Människan ger upphov till avloppsvatten varje dag. Kommunalt avloppsvatten är rikt på kol, kväve och fosfor, vilka har en stor miljöpåverkan. Vattenrening är i och med detta en nödvändighet för att minimera den antropogena inverkan på naturen och den biologiska mångfalden. Genom att rena vatten i avloppsreningsverk så kan halterna av dessa ämnen reduceras markant. Ett av många reningsverk är Himmerfjärdsverket som är beläget i Sverige, som bland annat använder deammonifikation vilket är en vattenreningsmetod för att rena ammoniumrikt avloppsvatten. I det här examensarbetet genomförs en livscykelanalys för att utvärdera hela reningsverkets miljöprofil under år 2019 och år 2015. Dessa två år använder sig utav två olika deammonifikationsmetoder, nämligen DEMON och DeAmmon. Resultaten utvärderas enligt följande miljöpåverkanskategorier: växthuseffekt, övergödning i marina- och sötvattensekosystem, humantoxicitet, ozonnedbrytning och försurning.  Livscykelanalysen genomfördes i mjukvaran GaBi med ecoinvent version 3.3 som databas och ReCiPe som metod. Resultaten tyder på att de största bidragande orsakerna till miljöpåverkan beror på anaerob rötning av slam, vilket är en process som stabiliserar slam och även från utsläpp till mark som uppkommer genom deponering av rötat slam. Andra faktorer som bidrar till miljöpåverkan är kemikalier, utsläpp av det behandlade avloppsvattnet och övriga uppkomna utsläpp från olika processer. Inom analysens gränser så dras även slutsatsen att det inte är någon markant skillnad på de två reningsmetoderna. / We, the humans, give rise to wastewater everyday. Municipal wastewater is rich in carbon, nitrogen and phosphorus, of which have large impacts on the environment. Wastewater treatment is therefore a necessity to minimize the anthropogenic impacts on both nature and biodiversity. To reduce the content of these substances, the wastewater is treated in wastewater treatment plants. One of them is Himmerfjärdsverket located in Sweden that uses, among others, deammonification of which is a biological technology for treating ammonium rich wastewaters. In this thesis, a life cycle assessment is conducted in order to do an overall evaluation of the environmental profile of this entire plant during two different years, 2019 and 2015. These years also have different deammonification technologies implemented, DEMON and DeAmmon. The results are evaluated upon the following impact categories: climate change, freshwater and marine eutrophication, human toxicity, ozone depletion and acidification.The impact assessment is conducted in GaBi software with the database ecoinvent version 3.3 and ReCiPe as method. Results indicate that the main contributors to pollution are due to anaerobic digestion, which is a process that stabilize sludge and also from emissions to soil that arise from disposal of digested sludge. Other large impacts come from chemicals that are added to the process, the effluent and other arising emissions from the different processes. It is further concluded that there are no major differences between the two deammonification technologies within the boundaries of this assessment.

As society grapples with challenges of net zero emission, one big remaining challenge is heavy and aviation traffic due to the associated challenge of electrifying these sectors. One potential solution for this is E-fuels. E-fuels are hydrocarbon produced from electrolysis hydrogen and carbon dioxide that receive all their energy from renewable non-organic sources. The simplest E-fuel is methanol. Currently methanol is mainly produced from syngas derived from natural gas reforming also known as steam-methane reforming (SMR). A SMR process break down methane into hydrogen, CO2, and CO with the uses of steam. This syngas is then hydrogenated and forms methanol. One alternative production route to the classic syngas hydrogenation is to capture CO2 and add electrolysis hydrogen and then hydrogenate the mixture to from E-methanol.  This thesis aims to compare the traditional production method with joint SMR-flue gas CO2 hydrogenation plant as well as a direct air capture (DAC) CO2 hydrogenation plant. This comparison will be evaluated by their engineering performance, economic performance, and environmental performance.  This evaluation is done with process simulations in Chemcad as well as Excel. In Chemcad the desulfurization step, SMR, carbon capture, and distillation is simulated. The hydrogenation reactors are simulated in Excel with kinetic data. This process data in the foundation of the engineering performance and is used to determine hydrogen and carbon utilization along with energy and water demand. For the economic evaluation CAPEX is calculated from prices of related units adjusted for size and inflation. The OPEX is based on simulation data and modelled in Excel along with net present value (NPV). The environmental performance focuses on global warming potential as well as fossil resources depletion (FD).  