Two research projects of the National Research Programme “Resource Wood” have developed new processes to replace petroleum with wood for the production of important chemicals. These precursors are used in the manufacture of pharmaceuticals, plastics or fertilisers.
Petroleum means fuel, but not only: petrochemicals are a core ingredient of the chemical industry. Without oil, there would be no plastics and few pharmaceuticals or fertilisers. Finding a renewable resource as an alternative to oil will be crucial to face the foreseeable decline in oil extraction.
Two research projects of the National Research Programme “Resource Wood” (NRP 66) have made significant advances towards replacing oil with biomass derived from plants, in particular from wood. Their goals are complementary, as each one uses one of the two main constituents of wood: cellulose and lignin. These are the two most common organic components on Earth and, importantly, are renewable.
Sviatlana Siankevich of EPFL has designed new catalytic processes to efficiently transform cellulose into hydroxymethylfurfural (HMF), a very important precursor for the production of plastics, fertilisers or biofuels.(*) Inspired by the action of fungi degrading rotting wood, the team of Philippe Corvini at FHNW in Muttenz (BL) has selected enzymes capable of cutting lignin into aromatic compounds useful for making solvents, pesticides, plastics such as polystyrenes as well as active pharmaceutical ingredients.
Chemicals instead of paper
Cellulose is a long chain of carbohydrate (sugar) molecules and accounts for about two-thirds of wood’s weight. “It is mainly used for paper production, and the residuals could be better valorised by being transformed into useful chemicals,” says Sviatlana Siankevich of EPFL’s Institute of Chemical Sciences and Engineering.
With colleagues from Queen’s University in Canada and the National University of Singapore, the EPFL team led by chemist Paul Dyson synthesised several types of ionic liquids (molten salts) to convert cellulose into HMF, an important molecule for the production of commodity chemicals. In a single step, their reaction reached a 62% yield, a new record.
“Our procedure operates at mild conditions, that is, without very high temperatures or pressure or strong acids”, says Siankevich. “We’ve also been able to reduce the amount of undesired by-products, an important point if the reaction is to be scaled up for industrial processes. Our process can work with wood, but it’s often easier to use cellulose extracted from herbaceous plants.”
At the Fachhochschule Nordwestschweiz (FHNW) in Muttenz, Philippe Corvini and his PhD student Christoph Gasser are developing ways to use lignin, a long molecule which gives trees their rigidity and makes up around 15%-40% of the wood content. “Until now, lignin was not very much valorised, but often simply burned,” says Corvini. “But it can be cut into aromatic structures, molecules based on the famous carbon hexagon ubiquitous in organic chemistry. These components represent huge volumes for the chemical industry, and have been so far almost exclusively obtained from petroleum. Lignin is presently the most serious alternative.”
Some fungi secrete a combination of enzymes to degrade lignin and chop it into smaller pieces. Corvini’s team at FHNW screened the combinations of dozens of such enzymes to select the most efficient.(**) By adding a further catalytic step, they managed to transform 40% of the lignin into very small molecules such as vanillin. The process is of interest to the chemical industry, and collaboration with a lignin producer is already underway. “Most of the lignin today is obtained from wheat or rice straw,” says Corvini. “But soft wood such as spruce could prove useful as its lignin is easy to break down.”
The FHNW team also developed a way to reuse the enzymes. “We have attached them onto iron nanoparticles coated with silica, explains the researcher. After the reaction, we simply approach with a magnet to attract the particles and recover the enzymes.” As these can be reused up to ten times, the energy and resources needed to produce them is significantly reduced and fits well into the concept of “green chemistry”.
All of the wood
To be economically viable, wood as a replacement for petrochemicals must be used to the greatest extent possible. “Extracting only one component from wood in small quantity is not enough,” says Sviatlana Siankevich. “We need to find complementary processes to use all of it.” But more aspects must be considered to assess whether wood can serve as an economically viable substitute for oil. A third project of NRP 66 has recently carried out a sustainability assessment of the production of succinic acid, another important chemical, from wood residues.(***) The study from ETH Zurich and EPFL shows that smart process design can lead to energy savings and environmental benefits, key factors for biorefineries to be competitive.
(*) S. Siankevich et al.: Direct conversion of mono- and polysaccharides into 5-hydroxymethylfurfural using ionic liquid mixtures. ChemSusChem (2016); doi: 10.1002/cssc.201600313
(**) C. Gasser and P. Corvini (submitted)
(***) M. Morales et al.: Sustainability Assessment of Succinic Acid Production Technologies from Biomass using Metabolic Engineering. Energy & Environmental Science (2016); doi: 10.1039/C6EE00634E
(The first publication is available to the media upon request: firstname.lastname@example.org)
Institute of Chemical Sciences and Engineering
Tel.: +41 21 693 98 61
Institute for Ecopreneurship
Tel.: +41 61 467 43 44
Resource Wood (NRP 66)
In collaboration with industry, forest owners and authorities, the National Research Programme “Resource Wood” (NRP 66) aims to generate scientific insights and practical solutions to optimise the exploitation and use of wood in Switzerland. The overall final recommendations of NRP 66 will be published in summary reports in 2017. The Swiss National Science Foundation was commissioned (SNSF) by the Federal Council to run the programme.
http://www.snf.ch/en/researchinFocus/newsroom/Pages/news-160706-press-release-re... - Press release and related links
Media - Abteilung Kommunikation | idw - Informationsdienst Wissenschaft
First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife
Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering