While considerable progress has been made towards understanding the effect that membrane-based layer-by-layer (LbL) immobilizations have on the activity and stability of enzymatic catalysis, detailed work is required in order to fundamentally quantify and optimize the functionalization and operating conditions that define these properties. This work aims to probe deeper into the nature of transport mechanisms by use of pressure-induced, flow-driven enzymatic catalysis of LbL-functionalized hydrophilized poly(vinyldiene) (PVDF)-poly(acrylic acid) (PAA)-poly(allylamine hydrochloride) (PAH)-glucose oxidase (GOx) membranes. These membranes were coupled in a sealed series following cellulose acetate (CA) membranes for the elimination of product accumulation within the feed-side solution during operation. At pH = 6 and T = 21oC, the enzymatic catalysis of LbL-immobilized GOx from Aspergillus niger performed remarkably well in comparison to the homogeneous-phase catalysis within an analogous aqueous solution. On average, the enzymatic turnover was 0.0123 and 0.0076 mmol/(mg-GOx)(min) for the homogeneous-phase catalysis and the LbL-immobilized catalysis, respectively. Multiple consecutive permeations resulted in replicable observed kinetic results with R2 > 0.95. Permeations taking place over the course of a three week trial period resulted in a retention of >90% normalized activity when membranes were removed when not in use and stored at -20oC, whereas the homogenous-phase kinetics dropped below 90% normalized activity in under one day.

Polystyrene (PS) is an important commodity polymer. In its most commonly used form, PS is a high molecular weight linear polymer, typically produced through free-radical polymerization, which is a well understood and robust process. This process produces a high molecular weight, clear thermoplastic that is hard, rigid and has good thermal and melt flow properties for use in moldings, extrusions and films. However, polystyrene produced through the free radical process has a very broad molecular weight distribution, which can lead to poor performance in some applications. To this end, nitroxide-mediated radical polymerization (NMRP) can synthesize materials with a much more consistently defined molecular architecture as well as relatively low polydispersity than other methods. NMRP involves radical polymerization in the presence of a nitroxide mediator. This mediator is usually of the form of a stable radical which can bind to and disable the growing polymer chain. This will “tie up” some of the free radicals forming a dynamic equilibrium between active and dormant species, through a reversible coupling process. NMRP can be conducted through one of two different processes: (1) The bimolecular process, which can be initiated with a conventional peroxide initiator (i.e. BPO) but in the presence of a stable nitroxide radical (i.e. TEMPO), which is a stable radical that can reversibly bind with the growing polymer radical chain, and (2) The unimolecular process, where nitroxyl ether is introduced to the system, which then degrades to create both the initiator and mediator radicals. Based on previous research in the group, which included experimental investigations with both unimolecular and bimolecular NMRP under various conditions, it was possible to build on an earlier model and come up with an improved detailed mechanistic model. Additionally, it was seen that certain parameters in the model had little impact on the overall model performance, which suggested that their removal would be appropriate, also serving to reduce the complexity of the model. Comparisons of model predictions with experimental data both from within the group and the general literature were performed and trends verified. Further work was done on the development of an additionally reduced model, and on the testing of these different levels of model complexity with data. The aim of this analysis was to develop a model to capture the key process responses in a simple and easy to implement manner with comparable accuracy to the complete models. Due to its lower complexity, this substantially reduced model would me a much likelier candidate for use in on-line applications. Application of these different model levels to the model-based D-optimal design of experiments was then pursued, with results compared to those generated by a parallel Bayesian design project conducted within the group. Additional work was done using a different optimality criterion, targeted at reducing the amount of parameter correlation that may be seen in D-optimal designs. Finally, conclusions and recommendations for future work were made, including a detailed explanation of how a model similar to the ones described in this paper could be used in the optimal selection of sensors and design of experiments.