The DAC system has both the highest hydrogen and carbon utilization at 98% and 96,9% respectively but suffer from the highest energy and water demand. Both flue gas method and syngas method have similar hydrogen utilization at around 83,5%, but they differ significantly with carbon utilization with 87,2% and 64,7 respectively. The syngas method has the highest net profit per ton methanol along with the highest NPV and the lowest CAPEX cost out of all three methods. The flue gas method still produces a net profit, but significantly lower than the syngas method. Its CAPEX is also significantly higher than its NPV. The DAC system as negative net profit as well as the highest CAPEX by a wide margin. The environmental impact of the flue gas system is significantly lower than that of the syngas route with less than a fourth of the CO2 eq. emissions. It also has a lower FD due to its higher carbon utilization which results in a higher yield methanol per ton natural gas.  Whilst the flue gas hydrogenation has several advantages over the syngas route and the economic improvements with better optimization for the carbon capture units would bring the net profit per ton methanol more in line with the syngas route, as of today it still is not economically defensible. / När samhället kämpar med utmaningarna kring nettonollutsläpp, kvarstår en stor utmaning inom tung- och flygtrafik på grund av den associerade svårigheten med att elektrifiera dessa sektorer. En potentiell lösning för detta är E-bränslen. E-bränslen är kolväten producerade från elektrolysväte och koldioxid som får all sin energi från förnybara icke-organiska källor. Den enklaste E-bränslen är metanol. För närvarande produceras metanol främst från syntes gas som kommer från naturgasreformering, även känd som ångmetanreformering (SMR). En SMR-process bryter ner metan till väte, CO2 och CO med hjälp av ånga. Denna syntes gas får sedan genomgå hydrering för att bilda metanol. Ett alternativa till denna produktionsmetod är att fånga CO2 och tillsätta elektrolysväte och sedan låta blandningen hydrera för att bilda E-metanol.  Detta examensarbete syftar till att jämföra den traditionella produktionsmetoden med en gemensam SMR-rökgas-CO2-hydreringanläggning samt en direkt luftinfångning (DAC) CO2-hydreringanläggning. Denna jämförelse kommer att utvärderas utifrån deras tekniska prestanda, ekonomiska prestanda och miljöprestanda.  Denna utvärdering görs med processimuleringar i Chemcad samt Excel. I Chemcad simuleras avsvavlingssteget, SMR, koldioxidsinfångning och destillation. Hydreringsreaktorerna simuleras i Excel med kinetiska data. Processdata från dessa simuleringar utgör grunden för den tekniska prestandan och används för att bestämma väte- och kolutnyttjande tillsammans med energi- och vattenbehov. För den ekonomiska utvärderingen beräknas CAPEX från priser på relaterade enheter justerade för storlek och inflation. OPEX baseras på simuleringsdata och modelleras i Excel tillsammans med nettonuvärde (NPV). Miljöprestandan fokuserar på den globala uppvärmningspotentialen samt utarmningen av fossila resurser (FD).  DAC-systemet har både den högsta väte- och kolutnyttjande på 98 % respektive 96,9 %, men lider av det högsta energi- och vattenbehovet. Både rökgasmetoden och syntesgasmetoden har liknande väteutnyttjande på cirka 83,5 %, men de skiljer sig betydligt när det gäller kolutnyttjande med 87,2 % respektive 64,7 %. Syntesgasmetoden har den högsta nettoförtjänsten per ton metanol samt det högsta NPV och den lägsta CAPEX-kostnaden av alla tre metoder. Rökgasmetoden ger fortfarande en nettoförtjänst, men betydligt lägre än syntesgasmetoden. Dess CAPEX är också betydligt högre än dess NPV. DAC-systemet har negativ nettoförtjänst samt den högsta CAPEX med en bred marginal. Miljöpåverkan från rökgassystemet är betydligt lägre än den från syntes gas metoden med mindre än en fjärdedel av CO2-ekvivalenta utsläpp. Det har också en lägre FD på grund av sitt högre kolutnyttjande vilket resulterar i ett högre utbyte av metanol per ton naturgas.  Trots att rökgashydrering har flera fördelar över syntesgasvägen och de ekonomiska förbättringarna med bättre optimering för koldioxidavskiljningsenheterna som skulle få nettoförtjänsten per ton metanol mer i linje med syntesgasvägen, är metoden fortfarande inte ekonomiskt försvarbart i dagsläget.

