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No. of bitstreams: 1 TeseLJC.pdf: 3758058 bytes, checksum: 4551fb3e08abee5796d1f863288fd5ae (MD5) Previous issue date: 2016-02-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / In this work it was evaluated, firstly, the performance of four impellers configurations in the enzymatic hydrolysis of sugarcane bagasse. The configurations evaluated were: (1): Rushton turbine - Rushton turbine; (2): Elephant ear down-pumping and Rushton turbine; (3): Rushton turbine and Elephant ear up-pumping; (4): Elephant ear downpumping and Elephant ear up-pumping. The choice of the best impeller configuration was based in mixing efficiency, characterized by the mixing time. The configurations were also evaluated considering the conversion of cellulose to glucose, power consumption as well as the rheological behavior during hydrolysis. The hydrolysis experiments were carried out in batch stirred tank reactor (3 L) using 10% w/v of solids (pH 4.8; 50°C; 470 rpm), 10 FPU· g-1 biomassa for 96 h. The configuration (4) showed the lowest mixing time and energy efficiency values (ratio of conversion of cellulose to glucose and total energy consumption) of 78.9%·MJ-1. Further, to get a high concentration of glucose associated with low power consumption, it was investigated two operating modes: batch and fed-batch. The strategies evaluated were: E1 [20%]; E2 [10(E)+5+5%]; E3 [5(E)+5+5+5%]; E4 [5(E)+5+5+5%], and E5 5(E)+5(E)+5(E)+5(E)%]. The best energy efficiency was obtained for the E5 strategy in which substrate and enzyme were added simultaneously (0.35 kgglicose·kWh-1). This value was 52% higher than that obtained in the single batch operation (E1). In continuation of the work were carried out enzymatic hydrolysis of exploded and hydrothermal bagasse and cane straw submitted to hydrothermal pretreatment. The experiments were carried out under the conditions: solids loading of 10 (w/v), pH 4.8; 50 ° C; 470 rpm and 10 FPU·g-1 biomass for 96 h. The efficiency obtained in the enzymatic hydrolysis of steam explosion sugarcane bagasse proved to be 41 and 46% higher than the hydrolysis of hydrothermally pretreated sugarcane straw and bagasse, respectively. Finally, a scale-up protocol with a scale factor equal to 1000 was proposed. It was analyzed the maintenance of two parameters on larger scale: the constancy of the mixing time (tm) and the constancy of the power consumption per unit volume (P/V). In turn, maintenance P/V parameter constant, the mixing time and the new scale power consumption (3000L) were approximately 4 and 1000 times higher, respectively, than those values obtained in the smaller scale (3L). / Neste trabalho avaliou-se, primeiramente, o desempenho de quatro configurações de impelidores na hidrólise enzimática do bagaço explodido de cana-de-açúcar. As configurações avaliadas foram: (1): turbina Rushton – turbina Rushton; (2): Elephant ear down-pumping e turbina Rushton; (3): turbina Rushton e Elephant ear up-pumping; (4): Elephant ear down-pumping e Elephant ear up-pumping. A escolha da melhor configuração de impelidores foi baseada na eficiência de mistura, caracterizada pelo tempo de mistura. As configurações também foram avaliadas considerando a conversão de celulose em glicose, o consumo de potência, bem como o comportamento reológico durante a hidrólise. Os experimentos de hidrólise em batelada foram realizados em reator tipo tanque agitado (3 L) utilizando 10% m/v de sólidos (pH 4,8; 50°C; 470 rpm), 10 FPU·g-1 biomassa por 96 h. A configuração (4) apresentou os menores valores de tempo de mistura e uma eficiência energética de 78,9 %·MJ-1. Com o intuito de obter-se alta concentração de glicose associada a um baixo consumo de potência, investigou-se dois modos de operação: batelada e batelada alimentada. As estratégias avaliadas foram: E1 [20%]; E2 [10(E)+5+5%]; E3 [5(E)+5+5+5%]; E4 [5(E)+5+5+5%] e E5 [5(E)+5(E)+5(E)+5(E)%]. Os melhores resultados foi obtido na estratégia E5, obtendo uma eficiência energética de 0,35 