is Mg, and the active metal is one or two of Fe and Mo; in terms of oxide, the content of Mg in the catalyst is 0.75 wt%-1.0 wt%, and the content of the active metal is 5 wt%-15 wt%. The catalyst provided by the invention can regulate and control gas product distribution of catalytic pyrolysis of oil-rich coal and increase the content of tar products.

Description

Technical Field

[0001] The present invention belongs to the technical field of heterogeneous thermal catalysis, and specifically relates to a catalyst for regulating catalytic pyrolysis products of oil-rich coal by modification with trace amounts of Mg, and a preparation method and application thereof. Background Art

[0002] Coal resources still dominate energy sources at the current stage and in the medium and long term, especially in the oil and gas and chemical industries, where the importance of coal resources is particularly prominent. As an important raw material for the production of oil, gas and high-value-added chemicals, oil-rich coal has obvious advantages over other types of coal resources in improving oil and gas conversion efficiency and reducing production economic costs. Its unique properties make it the focus of attention in the process of coal resource utilization and conversion. After pyrolysis, oil-rich coal can generate a large amount of organic matter, which can be further converted into low-carbon, high-value-added chemical products, which can not only significantly improve the utilization rate of coal resources, but also effectively achieve the "carbon reduction" goal, in line with the strategic needs of green development.

[0003] At present, the coal coking process commonly used in industry is the main technical path to achieve coal oil extraction. It heats coal under air-tight conditions to cause a series of complex physical and chemical reactions to produce a variety of products such as coke, semi-coke and asphalt. These products are not only an important source of fuel production, but are also widely used in the production of waterproof and anti-corrosion materials, playing a vital role in civil and industrial production. Therefore, the design and development of high-performance pyrolysis catalysts that can maximize the precise utilization of oil-rich coal resources has become the key to technological breakthroughs. Efficient pyrolysis catalysts can not only improve the efficiency of oil and gas conversion, but also optimize the entire coal chemical industry chain, reduce energy consumption and costs in the production process, and thus ensure the efficient and clean use of coal resources. In summary, the efficient utilization of oil-rich coal resources is the key to ensuring energy security. By developing advanced catalysts, we can promote the green transformation of coal energy structure while achieving efficient resource utilization.

[0004] The Chinese patent application with publication number CN 102580726 A provides a coal pyrolysis catalyst and a preparation method thereof that can improve the yield of tar produced by coal pyrolysis. The active components of the catalyst are a mixture of one or more of the precious metals Pt, Pd, Ru, Rh and Ni, and the carrier is a mixture of one or two of Al2O3, SiO2 and TiO2. During the coal pyrolysis process, the mixed gas (including the mixed gas produced by coal pyrolysis or the natural gas introduced from the outside) first passes through the catalyst bed, and after catalytic treatment, it is circulated back to the coal pyrolysis reactor by the fan to improve the yield of tar. The catalyst can further improve the yield of tar through hydrogenation reaction under the same conditions, while having a long service life and good regeneration performance.

[0005] The Chinese patent application with publication number CN 112808276 A provides a method for preparing a catalyst for pyrolysis of low-rank coal. The method uses γ-Al2O3 as a carrier, and the prepared catalyst shows a significant improvement effect in the pyrolysis and catalytic cracking of bituminous coal, and can effectively increase the yield of tar and fuel gas. The prepared catalyst has high activity and excellent catalytic performance. Using γ-Al2O3 as a carrier not only improves the mechanical strength and physical properties of the catalyst, but also can be fully mixed with coal during the catalytic cracking process, thereby significantly improving the oil yield and gas yield, and increasing the content of hydrogen and methane in the gas product.

