The process conditions and fractionation efficiency of two hydrocyclone designs, a novel and a conventional conical design, were evaluated. The novel design comprised a modified inlet section, where the pulp suspension had to pass a narrow ring-shaped opening, and a very compact fractionation zone. The influence of feed concentration and fine fraction mass ratio was studied. The trials were performed with never-dried, unrefined bleached chemical softwood pulp. Fractionation efficiency was evaluated in terms of change of surface roughness of handsheets made out of the fractions and the feed pulp respectively. The fractionation efficiency increased considerably with decreasing fine fraction mass ratio, especially at higher feed concentrations. This finding prompted a hypothesis on the existence of a radial gradient in the composition of the suspension inside the novel hydrocyclone. Using the novel hydrocyclone in a feed-forward fractionation system would therefore prove to be more favourable as a larger total fine fraction of better properties can be obtained. A three-stage feed-forward fractionation system was evaluated in laboratory scale. Here, it was indeed possible to extract fine fractions with improved surface properties in each of the three consecutive stages. All three fine fractions had about the same surface roughness. The fractionation performance of the novel design was benchmarked against that of a conventional, best available technology (BAT) design. In terms of fractionation efficiency, the BAT design performed better. However, the fractions produced with the novel hydrocyclone had a much smaller difference in concentration, implying a much less pronounced enrichment of fines in the fine fraction. It is unclear, to what extent the lower share of latewood fibres and the increased fines content, respectively, contributed to the improved surface roughness of the fine fractions. However, it is clear that the lower enrichment of fines in the novel hydrocyclone makes it easier to install it in industrial applications without a need for auxiliary equipment to redistribute large water flows. / <p>QC 20101014</p>

Electrically induced adhesive debonding is a process where an adhesive can be debonded at command with help of an applied voltage. To make this process function, the adhesive is  bonded between two metal substrates. In this study an epoxy adhesive is adhered between two aluminium foils forming a laminate structure. The adhesive is made ionically conductive by an addition of an ionic liquid before the curing. This arrangement forms an electrochemical cell, where the metal substrates act as the electrodes while the ionically conductive adhesive acts as the electrolyte. When a voltage is applied over the laminate, a current passes due to electrochemical reactions at the electrode interfaces and ionic transport in the adhesive. This type of material can potentially be used in a wide range of applications. This includes making adhesive joints in automotives to both reduce the total weight but also to simplify the disassembly after end-of-life, enabling an inexpensive recycling process. Another potenital use for debondable adhesives is within consumer packaging. Here it could be possible to pack and transport goods using less packaging material as well as making the handling easier.  The aim of this study was to increase the understanding about the processes leading to debonding. This knowledge is important in the development of new types of debonding adhesives. In this study, the commercial laminate Sinuate® was used as a model system. The experiments were focused on the electrochemical behavior and were performed mainly using galvanostatic polarization and electrochemical impedance spectroscopy. Information about the chemistry of debonding was collected with techniques such as scanning electron microscopy (SEM), mass spectrometry (MS) and Raman spectroscopy. The debonding did always take place at the anodic interface, separating the adhesive and the anode aluminium foil. It was found that the total cell resistance increased drastically during polarization, and that essentially all of this increase originated within the anodic half of the laminate. Examining the resistance behavior with EIS, it was found that the increase in total resistance was reversible. The anodic  electrochemical reaction during polarization was determined to consist mainly of an oxidation of aluminium, while the major reaction at the cathodic interface was reduction of water into hydrogen. The debonding process, which took place at the anodic interface, could be related to reaction products formed in the polarization process. These products grew out from the anodic aluminium surface into the adhesive. A debonding mechanism is proposed where these products induce an increase in the adhesive volume, causing stresses at the interface which ultimately result in debonding. / Elektriskt framkallad delaminering är en process som gör att en limfog kan fås att släppa på kommando med hjälp av en pålagd elektrisk spänning. För att processen ska fungera måste limmet vara bundet till två metallytor. I den här studien används ett epoxylim, bundet mellan två folier av aluminium, vilket bildar en laminatstruktur. Limmet gjordes jonledande genom en tillsats av en jonvätska innan härdningen. Detta laminat bildar en elektrokemisk cell, där metallytorna agerar som elektroder och limmet som elektrolyt. När en elektrisk spänning läggs över laminatet, uppstår en elektrisk ström till följd av elektrokemiska reaktioner vid elektrodytorna och jontransport i limmet.  Dessa material skulle kunna användas inom ett brett spektrum av användningsområden. Exempel på detta är användandet av limmade fogar i fordon, vilket skulle både minska fordonens vikt och underlätta demonteringen efter livscykelns slut. En förenklad demontering skulle resultera i en billig återvinningsprocess. Andra exempel på användningsområden för elektriskt släppbara limmer är konsumentförpackningar. Inom detta område skulle varor kunna packas med mindre mängd förpackningsmaterial och hanteringen under transport och uppackning skulle kunna förenklas.  Målet med det här arbetet var att öka förståelsen kring processerna som leder till delaminering. Dessa kunskaper är viktiga för utvecklande av nya sorter av elektriskt släppande limmer. Det kommersiella laminatet Sinuate® användes som ett modellsystem. Experimenten fokuserades kring elektrokemin och utfördes främst med galvanostatisk polarisering och elektrokemisk impedansspektroskopi (EIS). Information om släpprocessens kemi inhämtades med tekniker som svepelektronmikroskopi (SEM), masspektrometri (MS) och Raman-spektroskopi. Det upptäcktes att delamineringen alltid skedde i det anodiska gränsskiktet, på så sätt att aluminiumfolien och limytan separerades. Polarisationsprocessen ledde till en drastisk ökning av den totala cellresistansen och större delen av denna härrörde sig från den anodiska delen av laminatet. Denna ökning i resistans fanns vara reversibel genom att använda EIS. Den elektrokemiska reaktionen vid anoden bestod till största delen av en oxidation av aluminium, medan den katodiska reaktionen bestod av en reduktion av vatten till vätgas. Processerna som ledde till släpp i det anodiska gränsskitet kunde härledas till SEM-resultaten, där reaktionsprodukter observerades. Dessa produkter växte ut från aluminiumytan och in i limmet. En släppmekanism föreslås, där de bildade produkterna orsakar en volymsökning i limmet, vilket leder till spänningar i gränsskiktet som i sin tur gör att limmet släpper. / QC 20101222