kgglicose∙kWh-1. Este valor foi 52% maior do que o obtido na operação em batelada simples (E1). Na continuação do trabalho, foi realizada a hidrólise enzimática do bagaço explodido e hidrotérmico e a palha de cana submetida ao pré-tratamento hidrotérmico. Os experimentos foram realizados em um reator de 3 L nas seguintes condições: carga de sólidos de 10% m/v (pH 4,8; 50°C, 470rpm ) e 10 FPU·g-1 biomassa por 96 h. A eficiência energética obtida na hidrólise do bagaço explodido mostrou-se 41 e 46 % superior aos pré-tratados de bagaço e palha hidrotermicamente, respectivamente. Finalmente, foi proposto um protocolo de aumento de escala com um fator de escala igual a 1000. Analisou a manutenção de dois parâmetros na escala maior: tempo de mistura (tm) e do consumo de potência por unidade de volume (P/V). Com a manutenção do parâmetro P/V constante, o tempo de mistura e consumo de potência da nova escala (3000L) foram aproximadamente 4 e 1000 vezes maiores, respectivamente, do que o obtido na escala menor escala (3L). / FAPESP: 2011/23807-1

Bakgrund: Utvecklingen inom informationsteknik (IT) har skapat många möjligheter för samhället, vilket har lett till framgångsrika IT-bolag som erbjuder digitala produkter och tjänster. IT-sektorn har en hög tillväxttakt vilket attraherar investeringar och skapar jobbmöjligheter. Trots detta är risken att misslyckas inom IT-sektorn hög, och många nystartade IT-bolag överlever inte de första åren på grund av den dynamiska och komplexa miljön de verkar i. Inom IT-sektorn finns det tusentals nystartade bolag, och begreppen 'start-up' och 'scale-up' används för att beskriva dessa. Ett start-ups är ett ungt bolag i ett tidigt utvecklingsstadie, medan scale-up är ett bolag som har nått nästa tillväxtfas och strävar efter att öka sin omsättning och etablera sin marknadsposition. Ledarskapet i dessa miljöer har visat sig spela en avgörande roll för framgång i både start-ups och scale-ups, då miljön är ytterst osäker och snabbföränderlig. Däremot är det fortfarande oklart vilken typ av ledare, och mer specifikt vilka ledarskapskompetenser, som bidrar till ett framgångsrikt start-up respektive scale-up. Tidigare forskning pekar även på att ledarskap är högst kontextrelaterat, och att de ledarskapskompetenser som är viktiga i en kontext inte behöver vara densamma i en annan. Ledarskapskompetenser bör därmed identifieras och utvecklas för att säkerställa att ledaren innehar rätt färdigheter, kunskap, beteende och egenskaper som krävs för att nå strategiska mål och prestationsförväntningar i den specifika miljön.  Syfte: Studiens syfte är att undersöka och få en ökad förståelse för vilka ledarskapskompetenser som associeras med framgång vid IT-bolags tillväxtfaser, start-up respektive scale-up. Metod: Studien har ett kvalitativt tillvägagångssätt och utgår från en hermeneutisk ansats eftersom den syftar till att förstå och tolka företeelser inom det valda forskningsområdet. Vidare används en abduktiv ansats, vilket medför att forskare i denna studie växlar mellan empirisk och teoretisk reflektion. För insamling av empiri har semistrukturerade intervjuer nyttjas med noga utvalda respondenter. Insamlad empiri har sedan analyserats genom en tematisk analys. Slutsats: Studiens resultat visar att det inte är någon markant skillnad mellan de ledarskapskompetenser som associeras med framgång i respektive tillväxtfas. Det tillkommer däremot några ledarskapskompetenser när bolaget skalar upp som relaterar till en ökad arbetsstyrka, vilket kräver mer fokus på struktur och omsorg av medarbetare. Vidare så pekar studiens resultat på att de ledarskapskompetenser som krävs i båda faserna kan behövas nyttjas annorlunda och till olika ändamål. De ledarskapskompetenser som anses krävas i båda tillväxtfaserna är visionär, uthållig, riskbenägen, strategisk, kundfokuserad, kunskapsorienterad, rekryteringsförmåga, omhändertagande, anpassningsbar och flexibel. De ledarskapskompetenser som tillkommer i scale-up är strukturförmåga, förtroende, kommunikativ och kunskapsöverförande.

