Alberto Bezama

Let us discuss how cascading can help implement the circular economy and the bio-economy strategies

Over the last years, several strategies have been set forth for establishing sounder and more sustainable production patterns, and consequently for the reduction of solid waste and appropriate use and reuse of natural resources. Among them, the circular economy strategy (e.g. European Commission, 2015) suggests the implementation of closed material loops in productive systems, aiming for optimal utilisation of available resources. In addition, for an appropriate use of biomass resources, the bio-economy strategy (BMEL, 2014; European Commission, 2012) introduces a value-added oriented hierarchical utilisation of biomass for the sustainable production of materials, chemicals, fuels and energy, after providing the sufficient and healthy supply of food and feed to meet the basic needs of society. Both strategies have in common a circular management of resources, which has raised several questions regarding their practicality (de Man and Friege, 2016; Lieder and Rashid, 2016; Velis and Vrancken, 2015). Many of these questions could be clarified if there were a clear vision on the meaning of the envisioned circularity. And in this regard, the first step should be to critically discuss the concept of cascading, which has been identified as one of the cornerstones of the bio-economy and the circular economy strategies. After all, how do we define cascading? What is its role in a future sustainable use of resources? And also importantly, how can we measure cascading and its effects on the system? This editorial addresses these three questions, aiming to establish the needs and challenges ahead for implementing the novel circular economy and bio-economy strategies.

Social life cycle assessment: in pursuit of a framework for assessing wood-based products from bioeconomy regions in Germany

PurposeWith many policies in Germany steering towards a bioeconomy, there is a need for analytical tools that assess not only the environmental and economic implications but also the social implications of a transition to a bioeconomy. Wood is expected to become a major biomass resource in bioeconomy regions. Therefore, this paper develops a social life cycle assessment (sLCA) framework that can be applied specifically to a wood-based production system in one of Germany’s bioeconomy regions.MethodsThis paper reviews and analyses existing sLCA approaches, in terms of how applicable they are for assessing a wood-based production system in a German bioeconomy regional context. The analysis is structured according to the standard phases of environmental life cycle assessment (LCA). However, we use the term social effects rather than social impacts, to acknowledge the unknown cause–effect relationship between an organisation’s activities and its social impacts. We also consider the establishment of regional system boundaries, as well as the relationship between the social effects and the product being assessed. Additionally, an approach for the development and selection of social indicators and indices is outlined. Furthermore, we discuss data requirements and present an approach for a social life cycle impact assessment method.Results and discussionA new conceptual framework for a context-specific sLCA to assess wood-based products manufactured in a bioeconomy region was developed. It enables sLCA practitioners to identify “social hotspots” and “social opportunities” from a regional perspective. The location and characteristics of these social hotspots and opportunities can be analysed, in particular, for major production activities in a bioeconomy region in Germany. Therefore, according to this framework, the development of social indices and indicators, the collection of data and the approach used for characterising social effects need to relate to the geographical context of the product being assessed. The proposed framework can, thus, help to identify, monitor and evaluate the social sustainability of wood-based bioeconomy chains in a regional context.ConclusionsThis framework requires a high level of detail in the social inventory and impact assessment phase, in order to assess the regional foreground activities in a German wood-based bioeconomy region. It enables sLCA studies to identify which social hotspots and social opportunities occur and where they are located in the wood-based production system of a regional bioeconomy.

When considering no man is an island - assessing bioenergy systems in a regional and LCA context: a review.

PurposeWith many environmental burdens associated with bioenergy production occurring at the regional level, there is a need to produce more regional and spatially representative life cycle assessment of bioenergy systems. On the other hand, such assessments also need to account for the global and cumulative impacts along the full bioenergy life cycle in order to support effective regional policy measures and decision making. Therefore, the challenge is to find a balance. In other words, how should we define the regional context for bioenergy system assessments in order to complement life cycle thinking? The aim of this review is to answer this question by providing an overview of important considerations when assessing bioenergy systems in a regional and LCA context and how these two contexts intersect. It also aims to help guide and orientate LCA practitioners interested in including more regional aspects in their bioenergy studies. Until now, such a review which explores the integration of regional and life cycle contexts in relation to bioenergy systems and their products has not been done.MethodsAs a first step, we define what we mean by the term region. We then look at the potential burdens relating to bioenergy systems and their relationship with the regional context. In a next step, we explore life cycle thinking and the intersection between the regional and LCA contexts by providing some examples from the literature. We then discuss the benefits and limitations of such regionally contextualized life cycle approaches in relation to bioenergy production systems and indeed other alternative biomass uses.Results and discussionThree regional contexts were identified to help orientate life cycle thinking aiming to assess the regional and nonregional environmental implications of bioenergy production. These contexts were as follows: “within regional,” “regional and ROW,” and “regionalized.” The added value of implementing a regionally contextualized life cycle approach is the ability, therefore, to include greater regional and spatial details in the assessments of bioenergy production systems, without losing the links to the diversity of global supply chains. Thus, providing greater geographical and regional insight into how such potential burdens can be reduced or shifted burdens avoided or how associated regional production activities could be optimized to mitigate such burdens.ConclusionsThe use of different regional contexts as proposed in this paper is not only useful to orientate life cycle thinking in relation to bioenergy systems but also for the assessment of alternative novel bio-based systems.

