This work begins with an introduction to catalysis focusing on heterogeneous systems and surface science phenomena. A study on the partial oxidation reaction of n-butane to maleic anhydride (MA) is presented in the first part. MA supplies are barely adequate for market requirements due to continued strong demand. Only slight improvement in catalytic performance would be welcome in the industrial community. The vanadium phosphorus oxide (VPO) catalyst was used in this work. The reaction is highly exothermic and the need to properly support the catalyst, not only for good dispersion but adequate heat dissipation is of crucial importance. For this, alpha-SiC commercial powders were used in synthesizing the catalyst due to its high thermal conductivity. Up to 25% MA yields were obtained and the reaction temperature was lowered by up to 28% using SiC/VPO mixed catalysts. The second part of this work is focused on the Fischer-Tropsch synthesis (FTS) process using cobalt silica supported catalysts. The main objective is the production of synthetic ultra high purity jet fuel (JP5). This is a very timely topic given the energy issues our world is facing. Almost all aspects of the FTS process have been extensively studied, however the effects of calcination temperature and silica support structure on the catalyst performance are lacking in literature. The catalysts were prepared using various silica supports. The catalysts had different drying and calcination temperatures. It was found that lower support surface area and calcination temperature catalysts exhibited higher activity due to lower support cobalt phase interaction. Co/silica catalysts calcined at 573K showed the highest CO conversion and the lowest CH4 selectivity. Catalysts prepared with 300m²/g support surface area exhibited 79.5% C5+ selectivity due to higher reducibility and less metal support interaction. The properties and performance of various prepared catalysts in both VPO and Co/silica systems are characterized by FTIR, XRD, BET, GC and XPS techniques. Theoretical FTS deactivation by sintering calculations and SiC/VPO particle temperature gradient calculations are presented as well. Finally, conclusions and future work on improving the yield and selectivity and scaling up the bench top setups are also presented.

Abstract: Isobutylene is a high demand chemical that contributes to the production of fuel, plastic, and rubbers. It is produced industrially by different processes, as a byproduct of steam cracking of naphtha or a fluidized catalytic cracking or by isobutane dehydrogenation. Catalytic dehydrogenation of isobutane is in increasing importance because of the growing demand for isobutylene and the better economic advantage compared to other isobutylene production processes. Isobutane dehydrogenation is an endothermic reaction and to achieve good yields; it is preferred to work at higher temperatures. At these temperatures, carbon deposition leads to catalyst deactivation, which requires the catalyst to be regenerated on a frequent basis. Most of the current processes to produce isobutylene use either expensive platinum-based metal or toxic chromium-based catalysis. Hence, there is a demand to search for alternative catalysts that are a relatively cheap and non-toxic. To achieve this goal, Zirconia-supported Iron catalysts were prepared. To study the effect of active phase distribution, different iron loadings were tested for impregnation (3% to 10%) and co-precipitation (10%-20%). The catalysts show promising results that can achieve an isobutylene selectivity and yield of 91% and 31%, respectively, with isobutane conversion of 35%.

Content: In this study, equipped charcoal of Ficus carica without impregnation, impregnated with potassium hydroxide (KOH), zinc chloride (ZnCl2) and phosphoric acid (H3PO4) was used for sorption comparison of trivalent chromium from tannery wastewater. The equipped charcoal is characterized before and after used by Fourier transforms infrared spectroscopy (FT-IR). The quantitative elemental analysis is performed of the charcoal using PGT Energy dispersive X-ray spectrometry (EDX). The trivalent chromium sorption efficacy of charcoal was examined investigating charcoal dose, contact time, and relative pH parameters. Batch sorption test revealed that Ficus carica charcoal without impregnation had the maximum sorption capacity of trivalent chromium as depicted Fig. 1a. At the same conditions, trivalent chromium sorption on the Ficus carica charcoal without impregnation, impregnated with potassium hydroxide, zinc chloride and phosphoric acid was 98.9%, 98.8%, 8.9 and 2.5%, respectively. It is noticeable that without impregnation charcoal has a higher sorption capacity. Conversely, impregnation with chemical required cost involvement, time-consuming, long process time, and safe. Fig.1b depicts a shift in the peak intensity which indicated the change of frequency in the functional groups of the charcoal due to chromium adsorption. It indicates various responsible functional groups for the removal of trivalent chromium through Ficus carica charcoal. The trivalent chromium removal efficiency with the Ficus carica charcoal without impregnation was achieved 98.9%. The study could be helpful to design the sorption of trivalent chromium from the tannery wastewater in-house prior to discharge. Take-Away: 1. Without impregnation, Ficus carica charcoal has a better trivalent chromium sorption capacity 2. Trivalent chromium sorption capacity was 98.9%

