Testing Surface‑Area Measurement Instrument for Biochar

Client

NSR (Nordvästra Skånes Renhållnings AB) is a municipal waste‑management company working to develop circular and sustainable solutions within waste handling. One of their initiatives is the production of biochar, where garden waste and other organic materials are converted through pyrolysis – a process carried out without oxygen supply. The biochar is used both as a soil amendment and as a means of long‑term carbon sequestration, helping to reduce climate impact. NSR’s biochar initiative is a central part of their strategy to close resource loops and create local solutions for sustainable development.

Background

Biochar is a fascinating material – not because of how it looks, but because of what is hidden inside. A piece of biochar feels light in the hand but can have an enormous internal surface area. Its porous structure consists of a network of microscopic channels and cavities, giving one gram of biochar a surface area equivalent to 50–500 square meters. That is roughly like fitting an entire house into a teaspoon. This large surface area is crucial for the function of biochar. The pores act as tiny reservoirs where water, nutrients, and microorganisms can attach and be retained. This allows soil to store more water during dry periods, reduces nutrient leaching, and provides more niches for microbial life to establish.

The project

NSR has a surface‑area measurement instrument used to analyze the specific surface area and pore structure of biochar. The instrument is based on gas adsorption, where nitrogen gas at different pressure intervals is used to determine the surface area. In this project, you will investigate how the instrument should be used and calibrated to produce reliable results for biochar.

Possible research questions include:
• Do multiple samples taken from the same biochar material yield similar results (reproducibility)?
• How should the biochar be processed to obtain a representative sample – broken, milled, sieved, or another method?
• How large are the variations between different samples and different types of biochar?
• How do ash content and pore structure influence the measurement results?

Wood‑based biochar can be used as the primary test material, but sewage‑sludge biochar and other biochar types are also of interest for analysis. The scope of the project can be adapted depending on specialization and academic level (bachelor’s/master’s).

Final delimitations are made in consultation with the university supervisor and the project client. Both the student and the client should be aware that appropriate academic grounding must be applied in the work.

Related sustainability goals