[0006] The Chinese patent application with publication number CN 112295565 A provides a method for synthesizing a multi-metal doped perovskite catalyst by a sol-gel method and applying it to the cracking catalysis of coal pyrolysis tar. After the precursor materials are mixed, pre-calcined and calcined, one or more of the metals La, Ni, and Fe are doped at the A and B positions of the structure, and then Ni is added on the basis to further improve the catalytic activity, and the catalyst synthesis path is improved by pre-calcining at a lower temperature to reduce the phenomenon of catalyst expansion and ejection. The prepared catalyst can greatly increase the yield of gases such as H2, CO, and CO2 in the reaction of catalytic pyrolysis of coal tar, while reducing the output of tar; in addition, the carbon deposition phenomenon of the catalyst is significantly improved compared with the commonly used commercial catalysts.

[0007] The Chinese patent application with publication number CN 105126805 A provides a catalyst for coal pyrolysis and its application, wherein the catalyst includes bentonite and water glass. The catalyst does not need to undergo preparation processes such as impregnation and roasting, and only requires a simple mixing of bentonite and water glass. The prepared catalyst not only has good selectivity for rich combustion gases such as H2, CO, CH4 and other hydrocarbons, but also can significantly increase the content of H2, CO, CH4 and other hydrocarbons in the pyrolysis gas produced by coal pyrolysis, thereby greatly increasing the calorific value of the pyrolysis gas; in addition, it can also effectively reduce the generation of CO2.

[0008] The Chinese patent application with publication number CN 119114069 A provides a high temperature resistant coal catalytic gasification alkali metal catalyst and its preparation method, the method comprising the following steps: pyrolysis treatment of coal base to obtain semi-coke, immersion of the semi-coke in an organic metal salt of alkali metal to form a catalyst precursor, adding a modifier to the catalyst precursor for modification treatment, and using ion exchange to compound active components of the modified catalyst precursor to obtain a composite catalyst. The catalyst prepared by the invention has a conversion rate of 89.1% and a cumulative methane production of 12.9 mmol·g after 300 min of reaction. -1The methane content of the product reaches 26.4%, showing excellent methane production performance.

[0009] Although the coal pyrolysis catalysts in the above-mentioned prior art can effectively improve coal conversion and pyrolysis gas products, they have certain limitations in the pyrolysis process of oil-rich coal. From the perspective of the catalyst itself, (1) the surface area of ​​perovskite-type catalysts is small and the active sites are not exposed enough. In long-term use, they will be affected by carbon deposition and high temperature conditions, which will seriously reduce the catalytic conversion efficiency; (2) Although the performance of precious metal catalysts is outstanding, the overall production cost is high, which affects large-scale industrial promotion; (3) Although carrier materials such as Al2O3, SiO2, and TiO2 have good mechanical strength and thermal stability, due to the poor performance of anchoring small-sized active metals, the loaded active metals will sinter or agglomerate on a large scale under high temperature conditions, which seriously affects the overall activity of the catalyst. From the perspective of oil and gas product distribution, most coal pyrolysis catalysts focus on improving the content of gas products and rarely consider the yield of tar, and the increase in tar yield is limited. Therefore, the directional regulation of the distribution of pyrolysis products is hindered, which seriously hinders the efficient utilization of oil-rich coal resources. Summary of the invention

[0010] In order to solve the above problems of the prior art, the present invention provides a catalyst for regulating the catalytic pyrolysis products of oil-rich coal and a preparation method and application thereof, which can regulate the distribution of gas products and increase the yield of tar.

[0011] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a catalyst for regulating the catalytic pyrolysis products of oil-rich coal, the catalyst comprising a 5A molecular sieve and an additive and an active metal loaded on the 5A molecular sieve, the additive being Mg, and the active metal being one or two of Fe and Mo; calculated as oxide, the Mg content in the catalyst is 0.75 wt%~1.0 wt%, and the active metal content is 5 wt%~15 wt%.

