Plenary Lecture

Prof. Petar Sabev Varbanov

Energy implications of circular economy solutions and renewable energy integration

While the current World situation is characterised by increased geopolitical tensions, the environmental and sustainability issues have not disappeared. Moreover, the radical improvement of resource-saving and emission reduction is an objective inherently aligned with the objectives of increased resilience and energy/resource security. In this context, Széchenyi István University has launched an ambitious research programme dedicated to sustainability in a variety of domains, including fundamental science, engineering, supply chains, business processes, and social science. Within these, the Circular Economy and the integration of renewable sources into the energy supply to the economy are important areas related to each other, with the potential to minimise resource demands and emissions to a sufficient degree.
This presentation is aiming to overview key developments in the mentioned areas, mapping them into a coherent vision for integrated symbiosis networks that minimise the need for fresh resources without compromising the level and pace of economic development and preserving the resilience of regional economies. The core developments centre around two concepts – (a) Process Integration and (b) Process Network Synthesis and Optimisation. The former is a family of methods for minimising resource intake while maximising recovery and reuse. The latter is a sub-area of Process Synthesis exploiting the powerful P-graph framework for optimising structurally complex networks.
The overview is followed by analysis and discussion, showing the high importance of energy and exploiting energy integration as a fundamental binding element of diverse activities in society and economy. This is leading to an integrated vision for energy recovery, reuse, and cascading via optimal integration, with the goal of achieving higher rates of circularity in the Circular Economy and maximising renewable energy share with actual emission reduction.

Keynote Lectures

Dr. Roland Ludwig

Selective enzymatic ligno-cel-lulose modification and de-polymerization

The bioeconomy relies strongly on biomass as a renewable resource for materials, chemicals and fuels. The complex polymeric structure of plant cell walls offers advantageous properties for its use as materials, e.g. in construction, because of its mechanical stability and resistance to degradation. Isolated carbohydrate polymers from plant cell walls, such as cellulose and hemicelluloses, can be used in a variety of applications, ranging from food to consumer products to building materials. The highly interconnected, polymeric structure of the cell wall, however, also poses a challenge to the separation of individual components as well as to the isolation of defined chemical building blocks as required for green biorefineries. Fungi secrete oxidoreductases at an early stage of biomass deconstruction to improve the accessibility of plant polymers to fungal hydrolytic enzymes. We are investigating this cascade depolymerization strategy to unravel different polymers without subjecting them to total hydrolysis and to use them in circular applications.
Lytic polysaccharide monooxygenases (LPMO) are a class of endo-acting peroxygenases that are formed in multiple forms by many organisms and cleave various carbohydrate polymers to soften up the cell wall for the separation of constituents (Munzone et al., 2024). The kinetic characterization of LPMOs is a prerequisite to apply their catalytic versatility in industrial processes. To this end, we developed electrochemical techniques in order to (i) study the activity of LPMOs in com-bination with other enzymes (oxidoreductases and hydrolases) on poplar wood, and (ii) to determine the preferred polymeric substrate of a given LPMO as well as its pH- and temperature-dependent activity, apparent catalytic constants, and turnover stability (Schwaiger et al., 2024). Our results show that LPMOs are highly efficient biocatalysts for the initial depolymerization of cellulose and hemicelluloses operating in the S3 layer of wo-od cells (Gacias-Amengual et al., 2022). Depending on the intensity of the enzymatic treatment, the polysaccharides are either only slightly modified, providing access points for further chemical modification, or depolymerized into mono- and oligosaccharides for various applications.

Assist. Prof. Dr. Uroš Novak

Developing safe and sustainable hydrophobic textile coating materials through design – Natural renewable solutions to mitigate the toxicity of polyfluoroalkyl substances (PFAS)

Per- and poly-fluoroalkyl substances (PFAS) are synthetic compounds widely utilized in various industries for their beneficial characteristics, such as hydrophobicity, lipophobicity, chemical inertness, exceptional lubricity, non-stick properties, high fire resistance, resistance to extreme temperatures, and durability against weathering. Despite their advantages, recent studies have revealed that PFAS compounds exhibit persistent, accumulative, and highly mobile properties that pose environmental risks. (Sharma et al. 2024) Recognizing the toxicity of PFASs, ongoing research in the HE project PROPLANET is investigating alternative options (https://www.proplanet- project.eu/). A significant portion of PFAS compounds is employed in the textile sector. Our in-depth contribution focuses on exploring natural-based hydrophobic coatings for textiles, utilizing materials like natural waxes, fatty acids, naturally occurring polymeric compounds (such as proteins, carbohydrates, aromatic polymers, and natural rubber), and other natural substances. The aim is to create environmentally sustainable methods for applying these coatings to textiles, including relevant modification processes. It critically evaluates the properties and longevity of natural solutions in comparison to PFAS-based coatings, emphasizing the importance of transitioning away from PFAS compounds towards nature- derived alternatives for imparting hydrophobic properties to textiles. In the keynote lecture the path towards creation of highly hydrophobic (WCA <120°) bio based coating composed of AKD-polysaccharide, chitosan/OSA modified starch coatings and chitosan/wax microcapsules will be shown.