The technique to produce pulp has improved and become more complex throughout the years. The purpose of pulping is to liberate the wood fibers and it can be done in two ways, either by chemically or mechanically separating the fibers. This thesis will focus on the commonly used kraft pulping process for eucalyptus and especially on the impregnation stage and how it affects kappa number and alkali consumption. This is done by studying the alkali charge, impregnation time and temperature for the impregnation stage while maintaining constant cooking parameters. This project has shown that the impregnation temperature affects the alkali consumption more than the impregnation time. A correlation between alkali consumption in the impregnation and the kraft cook was seen. When the consumption is high in the impregnation stage, a lower consumption was observed in the cooking stage. / Tekniken för framställningen av trämassa har utvecklats och blivit mer komplex genom åren. Massaframsställningens syfte är att separera träfibrerna ifrån varandra vilket kan utföras på två sätt, antingen på kemisk eller mekanisk väg. Denna studie kommer att fokusera på den beprövade sulfatkokningen och då i synnerhet hur impregneringssteget påverkar kappa numret och alkali konsumtion. För att uppnå detta studeras basningen för alkalin, impregneringstid och temperatur under impregneringen samtidigt som de övriga parametrarna hålls konstanta. Detta projekt har visat att impregneringstemperaturen påverkar alkali konsumtionen mer än tiden den impregneras. Andra studier som exempelvis Weiping Ban and Lucian A. Lucia 2003 och Joni Lehto & Raimo Alén 2013 har har också påvisat denna relation mellan alkali konsumtion och impregneringstemperaturen. Denna studie har även visat en alkali konsumtionstrend mellan impregneringen och sulfatkoket. När konsumtionen är hög under impregneringen så är den lägre i koket.

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>

Cellulosic fibers sized from the macro-scale to the nano-scale were prepared hierarchically from kenaf bast fibers using chemicals. The process began with a hermetical alkaline retting followed by a bleaching treatment. The bleached fibers were hydrolyzed using inorganic acid, from which microfibers and cellulose nanowhiskers (CNWs) were fabricated. Inorganic nanoparticle impregnation (INI) was used to treat the retted fibers for the improvement of the interfacial compatibility between the fiber and polypropylene (PP) matrix. The retted fibers and INI-treated fibers were used as reinforcement for the PP polymer composites. Film casting process was used to make CNW/PVA composites. The hermetical retting process used in this study produced fibers with high cellulose contents (81-92%) by removing the lignin and hemicelluloses. Higher retting temperature resulted in higher fiber surface hardness and elastic moduli. The tensile strengths and tensile moduli of the fibers decreased as the temperature increased. The SEM images showed the micropores in the cell wall structure for the fibers retted at over 130°C, providing the possibility to anchor nanoparticles into the cell wall. Surface morphology of the INI-treated fibers was examined with SEM, and showed that the CaCO3 nanoparticle crystals grew onto the fiber surface. Energy-dispersive X-ray spectroscopy (EDS) was used to verify the CaCO3 particle deposits on the fiber surface. As the size scale of the fibers decreased, the fiber crystallinity increased from 49.9% (retted fibers) to 83.9% (CNWs). About 23% á-cellulose in the raw kenaf bast fibers had been converted into CNWs. The retted fibers without INI treatment had poor compatibility with the polypropylene matrix. The INI treatment improved the compatibility between the fibers and the PP matrix, resulting in an improvement in kenaf fiber/PP composite tensile moduli and tensile strengths. The CNWs prepared from kenaf bast fiber gave excellent reinforcement for PVA composites. A nine percent increase of CNWs in the CNW/PVA composites yielded significant improvements in tensile strength and modulus of about 46% and 152%, respectively, compared with pure PVA.

Stable dinuclear complexes bis(heptane-2,4,6-trionato)dicopper(II) [Cu2(daa)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicopper(II) [Cu2(dba)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicobalt(II) [Co2(dba)2], and [6,11-dimethyl-7,10-diazahexadeca-5,11-diene-2,4,13,15-tetranato(4-)-N7N10O4O13;O2O4O13O15] copper(II)cobalt(II) [(CuCo(daaen)] were supported on Cab-O-Sil by the batch impregnation technique. The supported samples were characterized by UV-Vis, elemental analysis, X-ray powder diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and thermal gravimetric analysis (TGA). Elemental analysis and TGA data confirm that the Cu2(daa)2 complex loses one of its coordinated ligands upon adsorption onto silica in THF at greater than 4.43 wt% Cu loading. By contrast, at all Cu loadings the Cu2(dba)2 complex was adsorbed on the silica surface in CH2Cl2 without loss of ligand. XRD and DRIFTS results confirmed the formation of Cu2(dba)2 multilayer films on the Cab-O-Sil surface for samples containing greater than 2.64 wt% copper. The dinuclear cobalt complex and copper-cobalt complex also do not lose their coordination ligands upon adsorption on the surface. These two metal complexes are amorphous and did not produce XRD patterns. However, DRIFTS results confirm that the binuclear cobalt complex and the copper-cobalt complex begin forming multilayer films between 1.21and 2.53 wt% Cu. The Cu2(dba)2/silica precatalysts were subsequently converted to the catalysts by decomposing the organic ligands at 450 degrees Celsius followed by activation with 2% H2 at 250 degrees Celsius and were evaluated for methanol synthesis and methanol decomposition reactions. Kinetic studies demonstrated that the 3.70% Cu/silica[Cu2(dba)2] catalyst is more active for methanol decomposition than it is for methanol synthesis. The supported dinuclear cobalt and copper-cobalt precatalysts were converted to the catalyst by heating at 450 degrees Celsius followed by activation of the catalysts with 50% H2. Four different catalysts, 3.5% Co/silica[Co2(dba)2], 6.7% Co/silica[Co2(dba)2], 2.3% Co/silica[CuCo(daaen)], and 5.5% Co/silica[Co2(daa)2] were evaluated for the Fischer-Tropsch reaction at 350 degrees Celsius in a batch reactor. The supported binuclear cobalt catalyst produced C1-C7 alkanes and a significant amount of CO2. By contrast, the catalyst formed from heterobinuclear CuCo(daaen) showed the ability to convert syngas to aromatics with a narrow product distribution. In addition, the 6.7% Co/silica[Co2(dba)2] multilayer catalysts have above 98% conversion rates and 60% liquid hydrocarbon selectivity in a flow reactor.

