阅读说明：本技术 基于烘焙预处理木质素催化热解制备烷基酚的制备方法 (Preparation method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment ) 是由 陈登宇 岑珂慧 章一蒙 周建斌 高雯然 于 2020-06-28 设计创作，主要内容包括：本发明提出的是一种基于烘焙预处理木质素催化热解制备烷基酚的制备方法,包括如下步骤：1)木质素的预处理；2)木质素催化剂的制备；3)烷基酚的制备。本发明的优点在于：通过烘焙预处理、催化剂优化以及协同反应物等途径实现了烷基酚的高选择,得率大大提高,同时大大减少了积碳,保证了催化效果的持久性。(The invention provides a preparation method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment, which comprises the following steps: 1) preprocessing lignin; 2) preparing a lignin catalyst; 3) and (4) preparing alkylphenol. The invention has the advantages that: the high selection of alkylphenol is realized through ways of baking pretreatment, catalyst optimization, cooperative reactant and the like, the yield is greatly improved, carbon deposition is greatly reduced, and the durability of the catalytic effect is ensured.)

1. The preparation method for preparing the alkylphenol by catalytic pyrolysis of the lignin based on baking pretreatment is characterized by comprising the following steps of:

1) preprocessing lignin;

2) preparing a lignin catalyst;

3) and preparing alkylphenol biomass oil.

2. The method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment according to claim 1, wherein the pretreatment of lignin in step 1) specifically comprises the following steps: and (3) sending the lignin into a tube furnace, baking the lignin at 200 ℃ by taking nitrogen as protective gas, keeping the temperature for 2 hours, and cooling the lignin in the tube furnace under the protection of the nitrogen to obtain the lignin subjected to baking pretreatment.

3. The method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment as claimed in claim 2, wherein the lignin is apricot hull alkali lignin.

4. The method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment according to claim 1, wherein the preparation of lignin catalyst in step 2) specifically comprises the following steps: weighing a certain mass of zinc nitrate, fully stirring and dissolving in deionized water to obtain a zinc nitrate solution, weighing a certain mass of HZSM-5, adding into the zinc nitrate solution, stirring at room temperature for 4 hours, soaking for 20 hours to obtain a mixed solution, carrying out rotary evaporation on the soaked mixed solution at 80 ℃, drying at 80 ℃ for 5 hours, putting the obtained solid into a muffle furnace at 600 ℃ for calcination for 4 hours, cooling to room temperature, and crushing to 40 meshes to obtain the catalyst.

5. The preparation method for preparing alkylphenol based on catalytic pyrolysis of baking pretreatment lignin as claimed in claim 4, wherein the mass ratio of the zinc nitrate to the ZnO-loaded HZSM-5 is 1: 5; AL =100 for Si in HZSM-5.

6. The method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment according to claim 1, wherein the step 3) of preparing alkylphenol biomass oil specifically comprises the following steps: mixing the catalyst prepared in the step 2) with the pretreated lignin prepared in the step 1), adding 50% of acetone, mixing and stirring uniformly, loading into a vertical fast pyrolysis furnace, sealing, introducing nitrogen to exhaust air in the heating furnace, rapidly heating to 460 ℃, keeping for 10min, and collecting the biomass oil from a cooling tank connected with the heating furnace to obtain the high-selectivity and high-yield alkylphenol biomass oil.

7. The method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment as claimed in claim 6, wherein the mass ratio of the catalyst, lignin and acetone is 6:3: 1.

Technical Field

The invention relates to a preparation method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment, belonging to the technical field of biomass material preparation.

Background

The content of lignin in the lignocellulose biomass is the second place, the lignin-derived biomass oil or chemical can greatly improve the economy of the whole biomass refining process, and the lignin has a unique structure and rich aromatic unit content and is always considered as a potential raw material for producing biomass aromatic compounds.

At present, the technology of pyrolyzing lignin under the catalytic action of various catalysts to produce high-quality chemicals is gradually started in the technical field of biomass materials, and the distribution and yield of products are completely dependent on the acidity and pore size of the catalysts, the catalytic pyrolysis mode, the design of a reactor and reaction conditions. However, technical maturity, product yield, high selectivity and catalyst durability have been limiting the development of lignin conversion to high quality chemicals. At present, 95% of industrial lignin is reported to be mainly used by combustion, and the technology for selectively producing alkylphenol by using lignin is less. In the prior art, although a technology of converting lignin derivative phenolic compounds and methanol into alkylphenol by using co-synergism and under the action of pt/HZSM-5 catalyst through hydrodeoxygenation and methanol primary taste catalysis is adopted, the yield of alkylphenol in actual production only reaches 16.3%, and the demand of the current market can not be met.