The last 15 years have seen tremendous advances in using different metal catalysts to functionalize traditionally unreactive C–H bonds. Given the high potential of these seemingly ideal strategic bond forming reactions, the uptake of C–H activation in fine chemical manufacture is slow. Part of the reason for this deficiency is limited mechanistic understanding of these complex reactions. This can preclude industrial applications of either batch or continuous C–H activation processes. Owing to the synthetic utility of C–H activation reactions, it is highly desirable to design intensified processes for this family of transformations, what can possibly facilitate industrialisation of C–H activation reactions. Firstly, an ab initio process design of a novel C(sp3)–H activation reaction giving access to aziridines yielded a predictive mechanistic model that has been used in an in silico optimisation. The identified set of conditions was suitable for a scalable continuous process. A separation technique was developed, and the utility of the process was extended by a subsequent reaction, a nucleophilic ring opening. Secondly, a black-box optimisation of the investigated reaction was performed. The applied algorithm was able to identify a set of conditions fulfilling the set targets within few experimental trails. The second project has set out to design a process for a C–H oxidative carbonylation. A kinetic study has shown that the reaction is CO-starved even at elevated pressures and that there is an optimal CO concentration. The turn-over number was increased from 8 to nearly 500. Two scalable processes were then developed. The first was a batch process, characterised by a very low catalyst loading. The second was, to the best of author’s knowledge, the first continuous process for an oxidative carbonylation reaction. The continuous process was tested on several oxidative carbonylations yielding excellent results with virtually no optimisation performed. Finally, an environmental sustainability assessment was performed using both, simplified metrics and an LCI analysis. The developed mechanistic understanding allowed identification of sources of inherent inefficiencies of C–H activation reactions. Appropriate solutions to these obstacles were suggested. Thus, it is believed that a step towards generic principles of design of intensified, scalable processes for C–H activation-type reactions has been made.

As redes poliméricas são materiais amplamente estudados, pois suas propriedades especiais permitem que sejam aplicadas em áreas como indústria de fertilizantes, medicina, bioquímica, análises químicas dentre outras. A microestrutura de uma rede polimérica, em geral, exerce grande influência sobre as propriedades macroscópicas desses materiais e o interesse da influência dessa microestrutura nas propriedades finais são de interesse estratégico. As reações de ciclização influenciam no controle da microestrutura das redes poliméricas, é sabido que um aumento na diluição do sistema aumenta a incidência deste tipo de reações. A modelagem matemática da copolimerização do estireno-divinilbenzeno é um assunto amplamente estudado, porém poucos estudos foram realizados considerando as reações de ciclização com uma cinética definida e não um problema tipo caixa-preta. Este trabalho teve como principal objetivo o estudo da copolimerização de estireno-divinilbenzeno em solução e sua modelagem matemática com a inclusão das reações de ciclização intramoleculares. Sendo assim, reações de copolimerização de estireno-divinilbenzeno em soluções com baixas concentrações de monômeros foram realizadas em batelada em um reator de vidro, inicialmente foram utilizados dois modelos matemáticos para estudar o comportamento do sistema nestas condições, denominados: Modelo A e Modelo B. O Modelo A foi desenvolvido através do balanço de massa de todas as espécies no meio reacional e inclusão das reações de ciclização. O tamanho máximo dos polímeros mortos considerados neste modelo foi de 300 unidades monoméricas, pois devido à diluição acreditava-se que este tamanho máximo abrangesse todos os tamanhos de polímeros mortos, porém sua comparação com dados experimentais mostrou o contrário. O Modelo B foi baseado no modelo desenvolvido por Aguiar (2013) e utiliza o balanço de massa para as espécies não poliméricas e método dos momentos para as espécies poliméricas (radicais poliméricos e polímeros mortos). Este modelo utiliza também o Fracionamento Numérico para determinação das massas moleculares e ponto de gel, as reações de ciclização foram incluídas através do Método dos Caminhos. Quando comparados aos dados experimentais, o Modelo B mostrou-se mais realista com menores tempos de simulação e com menores problemas numéricos que o Modelo A, portanto este foi utilizado para o estudo do sistema em questão. Os resultados apresentados através do Modelo B indicam que o parâmetro atribuído à cinética das ligações cruzadas (Cp) foi de 0,05 e o valor do parâmetro de ciclização do menor segmento ciclizável (3 unidades monoméricas) foi de 130 s-1 para a temperatura de 90ºC, os valores para os demais tamanhos foram calculados através da equação de Rolfes e Stepto. Este trabalho é uma continuação ao trabalho de Aguiar (2013) e seus resultados mostraram