24 research outputs found

    DT-TV. Grafik till djungeltrumman.se:s webb-TV

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    The goal with the project was to make the graphic for Djungeltrumman.se´s upcoming webb-TV. Djungeltrumman.se is a clubguide on the internet and as a magazine. Their target group is people in the age between 18-34 with an interest for culture and nightlife that lives in a city where Djungeltrumman.se is active. The purpose of the project was to make a graphical frame that had the feelling of Djungeltrumman.se. The feeling should capture the interest of the target group and make them care more for Djungeltrumman.se. The graphics will contain an intro, information frames and presentations for the different parts in the program. In this project I focused on making the intro for the program. The other graphical content will later on be based on the intro. How can I make an intro that captures the interest of the targetgroup, again and again without them getting tired of it? With what and how do you present Djungeltrumman.se best in motion graphic? A television intro? What does the history tell about it? The making of the intro was focused on the three keywords, the city, energy and guidance. And from those words I made a colour pallet. The biggest decision was to build a real model of a city. With that I got a depth in the footage that never could be made in 3d. Every little part of the model had something to tell. Ruff edges and windows that were cut by hand gave a charming look. The result of my project was an intro that communicated the feeling of Djungeltrumman. se with my keyword the city, energy and guidance. It captures the interest of the viewer that wants to see it again and again

    Characterization and densification of carbonized lignocellulosic biomass

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    This thesis focuses on developing two main areas: characterization and densification of carbonized lignocellulosic biomass. Thermally treated biomass undergoes changes that enrich the content of carbon in the remaining solid fraction. The carbon content is correlated to the temperature and residence time of the treatment and affects the properties of the material as a fuel e.g. gross calorific value. Near infrared (NIR) spectroscopy was used to predict a wide range of variables from forest- and agro-based biomass thermally treated at 240 to 850 ˚C. The result showed that NIR provided excellent predictions e.g. for energy, carbon, oxygen and hydrogen contents. The changes of the biomass properties after thermal treatment, such as torrefaction, change also the pelletizing properties. A parametric study was conducted at bench scale in a single pellet press tool where four parameters were examined with respect to pellet quality responses. The study showed a narrow process window for pelletizing at around 5% moisture content. Further pelletizing studies in pilot scale demonstrated that higher moisture contents were needed for satisfying pellet quality. This indicated that there is a discrepancy between the material’s moisture content before pelletizing and at the actual moment of feed layer formation and pelletizing. By drying both torrefied and untreated material it was shown that torrefied materials dried at a significantly higher rate. Thus, observed uneven pellet production caused by feed layer breakage was related to the drying rate due to heat from friction in the pellet press channels. This was demonstrated by developing two methods for cooling the pelletizing process: one with direct cooling by water injection and one with indirect cooling by coils in the die, and hereby reduce drying and keep the moisture content at a level where pelletizing was possible. This showed that cooling of the pelletizing process can be beneficial for the pellet quality. The overall result for successful densification of thermally treated lignocellulosic biomass into a standardized commodity with high energy and bulk density stresses the need: (1) to find tools that characterize biomass facilitating suitable settings in the densification step; (2) to apply new innovative steps in sub-processes like cooling of the feed layer; and, finally, (3) to find matching combinations of torrefaction and pelletization

    Valorizing Assorted Logging Residues: Response Surface Methodology in the Extraction Optimization of a Green Norway Spruce Needle-Rich Fraction To Obtain Valuable Bioactive Compounds

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    During stemwood harvesting, substantial volumes of logging residues are produced as a side stream. Nevertheless, industrially feasible processing methods supporting their use for other than energy generation purposes are scarce. Thus, the present study focuses on biorefinery processing, employing response surface methodology to optimize the pressurized extraction of industrially assorted needle-rich spruce logging residues with four solvents. Eighteen experimental points, including eight center point replicates, were used to optimize the extraction temperature (40–135 °C) and time (10–70 min). The extraction optimization for water, water with Na2CO3 + NaHSO3 addition, and aqueous ethanol was performed using yield, total dissolved solids (TDS), antioxidant activity (FRAP, ORAC), antibacterial properties (E. coli, S. aureus), total phenolic content (TPC), condensed tannin content, and degree of polymerization. For limonene, evaluated responses were yield, TDS, antioxidant activity (CUPRAC, DPPH), and TPC. Desirability surfaces were created using the responses showing a coefficient of determination (R2) > 0.7, statistical significance (p ≤ 0.05), precision > 4, and statistically insignificant lack-of-fit (p > 0.1). The optimal extraction conditions were 125 °C and 68 min for aqueous ethanol, 120 °C and 10 min for water, 111 °C and 49 min for water with Na2CO3 + NaHSO3 addition, and 134 °C and 41 min for limonene. The outcomes contribute insights to industrial logging residue utilization for value-added purposes

