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.

A conventional exhaust gas after treatment system (EATS) for the Euro VI legislation contains four different catalyst. The first two (particulate filter system) remove particulates and the last two (SCR system) remove nitrogen oxides (NOx). The particulate filter system also optimizes the gas composition with respect to nitrogen monoxide (NO) and nitrogen dioxide (NO2). The performance of the SCR system has a strong dependency on the NO:NO2 ratio as the so called selective catalytic reduction (SCR) reaction is kinetically favored at a NO:NO2 ratio of 1:1. The diesel oxidation catalyst (DOC) is placed first in the EATS. Due to this placement, the DOC is subjected to a rough environment, e.g. high temperatures and oil/fuel impurities that with time will affect its performance, i.e. the catalyst ages. In this master thesis, the aging of the DOC has been empirically correlated to thermal load and sulfur exposure. The study shows that it is possible to predict how the NO oxidation performance decays as a function of thermal and sulfur exposure. The empirical relation was fitted against two aging cycles and validated against an additional four. The results show that the loss of catalytic activity can to a large extent be explained by the cycle it has been used on. / Ett konventionellt efterbehandlingssystem för Euro VI-standarden innehåller fyra olika katalysatorer. De första två rensar (partikelfiltersystemet) från partiklar och de två sista (SCR-systemet) tar bort kväveoxider (NOx). Partikelfiltersystemet reglerar även gassammansättningen med avseende på kvävemonoxid (NO) och kvävedioxid (NO2). Prestandan för SCR-systemet har ett starkt beroende på NO:NO2-förhållandet där ett förhållande på 1:1 är kinetiskt gynnat för den så kallade SCR-reaktionen (eng: Selective Catalytic Reduction). Oxidationskatalysatorn (DOC) sitter som ett första steg i efterbehandlingen. Placeringen medför att katalysatorn finns i en tuff miljö där den till exempel utsätts för hög temperatur och olje/bränsleföroreningar som över tiden påverkar dess prestanda. Detta brukar kallas att DOC:n åldras. I detta examensarbete har åldrandet av DOC:n korrelerats empiriskt till termisk belastning och svavelexponering. Studien visar att det är möjligt att förutsäga hur NO-oxidationsprestandan avtar som en funktion av termisk last och svavelexponering. Det empiriska modellen anpassades till två åldringscykler och validerades emot ytterligare fyra cykler. Resultaten visar att den kvarvarande katalytiska aktiviteten i stor utsträckning kan förklaras genom vilken cykel den har körts på.

Mankind has to provide a sustainable alternative to its energy related problems. Bioenergy is considered as one of the potential renewable energy resources and as a result bioenergy market is also expected to grow dramatically in future. However, logistic issues are of serious concern while considering biomass as an alternative to fossil fuel. It can be improved by introducing pretreated wood pellet. The main objective of this thesis is to address thermochemical behaviour of steam exploded pretreated biomass. Additionally, process aspects of torrefaction were also considered in this thesis. Steam explosion (SE) was performed in a laboratory scale reactor using Salix wood chips. Afterwards, fuel and thermochemical aspects of SE residue were investigated. It was found that Steam explosion pretreatment improved both fuel and pellet quality. Pyrolysis of SE residue reveals that alerted biomass composition significantly affects its pyrolysis behaviour. Contribution from depolymerized components (hemicellulose, cellulose and lignin) of biomass was observed explicitly during pyrolysis. When devolatilization experiment was performed on pellet produced from SE residue, effect of those altered components was observed. In summary, pretreated biomass fuel characteristics is significantly different in comparison with untreated biomass. On the other hand, Process efficiency of torrefaction was found to be governed by the choice of appropriate operating conditions and the type of biomass. / QC 20120110

The purpose of this project was the modeling, optimization and prediction of a hybrid system composed of a fuel cell, a dc-dc converter and a supercapacitor in series. Lab tests were performed for each device to understand their behavior, and then each one was modeled using software (Simulink). The validation of the model was done by comparing its results with measured data; finally the model was used for the optimization and the prediction of the hybrid system

