Steel is the worlds most used metal and 2016 the produced amount of steel was measured to a total1630 MT where the Blast Furnace (BF) - Basic Oxygen Steelmaking (BOS) process, which is the mostcommon steel process, stands for 75% of the world’s current crude steel production.The BOS process works by blowing oxygen at high velocity through a hot metal bath consisting of hotmetal from the blast furnace mixed with fluxing agents as slag formers and up to 30 weights% scrap.Due to the high focus on environmental aspects throughout the world, the importance of utilizing andrecycling scrap and by-products such as slag and dust has increased. But when byproducts are recycled,the risk of impurities in the refined hot metal increases. To be able to control the impurities and reducethe risk of getting off-specification end product, it is important to understand when and where theimpurities end up.Zinc and chromium are two of these impurities that may cause issues to the process. To prevent thisfrom happening BlueScope Steel, a steel plant based in Wollongong, Australia, with a productioncapacity of 3 million tons of crude steel, wants to find out where these elements come from and howthey partition. For zinc, it is observed that most of it will end up in the offgas, while for chromium it isnoted that the majority exits with the steel and slag. It is assumed for both elements that the missingamount enters with the shredded steel scrap (shred) to meet the required mass balance using industrialdata. Results showed that the shred needs to contain between 0.312% and 0.515% zinc in order tosatisfy the zinc balance for year 2014 to 2019. For chromium, the range is from 0.315% to 0.371%.Data analyses carried out using SIMCA UMETRICS, which is a multivariate program used to performPrincipal Component Analysis (PCA) and Partial Least Squares (PLS) regression, and normal regressionsdone in Excel showed that zinc in the crude steel cannot be used to calculate or predict the partitioningfactors for zinc between slag, melt and off gases, due to a R2 (Goodness of fit) of 0.144, where the highera R2 value is the better the fit to the model. Slag showed better results with an R2 of 0.473 This regressionwas only done for heats with Zn contents above the detection limit, so it will most likely only beapplicable to heats where relatively high amounts of zinc are expected to end up in the slag. The amountof zinc that ends up in the offgas was above 95% for all the heats modelled.For chromium, results for predicting the partitioning between slag and melt showed greater promise,an R2 of 0.663 was obtained for regression of chromium in crude steel, and an R2 of 0.566 was obtainedfor regression of chromia in the slag. Both values are considered acceptable when analyzing plant data.When comparing the two, using the regression from chromium in the crude steel gives a slightly moreaccurate result, with a partitioning difference of only +/- 0.03 and a 97-99% accuracy, compared to +/-0.05 for chromia in the slag with a 95-98% accuracy.The model is used to compare how different amounts of shred will impact the partitioning of the twoelements analyzed. It also looks at how newer generations of filter cake, containing higher amounts ofzinc will impact the partitioning of zinc between the phases, especially the concentration of zinc thatreports to the dust.

Boliden’s mineral processing plant in Garpenberg wanted to investigate their zinc-regrinding circuit. The re-grinding circuit had performed subpar when running as the total recovery of zinc was lowered and problem with the dewatering of the final concentrates was also noted. Therefore, the zinc re-grinding circuit is currently not being used. Furthermore, it was noted during investigations about silicate depressant that the zinc circuit had problems with coarse sized sphalerite particles locked with silica. Which could perhaps be liberated with the re-grinding circuit. The purpose was therefore to investigate how a re-grinding step could be used to liberate locked sphalerite particles from gangue. The practical part of the thesis involved lab-scale SMD-mill, re-grinding of the scavenger concentrate and cleaner tailings which are the two streams being fed to the SMD-mill in the plant. The re-grind was done in three fractions: bulk, +90µm and +125 µm fraction with subsequent lab-scale flotation afterwards to identify how the re-grinding effected the flotation results. Also, a small QEMSCAN analysis was performed for the +90 µm fraction to identify how liberation was improved by re-grinding. The flotation trials were performed with two references and two different intensities for the re-grinds.  The results showed an overall increase in grade of zinc in the concentrate with increased grinding for all the trials. SiO2 and MgO content (typical elements for silicate gangue) was also reduced in the zinc concentrate, showing that re-grinding helped liberate locked sphalerite particles. The QEMSCAN results showed that the liberation of sphalerite particles in the +90 µm fractions increased with re-grinding. For the bulk fraction scavenger concentrate the zinc recovery increased slightly, for the +90 µm fraction scavenger concentrate, a slight decrease in zinc recovery could be seen after re-grinding. The decrease in recovery was larger for the cleaner tailings (bulk and +90 µm) and was decreased further with increased grinding. However, for the +125 µm fraction tests, zinc recovery was increased for both scavenger concentrate and cleaner tailing. The references showed an overall high recovery but a zinc grade in the concentrate close to the feed grade of zinc and contained a high grade of SiO2. Indicating that without re-grinding the amount of free sphalerite is low. Overall, the re-grind and flotation tests pointed towards that value can be created for the plant by re-grinding the scavenger concentrate and cleaner tailing.

