Kalvin Durand receives the CRMR Winter 2025 Support Scholarship, valued at $5,000!
Congratulations to Kalvin Durand, recipient of the Winter 2025 Support Scholarship from the Renewable Materials Research Center (CRMR)! Kalvin is pursuing a Ph.D. in wood engineering and bio-based materials under the supervision of Tatjana Stevanovic Janezic and Denis Rodrigue.
This scholarship aims to promote university studies and research related to the CRMR’s focus areas by providing financial support to a graduate student (Master’s or Ph.D.) nearing the end of their program without other funding sources. Kalvin’s application stood out due to his exceptional academic performance, his scientific and personal achievements, as well as the quality and progress of his research project.
Congratulations to Kalvin for this well-deserved success! A special thank you also to the committee for their commitment and support throughout this process!
Project Title: Conversion of Rice Straw and Wheat Straw Hydrolysis Residues into Biopolymers and Silica
The primary goal of this project is to convert hydrolysis residues from agricultural waste, such as rice straw and wheat straw, into biopolymers and transform them into high-value products. Initially, the project focuses on identifying, extracting, and characterizing the chemical properties of cellulose, lignin, and silica from these agricultural residues using wood chemistry methods. Subsequently, the isolated components will be converted into high-value wood chemistry products and rigorously characterized.
Problem Statement – Transforming agricultural waste into high-value products is a complex challenge. Cereal plants, although fundamentally different from woody species in terms of morphology and life cycle, share similarities. They are all composed of biopolymers, extractives, and minerals. It would therefore be relevant to replace forest resources with agricultural residues to produce monosaccharides, lignin, cellulose, and silica.
Methodology – To achieve the first objective of the project, we adapted and optimized a series of separation and isolation processes for wood biopolymers to apply to agricultural residues. Specifically, we used an acid hydrolysis process to extract hemicelluloses, a lignin extraction process (Lifer) developed by Tatjana Stevanovic at Université Laval, and a silica extraction process. This first research phase presents a dual challenge: optimizing a process designed for hardwoods while applying it to an agricultural resource that has undergone pretreatment.
The various components of the agro-waste will be quantified, and the extraction processes will be optimized by studying the influence of various parameters on the recovery rates of hemicellulose, ash, and lignin. In the second phase, the extracted lignin, cellulose, and silica will be transformed into high-value wood products. Due to their increasing use in various industrial sectors, these compounds will be converted into nanomaterials. The two techniques selected for this transformation are the production of lignin nanoparticles via electrospray and cellulose microfibrils through high-intensity ultrasonication. The main objective of this phase is to produce materials with physicochemical properties comparable to those derived from wood, using the components isolated from agro-waste.
Expected Results- Initially, the primary components of rice straw and wheat straw—hemicellulose, lignin, cellulose, and ash—were quantified. These biomasses were then converted into silica-rich cellulose and high-purity lignin using the catalytic organosolv process developed in Dr. Stevanovic’s laboratory. The organosolv lignins obtained from rice straw and wheat straw were rigorously analyzed using spectroscopic and chromatographic methods.
Due to the high residual silica content in the cellulose pulps, studying the properties of the cellulose proved complex. Therefore, a mild silica extraction process was established and optimized using a weak base. The absence of silica in the ashes produced from purified cellulose, confirmed by elemental analysis, provided evidence of successful purification. The cellulose was then bleached and subjected to further analysis.
Using the electrospray method, lignin from rice straw was transformed into nanoparticles. Various parameters were optimized, such as lignin concentration, flow rate, applied voltage, and the distance between the nozzle and collector, using a response surface methodology. This allowed for the production of small, spherical, stable, and uniform nanoparticles. Finally, these lignin nanoparticles were incorporated into a polylactic acid (PLA) matrix. By grafting the lignin nanoparticles onto the PLA, a uniform dispersion of particles in the matrix was achieved, producing films with improved optical properties compared to mixtures containing unmodified lignin or ungrafted lignin nanoparticles. Furthermore, the grafted lignin nanoparticles increased the antioxidant capacity of the films, making them suitable for food packaging applications.
For cellulose, using high-intensity sonication, cellulose from rice straw was transformed into microfibrils. The sonication parameters, such as lignin concentration, nominal power, time, and cellulose concentration, were optimized to produce small, stable, and uniform cellulose fibers.
Potential Applications and Industrial Impacts – This project represents a significant advancement for sustainable development in the agricultural sector, by valorizing agricultural waste for the production of biopolymers used in material manufacturing. This innovative approach enables the treatment of agricultural waste while creating high-value products, with broad potential applications in various industrial sectors.
The conversion into nanoparticles improves the miscibility of lignin in various polymers, imparting exceptional properties such as thermal resistance, antioxidant stability, antibacterial properties, and UV protection. These characteristics are particularly interesting for the cosmetics (UV protection in sunscreens), pharmaceutical (drug delivery), and environmental (heavy metal absorption) sectors. The transformation into microfibrils enhances the mechanical strength and flexibility of cellulose fibers while reducing their density. These properties, when incorporated into composite materials, allow for the optimization of mechanical, thermal, and barrier performances, with applications in the paper, textile, cosmetic, pharmaceutical, and packaging industries.
Conclusion – Despite the transition to a more environmentally friendly society, many resources remain underutilized. Agricultural residues, although abundant, are often overlooked, yet they represent an ideal alternative to petroleum-based products, offering potential replacements for materials such as lignin and cellulose. This project proposes to valorize these agricultural residues through a biorefinery concept, transforming a largely underused resource into a versatile and sustainable raw material.