Biomass Technology Group (Netherlands)

Aiming at the low strength and poor water resistance of traditional biomass adhesives and the environmental risks of petroleum-based adhesives, this study developed a formaldehyde-free silk fibroin/gelatin (SF/GEL) biomass wood adhesive based on the synergistic effect of β-sheet structure and interfacial Schiff base reaction. Aldehyde groups were introduced on wood surfaces via “NaOH pretreatment-NaIO4 oxidation” modification. The β-sheet structure of silk fibroin enhanced the cohesion of the adhesive layer, while gelatin enhanced wettability. Under hot-pressing, aldehyde groups reacted with amino groups to form Schiff base covalent bonds, which combined with mechanical interlocking to realize interface strengthening. Under the optimal process (SF/GEL = 1:1, hot-pressing at 140 °C for 6 min), the dry strength of eucalyptus plywood reached 3.75 ± 0.25 MPa, and remained 2.95 ± 0.37 MPa after cyclic aging (soaking the specimens in boiling water for 4 h, followed by drying for 20 h, repeating this cycle twice; then testing the bonding strength after soaking the specimens in cold water for 1 h), exceeding the bonding strength requirement of 0.7 MPa specified in the GB/T 17657-2022 national standard. The dry strength of poplar plywood was 2.75 ± 0.30 MPa, and remained 1.98 ± 0.28 MPa after cyclic aging, also exceeding the 0.7 MPa bonding strength requirement of the GB/T 17657-2022 national standard. With renewable raw materials and environmentally friendly process, this adhesive provides a green and high-performance solution for the wood processing industry.

This paper presents a three-level parallel and PWM interleaved voltage source inverter with an active fourth leg (3LFVSI) for aerospace applications. The proposed topology effectively mitigates common-mode voltage (CMV), thereby reducing electromagnetic interference (EMI) while ensuring high system efficiency. The study presents a comprehensive analysis of the operational principles, modulation strategies, and circuit configurations of the 3LFVSI. Simulation results demonstrate its effectiveness in reducing high-frequency noise and commonmode current while significantly improving harmonic distortion. Additionally, the analysis highlights the fourth leg's role in synchronizing the CMV, enabling effective cancellation and enhancing overall system performance. The results confirm that the proposed topology reduces EMI noise while maintaining high efficiency in high-speed motor drive systems for more electric aircraft.

Modulating the electronic environment of single-atom metal catalysts is a promising yet challenging strategy to optimize their catalytic performance. Herein, electron-rich Ru single atoms were successfully confined within a CoOx matrix (Ru0.6CoOx) through a simple manual grinding-reduction strategy. The resulting Ru0.6CoOx catalyst demonstrated exceptional catalytic activity for the hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF), affording a nearly quantitative DMF yield with an impressive DMF productivity of 210.2 molDMF·mol–1Ru·h–1 at 160 °C. This productivity outperforms most of the noble metal-based catalysts for DMF production. Notably, Ru0.6CoOx also enabled the efficient conversion of HMF to DMF at a low reaction temperature of 120 °C or using a concentrated HMF solution (up to 20 wt %). Experimental studies combined with density functional theory calculations (DFT) revealed that the electronic interaction between the Ru species and CoOx generates electron-rich Ru single atoms, which serve as active sites to boost the H2 activation. Furthermore, the introduction of single Ru atoms was shown to increase the acidity of Ru0.6CoOx, thereby facilitating the cleavage of the C–OH bond during HMF hydrogenolysis. The boosted H2 activation ability and improved acidity of Ru0.6CoOx contribute significantly to its outstanding catalytic performance. This work provides valuable insights into the preparation of electron-rich single-atom metal catalysts for the catalytic hydrodeoxygenation of biomass-derived chemicals.

Abstract Microcrystal cellulose (MCC) is a green and sustainable resource that widely exists in various lignocellulose species in percentage 10–30%. The fine powder of MCC is often discarded in industrial productions that use lignocellulose as feedstock. The crystal structure of two types of MCC (sugarcane pith and bamboo pith) and their derived carbon materials are studied, and the key findings are summarized as follows. (1) In the MCC refined from sugarcane pith, there are large amount of cellulose 2D crystal, which can be converted to valuable 2D graphene crystal. (2) In the MCC refined from bamboo pith there are large amount of amorphous microcrystal cellulose, which can be converted to soft and elastic graphene microcrystal (GMC). (3) The 2D cellulose in MCC of sugarcane pith has large surface area and is easily to be degraded to sugars by acid-base hydrolysis reaction, which can be carbonized to Fullerenes-like carbon spheres. (4) The crystal structures of MCC derived carbon materials are strongly impacted by the crystal structures of MCC, and the carbonization reaction of MCC follows “in situ carbonization” and “nearby recombination” mechanism. In general, the results from this study may open a new way for value-added applications of microcrystal cellulose.

Pyrolysis oil from lignocellulosic biomass can be fractionated into a lignin and sugar fraction. We here provide a review on the structure, properties, depolymerisation strategies and applications for pyrolytic lignin in the framework of a biorefinery.

Reverse electrodialysis (RED) is one of the techniques able to harvest energy from the salinity gradient between different salt solutions. There is a tradeoff between efficiency and generated power in a RED stack. This paper focuses on efficiency. A simple model is presented to calculate the efficiency in a co-flow or counterflow operated stack. Moreover, the efficiency can be improved by applying multistaging; the stacks in such a system can also be interconnected externally in co- and counterflow. The four combinations of internally and externally flow modes are the base of further considerations concerning procedures for optimization of these configurations. Three methods for optimization the energy efficiency in a multistage system are discussed: (A) successively maximizing the power of each individual stage, (B) maximizing the power of the whole system by adjusting the electrical current in all stages simultaneously, and (C) maximizing the power of the whole system by adjusting the same current through each stage. Method C is the most attractive because it only requires one converter (cheaper and easier to control) while the results are hardly inferior to B and much better than A. An alternative to multistaging is electrode segmentation and the advantages and disadvantages of both systems are briefly discussed.