[pt] No presente trabalho foi investigada a microfabricação de reatores fotocatalíticos de polidimetilsiloxano (PDMS) para o estudo comparativo de aumento de escala entre micro- e mesorreatores, e lignocelulósicos de bambu para reação de cicloadição alcino-azida catalisada por cobre(I) (CuAAC) em fluxo contínuo. Nesse cenário, foi desenvolvida uma configuração experimental de scale-up e numbering-up de sistemas meso- e microfluídicos fotocatalíticos, respectivamente, para comparar a eficiência de fotodegradação de TiO2/P25 em rodamina B (RB) e azul de metileno (em inglês, Methylene Blue, MB) sob irradiação UV. Os resultados obtidos sugerem que o aumento do volume (scale-up) reduz os valores de D(por cento), enquanto que numbering-up mantém a eficiência fotocatalítica com redução significativa do tempo de reação. M6-60 (micro)L apresentou melhor desempenho entre os dispositivos, com degradação total do MB (1,2 x 10-5 mol L-1) em apenas 1h, e foto-oxidação total de fenol (1,2 x 10-4 mol L-1) em 4h. Além disto, M6-60 (micro)L apresentou menor consumo de energia elétrica por ordem (0,012 kWh m-3) e maior rendimento quântico (2,6 x 10-2) em comparação com os outros dispositivos. O desenvolvimento de suportes sólidos lignocelulósicos apresentou importantes características para os processos de funcionalização de TEMPO-TAL com íons Cu(II) e Zn(II) e CuNPs. Os suportes foram devidamente caracterizados por MEV/EDS e FT-IR. Os resultados para a reação de CuAAC mostraram rendimentos de 79-82 por cento com reciclabilidade de até 7 vezes e lixiviação média de cobre de 1,30 ppm, e foram importantes para o desenvolvimento do microrreator de bambu. A microfabricação do microrreator lignocelulósicos de bambu (L(micro)R) foi realizada a partir de etapas de cortes, sem utilização de técnicas caras e sala limpa. L(micro)R mostrou fácil prototipagem e rápida oxidação com N-oxil-2,2,6,6-tetrametilpiperidina (TEMPO) e funcionalização com íons cobre (Cu-L(micro)R) e nanopartículas de cobre (CuNPs-L(micro)R). O desempenho de CuAAC em fluxo contínuo do Cu-L(micro)R foi demonstrado através da realização de estudos de reciclabilidade e rendimentos em diferentes taxas de fluxo (0,1 a 0,8 mL min-1). Cu-L(micro)R apresentou rendimentos de 60 por cento a 96 por cento para 5 tipos de reações CuAAC, indicando promissora aplicação na área de catálise em dispositivos microfluídicos. Todas as reações foram realizadas em regime de fluxo com MeOH:H2O (2:1) e lixiviação de cobre inferior a 6,0 ppm, produzindo uma série de 5 derivados de 1,2,3-triazol 1,4-dissubstituídos com boa eficiência em um ambiente com poucos recursos. CuNPs-L(micro)R apresentou limitação para realização de CuAAC por não alcançar as condições ideais de aquecimento, exigidas para ocorrência da reação. / [en] The present work had two main objectives. The first refers to the development of polydimethylsiloxane photocatalytic microreactors (PDMS) for the comparative scale-up study between micro- and mesoreactors. The second focused on the development of bamboo lignocellulosic microreactors for copper(I) catalyzed alkine-azide cycloaddition reaction (CuAAC). In this scenario, an experimental scale-up and numbering-up configuration of photocatalytic meso- and microfluidic systems were developed, to compare, respectively, the photodegradation efficiency of TiO2-P25 in rhodamine B (RB) and methylene blue (MB) under UV irradiation. The obtained results suggest that the scale-up reduces the values of D (percent), while numbering-up maintains the photocatalytic efficiency with a significant reaction time reduction. The best photocatalytic microfluidic system was M6-60 (micro)L, which presented total MB degradation (1.2 x 10-5 mol L-1) in only 1h, and total phenol photo-oxidation (1,2 x 10-4 mol L-1) in 4h. Furthermore, M6-60 (micro)LM6 had lower electrical energy consumption (0,012 kWh m-3) and higher quantum yield (2,6 x 10-2) compared to others. The development of solid lignocellulosic supports showed important characteristics for the TEMPO-TAL functionalization processes with Cu(II), Zn(II) ions and CuNPs. The supports were properly characterized by SEM/ EDS and FT-IR. The results for the CuAAC reaction showed yields of 79-82 percent with recyclability of up to 7 times and average copper leaching of 1.30 ppm, and were important for the development of the bamboo microreactor. The microfabrication of the bamboo lignocellulosic microreactor (L(micro)R) was performed from cutting steps, without using expensive techniques and clean room. L(micro)R showed easy prototyping and rapid oxidation with N-oxyl-2,2,6,6-tetramethylpiperidine (TEMPO) and functionalization with copper ions (Cu-L(micro)R) and copper nanoparticles (CuNPs-L(micro)R). Cu-L(micro)R continuous flow CuAAC performance was demonstrated by conducting recyclability and yield studies at different flow rates (0.1 to 0.8 mL-1). Cu-L(micro)R presented 60 percent to 96 percent yields for 5 types of CuAAC reactions, indicating promising application in the area of catalysis in microfluidic devices. All reactions were performed under a MeOH:H2O (2:1) flow regime and copper leaching below 6.0 ppm, producing a series of 5 efficiently 1,4-disubstituted 1,2,3-triazols derivatives in a resource-poor environment. CuNPs-L(micro)R presented limitation for CuAAC because it did not reach the ideal heating conditions required for the reaction to occur.