This thesis project investigates the granular flow of wood pellets inside a pilot-scale rotary kiln and its impact on the pyrolysis process. The study focuses on two key factors that must be determined to evaluate their effects on pyrolysis: the mass flow rate delivered by the feeding system at different motor frequencies and the mean residence time (MRT) of the wood pellets. The research is divided into two parts: the first characterizes granular flow without heat application, while the second examines the system behavior under high-temperature pyrolysis conditions. For the first part, the mass flow rate was assessed by measuring the emptying time of the feeding silo at different screw velocities. In contrast, the MRT was determinedwith two scenarios: (1) batches of different masses of wood pellets and (2) continuousfeed until a stable solid bed was formed that allowed tracer particle tracking. In the second part of the study, the drum’s rotational speed and fed mass flow rate were varied. Results indicated a direct proportionality between the mass flow rate delivered by the feeding systems and the screw motor frequency. Additionally, the MRT was found to follow an inverse relation with the drum’s rotational speed if the process was done in batches. In contrast, the MRT was 20 minutes at a feeding rate of 51 kg h-1 and a drum’s rotational speed of 0.36 rad s -1 with a continuous feeding process. Finally, the study concludes that the wood pellet feed rate and drum rotational speed significantly influence the pyrolysis process in the rotary kiln. The system remained stable for wood pellets inside the rotary drum, starting with a feeding rate of 8 kg h-1 and scaling up until a maximum of 21 kg h-1. This behavior is evidenced by the direct proportionality between the evolution of flue gas and pyrolysis gas temperatures over time and the necessity to adjust air supply to maintain system stability.

Surface water is globally becoming more and more a scarce resource, and in Addis Ababa the capital of Ethiopia, river water quality has been degraded due to anthropological forcing for many years. Therefore, the study objective was to investigate causes and impact of surface water pollution in Kebena and Great Akaki rivers. The technical aspect of the study focused on analysing the parameters E. coli, phosphate, nitrate and total ammonia nitrogen in 34 different sampling sites in the western part of the Great Akaki catchment. The other aspect was to evaluate authorities’ and companies’ perspective on the water quality, usage and future plans to mitigate further pollution of rivers. Another perspective was to interview households and farmers regarding their view on usage, water quality and health risks. The main finding was a high surface water contamination in both Kebena and Akaki river, throughout the city, mostly from domestic, municipality and industrial wastewater and solid waste. E. coli concentrations exceeded thresholds given by WHO. Concentrations of phosphate and total ammonia nitrogen strongly indicated eutrophication. Nitrate values were lower than expected with no perceived healthrisk. The interview study with authorities, households and farmers indicated irrigation as the main usage. Little to moderate health risks perceived by farm users and high health risks perceived by authorities for farmers were found. Therefore, addressing a stronger collaboration between authorities and the local community is important. In addition, the implementation of mitigation strategies should be strengthened and the stakeholders need to be accountable for their actions. A continued monitoring of pollutants as well as a multi-sectoral approach to solidwaste and wastewater management will help improve the river water quality. / Ytvatten blir globalt allt mer en knapp resurs och i Addis Abeba, huvudstaden i Etiopien, har flodernas vattenkvalitet under många år försämrats på grund av antropogen påverkan. Denna studie syftar till att undersöka orsaker och påverkan på ytvattenföroreningar i floderna Kebena och Akaki. Den tekniska aspekten av studien inkluderar vattenanalyser av parametrarna E.coli, fosfat, nitrat och totalt ammonium kväve som utfördes på 34 olika provtagningsplatser i västra delen av Great Akakis avrinningsområde. Den andra aspekten var att utvärdera myndigheters och företags perspektiv på vattenkvalité, flodvattnets användningsområden och framtida planer för förbättring av föroreningsgraden i floderna. Ett annat perspektiv var att intervjua hushåll och lantbrukare angående deras bild av ytvattenanvändning, om vattenkvaliteten och hälsorisker. Studiens huvudsakliga upptäckt är en genomgående hög föroreningsgrad i stadens flodvatten. Föroreningen består till största del av avlopp och avfall från hushåll, kommuner och industrier. Koncentrationerna av E.coli överskred WHO:s gränsvärden. Halterna av fosfat och totalt ammoniumkväve indikerade övergödning. Nitratvärdena visade lägre halter än förväntat och därmed ingen påvisad hälsorisk. Intervjustudien med myndigheter, hushåll och lantbrukare påvisade att ytvattnet mest används för bevattning av åkermark. Lantbrukarna uppfattade en liten till medelhög hälsorisk med denna användning, medan myndigheter ansåg att lantbrukarna utsattes för en hög risk. Därför är ett starkare samarbete mellan myndigheter och samhället viktigt. Dessutom behöver implementationen av förbättringsåtgärder förbättras och alla aktörer måste göras ansvariga för sina handlingar. En fortsatt övervakning av föroreningar och ett multi-disciplinärt arbetssätt vid avfall- och avloppshantering kommer att vara till hjälp vid förbättring av vattenkvaliteten i floden.