que as simulações das variáveis: concentração de duplas ligações pendentes, Massa Molecular Mássica Média (Mw) e polidispersidade aproximaram-se mais dos dados experimentais quando as ciclizações são incluídas no modelo quando comparadas à abordagem sem a inclusão das reações de ciclização. / Polymer networks are widely studied materials; their especial properties allow them to be applied in areas such as the fertilizer industry, medicine, biochemistry, chemical analysis among others. In general, the polymer network microstructure has influence in macroscopic properties of materials, hence the interest of such microstructure in final properties are of strategic interest. The cyclization reactions influence in the microstructure control of polymer networks. It is known that an increase in systems dilution can increase the cyclization reactions incidence. Mathematical modeling of copolymerization of styrene-divinylbenzene is a widely studied subject, but few studies have been conducted considering the cyclization reactions with a defined kinetic and not a problem black-box type. This work aimed to study the styrene-divinylbenzene copolymerization solutions and their mathematical modeling with the inclusion of intramolecular cyclization reactions. Thus, solution copolymerization of styrene and divinylbenzene was carried out at low concentration of monomers in batch reactor. Two mathematical models were initially used to analize the behavior of the system, which were called: Model A and Model B. The Model A was developed by molar balance of species in the reaction medium and includes cyclization reactions, which were considered to happen in polymer chains with 300 or less monomer units. Due the dilution was believed that this number of units covering all sizes of dead polymers, but comparison between Model A an experimental data proved otherwise. The Model B was based in model of Aguiar (2013), and uses the mass balance for non-polimerics species and moments methods for polimerics species. Model B also uses numerical fractionation for average molecular weight and gel point determination, and the method of paths to approach cyclization reactions. When compared to experimental data, Model B proved more realistic, presenting shorter simulation times and less numerical problems than Model A. Therefore Model B was chosen to represent the system. The results presented by Model B indicate that the parameter assigned to the kinetics os crosslink (Cp) was fitted at 0,05 and cyclization rate constant for paths with 3 monomer units was fitted 130 s-1 at temperature of 90°C. The cyclization rate constants for longer paths were calculated trough Rolfes and Steptos equation. This work is a follow up to Aguiars work (2013) and the results showed that the simulation of variables: concentration of pendant double bonds, average molecular weight and polidispersity better predicted when the cyclization rate constants are greater than zero.

Abstract embargoed until 2030-11-11

Producing gasoline-type fuels from lignocellulosic biomass has two advantages over producing alcohol-type fuels from plant sugars: gasoline has superior fuel characteristics and plant lignin/cellulose does not compete with human food supplies. A promising technology for converting lignocellulose to fuel is catalytic fast pyrolysis (CFP). The process involves injecting finely ground biomass into a fluidized bed reactor (FBR) at high temperatures, which reduce the biomass to gases that react inside the catalyst particles. This entails complex hydrodynamics to efficiently mix a stream of biomass into a catalyst bed that is fluidized by a separate stream of inert gas. Understanding the hydrodynamics is complicated by the fact that the entire process occurs inside a heavily insulated, opaque, reactor vessel. Numerical simulations offer a promising approach to understanding, predicting, and optimizing hydrodynamic mixing in a CFP biomass reactor. The purpose of this research is to understand the simulation techniques and statistical measures appropriate for quantifying mixing in a CFP biomass reactor. The methodology is validated against the canonical configuration of a non-reacting, single-inlet fluidized bed. A new finding is that the minimum bubbling velocity may be predicted by a significant increase in temporal variance of the pressure drop. The methodology is then applied to a non-canonical FBR in which biomass is injected into the catalyst bed via a vertical center tube. Since no hydrodynamic mixing data exist from laboratory experiments, mixing is inferred from the aromatics yield from the laboratory reactor. Flow configurations with which simulations demonstrate the best mixing have the highest aromatic yields in the experiments. The simulations indicate that when the bed is in the bubbling regime, the gasified biomass from the center tube is efficiently mixed radially throughout the catalyst bed. If the flow rate of inert gas is insufficient to bubble the bed, then the gasified biomass exits the center tube, reverses direction, and flows upward along the tube's outside wall. Provided the bed is bubbling due to the inert gas stream, the upper limit on the flow through the center tube, and thus the aromatic yield potential, has yet to be determined.