Odorous volatile organic compounds emissions from fried-food industries posed severed pollution problems both to the workers and the surrounding inhabitants. These industries need to look for cost effective and efficient methods to reduce these emitted gases.  Several solutions such as the use of centrifugation, scrubbers, ion exchangers, biofiltration, condensation, adsorption, absorption, and incineration have been exploited to reduce these smelling gases. Centriair in collaboration with KTH aim at using UV light in combination with ozone and hydrogen peroxide to degrade these odorous VOCs emitted from the frying of meat balls (SCAN) and chips. Several volatile organic compounds which are odorants with low threshold values were identified in the emitted gases from meat frying which includes: aldehydes, sulphur containing compounds, ketones, pyrazines, and alcohols. The type and concentration of these odorants emitted depends among other things primarily on the type of oil used during the frying process.  This work focuses on the use of advanced oxidation processes to abate theses odorous gases. The effect of UV dosage and the use of hydrogen peroxide were tested in a flow reactor. Ozone producing UV lamps were used for the treatment of 2,4-decadienal, Hexanal, furfural, and 2,5-dimethylpyrazine. A simultaneous chemical and odour analysis was done using a GC/MS Olfactometry system. UV/Ozone/H2O2 was effective in reducing the volatile organic compounds tested thus reducing the odor concentration. The percent removal was proportional to the energy dosage.

