阅读说明：本技术 一种调控生物炭形貌结构的方法 (Method for regulating morphology structure of biochar ) 是由 周南 李娟� 周智 钟美娥 于 2019-01-08 设计创作，主要内容包括：本发明属于生物炭制备领域,具体公开了一种调控生物炭形貌结构的方法,将包含木质纤维素类生物质、HPMC、磷酸的原料水溶液在含氧气氛下、100-400℃下碳化；通过控制原料水溶液中所添加磷酸的浓度和/或固液比,调控碳化产物的形貌。本发明发现,在所述的包含木质纤维素类生物质、HPMC、磷酸的原料水溶液中,通过控制原料水溶液中的磷酸的浓度、在此基础上进一步辅助于对固液比的控制,可以调控在含氧气氛下碳化得到的生物炭的形貌。(The invention belongs to the field of biochar preparation, and particularly discloses a method for regulating and controlling the morphology structure of biochar, which comprises the steps of carbonizing a raw material aqueous solution containing lignocellulose biomass, HPMC and phosphoric acid at the temperature of 100-400 ℃ in an oxygen-containing atmosphere; the morphology of the carbonized product is regulated and controlled by controlling the concentration and/or the solid-liquid ratio of the added phosphoric acid in the raw material water solution. The invention discovers that in the raw material aqueous solution containing the lignocellulose biomass, the HPMC and the phosphoric acid, the morphology of the biochar obtained by carbonization in an oxygen-containing atmosphere can be regulated and controlled by controlling the concentration of the phosphoric acid in the raw material aqueous solution and further assisting in controlling the solid-to-liquid ratio.)

1. A method for regulating and controlling the morphology structure of biochar is characterized by comprising the following steps: carbonizing a raw material aqueous solution containing lignocellulose biomass, HPMC and phosphoric acid at 100-400 ℃ in an oxygen-containing atmosphere; the morphology of the carbonized product is regulated and controlled by controlling the concentration and/or the solid-to-liquid ratio of phosphoric acid in the raw material aqueous solution, and the method specifically comprises the following regulation and control modes:

mode A: regulating the concentration of phosphoric acid in the raw material aqueous solution to 35-50%, wherein the solid-liquid ratio is 1g: 1-5 ml, and carbonizing to obtain powdered biochar;

mode B: regulating the concentration of phosphoric acid in the raw material aqueous solution to 70-80% and the solid-to-liquid ratio to be 1g: 12-20 ml, and carbonizing to obtain sludge-like biochar;

mode C: regulating and controlling the concentration of phosphoric acid in the raw material water solution to be 65-95% and the solid-to-liquid ratio to be 1g:1 ml-10 ml, and preparing the 3D three-dimensional structure biochar.

2. The method of modulating the morphology of biochar as claimed in claim 1, wherein: the lignocellulose biomass is at least one of pericarp, plant straw, town solid organic garbage, energy plants, wood and agricultural waste.

3. The method of modulating the morphology of biochar as claimed in claim 2, characterized in that: in the mode C, the lignocellulose biomass is pericarp, and the 3D blocky structure biochar is prepared;

preferably, the pericarp is banana peel and/or durian peel.

4. The method of modulating the morphology of biochar as claimed in claim 2, characterized in that: in the mode C, the lignocellulose biomass is plant straws, and the elastic aerogel biochar with a 3D structure is prepared;

the plant straw is tobacco stem and/or tobacco leaf.

5. The method for regulating the morphology structure of biochar as claimed in any one of claims 1 to 4, characterized in that: in the mode C, the concentration of phosphoric acid in the raw material water solution is 65-70%, and the solid-to-liquid ratio is 1g: 5-10 ml.

6. The method of modulating the morphology of biochar as claimed in claim 1, wherein: in the mode A, the concentration of phosphoric acid in the raw material aqueous solution is 35-40%, and the solid-to-liquid ratio is 1g: 1-5 ml.

7. The method of modulating the morphology of biochar as claimed in claim 1, wherein: in the mode B, the concentration of phosphoric acid in the raw material aqueous solution is 75-80%; the solid-liquid ratio is 1g: 15-20 ml.

8. The method of modulating the morphology of biochar as claimed in claim 1, wherein: in the raw material water solution, HPMC is 0.02-0.6 of lignocellulose biomass by weight: 1.

9. the method of modulating the morphology of biochar as claimed in claim 1, wherein: the carbonization time is 2-36 h.

