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Gesamtökologische Bewertung der Kaskadennutzung von Holz Umweltauswirkungen stofflicher und energetischer Holznutzungssysteme im Vergleich
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... (1) Production of new bio-based materials may require an increased manufacturing intensity, and expansion of production capacities for these materials may lead to an increased demand for regional fresh wood resources; (2) Rising final energy demands for fossil-based process energy supplies in the wood manufacturing sector [3] and competition for wood-based energy carriers may require more energy-efficient processes or innovations in fuel substitution; (3) Additional capacities may increase the competition between material and energy-related use of available woody biomass resources and thus set strong constraints on the implementation and optimization of waste-wood cascading systems [4]; (4) The varying degrees of industrial symbiosis among value-added industrial networks may have their own trade-offs in impact mitigation and resource substitution [5]. ...
... (1) Production of new bio-based materials may require an increased manufacturing intensity, and expansion of production capacities for these materials may lead to an increased demand for regional fresh wood resources; (2) Rising final energy demands for fossil-based process energy supplies in the wood manufacturing sector [3] and competition for wood-based energy carriers may require more energy-efficient processes or innovations in fuel substitution; (3) Additional capacities may increase the competition between material and energy-related use of available woody biomass resources and thus set strong constraints on the implementation and optimization of waste-wood cascading systems [4]; (4) The varying degrees of industrial symbiosis among value-added industrial networks may have their own trade-offs in impact mitigation and resource substitution [5]. ...
Bioeconomy regions are a young concept representing emerging amalgamation points for the implementation of cross-sectoral value-added chains. When sustainable bioeconomy strategies are rolled out, their proof-of-concept implies that industrial R&D activities should lead to impact decoupling and that the valorization of locally available lignocellulosic biomass has to contribute to an increase in added value. Furthermore, regional co-benefits for society and a positive influence on local environmental and socioeconomic conditions are major factors. The fulfillment of these strategic goals would be a milestone achievement when progressing from the blueprint development and the road-mapping stage towards socially accepted and sustainable wood-based bioeconomy strategies. For regional industrial and science stakeholders who run pilot facilities for process upscaling and for energy and material flow integration, this requires well-orchestrated integrative processes, which go beyond conventional "Life Cycle Management" approaches. It is obvious that assessing and monitoring such integrative systems will have to account for different stakeholder perspectives and for detailed technology deployment and resource conversion scenarios. Applying a sustainability index methodology in a case study region must include an evaluation of the whole supply chain and the process networks associated with the characteristic products of the evaluated region. To date, no such integrative assessment methods exist in the literature. Therefore, the aim of this paper is to lay out, on the basis of a practical example in the case study region of Central Germany, an assessment of the sustainability level of wood-based bioeconomy networks by applying the Sustainability Monitoring Tool-SUMINISTRO"-to examine regional bio-based industry networks.
... Though there are differences in the definitions of cascading between countries and circumstances (Fraanje 1997;Keegan et al. 2012;Gärtner et al. 2013;Carus et al. 2014;Dewulf et al. 2015), the common idea of cascading wood involves the sequential use of solid wood in applications in which the intrinsic quality of the material is retained for as long a time as possible, thereby fully realising the resource potential (Keegan et al. 2012;Gärtner et al. 2013;Dewulf et al. 2015). Several researchers have explored the flows of cascaded wood, including the benefits to be obtained from cascading. ...
... Though there are differences in the definitions of cascading between countries and circumstances (Fraanje 1997;Keegan et al. 2012;Gärtner et al. 2013;Carus et al. 2014;Dewulf et al. 2015), the common idea of cascading wood involves the sequential use of solid wood in applications in which the intrinsic quality of the material is retained for as long a time as possible, thereby fully realising the resource potential (Keegan et al. 2012;Gärtner et al. 2013;Dewulf et al. 2015). Several researchers have explored the flows of cascaded wood, including the benefits to be obtained from cascading. ...
The aim of this study was to explore potential cascading flows and the measures that could be taken to enhance cascading potential. The results reveal that the potential cascading flow needs to be considered in light of the length and condition of the wood recovered from buildings, rather than the cross-section. For instance, wood in the roof structure such as ‘1 × 4’ or ‘1 × 6’ was recovered with most of the original length intact and with minimal damage, which is suitable for direct reuse. In contrast, wood in walls, floors and ceilings such as ‘2 × 2’, ‘2 × 3’ or ‘2 × 8’ was recovered in poor condition in terms of both length and the occurrence of damage. To enhance cascading potential, the development of the jointing systems and considering the reuse of whole elements of the unit parts should be further investigated. © 2017 IWSc, The Wood Technology Society of the Institute of Materials, Minerals and Mining
... From an environmental perspective, expectations on wood cascading include a reduction of environmental impacts through the substitution of energy-intensive materials, an increase in resource efficiency as well as a prolonged storage of carbon sequestered in wood (Gärtner et al., 2013;Höglmeier et al., 2014;FAO, 2017;Risse et al., 2017;Suter et al., 2017;Mehr et al., 2018;Risse et al., 2019). So far, life cycle assessment (LCA) studies mainly focus on direct effects (e.g., savings due to the lower energy requirements for drying recovered wood as opposed to virgin wood) of wood cascading. ...