    Combining behavioural TOPSIS and six multi-criteria weighting methods to rank biomass fuel pellets for energy use in Sweden

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    EU energy and climate policies continue to drive interest in biomass fuel pellets which can be produced from a wide variety of feedstock. The use of multi-criteria decision analysis (MCDA) to support feedstock selection has the potential for more transparent and better decision-making. This study applies the behavioural TOPSIS, a prominent MCDA technique, to rank pellets for energy use in Sweden produced from under-utilised forest and agricultural biomass. Seven criteria were used to assess and rank the biomass pellets. The alternatives include 88 types of pellets from 11 biomass materials. Possible attitudes of an expert towards the risk of losses (risk averse, risk neutral and risk-seeking) were combined with six sets of criteria weights obtained using six weighting methods – a total of 18 input settings (scenarios). Despite having different input settings, almost identical results were obtained in all scenarios, meaning that the rankings were stable and consistent. Across all 18 scenarios, pellets produced from a reference spruce/pine sawdust blend are ranked ahead of other pellet types. Pellets produced from Scots pine bark exhibited stable and consistent rankings across all scenarios; and thus this biomass is the second-best overall. The next best materials overall are poplar, reed canary grass and wheat straw, whereas torrefied pellets (torrefied beech, poplar and wheat straw) were ranked last in all scenarios. Combining behavioural TOPSIS and a variety of criteria-weighting methods is a meaningful way of improving decision-making with respect to producing a more valid and reliable ranking of biomass fuel pellets for energy use in Sweden

    Gasification of pure and mixed feedstock components: Effect on syngas composition and gasification efficiency

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    The aim of this work was to investigate whether the use of individual tree components (i.e., stem wood, bark, branches, and needles of spruces) as feedstocks during oxygen blow gasification is more efficient than using mixtures of these components. Experiments were performed at three oxygen levels in an 18-kW oxygen blown fixed bed gasifier with both single and mixed component feedstocks. The composition of the resulting syngas and the cold gas efficiency based on CO and H-2 (CGE(fuel)) were used as response variables to evaluate the influence of different feedstocks on gasification performance. Based on the experimental results and data on the composition of similar to 26000 trees drawn from a national Swedish spruce database, multivariate models were developed to simulate gasifier performance under different operating conditions and with different feedstock compositions. The experimental results revealed that the optimal CGE(fuel) with respect to the oxygen supply differed markedly between the different spruce tree components. Additionally, the models showed that co-gasification of mixed components yielded a lower CGE(fuel )than separate gasification of pure components. Optimizing the oxygen supply for the average tree composition reduced the CGE(fuel) by 1.3-6.2% when compared to optimal gasification of single component feedstocks. Therefore, if single-component feedstocks are available, it may be preferable to gasify them separately because doing so provides a higher gasification efficiency than co-gasification of mixed components

    A review on wood powders in 3D printing: processes, properties and potential applications

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    Three-dimensional (3D) printing is a technology that, for a multitude of raw materials, can be used in the production of complex structures. Many of the materials that currently dominate 3D printing (e.g. titanium, steel, plastics, and concrete) have issues with high costs and environmental sustainability. Wood powder is a widely available and renewable lignocellulosic material that, when used as a fibre component, can reduce the cost of 3D printed products. Wood powder in combination with synthetic or natural binders has potential for producing a wide variety of products and for prototyping. The use of natural binders along with wood powder can then enable more sustainable 3D printed products. However, 3D printing is an emerging technology in many applications and more research is needed. This review aims to provide insight into wood powder as a component in 3D printing, properties of resulting products, and the potential for future applications

    Using macromolecular composition to predict optimal process settings in ring-die biomass pellet production