The huge energy demand of our society is causing fossil fuel resources to diminish rapidly. Therefore, it is critical to search for alternative energy resources. Biomass is currently both abundant and inexpensive. Biofuels (fuels produced from biomass) have the potential to replace fossil fuels if a cost effective process can be develop to convert biomass into fuels. Catalytic fast pyrolysis is a technology that can convert biomass into gasoline ranged aromatics in a single step. By heating biomass quickly to an intermediate temperature, biomass will thermally decompose into small molecules which can fit into zeolite catalyst pores. Inside the catalyst pores, these small molecules undergo a series of reactions where aromatics are formed along with olefins, CO, CO2, CH4 and water. Gallium promoted ZSM-5 catalyst has been shown to promote small alkanes aromatization, thus it has the potential to increase aromatic yield in catalytic fast pyrolysis process. The focus of the thesis is to study the behavior of catalyst fast pyrolysis of biomass over Gallium promoted catalyst, and explore various ways to utilize the gas phase olefins to increase the aromatic yield. [CG1] The effect of reaction parameters (temperature, weight hourly space velocity, and fluidized gas velocity) on catalytic fast pyrolysis of biomass with Ga/ZSM-5 were studied in a fluidized bed reactor using pine saw dust as the biomass feed. The product distribution and hydrocarbon selectivity are shown to be a strong function of temperature and weight hourly space velocity. Compared to ZSM-5 catalyst at the same reaction conditions, Ga/ZMS-5 has been shown to increase the aromatic yield by 40%. Olefins can be recycled back to the CFP fluidized bed reactor to further increase the aromatic yield. The olefin co-feeding with pine saw dust experiments indicates that co-feeding with propylene can increase the aromatic yield, however, co-feeding with ethylene will cause a decrease in aromatic yield. In both co-feeding experiments, an increase in the amount of coke formed was also observed. Besides a simple olefin recycle, another possible way to utilize these olefins, while avoiding the high cost to separate them from other gas phase products (CO, CO2 and CH4),is adding a secondary alkylation unit after the fluidized bed reactor. The alkylation unit could provide a way to produce additional ethylbenzene after the main CFP process. Three zeolite catalysts (ZSM-5, Y-zeolite and Beta zeolite) were tested in the alkylation unit, and ZSM-5 catalyst shows the highest activity and selectivity in the alkylation of benzene and ethylene.