In this work, the preparation of photocatalysts’ metal support for applications in purification of industrial gas emissions has been studied. The supports normally used in literature are ceramics, but they are not suitable for industrial applications. Stainless steel and aluminium are much more common in full-scale reactors and were therefore chosen in this investigation. Chemical etching, anodisation, electrochemical DC etching and AC etching treatment methods were used to modify the surface morphology of aluminium and stainless steel plates in order to improve the mechanical stability of photocatalyst (TiO2) coating. Two-part epoxysiloxane hybrid (ESH) and sodium silicate adhesives have been evaluated for use as TiO2 binder. Dip and spray coating techniques were employed for preparing TiO2 coatings on blank plates, pretreated plates, ESH and sodium silicate coated plates. Stainless steel electrochemically etched in dilute aqua regia gave the most mechanically stable coating. It was demonstrated that a high microscale surface roughness of the support improves the mechanical stability of TiO2. Additionally, photocatalytic performance of the coating was higher than that coated on ceramic support. The mechanical stability of TiO2 coated on ESH and sodium silicate using dip and spray coating techniques was exceedingly improved. However, Energy Dispersive Spectroscopy (EDS) analysis showed that TiO2 was embedded in the adhesives. Nevertheless, sprinkling of TiO2 powder on sodium silicate presented a very stable coating regardless of high TiO2 loading. It was also shown that coating of sodium silicate on pretreated plates did not a↵ect the mechanical stability of TiO2 coating. A well coated and uniform surface of TiO2 was achieved by spray coating technique.

In vitro dissolution assays are used to study how a pharmaceutical formulation will behave in vivo. The assay is performed to estimate how the API of the dosage form is released in the body after administration.  A previous ATT transfer of Crestor showed a significant difference in the dissolution results between the manual and automatic method, leading to the manual method of Crestor failing to transfer. Only the automatic dissolution analysis was established at AstraZeneca Sweden Operations. The aim of the study was to optimise the manual dissolution method of the immediate-release tablet with USP apparatus II (paddle).  The optimisation of the manual dissolution method was initiated with a replication of original issues of the method, where the previously observed problem during the ATT transfer was not recreated. An equivalence study of the manual method was therefore initiated. The equivalence study showed that the manual dissolution method for Crestor of the strengths 5, 10 and 20 mg could claim equivalence to the automatic dissolution method. However, the strength of 40 mg could not claim equivalence, which may be due to the fact that a too small sample size was used and that the data obtained for the strength was insufficient. The strength of 40 mg needs to be further analysed to obtain data with the same sample size as for the other strengths to determine with certainty whether Crestor 40 mg can claim equivalence or not.

Rapporten behandlar arbetet med att förfina, utveckla och dokumentera en beräkningsmodell för simulering av biologisk nedbrytning och temperaturförhållanden i luftade dammar. En luftad damm är en enkel typ av biologisk rening där mikroorganismernas biologiska nedbrytningen av oganiskt material påskyndas genom att syre tillförs – vanligen med hjälp av ytluftare.  Arbetet är ett examensarbete inom ramen för högskoleingenjörsutbildning i kemiteknik vid KTH och har utförts på uppdrag av ÅF Industry AB som har använt beräkningsmodellen sedan 1970-talet. Modellen togs fram med hjälp av tidigare forskning, data från befintliga anläggningar och nedbrytningsförsök utförda i laboratorieskala. I arbetet har ingått att sammanställa och dokumentera erfarenheter och bakgrund till de beräkningsformler och konstanter som används i modellen. Vissa förenklingar har gjorts genom att lösa ut parametrar ur ingående beräkningssamband och genom att avläsningar ur diagram och successiv anpassning har ersatts med beräkning från en kurvekvation.   En kortfattad bakgrundssammanfattning av biologisk rening och luftare finns för att ge läsaren en uppfattning om grunderna till arbetet. Vidare finns bakgrund om Korsnäs Gävle vars luftade damm har legat till grund för simuleringar för att visa att modellen fortfarande ger pålitliga resultat efter ovan nämnda förändringar. Vissa kontrollberäkningar har också gjorts på data från Billerud Karlsborgs luftade damm. Dessa verifierade att trots att simuleringarna under examensarbetet gjorts med Korsnäs data fungerar modellen på olika dammar. Känslighetsanalys för att studera hur förändringar i olika indata påverkar beräkningsresultatet har visat hur viktigt det är att ha god felmarginal på de temperaturer och hastighetskonstanter som ska användas i modellen. Vissa av de i modellen ingående historiskt framtagna ”standardvärden” måste användas med viss försiktighet, eftersom sammansättningen av olika delavlopp från skogsindustrin har ändrats sedan modellen togs fram. Detta gäller framförallt hastighetskonstanter vilka förändrats kraftigt med nya processer inom pappersindustrin. Modellen är ett bra redskap för översiktliga simuleringar av reningseffekter och avkylning vid processförändringar om man håller sig någorlunda nära de förhållanden för vilka olika faktorer för aktuell luftad damm är framtagna. Modellens ekvationer bygger på nedbrytning av organiskt material uttryckt som biologisk syreförbrukning BOD (biological oxygen demand). Användbarheten skulle öka om motsvarande samband skulle kunna tas fram även för COD (kemisk syreförbrukning) eller TOC (totalt organiskt kol), idag vanligare analysmetoder. Detta skulle dock kräva en stor omarbetning av modellen, för att kunna ta hänsyn till svårnedbrytbart organiskt material. Med hjälp av omräkningsfaktorer mellan BOD och TOC eller COD i in och utgående avlopp kan modellen användas i sin nuvarande utformning även med ett fåtal BOD-analyser och löpande data för COD eller TOC.   Nyttan av modellen skulle öka väsentligt om den kunde anpassas till aktivslamanläggningar, som idag är en betydligt vanligare reningsmetod. En sådan anpassning skulle dock kräva både laboratorieförsök och omfattande kontroller mot data från fullskaleanläggningar.