[0012] In a second aspect, the present invention provides a method for preparing the catalyst for regulating the catalytic pyrolysis product of oil-rich coal, comprising the following steps: Step 1: dissolving a magnesium-containing compound in water, dripping the obtained impregnation solution onto a 5A molecular sieve, and drying to obtain a carrier modified with a Mg additive; Step 2: dissolving a molybdenum-containing compound and / or an iron-containing compound in water, dripping the obtained impregnation solution onto the carrier modified with the Mg additive, and then sequentially performing drying and calcining treatments to obtain a catalyst for regulating the catalytic pyrolysis products of oil-rich coal.

[0013] Preferably, in step 1, the magnesium-containing compound is magnesium nitrate.

[0014] Preferably, in step 1, drying is performed at room temperature for 10 to 14 hours.

[0015] Preferably, in step 2, the molybdenum-containing compound is at least one of molybdenum oxide, molybdate and paramolybdate.

[0016] Furthermore, the molybdate is ammonium molybdate.

[0017] Preferably, in step 2, the iron-containing compound is at least one of iron oxide, iron nitrate and iron phosphate.

[0018] Preferably, in step 2, the drying temperature is 60-120° C., and the drying time is 1-12 h.

[0019] Preferably, in step 2, the calcination temperature is 300-900° C., and the calcination time is 4-8 h.

[0020] In a third aspect, the present invention provides the use of the catalyst for regulating the catalytic pyrolysis products of oil-rich coal in the catalytic pyrolysis of oil-rich coal.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The present invention implants a trace amount of Mg additive with a large ionic radius and weak electronegativity into a 5A molecular sieve framework with a porous structure and low price, which has high selective adsorption and fast adsorption speed, and loads Fe and / or Mo active metals, thereby obtaining a loaded non-precious metal oil-rich coal pyrolysis catalyst that can directionally regulate the distribution of oil-rich coal products. The 5A molecular sieve has a self-solidified and uniform microporous structure to promote the cracking and cyclization of aliphatic hydrocarbons in the pyrolysis volatiles and the dissociation of small molecular gases. In addition, the introduction of a trace amount of Mg additive into the framework can regulate the physical and chemical properties of the molecular sieve surface, such as the metal coordination environment, so as to regulate the interaction between the loaded active metal and the carrier, thereby improving the active metal anchoring performance. The geometry and electronic structure of the constructed Fe and Mo active metal clusters are endowed with the function of "recognizing" different oil-rich coal molecular fragments rich in functional groups due to the influence of the physical and chemical properties of the carrier surface. Its essence is to optimize the distribution of gas products by appropriately adjusting the metal ratio (such as Fe, Mo, Mg, etc.) in the catalyst, and further realize the regulation of the distribution of different gas products by adjusting the proportion of active metals, increase the proportion of hydrogen, increase the yield of tar, and may also help to increase the proportion of light hydrocarbons such as methane, ethylene, and propylene in the gas products. At the same time, the proportion of active metals can also inhibit some reaction processes that are not conducive to the target gas products, thereby reducing the generation of some recombinant gases (such as CO, CO2) and other heavy gases; therefore, by adjusting the proportion of active metals, the yield of tar can be increased while increasing the gas production rate, optimizing the cracking and aromatization reactions of coal, and thus achieving a balanced distribution of coal tar and gas products. In addition, the introduction of trace Mg additives can overcome the defects of 5A self-solidification thermal stability and poor acid and alkali resistance and improve the catalyst's anti-coking performance, thereby obtaining oil-rich coal pyrolysis products with better yield and quality.

[0022] The catalyst of the present invention has a significant effect on the pyrolysis effect of oil-rich coal and the regulation of its product distribution. On the basis of greatly improving the pyrolysis yield of oil-rich coal, it achieves the purpose of directional regulation of the distribution of pyrolysis products and increasing oil and improving quality. This research provides an effective technical solution and practical reference for the efficient utilization of oil-rich coal and the development of clean energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a conceptual diagram of the design of the non-precious metal Fe and Mo series oil-rich coal pyrolysis catalysts of the present invention.