Additive manufacturing (AM), also called 3D-printing, are technologies where parts are formed from the bottom up by adding material layer-by-layer on top of each other. Electron Beam Melting (EBM) is an AM technique capable of manufacturing fully solid metallic parts, using a high-intensity electron beam to melt powder particles in layers to form finished components. Compared to conventional machining, EBM offers enhanced efficiency for production of customized and patient specific parts such as e.g. dental prosthetics. However, dental prosthetics are challenging to produce by EBM, as their small sizes mean that mechanical and surface properties may be altered as part sizes decreases. The aim of this thesis is to gain new insights that could lead to optimization for production of small sized components in the EBM. The work is focused to understand the process-property relationships for small size components production. To improve the surface resolution and part detailing, a smaller sized powder was used for production and compared to parts made with standard sized powder. The surface-, chemical and mechanical properties were evaluated for parts produced with both types of powders. The results indicate that the surface roughness may be influenced by powder and build layer thickness size, whereas the mechanical properties showed no influence of the layer-wise production. However, the mechanical properties are dependent on part size. The outermost surface of the parts consists of a surface oxide dominated by TiO2, formed as a result of reaction between the surface and residual gases in the EBM build chamber. The surface oxide thickness is comparable to that of a conventionally machined surface, but is dependent on build height. This work concludes that the surface resolution and component detailing can be improved by various measures. Provided that proper process themes are used, the EBM manufactured material is homogenous with properties comparable to conventional produced titanium. It has also been shown that the material properties will be altered for small components. The results point towards different ways of optimizing manufacturing of dental prosthetics by EBM, which will make dental prosthetics available for an increased number of patients.

During this master thesis, the possibility of ammonia removal from digestate in combination with after hygienization has been investigated. The aim of the work was to see how much ammonia that could be removed but also the properties of other process parameters such as TS/VS content, pH and alkalinity of the digestate. It was also of interest to study the energy balances for a process that combines ammonia stripping with after hygienization. The purpose of hygienization in a biogas plant is to kill pathogens. To study ammonia stripping combined with after hygienization, a prototype of an ammonia stripper was built in a laboratory. The digestate was heated to the hygienization temperature of 70 °C and air was led through with the help of a peristaltic pump by the end of the system. Condensate was trapped in a bottle by cooling the tube and the gases were brought to another bottle containing 1 M sulfuric acid. Ammonia and sulfuric acid reacted and formed ammonium sulfate. The process was also tested with closed system using vacuum to decrease the boiling point and thereby create more condensate. The results from the experiments showed that with an air stripping process most of the ammonium was trapped in the sulfuric acid while with a vacuum process more ammonium was trapped in the condensate. The most important parameters to achieve a good ammonia removal were air flow and time. With the vacuum system, more condensate was removed. The removal of condensate could make it possible to recirculate process fluid from the stripping process and thereby save energy in the centrifugation part which is used to create a solid part of the bio digestate. It was concluded from the experiments that air stripping is more effective when it comes to ammonium recovery. The process could be improved by using higher air flow which could decrease the time to less than one hour, which is the desired hygienization time. However, it is desired to keep the pump flow as low as possible since it is energy consuming. A chemical increase of the pH would also be of interest to try since previous tests showed a strong correlation between high pH-value and good ammonia stripping. More tests overall are of interest to ensure a reliable result. Still, the combination of after-hygienization and ammonia stripping would contribute to a better environment and a sustainable agriculture with a natural and nutritious digestate.