... ). Diese Herausforderung ist jedoch nicht Untersuchungsgegenstand dieser Studie.Ein Umweltentlastungspotenzial ist durch die stoffliche Verwertung von Sperrmüllbestandteilen nur vorhanden, wenn die Materialien mit vertretbarem Aufwand sortiert und vorbehandelt werden können und die rezyklierten Materialien an anderer Stelle Neumaterial in der Produktion ersetzen können. Dies ist beispielsweise bei der werkstofflichen Verwertung von Kunststoffen möglich, allerdings ist auch hier aufgrund materialtechnischer Probleme der Rezyklateinsatz und somit der Markt begrenzt.Grundsätzlich ist eine möglichst lange Kaskadennutzung von Holz vor der endgültigen energetischen Verwertung mit den geringsten Umweltauswirkungen verbunden(Gärtner et al., 2013;Vis et al., 2016). Dennoch führt eine Aufbereitung von Altholz, für das anschließend kein Bedarf zur weiteren Verwertung besteht, zu einem unnötigen Energieverbrauch.Eine getrennte Abfuhr oder eine Sortierung des heterogenen Sperrmülls ist mit erheblichem finanziellem und energetischem Aufwand verbunden. ...
A comprehensive analysis of end-of-life tire disposal in Germany was carried out. For this purpose, the legal basis, the material flows, their accounting and the companies involved were considered. Various European end-of-life tire disposal systems were compared, the possibilities and limits of recycling were considered, and a wide range of additional information on the subject of end-of-life tire recycling was compiled.
Available for download on the website of the Federal Environment Agency (UBA) in two languages: German and English.
... Die restlichen 80 % werden direkt, ohne vorherige Nachnutzung, thermisch verwertet (Bundesverband der Altholzaufbereiter und -verwerter, 2018). Dabei sollte der Rohstoff Holz grundsätzlich solange wie möglich in Form einer Kaskadennutzung im Kreislauf gehalten werden und erst, wenn keine stoffliche Nachnutzung technisch mehr möglich ist, sollte die, finale, thermische Verwertung vollzogen werden (Gärtner et al., 2013). ...
Aufgrund von Rohstoffknappheit auch bei nachwachsenden Rohstoffen kann das Recyceln von Holz und Holzwerkstoffen auch im Möbelsektor nur an vor-letzter Stelle, vor der thermischen Verwertung, stehen. Davor gilt es, schon bei der Produktion den Materialeinsatz zu reduzieren bzw. Möbel so zu gestalten, dass eine verlängerte Nutzung möglich ist. Insgesamt muss die Produktnutzung intensiviert werden. Dafür sind unter anderem geeignete Businessmodelle er-forderlich. Hiermit beschäftigt sich das Projekt PERMA an der HNEE. Wird Holz dann zum Altholz, muss die Nachnutzungsquote deutlich erhöht werden. Mit der Identifizierung und Indexierung von Altholz befasst sich daher das Kooperati-onsprojekt WIn-Altholz. Sind allerdings Holzspan-und Holzfaserwerkstoffe be-schädigt oder werden nicht mehr benötigt, gibt es bisher keine sinnvollen Nach-nutzungsszenarien. Das Forschungsprojekt "Respan" will nun ein Recyclingver-fahren entwickeln, dass die Nachnutzung möglichst aller Bestandteile der Werk-stoffe realisiert.
... In a subsequent work, Fraanje (1997) linked the implementation of cascade use with wood. Various authors have indicated the reduced environmental impacts achieved by the cascade use of wood (Budzinski et al., 2020;Gärtner et al., 2013;Höglmeier et al., 2015b;Mehr et al., 2018;Risse et al., 2017;Suter et al., 2017) The material use of recovered timber directly competes with energy use (Husgafvel et al., 2018). Currently, wood cascading concepts are still limited to the degradation of the material quality, in particular dimension (Risse et al., 2019). ...
