Bio-based Circular Economy Research Articles

Residual biomass as resource – Life-cycle environmental impact of wastes in circular resource systems

Abstract Within an envisioned circular bio-based economy, a key component is the valorization of biomass wastes and residues into valuable products. If the commonly used method of life-cycle assessment (LCA) is applied to such products, an update and adaptation of LCA practice is needed regarding potentially outdated assumptions of residual resources as free from environmental impact. This paper therefore presents and discusses LCA approaches to evaluating residual biomass as resources, and implications of different approaches to LCA results and decision-making. Based on an analysis of 31 LCA studies of bio-based products, and on a model for recycling in LCA, we discuss alternatives to zero-burden assumptions for biomass residues. The studied literature shows a variety of approaches to assessing the impacts of residues, including views of relevant characteristics and causality in primary production systems, and intended use and interpretation of LCA results. In general, acknowledging upstream impacts through a simple model of recycling and allocation entails that the environmental characteristics of primary production systems reflect on by-products and residues. We argue that LCA studies of residue valorization must recognize the potential value of residues by considering upstream impacts, and thereby avoid both misconceptions of residues as per default environmentally preferable resources, and unintentional support for high-impact primary production systems. Residues as resources require this adaptation in LCA practice in order to avoid misguided decisions for a low-impact, bio-based and circular economy.

A research challenge vision regarding management of agricultural waste in a circular bio-based economy

Agricultural waste is a huge pool of untapped biomass resources that may even represent economic and environmental burdens. They can be converted into bioenergy and bio-based products by cascading conversion processes, within circular economy, and should be considered residual resources. Major challenges are discussed from a transdisciplinary perspective, focused on Europe situation. Environmental and economic consequences of agricultural residue management chains are difficult to assess due to their complexity, seasonality and regionality. Designing multi-criteria decision support tools, applicable at an early-stage of research, is discussed. Improvement of Anaerobic Digestion (AD), one of the most mature conversion technologies, is discussed from a technological point of view and waste feedstock geographical and seasonal variations. Using agricultural residual resources for producing high-value chemicals is a considerable challenge analysed here, taking into account innovative eco-efficient and cost-effective cascading conversion processes (bio-refinery concept). Moreover, the promotion of agricultural residues-based business is discussed through industrial ecology, to promote synergy, on a local basis, between different agricultural and industrial value chains. Finally, to facilitate a holistic approach and optimise materials and knowledge flows management, the connection of stakeholders is discussed to promote cross-sectorial collaboration and resource exchange at appropriate geographic scales.

Towards a new generation of functional fiber-based packaging: cellulose nanofibers for improved barrier, mechanical and surface properties

The present work shows the suitability of using industrial fluting papers as raw material for the development of four different substrates, enzymatically refined and/or containing cellulose nanofibers (CNF) in bulk. These four substrates were deeply studied and treated with different coating formulations, containing CNF, polyvinyl alcohol (PVA), native starch and alkyl ketene dimer, with the purpose of evaluating the benefits of using fiber-based packaging paper with improved mechanical, physical and barrier properties. The results showed that if CNF are coated in combination with PVA the tensile properties of paper can be significantly improved, as well as the grease resistance, whereas the air permeability and water vapor transmission rate decrease. The obtained papers present interesting vapor and air barrier properties, at the same time that unconceivable limits of breaking length are achieved (6.44 km). In addition, when a second layer of alkyl ketene dimer was coated on both sides of paper, the water contact angle was significantly improved, being higher than 115°. Overall, the present work shows the feasibility of recycled fibers for the production of high value-added papers that can be used for packaging purposes due to their improved barrier and mechanical properties, and contributes therefore for the bio-based circular economy.

The Seven Challenges for Transitioning into a Bio-based Circular Economy in the Agri-food Sector.

Closed-loop agri-food supply chains have a high potential to reduce environmental and economic costs resulting from food waste disposal. This paper illustrates an alternative to the traditional supply chain of bread based on the principles of a circular economy. Six circular interactions among seven actors (grain farmers, bread producers, retailers, compostable packaging manufacturers, insect breeders, livestock farmers, consumers) of the circular filière are created in order to achieve the goal of "zero waste". In the model, two radical technological innovations are considered: insects used as animal feed and polylactic acid compostable packaging. The main challenges for the implementation of the new supply chain are identified. Finally, some recent patents related to bread sustainable production, investigated in the current paper, are considered. Recommendations are given to academics and practitioners interested in the bio-based circular economy model approach for transforming agri-food supply chains.