Europeiska Unionen presenterade den 8 juni 2020 sin vätgasstrategi i syfte för att minska koldioxidutsläppen. Det unionen vill uppnå med sin vätgasstrategi är att uttnytja konceptet Power-to-X där elektricitet omvandlas till energi. Om elektricitetkällan kommer från förnyelsebar energi kommer grön vätgas produceras. Problemet med vätgas idag är lagring, transport och hanteringstrukturen för ämnet men vätgas kan lagras i flertal applikationer. En av de mest lovande lagringsalternativen är ammoniak som bildas när vätgas med kvävgas reagerar med varandra via ammoniaksyntes. Eftersom vätgasproduktionen idag använder fossila bränslen kommer även dess applikation göra det, men med grön vätgas kommer dess applikation även att bli grön. Idag står ammoniakproduktion för 2 % av fossilbränsleanvändning globalt och frigör mer än 400 miljoner ton CO2 årligen. Dessa utsläpp skulle försvinna om produktionen av ammoniak gjordes med Power-to-X konceptet. Syftet med detta examensarbete är att undersöka förutsättningarna ur ett ekonomiskt, tekniskt och säkerhetsmässigt hållbart Power-to-X koncept i form av en Grön Ammoniakanläggning i Norra Sverige. Det innebär att processer för en ammoniakproduktion skall analyseras ur ett teknisk synvinkel där fokus på funktion mot grön ammoniak är i fokus. Den ekonomiska synvinkeln innebär vad kapitalkostnaden (CAPEX) blir för anläggningen samt driftkostnaden (OPEX) som processen får. Arbetet innehåller först en analys av de processer som krävs för att kunna producera ammoniak. Därefter en analys över möjliga tekniker för dessa processer, hur väl de fungerar mot grön ammoniak och vilka antaganden som är i detta arbete. Anläggningen skulle vara storskalig vilket innebär en produktion på 500 ton NH3 $/dag. Det är även antaget en kontinuerlig eltillförsel samt att elnät redan är tillgänglig. Detta gav att vätgasproduktionen gjordes med en PEM-elektrolys, där kvävgas fås från kryogen destillation och ammoniak produceras med HB-processen. Resultatet visades att anläggningens CAPEX och OPEX blev 2 820 MSEK respektive 1 272 MSEK/år. Den dominerande faktorn för kapitalkostnaden var för vätgasproduktion som utgjorde 60 % av CAPEX. Den höga kostnaden för PEM-elektrolys är dels för att utvecklingen av processen inte är fullbordad, där utvecklingen för tekniken skulle kunna ge en stor kostnadsreducering. Det elbehov som anläggningen kräver är 1,6 TWh och och utgör en påverkan på OPEX är 55,4 %. Den process som kräver mest energi är vätgasproduktionen vilket omfattar 94 % av hela anläggningens totala elbehov. En stor anledning till de dyra driftkostnaderna är elpriset. I detta arbete valdes elpriset till ett medelvärde för SE1 i Sverige under en 10 års period. I ett verkligt scenario hade vätgasproduktionen kunnat optimeras för uppnå billigare drift.

The kraft process is a complex system with many variables, and though the process is fairly well understood, there is still much we do not know.      This thesis examines some aspects of the kraft process that could prove to be of interest for the pulp and paper industry, specifically, the impact of wood chip impregnation and of the chemical structure of xylan on spruce kraft pulp. The intent is to suggest modifications to the kraft process as it is used today.      The effect of wood chip impregnation varies with the prevalent conditions, and increases the effect of the subsequent kraft cook. Longer impregnation at a lower temperature was found to increase screened pulp yield, reduce shives content, make it possible to reach a certain kappa number at a lower H-factor, and make it possible to reach a certain kappa number at a lower total alkali consumption.      Xylan has previously been found to have a strength-enhancing effect on pulp, and the chemical structure of the xylan in question was found to be the main strength-enhancing factor. For spruce xylan, the structure that provides the largest increase in strength is not the same as the structure that increases the yield the most. Removing xylan was determined to have a negative impact on pulp strength.      Xylan extracted from agro waste can be used as an additive to increase pulp strength. This could be viable, especially when combined with the production of green plastics from hemicelluloses extracted from the agro waste.      A suggested configuration of a future pulp mill is presented, incorporating the following modifications to the now standard kraft cooking system: impregnation at a lower temperature for a longer time; extracting xylan-enriched black liquor at an early stage of the impregnation or cook, and adding this liquor at a late stage of the cook; terminating the cook at a higher kappa number; increasing oxygen delignification to compensate for the increased kappa number at the end of the cook, keeping the kappa number constant going into the bleaching plant; and adding agro-waste xylan during oxygen delignification. / <p>QC 20150525</p>