CO2 separation is one of the most important roles in CO2 mitigation target as many human production activities (e.g., cement, iron and steel, and biogas productions) cause CO2 emissions. The solvent-based absorption is the most mature technology for CO2 separation, where different solvents capture CO2 either in chemical or physical absorptions. However, different solvents used in the process always suffer from various problems. For example, the high energy penalty for solvent regeneration, the high solvent loss caused by high volatility and the solvent degradation, and the equipment corrosion are the major concerns of chemical solvent. For the physical solvents, the co-absorption of components other than CO2 reduces the solvent selectivity and increases the operation complexity. Therefore, deeper knowledge about the developed process and new solvent development are the two major ways of overcoming the above-mentioned problems. The goal of this work was to perform systematic studies on both conventional process and novel solvent system(s) for CO2 separation. The CO2 separation with MEA-based process was selected in the field of the conventional approach to capture CO2 from the industrial flues gases. The MEA solvent concentration was identified first, and the effect of three selected parameters, i.e., CO2 concentration, gas flow rate, and CO2 removal rate on capital cost, operational cost, and annual total cost, was evaluated to reduce the energy demand and process cost. 20% MEA solvent is identified as the optimal concentration. According to the parameter study, the CO2 concentration shows the most significant effect, followed by the gas flow rate, and the CO2 removal rate causes the smallest effect. When varying the selected parameters, CAPEX has a greater change in percentage value than OPEX; however, OPEX was the most important one to the total cost owing to its larger absolute value (approximately 3 times of CAPEX). For the solvent development, a conventional polyamine PEHA was selected as it exhibits high thermal stability, low toxicity, and low vapor pressure. Lab testing indicates the 20 wt.% PEHA solution has the best CO2 absorption performance. By using the real bio-syngas from a pilot-scale fixed bed gasifier, the gases other than CO2 (i.e., CO, H2, CH4) were not absorbed in PEHA to any significant extent even at relatively high pressure, and their presence did not affect the CO2 absorption capacity significantly. 20 wt.% PEHA aqueous solvent is a promising chemical solvent for separating CO2 from bio-syngas. For the newly developed novel solvent, ionic liquid (IL) has drawn significant attention as a substitute of conventional solvents due to its superior properties, such as negligible vapor pressure, high thermal stability, and tunable structure. Among many studied ILs, the superbase IL named 1, 8-diazabicyclo-[5,4,0]undec-7-ene imidazole ([HDBU][IM]) shows a very promising CO2 absorption capacity (4.41 mol-CO2/kg-IL), while the high viscosity is a critical issue to cope with. Herein, adding cosolvent was selected as the method to mild the viscosity problem and maintain a high level of CO2 absorption capacity. The dimethyl ethers of polyethylene glycol (DEPG) was selected as the cosolvent of superbase-derived IL [HDBU][IM], and the optimal mass ratio (IL: cosolvent) was identified at 2:1. The temperature effect was studied, showing the high CO2 absorption capacity is favored with low temperature. The effect of gases (CH4, N2) presented in the inlet gas other than CO2 was positive in terms of CO2 selectivity. The thermodynamic modeling agreed well (ARD < 2.37%) with the experimental results. The [HDBU][IM]-DEPG binary system is a promising candidate for separating CO2 from CH4 and N2, and more research will be conducted in the future.