Cascade use indicators for selected biopolymers: Are we aiming for the right solutions in the design for recycling of bio-based polymers?

When surveying the trends and criteria for the design for recycling (DfR) of bio-based polymers, priorities appear to lie in energy recovery at the end of the product life of durable products, such as bio-based thermosets. Non-durable products made of thermoplastic polymers exhibit good properties for material recycling. The latter commonly enjoy growing material recycling quotas in countries that enforce a landfill ban. Quantitative and qualitative indicators are needed for characterizing progress in the development towards more recycling friendly bio-based polymers. This would enable the deficits in recycling bio-based plastics to be tracked and improved. The aim of this paper is to analyse the trends in the DfR of bio-based polymers and the constraints posed by the recycling infrastructure on plastic polymers from a systems perspective. This analysis produces recommendations on how life cycle assessment indicators can be introduced into the dialogue between designers and recyclers in order to promote DfR principles to enhance the cascading use of bio-based polymers within the bioeconomy, and to meet circular economy goals.

Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia

The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories.

The knowledge-based bioeconomy and its impact in our working field

In recent years, there has been a great deal of discussion about the vision of the bieoconomy at regional, national and international levels. This discussion has involved many in the scientific community, including Waste Management & Research, which has published several editorials and original manuscripts on this subject. This increasing attention to the bioeconomy stems from growing global interest in major energy and materials transition processes, such as circular economy and the energy transition, among others. The term energy transition relates to the envisaged change in the structures of national energy systems, not only in terms of an increased share of renewable resources, but also through the introduction of energy-saving measures and decentralised energy generation networks that allow an overall enhancement of the overall system’s efficiency. One common point of all these processes is their aim to attain sustainable use of the Earth’s finite resources. In the bioeconomy field, the challenge is, therefore, to find room for the next wave of innovations that can boost technologies, products and services out of the available purpose-grown and waste-sourced biomass to support the establishment of a more sustainable society. This challenge is a particularly tricky one, considering that although the term ‘bioeconomy’ is relatively new, the basis of the bioeconomy is already in place, and it is formed by the already existing, traditional industries and sectors, such as (among others) agricultural and forestry sectors, as well as the food processing and pulp and paper industries. However, the bioeconomy field is not limited to the traditional raw materials (e.g. wood or agricultural residues). It includes also new promising raw materials, such as bacteria and fungi. The goal of introducing them is clear: To diversify the feedstock basis for the bioeconomy and thus to establish an overall production system that is far superior to todays and is at the same time sustainable.

Lessons learned for a more efficient knowledge and technology transfer to South American countries in the fields of solid waste and contaminated sites management

The present paper describes the development, performance and conclusions derived from three know-how and technology transfer projects to South American countries. The first project comprised a collaborative study by European and South American universities to find sustainable solutions for Chilean and Ecuadorian leather tanneries which had underachieving process performances. The second project consisted of investigations carried out in a Brazilian municipality to enhance its municipal solid waste management system. The final collaborative programme dealt with the initial identification, evaluation and registration of suspected contaminated sites in an industrial region of Chile. The detailed objectives, methods and procedures applied as well as the results and conclusions obtained in each of the three mentioned projects are presented, giving special attention to the organizational aspects and to the practical approach of each programme, concluding with their main advantages and disadvantages for identifying a set of qualitative and quantitative suggestions, and to establish transferable methods for future applications.

Potential of biogas production from swine manure supplemented with glycerine waste

In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

Assessment and optimization of an ultrasound-assisted washing process using organic solvents for polychlorinated biphenyl-contaminated soil.

The goal of this work was to evaluate a washing process that uses organic solutions for polychlorinated biphenyl (PCB)-contaminated soil, and includes an ultrasound pre-treatment step to reduce operational times and organic solvent losses. In a preliminary trial, the suitability of 10 washing solutions of different polarities were tested, from which three n-hexane-based solutions were selected for further evaluation. A second set of experiments was designed using a three-level Taguchi L27 orthogonal array to model the desorption processes of seven different PCB congeners in terms of the variability of their PCB concentration levels, polarity of the washing solution, sonication time, the ratio washing solution/soil, number of extraction steps and total washing time. Linear models were developed for the desorption processes of all congeners. These models provide a good fit with the results obtained. Moreover, statistically significant outcomes were achieved from the analysis of variance tests carried out. It was determined that sonication time and ratio of washing solution/soil were the most influential process parameters. For this reason they were studied in a third set of experiments, constructed as a full factorial design. The process was eventually optimized, achieving desorption rates of more than 90% for all congeners, thus obtaining concentrations lower than 5 ppb in all cases. The use of an ultrasound-assisted soil washing process for PCB-contaminated soils that uses organic solvents seems therefore to be a viable option, especially with the incorporation of an extra step in the sonication process relating to temperature control, which is intended to prevent the loss of the lighter congeners.