Many organisations aim to grow and increase their profitability, yet not many start-ups manage to survive beyond birth. The transformation into a well-established enterprise is generally seen as a big obstacle to tackle. Further on, project based organisations faces several challenges during scale-up such as how to maintain customisation within customer projects and how to keep up across-functional integration. This thesis addresses how a start-up manufacturing enterprise can scale-up its customer project management. Accordingly, the aim of this thesis is to get a better understanding of the difference between a start-up and an incumbent enterprise, and in turn highlight how to maintain customised operations in a project based organisation. The basis for this thesis is a case study conducted at Northvolt, a lithium-ion battery manufacturing enterprise located in Sweden. The outcome was performed through a collaboration with Northvolt’s customer project management department, and an analysis of conducted best-practice interviews together with a literature review. The empirical findings can be summarised in the following: • First, a growing enterprise needs to implement industry quality standards through the identification of standardised modules. Likewise, an enterprise needs to find which layers to keep flexible and create an environment that enables customisation. • Second, the dynamics within organisational structures can be illustrated as a cradle moving back and forth. An external platform enables new product development. • Third, cross-functional integration is identified as a corner stone for scale-up, but also vital to maintain new product development and hence customisation. • Fourth, pushing down the ownership together with clear targets and milestones is crucial to facilitate a mindset that motivates the workforce in growing sustainable. At the end, this thesis provides Northvolt with some key aspects to have in mind while scaling-up their customer project management, and highlights the conceptual contribution. / En strävan efter uppskalning är vanligt förekommande för företag inom tillverkningsindustrin. Däremot är det inte en självklarhet att transformera ett start-up till ett väletablerat företag. Att omstrukturera verksamheten till en framstående och välfungerande organisation uppfattas i regel som en svår uppgift. Projektbaserade organisationer möter allt som oftast flera utmaningar under uppskalning, sa som att bibehålla kundanpassning inom kundprojekt samt att den tvärfunktionell kommunikationen ofta blir lidande. Den har uppsatsen adresserar huruvida ett tillverkningsföretag, som befinner sig inom start-upstadiet, kan skala upp sin kundprojektavdelning. Därmed syftar denna uppsats till är att ge en ökad förståelse av vad som skiljer ett start-up från ett väletablerat företag, samt identifiera huruvida det går att bibehålla kundanpassning inom växande projektbaserade organisationer. Grunden till denna uppsats är en fallstudie genomförd tillsammans med Northvolt, ett batteritillverkande företag baserat i Sverige. Resultatet är baserat på best-practice intervjuer samt en litteraturstudie, varav analysen ar utförd i samarbete med Nortvhvolts kundprojekt avdelning. Det empiriska resultatet kan kort sammanfattas enligt: • För det första, ett växande företag behöver implementera branschspecifika kvalitetsstandarder genom att identifiera vad som kan standardiseras. Likaså behöver ett företag specificera vilka delar som kan hållas flexibla för kundanpassning. • För det andra, en organisation pendlar allt som oftast mellan olika strukturer. Genom att skapa en extern plattform kan ett företag generera produktutveckling i allt högre grad. • För det tredje, tvärfunktionell kommunikation är en grundsten för uppskalning, men även en nyckel för att generera produktutveckling och därmed kundanpassning. • För det fjärde, att trycka ansvaret längre ner i hierarkin tillsammans med att implementera tydliga mål och hållpunkter utgör en grund för att ge arbetskraften den motivation som krävs för att växa hållbart. Till sist bidrar denna uppsats med några applicerbara verktyg som Northvolt kan ta tillhanda för att skala upp deras kundprojekt avdelning, och slutligen en redovisning av det konceptuella bidraget inom uppskalning av projektbaserade organisationer.

