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CN-121972174-A - Catalyst for catalytic pyrolysis of biomass tar and preparation method thereof

CN121972174ACN 121972174 ACN121972174 ACN 121972174ACN-121972174-A

Abstract

The invention relates to the technical field of metal materials, and relates to a catalyst for catalytic pyrolysis of biomass tar and a preparation method thereof, wherein the catalyst is prepared from, by mass, 5% -30% of NiO, 0.05% -15% of SiO 2 , 0.05% -10% of IVA metal oxide and 45% -94.9% of Al 2 O 3 . The catalyst has high activity, the catalytic cracking reaction temperature of tar is reduced, the carbon deposition speed of the catalyst is correspondingly reduced, and the reaction stability of the catalyst is improved.

Inventors

  • CHEN CHENG
  • SONG BANGYONG
  • LU HAIWEI
  • LI HUI
  • WANG LINLIN

Assignees

  • 上海卓然工程技术股份有限公司
  • 上海卓然数智能源有限公司

Dates

Publication Date
20260505
Application Date
20260107

Claims (10)

  1. 1. The catalyst for catalytic pyrolysis of biomass tar is characterized by comprising, by mass, 5% -30% of NiO, 0.05% -15% of SiO 2 %, 0.05% -10% of IVA metal oxide and 45% -94.9% of Al 2 O 3 .
  2. 2. The catalyst according to claim 1, wherein the catalyst is prepared from, by mass, 10% -20% of NiO, 1% -10% of SiO 2 %, 1% -5% of group IVA metal oxide and 65% -88% of Al 2 O 3 .
  3. 3. The catalyst according to claim 1 or 2, wherein the Al 2 O 3 has a crystalline phase of any one or a combination of at least two of γ -Al 2 O 3 、δ-Al 2 O 3 and η -Al 2 O 3 , preferably γ -Al 2 O 3 ; Preferably, the group IVA metal oxide is any one of tin oxide, germanium oxide, or lead oxide.
  4. 4. The method for preparing a catalyst for catalytic cracking of biomass tar according to claim 1 or 2, characterized in that the preparation method comprises: (1) Kneading an alumina raw material, a silica raw material, an IVA metal oxide and an extrusion aid, adding an acetic acid aqueous solution, continuously kneading, extruding, forming, drying and roasting to obtain a catalyst carrier; (2) Impregnating the catalyst carrier obtained in the step (1) with a sodium carbonate solution, then drying, spraying a nickel nitrate solution, washing with hot water, and then drying to obtain a catalyst precursor; (3) Roasting the precursor obtained in the step (2) to obtain the catalyst for catalytic pyrolysis of biomass tar.
  5. 5. The preparation method of claim 4, wherein the mass ratio of the extrusion aid to the alumina raw material in the step (1) is 0.04-0.08, and the extrusion aid is sesbania powder.
  6. 6. The preparation method according to claim 4, wherein in the step (1), the mass ratio of silica in the silica raw material to alumina in the alumina raw material is 0.01-0.16, and the silica raw material is silica sol.
  7. 7. The method according to claim 4, wherein the mass ratio of the group IVA metal oxide to alumina in the alumina raw material in the step (1) is 0.01 to 0.08.
  8. 8. The method according to claim 4, wherein the ratio of the mass of acetic acid in the aqueous acetic acid solution to the mass of alumina in the alumina raw material in the step (1) is 0.01 to 0.02.
  9. 9. The preparation method of the catalyst carrier according to claim 4, wherein the drying temperature in the step (1) is 60-150 ℃, the drying time is 6-12 hours, and the catalyst carrier is obtained by continuously roasting at 300-750 ℃ for 3-8 hours after the drying.
  10. 10. The preparation method of claim 4, wherein the time for immersing the sodium carbonate solution in the step (2) is 3-5 hours, the time for drying is 3-6 hours, and the time for spraying the nickel nitrate is 10-50 minutes; preferably, the temperature of the re-drying in the step (2) is 120-180 ℃, and the time of the re-drying is 3-6 hours; Preferably, the roasting temperature in the step (3) is 300-500 ℃, and the roasting time is 3-5 hours.