The transition of our economy towards a bioeconomy is likely to increase the demand for wood in the future. Because the roundwood supply is limited, wood cascading is a promising concept for meeting the growing demand. In this context, it is necessary to map the current timber market for analyzing potential options for the cascading of recovered timber, and for quantifying future amounts of recovered timber, differentiated by the type of semi-finished wood product and sectoral origin. Therefore, a material flow analysis (MFA) for Germany during 2019 is performed and a model for the prediction of the recovery of timber volumes (PRecTimber) is developed. This model is based on a distributed decay approach which considers sectoral lifetimes. Historical data for the domestic consumption of timber products are used to calculate the annual decay of various timber products entering consumption. The MFA results in about 62 Mm³ solid wood equivalents (SWE) of various wood raw material assortments being required in the domestic production of wood products. An increasing amount of recovered timber with a minimum of 26.6 Mm³ (13.1 Mt) for 2019 to 29.5 Mm³ (14.2 Mt) in 2050 can be expected. In 2050, the recovered timber is derived from the sectors construction with 52%, furniture with 30%, packaging with 15%, and others with 2% (mainly consisting of sawn wood and particleboard products). The results of the model can be used, to derive estimates of the dimension and quality of the future recovered timber accompanying the potentials for cascading.
... Die Verweildauer hängt von deren Lebensdauer der Holzprodukte und dem Grad des Recyclings ab. So kann durch eine stärkere Kaskadennutzung, also die Mehrfachverwendung des Rohstoffes Holz, die THG-Bilanz der Holzprodukte verbessert werden (Gärtner et al., 2013;Sikkema et al., 2013 Aus der globalen Perspektive wird -neben einer Verringerung des Waldverlustes und der Wiederaufforstung von Wäldern -die naturnahen Bewirtschaftung und Regeneration von Wäldern als eine kosteneffiziente natürliche Minderungsmaßnahme (Natural Climate Solution) gesehen. Ihr Beitrag zur Vermeidung einer gefährlichen Erwärmung und Erreichung des Pariser 2°-Ziels wird auf ein Potenzial von 0,5-1,5 Gt CO 2 /Jahr beziffert (Griscom et al., 2017). ...
... On the other hand, the further waste wood incineration is postponed into the future, the less that is known about future heat and electricity mixes and hence the potential substitution benefits. Most likely, cleaner energy technologies will be available and more widespread in the future, thus reducing or even effacing the potential substitution benefits thereof (Werner et al., 2010;Gärtner et al., 2013;Suter et al., 2016). Nonetheless, results underline the climate mitigation potential of long-lived wood products, which are predominantly found in the construction sector (Neubauer-Letsch et al., 2012). ...
This study assesses the environmentally optimal wood utilisation patterns under varying wood cascading options, using the example of Switzerland. Cascading is the use of the same wood unit in multiple, successive product cycles. To consider aspects relevant at the system level (e.g. stocks/flows, demand/supply constraints) as well as at the product level (e.g. process inventories), we present a model that combines material flow analysis (MFA), life cycle assessment (LCA) and mathematical optimisation to identify environmentally optimal wood use scenarios concerning climate change and particulate matter formation. We separately include the temporal dynamics of biogenic carbon flows, i.e. carbon uptake, storage and subsequent release, which may have a considerable influence on the climate change performance of wood products.
Results indicate that multiple cascading (mC) of wood can decrease environmental impacts: total systemic impact reductions over the modelled 200-year time horizon compared to single cascading (i.e. all waste wood is directly incinerated), are between 35–59 Mt CO2-eq. and 43–63 kt PM10-eq. Driving factors for the environmental impact of future wood use scenarios are: waste wood processing efficiency, wood storage effects (in case of biogenic carbon accounting), and available cascading options. Particularly, high quality wood cascade of wooden beams is a promising recycling path for reducing environmental impacts.
We conclude that by implementing wood cascading, future Swiss wood utilisation can be further improved in terms of environmental impact. The tool combination of dynamic MFA, LCA and optimisation proved to be suitable to identify environmentally optimal scenarios for a complex value chain.
Zusammenfassung
Dieses Kapitel präsentiert und bewertet den aktuellen Stand des Wissens zum Konnex Landnutzung und Klimawandel in Österreich aus dem systemischen Blickwinkel der UN Agenda 2030 für eine Nachhaltige Entwicklung. Dabei wird dem Thema entsprechend auf die Verflechtungen zwischen den lokalen, nationalen und internationalen Ebenen eingegangen. Die Menschheit befindet sich in kritischen, vielfältigen und vernetzten Krisen. Integrative und globale Lösungsansätze, wie sie in der Agenda 2030 festgeschrieben sind, haben für diese multiplen Krisen ein hohes Lösungspotenzial.
Als Beitrag zur nachhaltigen Automobilproduktion wird im Folgenden die Substitution mit umweltverträglichen Werkstoffen in Form von Holz und CO2-reduziertem Stahl im Karosserieanlagenbau evaluiert. Hierzu werden mittels einer Fallstudie bei einem Betriebsmittel des Anlagenbaus die Potenziale analysiert und resultierende Zielkonflikte identifiziert. Aus dieser geht hervor, dass die Werkstoffsubstitution eine wirksame Methode zur Reduzierung der Umweltwirkungen ist.