The fact that hydrogen is a clean and versatile fuel offers an attractive carbon-free source of energy and leverages the U.S. economy toward long-term sustainable economic growth. At an industrial scale, hydrogen production is mostly relying on methane steam reforming producing stoichiometric amounts of carbon oxides (CO and CO2), which imposes economic and environmental concerns. To mitigate the issue, we propose NH3 assisted anaerobic reforming of natural gas liquids (ethane and propane) as an alternative approach to produce COx free hydrogen. Here, in the first chapter, through comprehensive performance evaluation, characterization, and transient kinetic studies, it is shown that the atomically dispersed Re-oxo grafted into framework Al of the HZSM-5 zeolite are highly active and stable for the ammonia reforming of ethane and propane at temperatures comparable to steam reforming ≤ 650 °C. In the second chapter, an alternative non- noble Ni/Ga intermetallic compound (IMC) with various Ni to Ga ratios is synthesized through the solvothermal synthesis by forming the oxalate MOF precursor. The result indicates that while Ni-rich samples form pure Ni3Ga IMC with promising catalytic performance, the Ga rich catalyst consists of segregated phases of Ni/Ga IMC and Ga2O3 with ill-defined structure showing lower stability despite the high activity. In chapter 3, a bifunctional Ni/Ga supported ZSM-5 is successfully developed in ethane aromatization. Influence of metal function in early-stage and steady-state activity and stability as well as structure reactivity relation was investigated applying comprehensive characterization, performance test, deactivation modeling, and transient studies. The results suggest that a tandem reaction mechanism between Ni3Ga intermetallic compound, Ga cation, and Bronsted acid sites of zeolite is responsible for the superior performance of bimetallic catalysts compared to their monometallic counterpart. In the last chapter, applying transient kinetic technique, the mechanism of ethane aromatization over Pt and Zn supported ZSM-5 model catalysts was precisely explored. The results reveal that despite mechanistic differences between these catalysts, ethane amortization on both catalysts follows a hydrocarbon pool mechanism.

The increasing production of natural gas liquids attracts both academia and industry to develop on-purpose techniques converting those light alkanes to value-added chemicals. Dehydroaromatization is an alternative path for light alkane conversion to produce aromatics but still lacks active and stable catalysts. This work aims at the development of efficient dehydroaromatization catalysts by tuning the metal/acid bifunctionality of the Pt/HZSM-5 catalyst. Additionally, through co-processing light alkane with ammonia during the dehydroaromatization process, this study also proposes a new reaction system that could directly link the C-N bond for nitrile synthesis. The results suggested that the activity, selectivity, and stability of the monometallic Pt/HZSM-5 catalyst are highly dependent upon the Pt loading, the limit loading of 100 ppm is required to maintain sufficient metal functionality. To further minimize the Pt loading, the chemical properties of the Pt species were tuned by a second metal such as Zn or Cu. Consequently, the activity and stability of the catalyst are enhanced by orders of magnitude and the maximized metal functionality was achieved at Pt loading of 10 ppm. Characterizations show that Pt can be atomically dispersed as a hybrid [Pt1-Zn6] cluster in the Pt-Zn@HZSM-5 or forming single atom alloy type [Pt1-Cu4] ensembles in the Pt-Cu@HZSM-5. Specifically, the initial turnover frequencies of propane and ethane to BTX are up to 178.8 and 128.7 s-1 over the Pt-Cu@HZSM-5, up to 3-4 orders of magnitude higher than the state-of-the-art Pt-based catalyst. Furthermore, the deactivated catalyst can be continuously regenerated, demonstrating excellent stability of such a catalyst under hash oxidation conditions for coke burn-off. A new catalytic system named ammodehydrogenation (ADeH) for ethane selective conversion to acetonitrile, ethylene, and hydrogen over a bifunctional catalyst is proposed. Ethane ADeH over the Pt/HZSM-5 catalyst is active at low temperatures and atmospheric pressure for CH3CN production. The Pt/HZSM-5 shows high coke-resistibility during the ethane ADeH due to the strong interaction of NH3 with the acid sites of the catalyst. The catalyst can be further optimized by adding Co, the Pt-Co/HZSM-5 catalyst on ethane ADeH indicating that an appropriate balance between the metal and acid functionalities is critical for ethane ADeH.

