Turning hardwood dissolving pulp polysaccharide residual material into barrier packaging

Area of Science:

• Wood Chemistry
• Materials Science
• Biorefining

Background:

• Pulping processes generate wood hydrolysates rich in xylan.
• Xylan-rich streams are potential sources for renewable materials.
• Optimizing pre-hydrolysis for dissolving pulp can yield valuable co-products.

Purpose of the Study:

• To investigate the potential of birch wood hydrolysates from pre-hydrolysis for renewable film production.
• To evaluate the impact of pre-hydrolysis conditions and subsequent fractionation on film properties.
• To assess the performance of crude versus fractionated hydrolysates in film formation.

Main Methods:

• Pilot-scale pre-hydrolysis of birch chips under varied conditions.
• Characterization of wood hydrolysates, focusing on xylan content.
• Production of renewable films from hydrolysates.
• Evaluation of film properties, including oxygen barrier and mechanical integrity.
• Comparison of films made from crude and membrane-filtered hydrolysates.

Main Results:

• Wood hydrolysates were rich in xylan and suitable for film production.
• Films exhibited good oxygen barrier function and mechanical integrity, even at high humidity.
• Membrane filtration enriched higher molecular weight fractions but did not significantly improve film performance.
• Crude hydrolysates, without filtration, yielded films with acceptable tensile properties and oxygen barrier.

Conclusions:

• Birch wood hydrolysates are a viable source for producing high-performance renewable films.
• Pre-hydrolysis liquor can be directly used for film production without extensive purification.
• This approach offers a sustainable pathway for valorizing pulp process side streams.