RISE – Research Institutes of Sweden
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Upgrading of fast pyrolysis bio-oils to renewable hydrocarbons using slurry- and fixed bed hydroprocessing
No full textLiquefaction of lignocellulosic biomass through fast pyrolysis, to yield fast pyrolysis bio-oil (FPBO), is a technique that has been extensively researched in the quest for finding alternatives to fossil feedstocks to produce fuels, chemicals, etc. Properties such as high oxygen content, acidity, and poor storage stability greatly limit the direct use of this bio-oil. Furthermore, high coking tendencies make upgrading of the FPBO by hydrodeoxygenation in fixed-bed bed hydrotreaters challenging due to plugging and catalyst deactivation. This study investigates a novel two-step hydroprocessing concept; a continuous slurry-based process using a dispersed NiMo-catalyst, followed by a fixed bed process using a supported NiMo-catalyst. The oil product from the slurry-process, having a reduced oxygen content (15 wt%) compared to the FPBO and a comparatively low coking tendency (TGA residue of 1.4 wt%), was successfully processed in the downstream fixed bed process for 58 h without any noticeable decrease in catalyst activity, or increase in pressure drop. The overall process resulted in a 29 wt% yield of deoxygenated oil product (0.5 wt% oxygen) from FPBO with an overall carbon recovery of 68%. Correspondence Address: N. Bergvall; Research Institutes of Sweden AB, Borås, Box 857, SE-501 15, Sweden; This work was funded by the Swedish Energy Agency, project number 41253-2</p
Rethinking the diffusion of grassroots innovations : An embedding framework
No full textThis paper conceptualises the ways grassroots innovations (GIs) influence sustainability transitions. While research on GI diffusion tends to use the three-pathway model (replication, scaling up and translation), this paper rethinks GI diffusion through the lenses of an embedding framework. We illustrate this framework by applying it to the empirical case of ecovillages in the Global North and South. The results show that GIs become embedded in wider society through different dynamics: expansion, reframing, circulation of knowledge, shifting material arrangements and replication. The embedding framework brings clarity to diverse dynamics of diffusion and is particularly able to grasp the cultural, cognitive, economic and environmental impacts of GI initiatives. This work was supported by the Swiss National Science Foundation (SNSF) (grant number 10001A_197351 ).</p
Relationship between hemolysis and lipid oxidation in red blood cell-spiked fish muscle; dependance on pH and blood plasma
No full textThe relationship between hemolysis and lipid oxidation was explored in red blood cell (RBCs)-spiked washed cod mince (WCM). At pH 6.8 and 3 ± 1 °C, intact RBCs (71 µM Hb) delayed lipid oxidation by 1 day compared to WCM with partly or fully lysed RBCs which oxidized immediately. Intact RBCs also lowered peak peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) with up to 59.5% and 48.1%, respectively. Adding 3% (v/w) blood plasma to RBC-spiked WCM delayed the lipid oxidation onset from 1 to 3–4 days without delaying hemolysis. At pH 6.4 the oxidation onset in RBC-WCM was the same as for pH 6.8 while at pH 7.2–7.6 lipid oxidation was suppressed for 7 days. Micrographs revealed RBC-lysis from day 2 at pH 6.4 but at pH 7.6, RBC stayed intact for ≥ 7 days. Thus, assuring presence of plasma-derived antioxidants and/or elevating muscle pH to avoid hemolysis can aid valorization of blood rich underutilized fish raw materials. This work was supported by the Swedish research council for sustainable development (FORMAS) Grant no. 2016-01181. This project has also received funding from Region Västra Götaland (project RUN 2019-00345) and the Bio Based Industries Joint Undertaking (JU) under grant agreement (No 837726). The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio Based Industries Consortium</p
Experimental and numerical investigation on bearing behavior of hybrid thin/thick-ply composite laminates
No full textExperimental and numerical studies were carried out to characterize hybrid thin- and thick-ply composite laminates and assess modelling capabilities. Five different composite laminates were manufactured using a single material system with varying proportions of thin plies (0%, 50%, and 100% thin-ply). Bearing tests were performed and the results from the tests were investigated. The results showed that performance, in terms of bearing strength at onset of damage and ultimate bearing stress, increased proportionally with the increasing amount of thin plies within the laminate. Microscopic examination of the failure modes for all laminates was performed at the center of the hole to determine the dominant failure mode. The numerical investigation uses a highly detailed mesoscale model previously validated for crash simulations but never used successfully to bearing damage areas. The results showed a good correlation regarding both the load response and the morphology of damage.
