Why?
The pulp and paper industry has the potential to be a major player in the change towards a bio-based circular economy. With its currently wide selection of available products, as well as promising new alternatives derived from side streams, it can aid in decreasing the production and consumption of fossil-based material. Yet, it faces the challenge of an increasing global energy demand and raw material scarcity. There is, thus, an ever-present need for a better understanding of the process, in order to increase efficiency and decrease material use. However, wood is a heterogenous material, with large differences – both structural (fiber types and dimensions) and chemical (structure and amount of lignin and holocellulose – between species, geographical location, and different parts of the same tree. A full understanding of the effects this has on the pulping behaviours and proceeding pulp properties is lacking, especially so for many hardwoods which has seen far less research compared to common softwoods such as spruce and pine.
One key step in pulping research is analyzing the residual lignin remaining in the wood after pulping. Analytical methods in this area are in many cases lacking, especially so for qualitative methods, such as for determining the molecular weight and structure of the residual lignin. This stems from the inherent difficulties in extracting the lignin, without heavily affecting the structure. Various methods of extracting lignin exist, each with their own pros and cons. Further research regarding the applicability of these methods will help in granting valuable insights on the changes of lignin during pulping, which in turn is paramount to understanding, and hence being able to improve, the pulping process.
Project description
The project consists of two main parts:
- Evaluation of selected methods for isolating lignin from wood pulp.
- Characterization of isolated material, in terms of molecular weight and structural motifs.
The emphasis will initially fall on method development for the isolation procedures, but may change towards the following characterization depending on the results. The thesis involves extensive experimental work and potential analytical tools that may be used include 2D-NMR, GPC and HPAEC, as well as lab-scale reactors for simulating kraft cooks. There is also potential for the results to be part of future publications in scientific journals.
Prerequisites
The applicants should preferably have a background in chemical engineering, wood chemistry and process technology with a collaborative approach. The project can be performed in pair.
Project start
January 2024 or according to agreement
Contact details:
Supervisor: Linus Kron, linus.kron@chalmers.se
Industrial contact: Jim Parkås, Södra, jim.parkas@sodra.com
Examiner: Merima Hasani, merima.hasani@chalmers.se