[0025] Figure 2The XRD spectra (a) and H2-TPR (b) spectra of the catalyst of Example 1 and the catalysts of Comparative Examples 8 and 9 of the present invention are shown. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0028] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0029] The catalyst for regulating the catalytic pyrolysis product of oil-rich coal of the present invention uses metal Fe or Mo or FeMo dual system as active metal, Mg as auxiliary agent, and 5A molecular sieve as carrier. Calculated as oxide, the content of Mg in the catalyst is 0.75 wt%~1.0 wt%, and the content of active metal is 5 wt%~15 wt%.

[0030] The catalyst of the present invention, after introducing a trace amount of metal additive Mg into the 5A molecular sieve framework, will greatly weaken the electron density around the oxygen atoms in the 5A molecular sieve framework because its electronegativity (1.31) is smaller than that of Al (1.61) and Si (1.90) in the 5A molecular sieve framework, so as to achieve the purpose of hydroxyl density regulation and pH regulation, and at the same time, change the interaction between the active metal and the carrier, and build a small-sized electron-rich active area. In addition, the Mg ion radius (about 0.72Å) is larger than that of Si. 4+ (about 0.40 Å) and Al 3+(about 0.54 Å), after introduction, it will produce an expansion effect on the framework (replacing Si or Al) structure of the 5A molecular sieve, causing the size and shape of the 5A molecular sieve pores to undergo local geometric deformation, thereby affecting the adsorption characteristics of the catalyst and the diffusion behavior of the reactant molecules, thereby improving the selective adsorption and mass transfer efficiency of the reactant molecules, especially for some reactions that are sensitive to pore size. In addition, larger Mg ions can also stabilize the 5A molecular sieve framework to enhance the thermal stability and anti-sintering performance of the active metals loaded on its surface, and prevent the collapse of the 5A molecular sieve framework and the deactivation of the constructed high-activity areas under harsh reaction conditions, which is particularly important for the in-situ pyrolysis process of oil-rich coal underground.

[0031] The catalyst for regulating the catalytic pyrolysis product of oil-rich coal in the present invention can be prepared by an impregnation method, and the specific preparation method comprises the following steps: Step 1: dissolving a magnesium-containing compound in water, dripping the obtained impregnation solution onto a 5A molecular sieve, and drying to obtain a carrier modified with a Mg additive; Step 2: dissolving a molybdenum-containing compound and / or an iron-containing compound in water, dripping the obtained impregnation solution onto the carrier modified with the Mg additive, and then sequentially performing drying and calcining treatments to obtain a catalyst for regulating the catalytic pyrolysis products of oil-rich coal.

[0032] Wherein, in step 1, the magnesium-containing compound is preferably magnesium nitrate, and the drying is specifically performed by placing it at room temperature for 10 to 14 hours.

[0033] In step 2 of the preparation method of the present invention, the molybdenum-containing compound is at least one of molybdenum oxide (MoO2), molybdate and paramolybdate, wherein the molybdate is preferably ammonium molybdate ((NH4)2MoO4); the iron-containing compound is at least one of iron oxide (Fe2O3), iron nitrate (FeN3O9·9H2O) and iron phosphate (FePO4).

[0034] In step 2 of the preparation method of the present invention, the drying temperature is 60-120° C., the drying time is 1-12 h, the roasting temperature is 300-900° C., and the roasting time is 4-8 h.

[0035] The catalyst of the present invention can be used to catalyze the pyrolysis of oil-rich coal, and has a significant effect on regulating the pyrolysis effect of the oil-rich coal and the distribution of its products. On the basis of greatly improving the pyrolysis yield of the oil-rich coal, the purpose of directional regulation of the distribution of pyrolysis products and increasing oil and improving quality is achieved.

[0036] The oil-rich coal selected in the embodiment of the present invention comes from a coal mine in Huangling County, Yan'an City, Shaanxi Province (hereinafter referred to as Huangling oil-rich coal).