Description

Catalyst for catalytic pyrolysis of biomass tar and preparation method thereof Technical Field The invention relates to the technical field of metal materials, in particular to a catalyst for catalytic pyrolysis of biomass tar and a preparation method thereof. Background In biomass gasification, tar is inevitably produced due to the high volatile content of biomass. Under normal working conditions, tar in the biogas easily blocks a conveying pipeline, so that downstream equipment cannot normally operate, and the operation cost is greatly increased. Tar in biomass gas limits the spread of biomass gasification commercialization. Therefore, finding an efficient tar removal method is of great importance to the development of biomass gasification processes. The biomass tar removal methods are classified into physical methods and chemical methods. The physical method mainly comprises a washing method, a filtering method and a cyclone separation method. Although the physical method has the advantages of low cost, convenient operation and the like, the physical method only separates tar from biomass gas, does not fully utilize the energy contained in the tar, and can cause the problem of secondary pollution to the environment. Chemical methods include high temperature cracking and catalytic cracking. The high-temperature pyrolysis method can convert most of tar at the temperature of above 1000 ℃ and has high energy consumption. The catalytic cracking method can crack most of tar into small molecular compounds at 700-900 ℃. The catalytic cracking method not only improves the quality of the fuel gas, but also reduces the problem of secondary pollution. In the catalytic cracking process of tar, the catalyst is critical. The nickel-based catalyst is a common tar cracking catalyst, and the existing common commercial nickel-based catalyst has the following defects of (1) high production cost, (2) easy carbon deposition at high temperature, (3) easy sintering at high temperature and (4) short service life. CN101693204a discloses a method for preparing a catalyst using gamma-Al 2O3 as a carrier, niO as an active component, la 2O3、CeO2 and MgO as auxiliaries. The catalyst uses rare earth elements, has high cost and is not easy to popularize. CN101485989a discloses a preparation method of a coal gas tar cracking catalyst which takes Ni as an active component, alkaline earth metal or alkali metal as an auxiliary agent and Ce and Zr modified gamma-Al 2O3 as a carrier. The catalyst lacks high-temperature stability data, and cannot judge whether the requirement of industrial application is met. CN102179247a discloses a preparation method of hollow spherical nickel-based catalyst for catalytic cracking of tar. The preparation process of the catalyst carrier is complex, and is not beneficial to industrialized popularization. The catalyst in the technology has the advantages of high preparation cost, complex preparation process and no stability data, and is not beneficial to industrial application. Therefore, the development of the catalyst with low cost, high activity, high stability and simple preparation process has important significance. Disclosure of Invention The invention aims to solve the technical problems that the existing catalyst is high in preparation cost, easy to accumulate carbon at high temperature, easy to sinter and deactivate and poor in high-temperature stability. In order to solve the technical problems, in the first aspect, the invention provides a catalyst for catalytic cracking of biomass tar, wherein the catalyst comprises, by mass, 5% -30% of NiO (for example, 5%, 6%, 10%, 20%, 25% or 30%, etc.), 0.05% -15% of SiO 2 (for example, 0.05%, 0.1%, 1%, 5%, 10% or 15%, etc.), 0.05% -10% of IVA metal oxide (for example, 0.05%, 1%, 2%, 8% or 10%, etc.), and 45% -94.9% of Al 2O3 (for example, 45%, 50%, 70%, 80%, 94.9%, etc.). The catalyst provided by the invention is modified by adopting silicon oxide and IVA metal oxide. The alumina carrier is modified by the silica, so that the surface acidity of the alumina with weaker acidity can be enhanced, and the catalytic cracking of tar is facilitated; in addition, the hydrothermal stability of the alumina carrier modified by the silicon oxide is enhanced, so that the catalyst has anti-sintering capability. The IVA metal oxide has the modification effects that (1) the interaction between the IVA metal oxide and nickel oxide can improve the thermal stability and sintering resistance of the active metal Ni, and (2) the addition of the IVA metal oxide can improve the dispersity of the active metal Ni and improve the activity of the catalyst. The modified nickel-based catalyst effectively improves the activity of the catalyst and enhances the high-temperature stability and sintering resistance of the catalyst. Preferably, the catalyst is prepared from, by mass, 10% -20% of NiO, 1% -10% of SiO 2, 1% -5% of IVA metal oxide and 65% -88% of Al 2O3. In the invention, the content