10. The method of modulating the morphology of biochar as claimed in claim 1, wherein: washing the carbonized product with distilled water and alkali liquor to neutrality.

Technical Field

The invention belongs to the field of biochar preparation, and particularly relates to a method for preparing biochar with different morphological structures in a controlled manner under a low-temperature open environment.

Background

Biochar is a solid product generated by high-temperature thermal cracking of a biological organic material (biomass) in an anoxic or anaerobic environment. The carbon dioxide slow release fertilizer can be used as a high-quality energy source and a soil conditioner, can also be used as a reducing agent, a fertilizer slow release carrier, a carbon dioxide sealing agent and the like, is widely applied to carbon fixation emission reduction, water source purification, heavy metal adsorption, soil improvement and the like, and can provide a solution for global-critical hot spot problems such as climate change, environmental pollution, soil function degradation and the like to a certain extent.

The method for manufacturing the biochar is an economical and feasible mode for fixing the carbon dioxide, the carbon dioxide absorbed in trees and crops is solidified, the product biochar is stored in soil and cannot be changed for thousands of years, and the soil fertility and the crop yield are improved while renewable energy is produced.

Modern methods for making biochar heat plant waste at high temperature in a low oxygen environment to decompose it.

The biochar with different morphological structures is prepared in a regulating and controlling manner, so that the structure of the biochar is enriched, and the biochar can be more conveniently applied to carbon fixation and emission reduction, water source purification, heavy metal adsorption and soil improvement. For example, the three-dimensional blocky biochar is easy to recycle in practical application.

However, the prior art also lacks a method for regulating the morphology of the biochar.

Disclosure of Invention

The first purpose of the invention is to provide a method for preparing biochar with different morphologies in a controlled manner under a low-temperature open environment.

A method for regulating and controlling the morphology structure of biochar comprises the steps of carbonizing a raw material aqueous solution containing lignocellulose biomass, HPMC and phosphoric acid at the temperature of 100-400 ℃ in an oxygen-containing atmosphere; the morphology of the carbonized product is regulated and controlled by controlling the concentration and/or the solid-to-liquid ratio of phosphoric acid in the raw material aqueous solution, and the method specifically comprises the following regulation and control modes:

mode A: regulating the concentration of phosphoric acid in the raw material aqueous solution to 35-50%, wherein the solid-liquid ratio is 1g: 1-5 ml, and carbonizing to obtain powdered biochar;

mode B: regulating the concentration of phosphoric acid in the raw material aqueous solution to 70-80% and the solid-to-liquid ratio to be 1g: 12-20 ml, and carbonizing to obtain sludge-like biochar;

mode C: regulating and controlling the concentration of phosphoric acid in the raw material water solution to be 65-95% and the solid-to-liquid ratio to be 1g:1 ml-10 ml, and preparing the 3D three-dimensional structure biochar.

The invention discovers that in the raw material aqueous solution containing the lignocellulose biomass, the HPMC and the phosphoric acid, the morphology of the biochar obtained by carbonization in an oxygen-containing atmosphere can be regulated and controlled by controlling the concentration of the phosphoric acid in the raw material aqueous solution and further assisting in controlling the solid-to-liquid ratio. The research of the invention finds that under the carbonization temperature of the oxygen-containing atmosphere and the lower concentration range, the powdery biochar can be obtained under different solid-liquid ratios. The concentration of phosphoric acid in the raw material aqueous solution is improved, the solid-to-liquid ratio of the solution is further improved, and sludge-like biochar can be obtained; under the condition of higher phosphoric acid proportion, the biochar with the 3D shape can be obtained by adopting a lower solid-liquid ratio.

The research of the invention finds that the precise regulation and control of the morphology of the biochar needs to use phosphoric acid as a medium, HPMC as a structure stabilizer, oxygen-containing atmosphere and temperature carbonization as the premise, and the morphology of the biochar can be controlled by regulating and controlling the concentration and the solid-liquid ratio of the phosphoric acid on the premise. That is, accurate control of biochar needs to be realized in coordination with operations and parameters such as the type, concentration, carbonization atmosphere, carbonization temperature, solid-to-liquid ratio, and the like of acid.

The solid-liquid ratio refers to the ratio of the weight of a solid part to the volume of a liquid part in a raw material aqueous solution; the solid portion refers to the total weight of lignocellulosic biomass and HPMC.

Preferably, in the mode A, the concentration of the phosphoric acid is 35-45%; more preferably 35 to 40%. The solid-liquid ratio is 1g: 1-5 ml.