Per- and polyfluoroalkyl substances (PFAS) are a group of organohalogens that bioaccumulate in biota, have toxicological effects and are persistent in the environment. Because of the fluorinated carbon chain, PFASs are present in many household and industrial products. The aim of this study is to investigate if PFASs are residues in ash from municipality incineration facilities and asses if the ashes can become a source of environmental pollution. In the method development three different extraction methods were tested (liquid-solid extraction with MeOH, liquid-solid extraction with acetone/hexane and Soxhlet extraction with MeOH) and evaluated by quantification of PFASs and extractable organic fluorine (EOF). The liquid-solid extraction with MeOH was chosen as the extraction method as the target PFASs were extracted from the ash samples while the other methods resulted in lower signals. The EOF had high blank raising questions about the suitability of the method for EOF. The results from analysing ashes from 11 facilities sampled in 2005 indicate that PFASs are occurring more often in fly ash than bottom ash (sum of PFAS 43,1- 950,7 pg/g) however the two samples with the highest detected amount of PFASs (1611 and 7169,5 pg/g) were both bottom ash. The PFASs that were found in the highest concentrations were at low parts per billion in concentration levels. Since the landfill sites around waste facilities are continuously refilled with new ash from the incineration there is a possibility that the landfills could become a source of environmental pollution in the future with continuously leeching from the added ashes.

Hydrogen peroxide and Lactic acid Wick index are some of the most important parameters when the liquid board will be quality assured of the manufacture. The goal of this study is to improve and develop the existing analysis methods that Billerud AB uses to analyze the edge penetration of hydrogen peroxide and lactic acid in liquid boards. The purpose of this work is to gain an increased understanding of the edge penetration in the different layers of the liquid carton. This will be investigated by developing the existing analytical methods by adding two different colors. The color allows us to visualize the penetration into the different layers. Thus, the goal is to map whether the colored analysis methods affect the analysis result depending on which color is used compared to the unstained analysis methods and whether there are advantages/disadvantages if the colored methods will be used compared to the unstained methods. Comparison between modified methods and non-modified methods was built on cardboard samples from the archive, but also fresh samples from the board machine. The theory that was used as a starting point to compare the colored methods with the original ones is Lucas Washburn's theory. Therefore, all the parameters found in the Lucas Washburn theory have been investigated for both colored/uncolored liquids. In addition, the wick index has also been compared. Results have shown that there is no major difference in wick index between the colored liquids and the uncolored ones. In contrast, color nr 1 gave good color penetration compared to color nr 2 due to the good compatibility between the liquids and the paint. Other advantages that could be found with the colored methods with color nr 1 are that the colored methods can be used to get an idea of how well the bonding has been in the different layers, the troubleshooting of the process, and detect handling errors that can lead to an incorrect value on the wick index.