[0037] Example 1 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0038] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 4.29 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 5 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 1, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo / Mg-5A coal pyrolysis catalyst.

[0039] Example 2 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0040] Step 2: Based on the catalyst, 0.51 g of Fe(NO3)3·9H2O (Fe content is 2 wt%) and 6.87 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 8 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 2, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo / Mg-5A coal pyrolysis catalyst.

[0041] Example 3 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0042] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 8.59 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 10 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 3, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo / Mg-5A coal pyrolysis catalyst.

[0043] Example 4 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0044] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 10 wt%) and 8.59 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 5 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 4, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo / Mg-5A coal pyrolysis catalyst.

[0045] Example 5 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.75 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0046] Step 2: Based on the catalyst, 2.53 g of Fe(NO3)3·9H2O (Fe content is 10 wt%) is dissolved to obtain an Fe-based impregnation solution. The prepared impregnation solution is dripped dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 5, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it is placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and a Fe / Mg-5A coal pyrolysis catalyst is obtained.

[0047] Example 6 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.75 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0048] Step 2: Dissolve 8.59 g of MoO3 (Mo content is 10 wt%) to obtain a Mo-based impregnation solution. The prepared impregnation solution is added dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 6, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, place it in a muffle furnace, heat it to 500 °C at a rate of 1 °C / min and keep it warm for 5 h, and obtain a Mo / Mg-5A coal pyrolysis catalyst.

[0049] Example 7 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.75 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0050] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 8.59 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 10 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 7, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and FeMo / Mg-5A coal pyrolysis catalyst was obtained.

[0051] Example 8 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0052] Step 2: Based on the catalyst, 2.53 g of Fe(NO3)3·9H2O (Fe content is 10 wt%) is dissolved to obtain an Fe-based impregnation solution. The prepared impregnation solution is dripped dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 8, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it is placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and a Fe / Mg-5A coal pyrolysis catalyst is obtained.

[0053] Example 9 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drip 1 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0054] Step 2: Based on the catalyst, 8.59 g of MoO3 (Mo content is 10 wt%) is dissolved to obtain a Mo-based impregnation solution. The prepared impregnation solution is dripped dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 9, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it is placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and a Mo / Mg-5A coal pyrolysis catalyst is obtained.

[0055] Comparative Example 1 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.25 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0056] Step 2: Based on the catalyst, 2.53 g of Fe(NO3)3·9H2O (Fe content is 10 wt%) is dissolved to obtain an Fe-based impregnation solution. The prepared impregnation solution is dripped dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 2, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it is placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and a Fe / Mg-5A coal pyrolysis catalyst is obtained.

[0057] Comparative Example 2 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.25 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0058] Step 2: Dissolve 8.59 g of MoO3 (Mo content is 10 wt%) to obtain a Mo-based impregnation solution. The prepared impregnation solution is added dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 3, dried in the dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, place it in a muffle furnace, heat it to 500 °C at a rate of 1 °C / min and keep it warm for 5 h, and a Mo / Mg-5A coal pyrolysis catalyst can be obtained.

[0059] Comparative Example 3 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 0.25 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve; after standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0060] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 8.59 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 10 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Comparative Example 4, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace, heated to 500 °C at a rate of 1 °C / min and kept warm for 5 h, and FeMo / Mg-5A coal pyrolysis catalyst was obtained.

[0061] Comparative Example 4 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it warm for 6 hours. Then, drop 1.5 wt% Mg(NO3)2 impregnation solution evenly on the surface of the 5A molecular sieve. After standing at room temperature overnight, a catalyst modified with Mg additive can be obtained, which is recorded as Mg-5A.

[0062] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 4.29 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 5 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 10, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo / Mg-5A coal pyrolysis catalyst.

[0063] Comparative Example 5 Step 1: Place the untreated 5A molecular sieve in a muffle furnace, heat it to 500°C at a rate of 1°C / min and keep it for 6 hours.