The utilization of fiber-based packages has started to take more place at the packaging sector but is still restricted by a lack of transparency. Today this challenge is tried to be solved by paying more attention on the characteristics of nanofibers and their possibilities. The usage of nanofibers is, however, facing issues such as long dewatering times, demand to modify pulp fibers and changes in production line machines. Therefore, the purpose of this study is to bring up new insights how to enhance the translucence in fiber-based packaging materials by an impregnation treatment without fiber modification, long dewatering time or toxic impregnation compounds. Four compounds sucrose octaacetate (SOA), sucrose acetate isobutyrate (SAIB), α-D-glucose pentaacetate (GPA) and polyvinylalcohol (PVA) were impregnated into a yellowish uncalendared base paper without surface sizing. The hypothesis was that it is possible to achieve significantly higher translucence of a glassine paper (&gt;&gt;50 %) by impregnation of a compound with a similar refractive index to cellulose and calendering. This study confirmed the hypothesis when calendered 23 % blade coated SAIB samples resulted in translucence over 64 %. At the same time, it was noticed that increase in density did not explain the increased translucence, but more important requirements were the properties of the impregnated compound such as melting point at room temperature, viscosity, amorphous structure and additives of the paper. It was also found that SAIB did not cause negative impacts on tensile strength or contact angle measurements. The results of this study offered fundamental information for the possible future steps towards transparent paper without pulp fiber modifications. / Användningen av fiberbaserade förpackningar ökar inom förpackningssektorn men är fortfarande begränsad av bristen på materialgenomskinlighet. Idag försöker man lösa denna utmaning genom att ägna mer uppmärksamhet åt nanofibrernas egenskaper och deras möjligheter. Användningen av nanofibrer står dock inför problem som långa avvattningstider, behov av att modifiera massafibrerna och förändringar i fiberlinjens utrustning. Därför är syftet med denna studie att ta fram nya insikter om hur man kan förbättra genomskinligheten i fiberbaserade förpackningsmaterial genom en impregneringsbehandling utan fibermodifieringar, långa avvattningstider eller giftiga impregneringskemikalier. Fyra föreningar; sackarosoktaacetat (SOA), sackarosacetatisobutyrat (SAIB), -D-glukospentaacetat (GPA) och polyvinyl alkohol (PVA) impregnerades i ett okalandrerat baspapper utan ytlimning. Hypotesen var att det är möjligt att uppnå signifikant högre genomskinlighet av ett glassinpapper (&gt;&gt;50%) genom impregnering av en förening med liknande brytningsindex som cellulosa följt av kalandrering. Denna studie bekräftade denna hypotes när kalandrerade 23 % bladbelagda SAIB-prover resulterade i genomskinlighet över 64 %. Samtidigt noterades att ökningen i densitet inte förklarade den ökade genomskinligheten utan viktigare krav var egenskaperna hos den impregnerade föreningen såsom smältpunkt vid rumstemperatur, viskositet, amorf struktur och tillsatser av papperet. Det visades också att SAIB inte orsakade negativ påverkan på draghållfasthet eller kontaktvinkelmätningar. Resultaten av denna studie visade grundläggande information för möjliga framtida steg mot transparent papper utan massafibermodifieringar.

Yes / Aluminium alloys are widely used structural materials in automotive, aerospace, and transportation, among several other notable industries. However, aluminium alloys' low hardness and poor tribological performance prevent potential use in applications requiring high contact pressures and wear resistance. This paper presents a novel two-step technique for enhancing the mechanical properties of the aluminium alloy by impregnating the surface with Ni-coating containing hard TiO2 nanoparticles using a high-intensity electric arc generated during tungsten inert gas welding. The results show that the process significantly changes the Microstructure and mechanical properties. The surface hardness increased from 0.48 GPa to 0.65 GPa with a corresponding change of Young's modulus from 15 GPa to 24 GPa of the treated surface.

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