Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cascading use is also beneficial for wood

11.12.2017

Another ten years — that is approximately how long sustainable forestry will be able to satisfy the continuously growing demand for wood. In Germany and Europe, new concepts are therefore being discussed for more responsible and efficient industrial use of the renewable, but still limited wood resources. Researchers at the Technical University of Munich (TUM) are using data from a European research project to analyze the potential efficiency of multiple use between harvesting and combustion of wood.

Does the cascading use of wood really lead to increased resource efficiency? For example, if the raw wood is first used to make construction elements, then slats for a table, and finally chipped and turned into chipboard before being burned for energy in a power plant?


The illustration shows the concept of cascading the use of wood with its individual stages.

(Source: Höglmeier 2015)

To answer this question, Michael Risse and Professors Gabriele Weber-Blaschke and Klaus Richter from the Chair of Wood Science at TUM set out to find suitable assessment methods.

A cascading system composed of many suppliers, manufacturers, and users is complex and costly. The material flows within and between the cascade steps are numerous and interwoven. As a theory, the concept has been described for years and has also been scientifically proven to save fossil resources, reduce greenhouse gas emissions, and increase value creation.

But so far, a targeted examination of resource efficiency has not yet been performed. Since biologically generating wood differs fundamentally from producing synthetic raw materials, it is important to examine whether and to what extent cascading use of renewable raw materials pays off in terms of efficiency.

In order to account for the characteristic features of cascading use, wood researcher Michael Risse applied the holistic life cycle approach and analyzed the exergy of all materials used, the internal recycling processes, and the consumption of other primary resources, such as the forest land areas required. Exergy refers to the percentage of energy that can be converted into work.

Savings primarily at the start of the production chain

In two scenarios, the TUM researchers compared the path of one metric ton of scrap wood with the provision of the same functions using fresh wood. In the first scenario, the recovered wood was initially processed into sawn wood and then two subsequent times into chipboard in a cascading system. In the reference scenario, the same products were manufactured, but this time out of fresh wood.

The result: In cascading use, the wood is utilized significantly more efficiently at a rate of 46 percent, compared to single use at 21 percent. The biggest savings are achieved at the beginning of the production chain due to the reduced use of fresh wood, which in turn reduces the required forest land area. Cascading use remains more efficient during the further processing of the wood, but to a significantly lesser extent. In both scenarios, the production of chipboard consumes the most resources, particularly the process of drying and gluing.

Resource-efficient processing still in its infancy

In real-world industrial use, cascading use is still in its infancy, as the necessary logistics processes and adapted process technology are not yet available. Furthermore: “Energetic utilization still has priority over the material use of wood,” lamented Professor Klaus Richter, who holds the Chair. Almost half of the 60 million metric tons of forest timber harvested each year are used to generate energy, either directly or within industrial processes.

The German Renewable Energy Sources Act (EEG) still encourages such usage until 2019, e.g. by subsidizing the generation of heat from wood energy with feed-in tariffs or by granting investment subsidies for heating installations such as wood pellet or wood chip heating systems. This one-sided incentive was already criticized in the comprehensive climate protection report for agriculture and forestry conducted in 2016, to which employees of the Chair of Wood Science also contributed.

Today, only a third of the recovered wood generated in Germany is being converted into chipboard; according to Richter, approximately seven million metric tons end up being burned directly in order to generate heat and electricity in power plants. For the wood scientist, this is at least one step too few. He and his team of researchers advocate a more intensive material use of wood: “Over the mid-term, we need to utilize wood more efficiently, i.e. multiple times as a material, before we burn or turn it into pellets. Its material properties do not stand in the way of cascading use. However, the processing and use of wood needs to be adapted from a planning and conceptual standpoint so that multiple use becomes a reality.”

According to doctoral candidate Michael Risse, additional analyses in the context of cascading use are also essential: “For example, during the efficiency analysis, the scarcity of the individual primary natural resources should also be taken into account.” For one, his published study does not take into account what is called the ‘substitution effect’, which makes another weighty argument for cascading use: “The use of wood products helps to avoid greenhouse gas emissions that result during the production of non-wood products such as steel or concrete — and that applies equally for each additional cascading stage,” Professor Richter explained. “Furthermore, wood is the only material that stores carbon — throughout its entire life cycle.”

This way, the carbon bound during the growth of the tree is removed from the atmosphere and is only released again at the end of the cascade — which should last as long as possible. “However, theoretical analyses alone won’t cut it. We need action from policymakers and the industry,” Richter emphasized.

Publication:
Michael Risse, Gabriele Weber-Blaschke and Klaus Richter: Resource efficiency of multifunctional wood cascade chains using LCA and exergy analysis, exemplified by a case study for Germany, Resources, Conservation & Recycling 126, 141-152, 2017. DOI: http://dx.doi.org/10.1016/j.resconrec.2017.07.045

Contact:
Prof. Dr. Klaus Richter
Technical University of Munich
Chair of Wood Science
Phone: +49 89 2180 6421
richter@hfm.tum.de

www.hfm.tum.de 

Weitere Informationen:

https://www.tum.de/nc/en/about-tum/news/press-releases/detail/article/34365/

Dr. Ulrich Marsch | Technische Universität München

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>