[0064] Step 2: Based on the catalyst, 1.26 g of Fe(NO3)3·9H2O (Fe content is 5 wt%) and 4.29 g of (NH4)6Mo7O 24 ·4H2O (Mo content is 5 wt%) to dissolve to obtain FeMo dual system impregnation solution. The prepared impregnation solution was added dropwise onto the Mg-5A carrier material (9.00 g) described in Example 10, dried in dark for 12 h, dried at 60 °C for 4 h, and dried at 120 °C for 12 h. Finally, it was placed in a muffle furnace and heated to 500 °C at a rate of 1 °C / min for 5 h to obtain FeMo-5A coal pyrolysis catalyst.

[0065] The catalysts obtained in each embodiment and comparative example were used to carry out catalytic pyrolysis reaction on Huangling oil-rich coal. The specific process was as follows: the catalytic pyrolysis performance of the catalyst was evaluated using the above-mentioned device. The inner diameter of the fixed bed reaction tube was 15 mm, the length was 550 mm, the coal sample particle size was 0.18~0.25 mm, and the catalyst particle size was selected to be 0.048~0.075 mm. Before the experiment, the prepared catalyst was mixed with the Huangling oil-rich coal sample in a ratio of 1:5 and placed in the reaction tube. The sealing of the device was tested, and the circulating cooling pump was turned on and cooled to -20 °C. The experimental process used nitrogen as the carrier gas, the temperature was programmed, the heating rate was 10 °C / min, the pyrolysis final temperature was 650 °C, and the timing was 1 h after the temperature reached 650 °C. When the temperature of the reaction tube reaches 200 °C, gas collection begins. After the reaction is completed, gas collection stops and the carrier gas continues to flow to cool the reaction tube. The mass of semi-coke and condensate after the reaction is weighed. The moisture content in the tar condensate is determined and calculated according to GB / T2288-2008 standard. The composition of gas products during pyrolysis is analyzed using Agilent GC gas chromatography (mainly C3 and below gas products are selected for normalization).

[0066] Table 1 shows the proportion (%) of gaseous products of pyrolysis of Huangling oil-rich coal after the introduction of the catalyst. It can be clearly seen from the data in the table that the introduction of the catalyst has led to significant changes in the proportion of hydrogen, carbon dioxide, carbon monoxide, and methane gaseous products (main gases). Example 1 When the Mg additive is 1 wt% and the Fe-Mo dual system is 10 wt% (the content of each component is 5 wt%), the proportion of hydrogen reaches the maximum value in all embodiments and comparative examples; especially compared with comparative example 5, the hydrogen content is greatly increased from 17.15% to 34.64%. The above results show that after adding a trace amount of Mg additive to the 5A molecular sieve framework, the loaded catalyst composed of the loaded Fe-Mo dual component can significantly promote the dehydrogenation process of hydrogen-rich functional groups in the oil-rich coal fragment, while giving the catalyst excellent performance of selective polycondensation. By comparing Example 1, Example 2, Example 8 and Example 9, it can be seen that although the total amount of active metals is the same, when Fe-Mo dual-system active metals are used, the proportion of hydrogen in the gaseous product increases, and methane, CO and CO2 decrease, compared with the use of Fe or Mo active metals alone. By comparing Comparative Example 3, Example 3 and Example 7, it can be seen that when Fe-Mo dual-system active metals are used, the proportion of hydrogen in the gaseous product increases with the increase of Mg additive content. By comparing Comparative Example 2, Example 6 and Example 9, it can be seen that when only Mo-based active metals are used, the proportion of hydrogen in the gaseous product gradually increases with the increase of Mg content. By comparing Comparative Example 1, Example 5 and Example 8, it can be seen that when only Fe-based active metals are used, the proportion of CO in the gaseous product gradually increases with the increase of Mg content. When extremely low Mg content (Comparative Example 3) or medium-low Mg content (Example 7) is introduced, although the Fe-Mo dual system content is 15 wt%, its pyrolysis effect is not as good as Example 1, but compared with Comparative Example 5, it still shows relatively excellent hydrogen production and polycondensation performance. When an excessive amount of Mg additive is introduced (Comparative Example 4), although the Fe-Mo dual system content is 15 wt%, the pyrolysis effect is closer to the pyrolysis effect without Mg additive (Comparative Example 5), which is much smaller than the pyrolysis effect of medium-low Mg doping, indicating that excessive Mg additive will seriously hinder the regulation of the pyrolysis products of oil-rich coal by the constructed active metal clusters. The above results show that by adjusting the active metal system or the Mg additive doping content, the proportion of different gaseous products can be regulated, thereby enhancing the utilization of the catalyst, or selecting different catalyst systems according to the proportion of raw materials in the subsequent process.

