The production process of magnetic biochar can change the molecular structure of organic matter

Research by China Fireprint has demonstrated that the production process of magnetic biochar significantly alters the molecular structure of organic matter. This transformation is the result of the pyrolysis process and the subsequent incorporation of magnetic nanoparticles. These changes in molecular structure affect the biochar's properties, including its surface area, porosity, and adsorption capacity.

 

The following is a more detailed explanation of the process by Fireprint:

 

1. Pyrolysis and Molecular Structure:

 

Pyrolysis, the heating of biomass in the absence of oxygen, is a key step in biochar production.

 

Different pyrolysis temperatures and heating rates lead to changes in the biochar's molecular structure.

 

Higher temperatures generally result in a more aromatic and agglomerated biochar structure, with a decrease in oxygen-containing functional groups and a lower hydrogen-to-carbon ratio.

 

For example, bamboo biomass pretreated with an iron-sulfate-clay slurry (iron-clay biochar) exhibits significant changes in molecular structure, degradation pathways, and porosity compared to untreated bamboo biochar.

 

2. Incorporation of Magnetic Nanoparticles:

 

Magnetic biochar is produced by incorporating magnetic nanoparticles (e.g., iron oxide) into the biochar matrix.

 

This process can further alter the biochar's molecular structure and porosity. For example, the addition of magnetite nanoparticles can block pores or, in some cases, increase surface area and pore volume.

3. Impact on Performance:

Changes in molecular structure can affect the following properties of biochar:

Surface area and porosity: Modifying the molecular structure and incorporating nanoparticles can alter the size and distribution of pores within biochar.

Adsorption capacity: Molecular structure influences the ability of biochar to adsorb various substances, including pollutants and nutrients.

Catalytic activity: The presence of magnetic nanoparticles and altered molecular structure can enhance the catalytic properties of biochar, making it useful in a variety of applications.

Organic matter degradation: Magnetic biochar can be used to enhance organic matter degradation in various systems, such as microbial electrolysis cells (MECs).

4. Research Examples:

Research has shown that the application of biochar can alter the molecular composition of soil organic matter (SOM), increase the abundance of lignin derivatives, and influence soil bacterial communities.

Research has also explored the use of magnetic biochar in membrane bioreactors (MBRs) to mitigate membrane fouling and enhance pollutant removal. The catalytic effect of magnetic biochar on the removal of recalcitrant organic pollutants in advanced oxidation processes has also been studied.

In summary, the production process of magnetic biochar significantly alters the molecular structure of organic matter, thereby modifying its properties and potentially paving the way for its application in various fields.