Nanoparticles of cerium dioxide was synthesized by gamma irradiation of aqueous solutions containing CeCl3 and CeBr3. ICP-OES was used to determine the precipitation yield. X-ray powder diffraction and transmission electron microscope were used to characterize the products. The crystal structurewas found by Fourier transform of high resolution electron microscope images,selected area electron diffraction, electron pair distribution function and X-ray powder diffraction. The morphology was examined from high resolution electron microscope images. The chemical composition was examined by electron energy loss spectra. Nanoparticles of 3-4 nm were found to agglomerate and fuse into cubic mesocrystals of 20-40 nm. Changing precursor did not influence the final product. An attempt to change the morphology by increasing the ionic strength with sodium perchlorate was made. At higher ionic strength, the morphology was more random and the yield increased. The size distribution also broadened. Future research can evaluate the catalytic activity of the samples, test other ions to increase the ionic strength to see if it is the ionic strength or the counterion that influences the growth, and do more analysis on the samples prepared. / Nanopartiklar av ceriumdioxid syntetiserades genom gammabestrålning av vatten innehållande CeCl3 och CeBr3. ICP-OES användes för att bestämma utfällningsutbytet. Röntgenkristallografi och transmissionselektronmikroskop användes för att karaktärisera produkterna. Kristallstrukturen hittades genom Fouriertransformering av elektronikmikroskopbilder med hög upplösning, selected area electron diffraction, elektronparfördelningsfunktion och röntgenkristallografi. Morfologi undersöktes från högupplösta elektronmikroskopbilder. Kemisk sammansättning undersöktes med elektronenergiförlustspektra. 3-4 nm stora nanopartiklar agglomerade i kubiska mesokristaller på 20-40 nm. De olika startmaterialen påverkade inte slutprodukten. Ett försök att ändra morfologin genom att öka jonstyrkan med natriumperklorat gjordes. Vid högre jonstyrka ändrades mesokristallernas morfologi till mer slumpmässig och utbytet ökade. Storleksfördelningen blev bredare. Framtida forskning kan utvärdera den katalytiska aktiviteten hos proverna, testa andra joner för att utröna om det är den förhöjda jonstyrkan eller valet av jon som påverkar tillväxten av partiklar, och göra flera analyser av de beredda proverna.

Electrowinning is an energy demanding process, in which the electrolysis accounts for the major part of the energy consumption. The anodic reaction in the electrolysis of zinc from sulphate based electrolytes is oxygen evolution, which has a standard potential of 1.23 V at 25 ºC. The lead anodes used in zinc electrowinning today have a high overpotential for oxygen evolution and the operating anode potential is as high as 2 V vs NHE. Since the lead anodes are not stable some of the lead can dissolve and incorporate in the zinc metal on the cathode. The lead anodes are also undesired because of health concerns. By introducing formic acid or methanol oxidation as anode reaction, the anode potential could be lowered significantly. This would reduce the energy consumption and also enable the use of new types of electrodes. The general aim of this thesis was to investigate how depolarised anodes for methanol and formic acid oxidation can be used in electrowinning processes. Several electrodes were shown to be suitable as anodes in zinc electrowinning. A high activity was obtained with porous electrodes, whereas a platinum coated titanium was the most stable electrode. The choice of electrode will however always be a compromise between activity, stability and costs. All electrodes were deactivated with time and the best method for reactivation tested in this study, was periodic current reversal (PCR). An operating procedure was established for methanol and formic acid oxidation on high surface area electrodes, Pt-TySAR®. With the use of PCR at process current density, a potential lower than 0.7 V vs NHE could be maintained for 36 hour in synthetic electrolyte. The use of formic acid oxidation resulted in lower potentials than the use of methanol oxidation. The activities for methanol and formic acid oxidation in industrial electrolyte were very low and chloride impurities were shown to cause the major part of the activity reduction. Even small amounts of chloride (10-6-10-5 M) affected the activity of the electrodes. The chloride impurities are considered as the main problem to overcome in order to introduce the oxidation of formic acid or methanol in the zinc electrowinning process. / QC 20101004