Disclosure of Invention

The invention aims to overcome the defects of the existing lignin catalytic production method and provides a preparation method for preparing alkylphenol based on catalytic pyrolysis of lignin subjected to baking pretreatment.

The technical solution of the invention is as follows: the preparation method for preparing alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment comprises the following steps:

1) pretreatment of lignin: sending lignin into a tube furnace, heating the lignin to a certain temperature in the tube furnace under the protection of nitrogen, preserving heat, cooling to obtain pretreated lignin, and performing preliminary pyrolysis, preliminary deoxidation, namely dehydration and deacidification on the lignin by reasonable temperature pretreatment;

2) preparation of lignin catalyst: weighing zinc nitrate, fully stirring and dissolving the zinc nitrate in deionized water to obtain a zinc nitrate solution, weighing HZSM-5, adding the HZSM-5 into the zinc nitrate solution, and stirring and dipping the mixture at room temperature to obtain a mixed solution; heating the dipped mixed solution for rotary evaporation, putting the solid obtained after drying into a muffle furnace for high-temperature calcination, cooling to room temperature and crushing to obtain a catalyst;

3) preparing alkylphenol biomass oil: adding acetone into the catalyst prepared in the step 2) and the pretreated lignin prepared in the step 1), uniformly mixing and stirring, placing into a vertical fast pyrolysis furnace, sealing, introducing nitrogen to evacuate air in the heating furnace, rapidly heating and keeping for a period of time, and collecting the biomass oil from a cooling tank connected with the heating furnace to obtain the high-selectivity alkylphenol biomass oil.

Compared with the prior art, the invention has the advantages that: the high selection of alkylphenol is realized through the ways of pretreatment, catalyst optimization, cooperative reactant and the like, the yield is greatly improved, carbon deposition is greatly reduced, and the durability of the catalytic effect is ensured.

Drawings

FIG. 1 is a process flow diagram of the preparation method of alkylphenol by catalytic pyrolysis of lignin based on baking pretreatment.

Detailed Description

The preparation method for preparing alkylphenol based on baking pretreatment lignin catalytic pyrolysis as shown in figure 1 comprises the following steps:

1) pretreatment of lignin

Selecting apricot hull alkali lignin, feeding the lignin into a tube furnace, keeping the temperature of the lignin at 200 ℃ for 2 hours by taking nitrogen as protective gas, and cooling the lignin in the tube furnace under the protection of the nitrogen to obtain the lignin subjected to baking pretreatment;

2) preparation of lignin catalyst

Weighing a certain mass of zinc nitrate, fully stirring and dissolving in deionized water to obtain a zinc nitrate solution, weighing a certain mass of HZSM-5, adding into the zinc nitrate solution, stirring at room temperature for 4 hours, and soaking for 20 hours to obtain a mixed solution, wherein the mass ratio of the zinc nitrate to the ZnO-loaded HZSM-5 (Si: AL = 100) is 1: 5; putting the soaked mixed solution into a rotary evaporator at 80 ℃, drying at 80 ℃ for 5h, putting the obtained solid into a muffle furnace at 600 ℃ for calcining for 4h, cooling to room temperature, and crushing to 40 meshes to obtain the catalyst;

3) preparation of alkylphenol biomass oil

Mixing the catalyst prepared in the step 2) with the pretreated lignin prepared in the step 1), adding 20% of acetone, and uniformly mixing and stirring, wherein the mass ratio of the catalyst to the lignin to the acetone is 6:3: 1; and (3) loading the biomass oil into a vertical fast pyrolysis furnace, introducing nitrogen to evacuate air in the heating furnace after sealing, then quickly heating to 460 ℃, keeping for 10min, and collecting the biomass oil from a cooling tank connected with the heating furnace to obtain the high-selectivity alkylphenol biomass oil.

The technical scheme of the invention is further illustrated by the following examples, and the experimental methods referred to in the following examples are all conventional methods in the technical field unless otherwise specified.