This thesis has as its principal goal the development of sustainable pressure-sensitive adhesives (PSAs). To that end, we examined polymer reaction engineering practices and polymer formulations through the lens of the 12 Principles of Green Chemistry. To begin with, we employed emulsion polymerization as our polymer synthesis method because of its use of water instead of hazardous solvents. We also replaced various petroleum-based components with bio-based alternatives (e.g., starch, cellulose nanocrystals), thereby reducing synthesis hazards, increasing product safety and increasing the amount of sustainably sourced raw materials in the PSA. However, changing the synthetic method as well as key components in the formulation presented significant challenges to maintaining PSA performance. This thesis illustrates the challenging path taken towards developing a fully renewable PSA. PSAs should display a specific balance of adhesion and cohesion. Typically, petroleum-based additives (which are often hazardous/toxic) such as tackifiers, cross-linkers, chain transfer agents and rheology modifiers are added to tailor latex properties to fit the intended application. However, because of their inherently opposing effects, an additive used to increase adhesion will weaken the cohesive forces of the polymer, and vice versa. Cellulose nanocrystals (CNCs) are sustainable nanomaterials that have been shown to be effective to resolve the adhesion/cohesion conundrum. In the first part of this project, we developed a new technique to increase CNC loading in emulsion-based PSA formulations beyond the 1-2% limits previously encountered due to high latex viscosity, colloidal instability, and poor film properties. The higher CNC loadings were shown to continuously improve shear strength but resulted in eventual decreases to tack and peel strength. In the second part of this project, we replaced the sulfated CNCs with carboxylated CNCs (cCNCs), which are produced by a process using a “greener” catalyst (i.e., hydrogen peroxide instead of sulfuric acid). The cCNCs’ carboxylate surface groups interacted strongly with the polymer matrix, ultimately leading to catastrophic coagulation. The interactions between cCNCs and other standard latex components were studied and through the creative manipulation of the emulsion polymerization process, a reproducible method to incorporate the cCNCs in a seeded semi-batch reaction yielded stable, high-quality latexes. In the third part of this project, the effect of the cCNCs on the adhesive properties of the nanocomposite latex films was studied and compared to the effects of the sulfated CNCs. AFM imaging revealed that cCNCs interact with latex particles and each other; thus, omitting ultrasonication at the preparation stage was shown to preserve these interactions and lead to greater property enhancements. In the fourth part of this project, starch nanoparticles (SNPs) were used to displace some of the petroleum-based monomer in the production of core-shell (SNP cores, acrylic shell) latexes. SNPs are renewably sourced, inexpensive, and biodegradable. The challenge of locating the SNPs into the particle cores was overcome by crosslinking the SNPs using a food grade cross-linker (sodium trimetaphosphate) and functionalizing them using a sugar-based monomer (EcoMer™). To tune the PSA properties to rival a range of commercial tapes, a method to incorporate CNCs to the SNP-latexes in situ was developed. In addition, because monomers such as 2-octyl acrylate (2OA), styrene, and acrylic acid can be bio-sourced, they were selected as the acrylic shell monomers to encapsulate the SNPs in the nanocomposite latexes. Due to supply chain challenges, n-octyl acrylate was used as a model monomer for 2OA to produce latexes with ~80% bio-content that rivaled commercial Post-It™ notes, masking tapes, and duct tapes. After addressing the sustainability of the polymerization method and polymer components, we posed the question: what are the effects of using renewably sourced and bio-sourced materials on the end-of-life of the PSAs? Because the infrastructure for biodegradation studies at the lab scale via composting does not exist in Canada (to our knowledge), we designed an in-house aerobic composting set-up consisting of a series of bioreactors and sensors capable of measuring the aerobic biodegradability of our polymers in a simulated composting environment. Although not fully tested, the composting setup was designed, and its construction was begun. Steps to complete the construction and validate its operation are detailed. The path towards sustainability is often long and complex. In this four-year study, the re-design of an adhesive synthesis process using a more sustainable approach, emulsion polymerization, along with an 80% bio-sourced formulation required significant corrective measures. Overcoming the technical challenges required mustering all the polymer reaction engineering tools at our disposal. Despite the time and effort required, achieving a more sustainable process is indeed within our grasp.