In the kingdom of Saudi Arabia (KSA), the current seawater desalination technologies are completely relying on burning unsustainable crude oil as their main energy driver. Saudi authorities have realized that the KSA is not going to be protected from the future global energy crisis and have started to set up a plan to diversify its energy resources. Membrane Distillation (MD) has emerged as an attractive alternative desalination process. It combines advantages from both thermal and membrane-based technologies and holds the potential of being a cost-effective separation process that can utilize low-grade waste heat or renewable energy. MD has four different configurations; among them is Air Gap Membrane Distillation (AGMD) which is the second most commonly tested and the most commercially available pilot-plant design. AGMD has a stagnant thin layer of air between the membrane and the condensation surface. This layer introduces a mass transfer resistance that makes the process require a large membrane surface area if a large quantity of fresh water is desired. This dissertation reports on experimental and theoretical work conducted to enhance the AGMD flux by removing non-condensable gases from the module and replacing it with either vacuum, liquid water or porous materials. At first, a mathematical model for AGMD was developed and validated experimentally to create a baseline for improvements that could be achieved after the removal of non-condensable gases. The mathematical model was then modified to simulate the process under vacuum where it showed a flux enhancement that reached 286%. The Water Gap Membrane Distillation (WGMD) configuration improved the flux by almost the same percentage. Since enhancing the flux is expected to increase temperature polarization effects, a theoretical study was conducted on the effect of temperature polarization in a Vacuum Membrane Distillation (VMD) configuration. The study showed that the effect of temperature polarization at small temperature difference (3-7) degree Celsius between the bulk feed and coolant temperatures is significantly high. This may indicate the importance of mitigating the effect of temperature polarization in large scale modules operating at small temperature difference across the membrane. The dissertation concluded with some recommendations for future work.

Traditionally, lead-based bearing overlays dominate the commercial automotive market and it has been proven that an excellent combination of properties can be attained through their use. However, lead is a toxic metal and a cumulative poison in humans. According to the European Union End-of-Life Vehicle (ELV) Directive proposed in 1997, vehicles that registered in'all the member states after 1st July 2003 should contain no lead, mercury, cadmium and hexavalent chromium. In this study, a new sulphate-gluconate electrolyte was used to produce multilayer SnCo coatings, aimed at a lead-free overlay for future market use. Tin-cobalt compositionally modulated alloy (CMA) coatings produced from sulphategluconate electrolytes have been previously examined as a potential replacement for lead-free bearing overlays [1]. However, some obstacles may exist which limit their potential use on an industrial scale. For example, long electroplating times are required to produce a thick coating which is very undesirable from an industrial viewpoint, and also the possible elemental interdiffusion occurring in the coating system under engine operating temperatures could rapidly deteriorate the coating properties. In addition, there is an increasing demand from automotive industry to further improve bearing overlay properties, for example for high performance and high compression ratio engines.