I dagens samhälle genereras en stor mängd avfall, där stora delar av avfallen förbränns vilket inte är gynnsamt för vare sig miljön eller klimatet. Därför finns det idag ett stort behov av klimatsmarta metoder där avfallen kan användas till att producera produkter som kan motverka klimatförändringar. Största delen av avfallen som genereras kommer från större företag som till exempel IKEA och de är i ständigt behov av nya metoder för att kunna använda sina avfall till klimatsmarta resurser. Att producera biokol av avfallen är en sådan klimatsmart metod, där biokolet är en hållbar produkt som både motverkar klimatförändringar och andra miljöproblem såsom övergödning. I denna rapport undersöktes två avfallsfraktioner från IKEA, vilka var Dust2k och Hogger. Det som undersöktes var hur lämpliga avfallsfraktionerna från IKEA är för produktion av biokol som skulle kunna appliceras i jordbruket samt hur denna lämplighet påverkas av avfallsfraktion och processförhållanden som används under pyrolysen. För att besvara frågeställningarna utfördes pyrolys på avfallsfraktionerna vid pyrolystemperaturerna 550℃ och 750℃, vilket gav fyra olika prover av biokol. Dessa prov analyserades med ett antal analysmetoder för att avgöra biokolets lämplighet som jordförbättrare och för att motverka klimatförändringar. De analyser som utfördes var elementaranalys, pH-mätning, termogravimetrisk analys (TGA), Brunauer-Emmet-Teller (BET) och svepelektronmikroskopi (SEM). Från pyrolysen och TGA kunde utbytet bestämmas, vilket uppgick till över 20% för samtliga prov. Elementaranalysen visade att biokol producerat av Hogger vid 900°C uppfyllde de EBC-krav som analyserades. Genom att mäta pH på avfallsfraktionerna samt biokolen gick det att se att pH höjdes under pyrolysen. Från BET och SEM erhölls information om porositet, ledningsförmåga och ytarea. Porositeten ökade med temperaturen och ledningsförmågan var högre för biokolet än biomassan. Ytarean låg mellan 347,2 m2/g och 422,8 m2/g och porvolymen mellan 0,173 cm3/g och 0,205 cm3/g. Det erhölls bäst egenskaper för avfallsfraktionen Hogger samt pyrolystemperaturen 750℃, vilket gjorde att slutsatsen att produktion av biokol från Hogger vid 750℃ lämpar sig bäst för användning som jordförbättrare kunde dras.

Bioelectrocatalytic systems are based on biological entities, such as enzymes, whole cells, parts of cells or tissues, which catalyse electrochemical processes that involve the interaction between chemical change and electrical energy. In all cases, biocatalysis is implemented by enzymes, isolated or residing inside cells or part of cells. Electron transfer (ET) phenomena, within the protein molecules and between biological redox systems and electronics, enable the development of various bioelectrocatalytic systems, which can be used both for fundamental investigations of enzymatic biological processes by electrochemical methods and for applied purposes, such as power generation, bioremediation, chemical synthesis and biosensing. Electrical communication between the biocatalyst’s redox centre and an electrode is essential for the functioning of the system. This can be established using two main mechanisms: indirect ET and direct ET. The efficiency of the ET influences important parameters such as the turnover rate of the biocatalyst, the generated current density and partially the stability of the system, which in their turn determine response time, sensitivity, detection limit and operational stability of biosensing devices or the power densities and current output of biofuel cells, and hence should be carefully considered when designing bioelectrocatalytic systems. This thesis focuses on approaches that facilitate ET in bioelectrocatalytic systems based on indirect and direct ET mechanisms. Both fundamental aspects of ET in bioelectrocatalytic systems and applications of such systems for biosensing and power generation are considered. First, a new hydrophobic mediator for oxidases – unsubstituted phenothiazine and its improved ET properties in comparison with commonly used mediators are discussed. Application of the mediator in electrochemical biosensors is demonstrated by glucose, lactate and cholesterol sensing. Utilisation of mediated biocatalytic cholesterol oxidation, as the anodic reaction for the construction of a biofuel cell acting as a power supply and an analytical device at the same time, is investigated to deliver a selfpowered biosensor. Also the enhancement of mediated bioelectrocatalysis by employment of microelectrodes as a transducer is examined. The effect of surface roughness on the current response of the microelectrodes under conditions of convergent diffusion is considered. The applicability of the laccase-based system for total phenol analysis of weakly supported water is demonstrated. Finally, a new electrochemical approach derived from collision-based electrochemistry applicable for examination of the ET process of a single enzyme molecule is described. All together, the results presented in this thesis contribute to the solution of the ‘electronic coupling problem’, arising when interfacing biomolecules with electronics and limiting the performance of bioelectrocatalytic systems in specific applications. The developed methods to facilitate ET will hopefully promote future biosensing devices and biofuel cells. I believe the new approach for investigation of ET processes at a single enzyme molecule will complement existing single molecule techniques, giving further insights into enzymatic ET mechanisms at the molecular level and filling the gap between fundamental understanding of biocatalytic processes and their potential for bioenergy production.