Luossavaara-Kiirunavaara AB (LKAB) rullar järnmalmslig till råkulor, som sedan bränns till pellets. Råkulorna bildas i rullkretsar som består av rulltrummor och rullsiktar. Under 2017 färdigställdes en pilotskaleanläggning för kulrullning i LKAB:s Agglomeringslaboratorium i Malmberget. Syftet med anläggningen är att prediktera dynamiken i en storskalig rullkrets, under olika betingelser. Detta examensarbete är ett första försök att i forskningssyfte studera gensvaret i LKAB:s pilotrullkrets. Syftet var att undersöka om pilotrullkretsen kan prediktera dynamiken och råkulekvalitet i rullning i storskaliga rullkretsar och målet var att fastställa ett effektivt körsätt. Kulrullning är inom LKAB:s kärnkompetens och därför har reagensursprung och karaktär samt dimensionering av rullkretsen lagts med sekretess. Kodnamn används både för sliger och reagens. Arbetet inleddes med att skapa ett körschema med målet att så många olika blandningar som möjligt kunde köras i pilotrullkretsen under en normal arbetsdag. Fem olika blandningar kunde köras. Fyra olika tillsatser testades: bentonit, ett flotationsreagens (FLOT), ett organiskt bindemedel (OB) och en ny utvecklingsprodukt (UTV). Första körningen i pilotrullkretsen var med varierande doseringar av bentonit eftersom dess inverkan i kulrullning är välkänt hos LKAB. Försök två och tre, med FLOT respektive OB, kunde jämföras mot tidigare erfarenhet från storskaliga försök. Det fjärde och sista försöket var ett test hur pilotrullkretsen predikterade utvecklingsprodukten UTV. Varje typ av försök utfördes två gånger. Pilotrullkretsen predikterade väl både dynamik och råkulekvalitet i alla de tre försöken där erfarenhet från storskaliga körningar var tillgängligt. Den nya, okända, UTV-produkten visade en förbättrad råkulekvalitet, utan att dynamiken i kretsen påverkades negativt. UTV kan därför vara ett intressant alternativ för ett framtida storskaligt försök hos LKAB. Det framtagna körschemat fungerade mycket väl. Ett ”grundanalyspaket” har skapats för att underlätta planering och genomförande för framtida pilotrullkretsförsök hos LKAB. Antalet personer som behövs vid rullkretskörningar beror på antalet blandningar och analyser. Vid enklare körningar behövs minst fem personer, utöver försöksledaren. Mer komplexa körningar kan kräva sju personer. / Luossavaara-Kiirunavaara AB (LKAB) produce pellets from magnetite iron ore. Pellets are formed by balling moist iron ore concentrate to green pellets, which are then burned to pellets. The green pellets are formed in balling circuits consisting of balling drums and roller decks for screening. In 2017 a pilot scale balling circuit with a drum was completed in LKAB's agglomeration laboratory in Malmberget. The purpose of the pilot balling circuit is to predict the dynamics in a full scale balling circuit under different conditions. This master degree project is an initial attempt to study the response in LKAB's pilot circuit in terms of green pellet quality and dynamics in the circuit. The goal was to determine an effective way to run experiments and to investigate whether the pilot circuit can predict the dynamics of balling in large-scale circuits. Pelletizing production is within LKAB's core competence, and therefore the origin and character of the reagents, as well as the design of the pilot balling drum circuit, are confidential. Code names are used for both iron ore concentrates and reagents. The work began by creating a test procedure with the aim of running as many different mixtures as possible in the pilot balling circuit during a normal working day. Five different mixtures could be run. Four different additives were tested: bentonite, a flotation reagent (FLOT), an organic binder (OB) and a new development product (UTV). The first experiment in the pilot balling circuit was run with varying doses of bentonite because its impact in balling is well known at LKAB. Experiment two and three, with FLOT and OB, could be compared to previous experience from large scale test runs. The fourth and last experiment was a test of how the pilot circuit predicted the behavior of a new development product UTV. Each type of experiment was performed twice. The pilot balling circle predicted well both dynamics and green pellet quality in all three experiments where experience from large-scale runs was available. The new, unknown, UTV product showed improved green pellet quality, without affecting adversely on the dynamics of the circuit. UTV can therefore be an interesting option for a future large scale run at LKAB. The developed working schedule worked very well. A "basic analysis package" has been created to facilitate planning of future experiments in the pilot balling circuit. The number of persons needed to run the circuit depends on the number of mixtures and analyzes. For smaller experiments, at least five people is required, in addition to the leader of the experiments. More advanced experiments will demand seven people.