Reservoir heterogeneities exhibit a wide range of length scales, and their interaction with various transport mechanisms control the overall performance of subsurface flow and transport processes. Modeling these processes at large-scales requires proper scale-up of both heterogeneity and the underlying transport mechanisms. This research demonstrates a new reservoir modeling procedure to systematically quantify the scaling characteristics of transport processes by accounting for sub-scale heterogeneities and their interaction with various transport mechanisms based on the volume averaging approach. Although treatments of transport problems with the volume averaging technique have been published in the past, application to real geological systems exhibiting complex heterogeneity is lacking. A novel procedure, where results from a fine-scale numerical flow simulation reflecting the full physics of the transport process albeit over a small sub-volume of the reservoir, can be integrated with the volume averaging technique to provide effective description of transport at the coarse scale. In a volume averaging procedure, scaled up equations describing solute transport in single-phase flow are developed. Scaling characteristics of effective transport coefficient corresponding to different reservoir heterogeneity correlation lengths as well as different transport mechanisms including convection, dispersion, and diffusion are studied. The method is subsequently extended to describe transport in multiphase systems to study scaling characteristics of processes involving adsorption and inter-phase transport. Key conclusions drawn from this dissertation show that 1) variance of reservoir properties and flow responses generally decrease with scale; 2) scaling of recovery processes can be described by the scaling of effective mass transfer coefficient (Keff); in particular, mean and variance of Keff decrease with length scale, similar in the fashion of recovery statistics (e.g., variances in tracer breakthrough time and recovery); 3) the scaling of Keff depends on the underlying heterogeneity and is influenced by the dominant transport mechanisms. To show the versatility of the approach for studying scale-up of other transport mechanisms, it is also applied to derive scaled up formulations of non-Newtonian polymer flow to investigate the scaling characteristics of the apparent viscosity and effective shear rate in porous media. / text

Cereals contain naturally occurring biopolymers (for example proteins and starches) that can be used as renewable raw materials in a variety of speciality chemical applications. The separation of protein and starch biopolymers from wheat is well established and relies on a group of proteins called glutens that have a unique network-forming functionality. Oat and other cereals do not naturally contain these gluten proteins and typically rely on chemical-based separation techniques which alter the chemical and physical structures and damage the inherent natural functionality of the biopolymers. This research study investigated the separation of the protein and starch fractions from cereals using the Al-Hakkak Process, a new aqueous process. This process involves adding water and wheat gluten protein to cereals that do not contain gluten. The wheat gluten interacts with the cereal proteins, facilitating the separation of the starch and protein fractions whilst retaining their inherent natural functionality. The aim of this research project was to investigate and optimise the pilot scale separation performance of the Al-Hakkak Process using oat flour. As very little prior research had been carried out, the focus was to characterise the oat starch and protein separation performance and gain an understanding of the mechanisms involved. A variety of techniques were employed. Large scale deformation rheology was used to gain an understanding of the oat-gluten dough rheology and establish the relationship between the rheology and the separation performance. Confocal scanning laser microscopy was used to investigate the structure of the oat-gluten protein network. The molecular interactions between the oat and gluten proteins were studied using gel electrophoresis. The network-forming functionality of the new oat-gluten protein was explored. The influence of various processing parameters on the pilot scale separation performance was investigated and the results compared with other data collected through the study to identify key processing parameters. This research programme has resulted in interesting, encouraging and some unexpected outcomes and these are discussed in detail in the thesis. It was concluded that an insoluble protein network formed in the oat-gluten dough and both kneading and extraction processes were found to contribute to the formation of this. A key conclusion was that the changes that took place in the oat-gluten dough were similar to, but not identical to, the changes that occur in wheat dough. It was proposed that the mechanism for the development of a protein network in oat-gluten dough differed from wheat dough for two main reasons: a) the presence of the oat flour disrupted the normal wheat gluten behaviour, and b) components in the oat flour altered the activity of the gluten proteins. The research identified key processing parameters for the Al-Hakkak Process including kneading time, gluten content, and sodium chloride content of the oat-gluten dough as well as sodium chloride concentration, pH, and temperature of the extract liquor. An important discovery was that the oat and gluten proteins interacted at a molecular level through reducible, covalent, bonding (most likely disulphide linkages) to form the insoluble protein network in the oat-gluten dough. It was concluded that these reducible bonds coupled the individual protein subunits to form new hybrid oat-gluten protein molecules (a combination of oat proteins and gluten proteins). Both insoluble and soluble proteins in the oat and gluten flour were involved in the formation of the insoluble protein network in the oat-gluten dough. This outcome has applications beyond the Al-Hakkak Process, as this new knowledge can be applied to the wider dough processing industry. It was concluded that the wheat gluten was the source of the protein network-forming functionality of the hybrid oat-gluten protein and that the oat proteins had a diluting effect. It was proposed that oat-gluten protein flour from the Al-Hakkak Process could be reused to replace the commercial wheat gluten flour in subsequent production batches. During spray drying of the starch stream, the soluble biopolymers in the extract liquor were found to act as an adhesive and glued individual starch granules together to form spherical agglomerates. Acidification of the extract liquor was found to enhance this agglomeration. It was proposed the acidified starch granules were sticker during spray drying due to the partial acid hydrolysis of the starch granule suface which enhanced the agglomeration.