[0067] Table 1 Proportion of gaseous products from pyrolysis of oil-rich coal (%)

[0068] Table 2 shows the proportion (%) of tar and semi-coke products generated by pyrolysis of Huangling oil-rich coal after the introduction of the catalyst. The results show that the introduction of the catalyst also caused a significant change in the proportion of tar. Example 1 When the Mg additive is 1 wt% and the Fe-Mo dual system is 10 wt% (the content of each component is 5 wt%), the proportion of tar reaches the highest value in all embodiments and comparative experiments. It shows that after the introduction of trace Mg additives, the catalyst loaded with the Fe-Mo dual system composition can significantly promote the pyrolysis process of oil-rich coal. Comparing Example 5 and Example 6 with Example 7, it can be seen that compared with the use of Fe or Mo active metals alone, when the Fe-Mo dual system active metal is used, the proportion of tar in the product is significantly increased. Comparing Comparative Example 1, Example 5, and Example 8, it can be seen that when only Fe-based active metals are used, the tar content in the product is significantly improved as the Mg content increases. Comparing Comparative Example 2, Example 6, and Example 9, it can be seen that when only Mo-based active metals are used, the tar content in the product gradually increases as the Mg content increases. Comparative Example 3, Example 7, and Example 3 show that when Fe-Mo dual-series active metals are used, as the content of Mg additive increases, the proportion of tar content in the product gradually increases. When extremely low Mg content (Comparative Example 3) or medium-low Mg content (Example 7) is introduced, although the Fe-Mo dual-series content is 15 wt%, its pyrolysis effect is not as good as that of Example 1, but the pyrolysis effect can still achieve the purpose of synchronously increasing tar. When an excessive amount of Mg additive is introduced (Comparative Example 4), its pyrolysis effect is much smaller than the pyrolysis effect of doping with medium-low Mg additives, indicating that the introduction of excessive Mg additives will greatly reduce the performance of pyrolysis of Huangling oil-rich coal. In summary, the above-mentioned catalyst can effectively improve the tar yield while achieving directional regulation of the distribution of pyrolysis products of oil-rich coal. This is because after introducing a trace amount of Mg additive with unique electronegativity and ionic radius into the 5A molecular sieve framework, the interaction between the active metals Fe, Mo and Fe-Mo bimetallic and the carrier is differentially regulated ( Figure 2 ), thereby giving the above-mentioned active metals different adsorption-pyrolysis characteristics, thereby effectively regulating the pyrolysis products of oil-rich coal and achieving the purpose of increasing oil and improving quality. The action mechanism diagram is shown in Figure 1 shown.