One of the main interests in commercial methane production is to maximize the gas yield, and it is thus appealing to use material with relative high methane potential. However, such material often results in process instability whereas ammonia inhibition is common. Removal of ammonia through adsorption is a fairly unexplored method in the field of biogas production, and could prove to be cost-effective.The adsorption capacity of pulp fibres from the paper making industry were investigated through batch adsorption experiments. Additionally, the fibres effect on small scale batch digesters in terms of methane production and cellulase activity was explored. Overall, the adsorption capacity of the pulp fibres was low, whereas Kraft hardwood had the highest adsorption capacity in both an aqueous ammonium solution and digester fluid at 11±3 and 60±20 mg g-1, respectively. The initial total ammonium nitrogen concentration had the highest effect on the adsorption capacity with a positive correlation. The pulp fibres seemingly had no effect on the ammonia inhibited anaerobic digestion systems. However, the cellulase activity was higher after day 5 in the anaerobic digestion systems with a high ammonia concentration.In essence, the overall results showed that the adsorption of the fibres was relatively low and most likely not suitable as a material to prevent ammonia inhibition in an AD.

This report details the development and validation of a model for the simulation of supported liquid membrane processes, as applied to the extraction of lanthanides. Supported liquid membranes are systems where two phases, usually aqueous, are separated by a third phase, typically organic, which acts as a membrane, in order to separate solutes from one phase to the other. The model employs an analytical solution to the diffusion equation for the organic phase and linear approximations of the resistances to mass transfer in the aqueous phase boundary layers. The goal of this model is to underline the importance of taking these boundary layer resistances into account. / Detta arbete introducerar, deriverar och evaluerar en matematisk modell för simulering av vätskemembranprocesser, tillämpat på vätskeextraktion av lantanider. Immobiliserade vätskemembran betecknar system där två faser oftast vatten, separeras av en tredje organisk fas som agerar membran för att separera och transportera lösta komponenter från den ena vattenfasen till den andra. Modellen utnyttjar sig av en analytisk lösning till diffusionsekvationen för den organiska fasen och linjära approximationer för motstånden mot masstransport i de båda vattenfasernas gränsskikt. Målet med modellen är att understryka vikten av att inkludera dessa gränsskikt i beräkningarna.

The basic ingredient of paper is the individual wood fibers. The property of the fibers depends on a variety of factors e.g., method of pulp production and processing. The final sheet quality depends in part on how the fibers interface between each other and therefore factors that affect the fiber size are of interest. The flexibility of the fibers depends in part on the pore water i.e., the fiber swelling. The sheet becomes less flexible at low water content which gives a loss in strength. Thus it becomes desirable to increase the water uptake. The experimental investigation described in this report consists of exposing the wood fibers to different ions and ionic strength and then measure the pore size by thermoporosimetry where a DSC (Differential Scanning Calorimeter) is used. DSC measures the freezing point of water in the pores of the wood fibers. As the freezing point varies with the pore size the size distribution can be determined. The results show that there are complications with thermoporosimetry measurements at different ion concentrations. The strength of the ionic solutions will contribute to a fictitious pore volume, which makes analysis difficult to interpret.