Doctor of Philosophy / Department of Chemical Engineering / Mary E. Rezac / Reversible organic reactions, such as esterification, transesterification, and acetalisation, have enjoyed numerous laboratory uses and industrial applications since they are convenient means to synthesize esters and ketals. Reversible organic reactions are limited by thermodynamic equilibrium and often do not proceed to completion. High yields for these equilibrium driven reactions can be obtained either by adding a large excess of one of the reactants, which results a reactant(s)/product(s) mixture requiring a separation, or by the selective removal of by-products. Conventional removal techniques including distillation, adsorption, and absorption have drawbacks in terms of efficiency as well as reactor design. Pervaporation membrane reactors are promising systems for these reactions since they have simpler designs, and are more energy efficient compared to conventional downstream separation techniques. This project created a general protocol that can guide one to carry out experiments and collect necessary data for transferring membrane reactor design concepts to the construction of industrial-scale membrane reactors for organic synthesis. Demonstration of this protocol was achieved by (1) experimental evaluation of membrane reactor performance, (2) modeling, and (3) scale-up. The capability of membranes for water/organic separations and organic/organic separations during reversible reactions was investigated. Our results indicated that enhanced membrane reactors selectively removed the by-product water and methanol from reaction mixtures and achieved high conversions for all investigated reactions. Second, modeling and simulation of pervaporation membrane reactor performance for reversible reactions were carried out. The simulated performance agrees well with experimental data. Using the developed model, the effects of permeate pressure and membrane selectivity on membrane reactor yield were examined. Finally, a scale-up on transesterification membrane reactors was carried out. The membrane modules investigated included a bench-scale flat sheet membrane, a bench-scale hollow fiber membrane module, and a pilot-scale hollow fiber membrane module. A 100% conversion was obtained by the selective methanol removal. It is found that with high methanol selectivity membranes, the reaction time to achieve a given conversion continuously decreases with increasing the methanol removal capacity of the reactor system. However, this is a highly nonlinear relationship.

Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that has to overcome several key challenges before achieving its ultimate goal of producing baseload power on a commercial scale. The economic challenge of deploying an OTEC plant remains the biggest barrier to implementation. Although small OTEC demonstration plants and recent advances in subsystem technologies have proven OTEC’s technical merits, the process still lacks the crucial operational data required to justify investments in large commercial OTEC plants on the order of 50-100 megawatts of net electrical power (MWe-net). A pre-commercial pilot plant on the order of 5-10 MWe-net is required for an OTEC market to evolve. In addition to the economic challenge,OTEC plants have potential for adverse environmental impacts from redistribution of nutrients and residual chemicals in the discharge plume. Although long-term operational records are not available for commercial sizeOTEC plants, synergistic operational data can be leveraged from the desalination industry to improve the potential for OTEC commercialization. Large capacity desalination plants primarily use membranes or thermal evaporator tubes to transform enormous amounts of seawater into freshwater. Thermal desalination plants in particular possess many of the same technical, economic, and environmental traits as a commercial scale OTEC plant. Substantial long-term economic data and environmental impact results are now widely available since commercial desalination began in the 1950s. Analysis of this data indicates that the evolution of the desalination industry could be akin to the potential future advancement of OTEC. Furthermore, certain scenarios exist where a combined OTEC-desalination plant provides a new opportunity for commercial plants. This paper seeks to utilize operational data from the desalination industry as a progressive approach towards OTEC commercialization.