[0069] Table 2 Proportion of tar and semi-coke from pyrolysis of oil-rich coal (%)

[0070] Figure 2 The XRD spectra and H2-TPR spectra of the catalysts of Examples 1, 8 and 9 of the present invention are shown in FIG. Figure 2As can be seen in (a), characteristic diffraction peaks belonging to 5A molecular sieve are observed at about 7.9°, 8.7°, 22.8°, 23.5° and 24.4°, indicating that the loading of active metal species after modifying the carrier material with Mg does not destroy the inherent crystal structure of the catalyst. At the same time, the XRD characteristic diffraction peaks of Fe2O3 and MoO3 species have not been observed, indicating that the loaded active metal oxides are highly dispersed on the surface of the catalyst carrier in the form of small-sized clusters, which will greatly improve the thermal decomposition activity of the catalyst. Figure 2 As can be seen in (b), four types of hydrogen consumption peaks appear in the range of 200~1000°C: (1) The center of the hydrogen consumption peak at about 300°C belongs to the reduction peak of Fe2O3 species to Fe species, (2) The center of the hydrogen consumption peak at about 600°C belongs to the reduction peak of Fe3O4 species to Fe species (Fe3O4→FeO→Fe), (3) The center of the hydrogen consumption peak at about 780°C belongs to the reduction peak of Mo (VI) species to Mo species, (4) The center of the hydrogen consumption peak at about 900°C belongs to the reduction peak of Mg (II) species to Mg species. With the increase of Fe content and the decrease of Mo content, the high-temperature hydrogen consumption peak also tends to move to low temperature. The above phenomena all indicate that the MSI between Mo species interacting with the molecular sieve support is weakened. This is attributed to the fact that the coordinated unsaturated oxygen and hydroxyl groups on the surface of the carrier synergistically induce local geometric deformation of small-sized active metal clusters, while the negative charge carried by the coordinated unsaturated oxygen changes the distribution of the surrounding electron cloud density. It can be seen that the modification of the carrier with trace Mg additives can significantly regulate the interaction between the 5A molecular sieve carrier and the metal, giving the active metal different adsorption-pyrolysis characteristics, thereby achieving the purpose of regulating the pyrolysis products and increasing oil quality.

[0071] The present invention illustrates the detailed process conditions and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process conditions and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process conditions and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of the raw materials of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., as well as the equivalent replacement and specific selection of the process conditions and process equipment of the present invention, all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A catalyst for regulating the catalytic pyrolysis products of oil-rich coal, characterized in that: The catalyst comprises a 5A molecular sieve and an auxiliary agent and an active metal loaded on the 5A molecular sieve, wherein the auxiliary agent is Mg, and the active metal is one or two of Fe and Mo; in terms of oxide, the content of Mg in the catalyst is 0.75 wt% to 1.0 wt%, and the content of the active metal is 5 wt% to 15 wt%.

2. The method for preparing the catalyst for regulating the catalytic pyrolysis products of oil-rich coal according to claim 1, characterized in that: The following steps are involved: Step 1: dissolving a magnesium-containing compound in water, dripping the obtained impregnation solution onto a 5A molecular sieve, and drying to obtain a carrier modified with a Mg additive; Step 2: dissolving a molybdenum-containing compound and / or an iron-containing compound in water, dripping the obtained impregnation solution onto the carrier modified with the Mg additive, and then sequentially performing drying and calcining treatments to obtain a catalyst for regulating the catalytic pyrolysis products of oil-rich coal.

3. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 1, the magnesium-containing compound is magnesium nitrate.

4. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 1, drying is performed at room temperature for 10 to 14 hours.

5. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 2, the molybdenum-containing compound is at least one of molybdenum oxide, molybdate and paramolybdate.

6. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 4, characterized in that: In step 2, the molybdate is ammonium molybdate.

7. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 2, the iron-containing compound is at least one of iron oxide, iron nitrate and iron phosphate.

8. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 2, the drying temperature is 60-120°C and the drying time is 1-12 h.

9. The method for preparing a catalyst for regulating catalytic pyrolysis products of oil-rich coal according to claim 2, characterized in that: In step 2, the calcination temperature is 300-900°C and the calcination time is 4-8 h.

10. Use of the catalyst for regulating the catalytic pyrolysis products of oil-rich coal according to claim 1 in the catalytic pyrolysis of oil-rich coal.

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