Fossil based energy resources are dominating the world’s primary energy consumption for the last century. However, with decreasing crude oil reservoirs and the role they play in global warming by emitting greenhouse gases, the focus has been turned towards improved utilization of renewable resources and the need for new, sustainable fuels and chemicals is more urgent than ever. Biomass is a carbon neutral resource that can be used to produce biofuels and other useful chemicals. One such chemical is 1-butanol (or simply butanol), which has great potential as a gasoline substitute because of its favorable fuel properties. Butanol can be produced from acetone, butanol and ethanol (ABE) fermentation using e.g. Clostridium acetobutylicum. However, the concentration of butanol in fermentation in the resulting broth is limited to ca. 20 g/L due to its toxicity for microorganisms. Butyric acid is a precursor to butanol, which is produced prior to butanol in ABE fermentation. Butyric acid is an important industrial chemical, which can be further converted into a number of commercial compounds e.g. acetate butyrate, butyl acetate and butanol. Arginine is a semi-essential amino acid that has vast applications in the field of pharmaceutical and food industry. In addition, arginine can replace inorganic nitrogen as nitrogen source in fertilizers. It can be produced via fermentation of sugars using engineered microorganism like E. Coli, but like butanol its concentration is restricted to approximately 12 g/L. Due to low concentration of these useful chemicals in the resulting fermentation broths recovery of these chemicals remain challenging with today’s options and therefore  novel recovery process should be developed. In this study, zeolite adsorbents were used to recover butanol, butyric acid and arginine from model and real fermentation broths. Zeolite MFI adsorbent efficiently adsorbed butanol from model solutions with a saturation loading of 0.11 g/g- zeolite. On the other hand, adsorption of butyric acid was found to be strongly pH dependent, with high adsorption below and little adsorption above the pKa value of the acid. A structured adsorbent in the form of steel monolith coated with a silicalite-1 film was also used and performance was evaluated by performing breakthrough experiments at room temperature using model ABE fermentation broths and the results were compared with those obtained using traditional adsorbent sin the form of beads. Desorption studies showed that a high quality butanol product with purity up to 95.2% for butanol-water system and 88.5% for the ABE system can be recovered with the structured silicalite-1 adsorbent. Further, zeolite X adsorbents in the form of powder and extrudates was used to recover arginine from a real fermentation broth and also from aqueous model solutions. To the best of our knowledge, this is the first time recovery of arginine from real fermentation broths using any type of adsorbent is reported. Arginine loading of 0.15 g/g was observed at pH 11 using zeolite X powder. The selectivity for arginine over ammonia and alanine from the fermentation broth at pH 11 was 1.9 and 8.3, respectively, for powder and 1.0 and 4.1, respectively, for extrudates. Synthesis gas (CO + H2) can be produced e.g.by gasification of lignocellulose biomass. This synthesis gas can be used to produce methanol, which subsequently may be converted into gasoline using zeolite ZSM-5 catalyst. However, during Methanol to Gasoline (MTG) process, undesirable carbon residue (coke) is formed that gradually reduces the activity of catalyst. It was hypothesized that intracrystalline defects in the zeolite formed during conventional synthesis may accelerate the deactivation rate by coke formation. In this work, a novel ZSM-5 zeolite catalyst essentially free of intracrystalline defects was synthesized and evaluated in the  MTG reaction,. The novel catalyst showed significantly higher resistance towards deactivation by coke formation as compared to a reference catalyst containing defects.

På SCA Östrands massafabrik i Timrå produceras två olika typer av pappersmassa,blekt sulfatmassa och kemitermomekanisk massa (CTMP). Idag produceras ungefär 430 000 ton blekt sulfatmassa och 95 000 ton CTMP per år. Just nu pågåren om- och nybyggnation av sulfatmassalinjen inom projektet Helios. Målet med projektet är att under 2018 ta i drift en fabrik med en kapacitet att producera 900 000 ton blekt sulfatmassa per år. I och med utbyggnaden har fabriken fått en ny miljödom (som ett resultat av verksamhetstillståndsansökan) med villkor attförhålla sig till. I miljödomen presenteras ett antal olika villkor; utredningsvillkor, utsläppsvillkor och riktvärden. Ett av villkoren är ett utredningsvillkor som gäller utredning av rökgasreningstekniken SNCR (selektiv icke-katalytisk reduktion) för att rena rökgaserna från fabrikens ångproducerande enheter, barkpannan (ÅP1)och sodapannan (SP6), från NOx. Syftet med examensarbetet var att i ett första steg i utredningen av utredningsvillkoret undersöka möjligheterna till att använda SNCR som rökgasrening på ÅP1 för att rena rökgaserna från NOx. För att utreda möjligheterna att använda SNCR på ÅP1 gjordes temperaturmätningar av rökgaserna i pannans övre del och en temperaturprofil över pannan bestämdes. Vidare undersöktes olika metoder av SNCR och andra sekundära rökgasreningsmetoder i en litteraturstudie och i en undersökning av marknaden som bland annat innehöll referensbesök på anläggningar med olika SNCR-system.En grov kostnadsmässig analys genomfördes också genom att beräkna teoretiskautsläppsmängder för de nya förutsättningarna efter Helios, NOx-avgiften och kemikalieförbrukningen i ett hypotetiskt fall där SNCR installeras. Under de förutsättningar som temperaturmätningarna gjordes framkom det att det inte är möjligt att använda sig av SNCR för att reducera NOx-utsläppen från ÅP1. Mätningarna visade dock att det är möjligt att använda SNCR som reningsmetod vid laster högre än 72 ton ånga/h om det finns ett linjärt samband mellan last(ton ånga/h) och rökgastemperaturen.