Sustainable Materials from Organosolv Fibers and Lignin, Kraft Fibers, and Their Blends
No full textThe aim of this study was to investigate new materials from organosolv fibers, organosolv lignin, kraft fibers, and their blends. The organosolv fibers showed reprecipitated lignin on the surface, a comparably low fiber length of 0.565 mm on average, and a high fines content of 82.3%. Handsheets were formed and thermopressed at 175 °C and 50 MPa, yielding dense materials (1050–1100 kg/m3) with properties different to that of regular paper products. The thermopressing of organosolv fibers alone produced materials with similar or better tensile strength (σb = 18.6 MPa) and stiffness (E* = 2.8 GPa) to the softwood Kraft reference pulp (σb = 14.8 MPa, E* = 1.8 GPa). The surface morphology was also smoother with fewer cavities. As a result, the thermopressed organosolv fibers exhibited higher hydrophobicity (contact angle > 95°) and had the lowest overall water uptake. Combinations of Kraft fibers with organosolv fibers or organosolv lignin showed reduced wetting and a higher density than the Kraft fibers alone. Furthermore, the addition of organosolv lignin to Kraft fibers greatly improved tensile stiffness and strength (σb = 23.8 MPa, E* = 10.5 GPa), likely due to the lignin acting as a binder to the fiber network. In conclusion, new thermopressed materials were developed and tested, which show promising potential for sustainable fiber materials with improved water resistance. Correspondence Address: J. Ruwoldt; RISE PFI AS, Trondheim, Høgskoleringen 6B, 7491, Norway; This article was funded by the Research Council of Norway via the FME Centre for environmentally friendly energy research Bio4Fuel, grant number 257622.</p
Toward Sustainability in All-Printed Accumulation Mode Organic Electrochemical Transistors
No full textAbstract This study reports on the first all-printed vertically stacked organic electrochemical transistors (OECTs) operating in accumulation mode; the devices, relying on poly([4,4?-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2?-bithiophen-5,5?-diyl]-alt-[thieno[3,2-b]thiophene-2,5-diyl]) (pgBTTT) as the active channel material, are fabricated via a combination of screen and inkjet printing technologies. The resulting OECTs (W/L ≈5) demonstrate good switching performance; gm, norm ≈13 mS cm?1, µC* ≈21 F cm?1 V?1 s?1, ON?OFF ratio > 104 and good cycling stability upon continuous operation for 2 h. The inkjet printing process of pgBTTT is established by first solubilizing the polymer in dihydrolevoglucosenone (Cyrene), a non-toxic, cellulose-derived, and biodegradable solvent. The resulting ink formulations exhibit good jettability, thereby providing reproducible and stable p-type accumulation mode all-printed OECTs with high performance. Besides the environmental and safety benefits of this solvent, this study also demonstrates the assessment of how the solvent affects the performance of spin-coated OECTs, which justifies the choice of Cyrene as an alternative to commonly used harmful solvents such as chloroform, also from a device perspective. Hence, this approach shows a new possibility of obtaining more sustainable printed electronic devices, which will eventually result in all-printed OECT-based logic circuits operating in complementary mode.This project received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no. 964677 (MITICS). The authors would like to thank Jessica Åhlin for valuable electrolyte discussions. A.M. and P.A.E. thank Vinnova for financial support (grant agreement no. 2023-01337). W.M., L.B., and A.G. thank the FWO Vlaanderen for financial support (WEAVE project G025922N and Ph.D. grant 1S70122N)</p
A Hybrid Discrete-Finite Element method for continuous and discontinuous beam-like members including nonlinear geometric and material effects
No full textThis paper introduces a novel formulation, called Hybrid Discrete-Finite Element (HybriDFEM) method, for modeling one-directional continuous and discontinuous planar beam-like members, including nonlinear geometric and material effects. In this method, the structure is modeled as a series of distinct rigid blocks, connected to each other through contact pairs distributed along the interfaces. Each of those contact pairs are composed of two nonlinear multidirectional springs in series, which can represent either the deformation of the blocks themselves, or the deformation of their interface. Unlike the Applied Element Method, in which contact pairs are composed of one single spring, the current approach allows capturing phenomena such as sectional deformations or relative deformations between two blocks composed of different materials. This method shares similarities with the Discrete Element Methods in its ability to model contact interfaces between rigid or deformable units, but does not require a numerical time-domain integration scheme. More importantly, its formulation resembles that of the classical Finite Elements Method, allowing one to easily couple the latter with HybriDFEM. Following the presentation of its formulation, the method is benchmarked against analytical solutions selected from the literature, ranging from the linear-elastic response of a cantilever beam to the buckling and rocking response of continuous flexible columns, and rigid block stackings. One final example showcases the coupling of a HybriDFEM element with a linear beam finite element.The first author is thankful for the financial support given by UCLouvain.</p