Preferably, in the aspect B, the concentration of phosphoric acid is 75 to 80%. The solid-liquid ratio is 1g: 15-20 ml.

Preferably, the method C: the concentration of phosphoric acid in the raw material water solution is 65-70%, and the solid-to-liquid ratio is 1g: 5-10 ml.

Preferably, the lignocellulose biomass is at least one of pericarp, plant straw, town solid organic garbage, energy plants, wood and agricultural waste.

The lignocellulose biomass is crushed by the existing method. Preferably, the crusher is used for crushing mainly and the bending is matched. For example, lignocellulosic biomass is broken by conventional methods to a particle size scale of 1.5cm or less.

Research shows that in the mode C, the concentration of phosphoric acid in the raw material aqueous solution and the solid-to-liquid ratio are regulated and controlled, and the lignocellulose biomass is further regulated and controlled, so that biochar with different morphologies can be obtained.

Further preferably, in the mode C, the lignocellulose biomass is pericarp, and the 3D blocky structured charcoal is prepared; preferably, the pericarp is banana peel and/or durian peel.

Further preferably, in the mode C, the lignocellulose biomass is plant straw, and the elastic aerogel biochar with a 3D structure is prepared; the plant straw is tobacco stem and/or tobacco leaf.

HPMC is added into the raw material aqueous solution, and the appearance of the raw material aqueous solution can be more beneficial to accurately regulating and controlling the appearance of the biochar. In addition, the research of the inventor also finds that the cooperation of HPMC and phosphoric acid is more beneficial to the complete structure of the biochar and the regulation and control of the morphology. Particularly in the mode C, the preferable HPMC and the phosphoric acid have better cooperativity, so that the biomass can be interweaved and connected under the condition, and the three-dimensional biochar is more favorably obtained.

Preferably, in the raw material aqueous solution, the HPMC is 0.02 to 0.6: 1; more preferably 0.2 to 0.3: 1.

And dispersing the lignocellulose biomass and the HPMC in a phosphoric acid solution, uniformly stirring, standing, and performing structure infiltration to obtain the raw material aqueous solution. The aqueous raw material solution is carbonized under the atmosphere and at the temperature.

The oxygen-containing atmosphere may be an atmosphere containing oxygen, such as oxygen; a mixed atmosphere of oxygen and a protective atmosphere. The protective atmosphere is, for example, nitrogen or an inert gas.

Preferably, the oxygen-containing atmosphere is air.

Preferably, the raw material aqueous solution is placed in an open container, carbonization is carried out at the temperature, and accurate regulation and control of the morphology of the biochar through the concentration of phosphoric acid and solid-liquid ratio can be facilitated through the interface effect.

Researches show that the carbonization temperature is also required to be controlled in order to accurately regulate and control the morphology of the biochar.

The preferable carbonization temperature is 100-200 ℃; more preferably 150 to 200 ℃.

The preferred carbonization time is 2 to 36 hours; preferably 12-24 h.

Preferably, the carbonized product is washed to be neutral by distilled water and alkali liquor.

The method comprises the steps of taking lignocellulose biomass as a raw material, obtaining biochar with different morphological structures by adjusting the concentration of phosphoric acid and the solid-liquid ratio within the temperature range of 140-150 ℃, and adjusting and controlling the shapes of the 3D hard structure and the three-dimensional aerogel biochar by adding HPMC and changing the shape of a reaction vessel.

The invention has the advantages that:

according to the invention, the biochar with different morphologies and structures is prepared in a controlled manner in a low-temperature open environment, so that energy is saved to a certain extent, and the biochar with different morphologies is controlled.

The biochar with different morphological structures is prepared under low temperature in a controlled manner, the structure of the biochar is enriched, and the biochar can be more conveniently applied to carbon fixation and emission reduction, water source purification, heavy metal adsorption and soil improvement

The method is simple and convenient to operate, and the biochar prepared by the mode C has a highly developed pore structure, a larger specific surface area and abundant active surface functional groups, and is easy to recycle in practical application of three-dimensional blocky biochar.

Drawings

FIG. 1 is a topographical view of biochar prepared in example 1;

FIG. 2 is a morphology chart of the biochar prepared in example 3;

FIG. 3 is a morphology of biochar made in example 5;

FIG. 4 is a topographical view of the biochar prepared in example 7;

FIG. 5 is an SEM photograph of a biochar material prepared in Experimental example 9.

Detailed description of the preferred embodiments

The present invention will be described in further detail with reference to specific examples.