Detta arbete är en delstudie i projektet Seafarm. Syftet med denna studie är att utreda om algen Laminaria Digitata och vassen Phragmites Australis är lämpliga substrat i en samrötningsprocess för biogasproduktion. Metoden som användes är experimentell och utfördes under 35 dagar med en tvåstegsreaktor bestående av en lakbädd och en UASB-reaktor. Under försökets gång upptäcktes vissa fel och brister hos apparatuppställningen vilka orsakade läckage och andra brister. Detta resulterade i ett systemförslag med skiss till en ny lakbädd samt optimering av driftparametrar om försöket ska återupprepas. Efter 35 dagar avslutades försöket och utifrån den data som sammanställts uppvisar processen en bra metanpotential på 589 liter CH 4/kg COD. Processen uppvisade en låg alkalinitet med ett sjunkande pH som till följd av inmatning. Detta var grunden för den låga belastningen som processen klarade av. För framtida försök för just dessa substrat så rekommenderas en tillförsel av buffert så att alkaliniteten ökar och även möjligheterna för en högre belastning.

During the production of steel, an oxide scale is formed on the surface and to achieve anadequate quality of the surface the scale needs to be removed. Acid pickling is a surfacetreatment where the oxide scale is removed by acid. Over time the amount of dissolved metals in the acid solution increases leading to a decrease in the pickling efficiency, hence the acid solution needs to be renewed. The renewing can be performed by an operation process called acid retardation. In this process, the spent pickling solution passes through a column packed with an ion exchange material, resin. The absorption of strong acids is preferred by the resin, hence the movement of the acids in the resin bed will be retarded relative to the movement of the metal ions. Regeneration of the resin occurs when water is passing through the resin bed counter current to the flow of the spent pickling solution. This generates a by-product with low acid and high metal content, and a product containing high acid and low metal. The aim of this thesis was to investigate the acid retardation with regards to separation efficiency and the behaviour of acid and metal in the column. The results can further be used as the groundwork for a deeper understanding of the acid retardation and how to optimize the process. Experiments were performed in lab-scale columns with synthetic spent pickling solutions containing sulfuric, nitric and hydrofluoric acid and iron in different mixtures. During the experimental work, variation of the acid and metal concentration, the type of resin and the height of the column were performed. The results from the experimental work show that a concentration dependence between the concentration of acid and metal exists and the performance of different resin types varies depending on the acid and metal solution tested. The height might also affect the separation, but it is recommended that this is further investigated. Other recommendations for further work with a focus on understanding the acid retardation for optimization include variations of the volume of solution added to the column, variation in flow rate and slurry packing of the resin.

Thermal oil oxidation is an important reason for the engine oil degradation in trucks. Having a comprehensive model that includes all the influential factors while it is feasible for being implemented in the ECUs, was aimed for this work. Therefore, the chemical investigating of the problem leaded to propose a first kinetic model and its thermal analysis caused modelling the oil thermal behaviour. The latter was developed for four compartments: Bearings, turbocharger, piston cooling and oil sump in the oil path through the lubrication system, because the highest oil temperature happens due to friction, combustion of fuels and exhaust gas transportation. Independency from the design parameters of the compartments and simplicity of models for the ECU implementation caused to investigate two various modelling hybrid approach: physical modelling and control theory approach. The first one was done for the bearings and piston cooling, and showed a high level of complexity leading to switch to the second approach. The latter was applied for all compartments while it satisfied requested requirements. To adjust and evaluate the models, an experimental campaign was devoted to acquiring the needed parameters with consideration of the project budget. Also using the previous simulation and experimental efforts at the company provided a possibility to develop flow rate sub-models used in the thermal modelling. The proposed model for all compartments, well predicted the oil thermal behaviour for both stationary and dynamic operating conditions. A comparison between the experimental data for the oil in the oil sump and turbo charger was done to show the reliability of the related models in both stationary and transient statuses. For the bearings, the simulation data for stationary condition were applied as a reference. The modelled oil temperature after piston cooling was compared to a set of experimental data that presented the probable temperature in some conditions close to stationary operating points.