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    This study was performed to investigate if the process settings that give high pellet durability can be modelled from the biomass’ macromolecular composition. Process and chemical analysis data was obtained from a previous pilot-scale study of six biomass assortments that by Principal Component Analysis (PCA) was confirmed as representative for their biomass types: hardwood, softwood bark, short rotation coppice (SRC), and straw and energy crops. Orthogonal Partial Least Squares Projections to Latent Structures (OPLS) models were created with the content of macromolecules as factors and the die compression ratio and the feedstock moisture content at which the highest pellet durability was obtained as responses. The models for die compression ratio (R2X = 0.90 and Q2 = 0.58) and feedstock moisture content (R2X = 0.87 and Q2 = 0.60), rendered a prediction error for obtained mechanical durability of approximately ±1%-unit, each. Important factors for modelling of the die compression ratio were: soluble lignin (negative), acetyl groups (negative), acetone extractives (positive), and arabinan (positive). For modelling of the feedstock moisture content, Klason lignin (negative), xylan (positive), water-soluble extractives (negative), and mannan (negative), were the most influential. Results obtained in this study indicate that it is possible to predict optimal process conditions in pelletizing based on the macromolecular composition of the raw material. In practice, this would mean a higher raw material flexibility in the pellet factories through drastically reduced risk when introducing new raw materials

    Pelleting torrefied biomass at pilot-scale – Quality and implications for co-firing

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    The co-firing of solid biofuels in coal plants is an attractive and fast-track means of cutting emissions but its potential is linked to biomass densification. For torrefied materials this topic is under-represented in literature. This pilot-scale (121–203 kg h−1) pelleting study generated detailed knowledge on the densification of torrefied biomass compared to untreated biomass. Four feedstock with high supply availability (beech, poplar, wheat straw and corn cob) were studied in their untreated and torrefied forms. Systematic methods were used to produce 180 batches of 8 mm dia. pellets using press channel length (PCL) and moisture content (MC) ranges of 30–60 mm and 7.3–16.6% (wet basis) respectively. Analysis showed that moderate degrees of torrefaction (250–280 °C, 20–75 min) strongly affected pelleting behaviour. The highest quality black pellets had a mechanical durability and bulk density range of 87.5–98.7% and 662–697 kg m−3 respectively. Pelleting energy using torrefied feedstock varied from −15 to +53 kWh t−1 from untreated with increases in production fines. Optimal pelleting MC and PCL were reduced significantly for torrefied feedstock and pellet quality was characterised by a decrease in mechanical durability and an increase in bulk density. Energy densities of 11.9–13.2 GJ m−3 (as received) were obtained

    Effect of torrefaction on properties of pellets produced from woody biomass

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    Torrefaction has been recognized as a promising strategy to improve handling and storage properties of wood-based pellets, thus producing a uniform-quality commodity with high energy density and hydrophobicity. In this work, pellets produced from spruce stem wood, bark, and forest residues were torrefied in a bench-scale tubular reactor at 225 and 275 °C with two residence times (30 and 60 min). The effects of torrefaction on general properties, grindability, mechanical properties, hydrophobicity, and microstructure of the studied pellets were investigated. The increase of torrefaction severity reduced mass yields, but the heating values and the fixed carbon content of the torrefied pellets considerably increased. The grindability of raw pellets was substantially improved after torrefaction treatment. The energy required for grinding torrefied pellets is less than 50% of the energy needed for grinding the untreated pellets. In comparison to untreated pellets, the particles from ground torrefied pellets have clearly smaller sizes in a narrower size range. The increase of torrefaction severity improved hydrophobicity of the pellets, which have high resistance to water uptake and maintain their integrity after immersion testing. Upon torrefaction treatment, the durability and tensile strength of the pellets slightly decreased. Scanning electron microscopy analysis results show that particles from wood pellets torrefied at 275 °C lost their fibrous structure with an evident decrease of length/diameter ratios compared to untreated wood pellets. The particles from ground torrefied pellets are more uniform in terms of shape and size. Torrefaction can considerably improve grindability and uniformity of wood-based pellets and make them more acceptable in pulverized fuel applications. Wood,Biomass,Energy,Durability,MaterialspublishedVersionPaid open acces
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