Pyrolysis and thermal properties of wood and high-density polyethylene
No full textSample tests were conducted to obtain thermal and kinematic parameters for wood and high-density polyethylene (HDPE) that were used in a series of intermediate scale tunnel fire tests with and without water-based fire suppressions systems. The thermal properties were measured using Transient Plane Source (TPS) and Transient Line Source (TLS). The pyrolysis kinetics parameters were tested based on Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Different methods were used to obtain pyrolysis kinetics parameters. Different oxygen concentrations exposed to samples were tested and the results showed its significant influence in the charring process.The work is part of the project “Mechanisms and performance of different fixed fire fighting systems in tunnels” funded by Swedish Research Council FORMAS (2019-00521)</p
Slutrapport inom Gothenburg Green City Zone (GGCZ): Metodik för analys och införande av klimatneutrala mobilitets- och transportlösningar i städer
No full textDenna rapport är ett arbetsdokument som har efterfrågats i arbetet inom Gothenburg Green City Zone (GGCZ), där det pågår en process för att ta fram en mer detaljerad planering för en övergång till helt fossilfria transporter i Göteborg. Rapporten resonerar först kring zonbegreppet, vilken forskning som tidigare gjorts, vilka slags zoner som redan finns och som implementerats i Sverige och Europa. Rapporten föreslår sedan en metodik för hur zoner kan definieras och hur en generell zonindelning skulle kunna upprättas som skulle kunna användas som mall för både Göteborg och andra städer. Arbetet är inte färdigt utan kommer att fortsätta under kommande år både inom RISE och tillsammans med övriga samarbetspartners. Det som kvarstår är att definiera i detalj vilka parametrar och egenskaper som gör en viss zon unik, exempelvis genom mätetal som stadsdelars täthet, demografi, socioekonomiska förhållanden, infrastruktur samt befintlig framkomlighet. Målet med arbetet har varit att utveckla och förbättra kunskapen om zonmetodiken, visa på dess möjliga fördelar och utveckla ett verktyg för att användas i omställningen och att hjälpa Göteborg och andra städer att lyckas med omställningen mot klimatneutrala transporter till år 2030
3R-Refinement principles : elevating rodent well-being and research quality
No full textThis review article delves into the details of the 3R-Refinement principles as a vital framework for ethically sound rodent research laboratory. It highlights the core objective of the refinement protocol, namely, to enhance the well-being of laboratory animals while simultaneously improving the scientific validity of research outcomes. Through an exploration of key components of the refinement principles, the article outlines how these ethics should be implemented at various stages of animal experiments. It emphasizes the significance of enriched housing environments that reduce stress and encourage natural behaviors, non-restraint methods in handling and training, refined dosing and sampling techniques that prioritize animal comfort, the critical role of optimal pain management and the importance of regular animal welfare assessment in maintaining the rodents well-being. Additionally, the advantages of collaboration with animal care and ethics committees are also mentioned. The other half of the article explains the extensive benefits of the 3R-Refinement protocol such as heightened animal welfare, enhanced research quality, reduced variability, and positive feedback from researchers and animal care staff. Furthermore, it addresses avenues for promoting the adoption of the protocol, such as disseminating best practices, conducting training programs, and engaging with regulatory bodies. Overall, this article highlights the significance of 3R-Refinement protocol in aligning scientific advancement with ethical considerations along with shaping a more compassionate and responsible future for animal research. Correspondence Address: M. Bäckberg; RISE Research Institutes of Sweden, Sweden. </p