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An initial evaluation of the scalability of extrusion foaming technology is conducted in this thesis. Both lab- and pilot-scale foam extrusion systems along with annular dies and flat dies were used to investigate the effects of extrusion system scale on the foam expansion. The effects of the processing conditions including die temperature and blowing agent content on the volume expansion of extruded polystyrene foams blown with carbon dioxide are presented. A systematic comparison of the effects of extrusion system scale on the expansion behavior of polystyrene foams blown with carbon dioxide at the consistent pressure-drop rate, demonstrated that the scale of the foam extrusion system does not affect the principles of the foaming process, and the effects of extrusion system size on the scale-up of foam techniques, such as shear rate and temperature uniformity, could be suppressed by tailoring the processing conditions and experimental parameters.

An initial evaluation of the scalability of extrusion foaming technology is conducted in this thesis. Both lab- and pilot-scale foam extrusion systems along with annular dies and flat dies were used to investigate the effects of extrusion system scale on the foam expansion. The effects of the processing conditions including die temperature and blowing agent content on the volume expansion of extruded polystyrene foams blown with carbon dioxide are presented. A systematic comparison of the effects of extrusion system scale on the expansion behavior of polystyrene foams blown with carbon dioxide at the consistent pressure-drop rate, demonstrated that the scale of the foam extrusion system does not affect the principles of the foaming process, and the effects of extrusion system size on the scale-up of foam techniques, such as shear rate and temperature uniformity, could be suppressed by tailoring the processing conditions and experimental parameters.

AbstractBackground: Among the biggest threats to mankind are various environmental problems which have been mainly triggered by human interference with the planet. There have been various ineffective efforts to mitigate these detrimental effects. Therefore, another solution might come in the form of social enterprises tackling the aforesaid environmental problems. However, to increase the impact, they need to scale up. It is therefore of paramount importance to understand their major scale-up challenges as well as proposed solutions to scale up successfully. Along with that, we also scrutinize further scale-up opportunities to uncover the hidden potential of scaling up. Purpose: The purpose of this study is to explore the relationship between social enterprises and their power to tackle environmental problems. We further build on what social enterprises tackling environmental problems must do to mitigate identified scale-up challenges successfully and to be able to seize any scale-up opportunity that comes their way with the main aim of scaling up their positive environmental impact.Method: Ontology – Relativism; Epistemology – Social Constructionism; Strategy –Qualitative, Exploratory; Approach – Inductive; Design – Grounded theory; Data Collection –10 semi-structured interviews; Sampling – Purposive, snowball; Data Analysis – Grounded AnalysisConclusion: Several factors hinder scaling up and solutions to those lie mainly in four key concepts i.e. business idea, value proposition, competency and collaboration. That has been presented in our proposed model (The Hot Air Balloon Model of Scaling Up). We believe that if these four key concepts are well addressed by SEEPs, they are likelier to overcome challenges as well as are in a better position to attract opportunities. Successful scale-up leads to better financial performance along with the overall objective of scaling up the positive environmental impact.

As the demand for oil and gas resources increases, the need to venture into more hostile environments becomes a dynamic focus in the petroleum industry. One problem associated with certain high risk formations is lost circulation. As a result, engineers have concentrated research efforts on developing novel Lost Circulation Materials (LCM’s) that will effectively treat thief zones. The most pioneering LCM’s require mixing energy to activate a reaction involving two or more chemicals. However, minimal research has been conducted to accurately predict downhole mixing capabilities. Therefore, this research focuses on developing a correlation between laboratory experiments and scaled model experiments for accurate prediction of downhole mixing energies in terms of flow rate for adequate mixing of lost circulation prevention fluids.

Atom transfer radical polymerization (ATRP) is a dynamic technique that possesses tremendous potential for the synthesis of novel polymeric materials not possible through conventional free radical polymerization. However, its use on an industrial scale has been limited by the high level of transition metal complex required. Significant advances have been made in the last 5 years towards lowering the level of copper complexes used in ATRP, resulting in novel variants called “activator regenerated by electron transfer” (ARGET) and “single electron transfer-living radical polymerization” (SET-LRP). To fully realize the potential of ATRP, its use in industrially relevant processes must be studied. Continuous processes such as tubular flow reactors and stirred tank reactors (CSTR) can reduce waste, improve productivity and facilitate process scale-up when compared to common batch reactors. The combination of low copper concentration ATRP techniques and continuous processes are especially attractive towards the design of a commercially viable process. This thesis presents a study into ARGET ATRP and SET-LRP as applied to continuous tubular and stirred tank reactors for the production of acrylic and methacrylic polymers. The equilibrium which governs polymerization rate and control over molecular architecture is studied through batch ARGET ATRP experiments. The improved understanding of ARGET ATRP enabled the reduction of ligand from a 3 to 10 fold excess used previously down to a stoichiometric ratio to copper salts. ARGET ATRP was then adapted to a continuous tubular reactor, as well as to a semi-automated CSTR. The design of the reactors and the effect of reaction conditions such as reducing agent concentration and residence time are discussed. The use of common elemental copper(0) such as copper wire and copper tubing is also investigated with SET-LRP for room temperature polymerization of methyl acrylate. SET-LRP is adapted to a CSTR to observe the effects of residence time on reaction rate, molecular weight control as well as copper consumption rate. The use of copper tubing as a catalyst source for SET-LRP is demonstrated and the design of a continuous tubular reactor using a combination of copper and stainless steel tubing is discussed. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-04-30 16:01:28.916

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The cleaning and dewatering of ultrafine (minus 44 micron) coal slurries is one of the biggest challenges faced by coal industry. Existing commercial technologies cannot produce sellable products from these ultrafine streams; therefore, the industry is forced to discard this potential energy resource to waste impoundments. This practice also has the potential to create an environmental hazard associated with blackwater pollution. To address these issues, researchers at Virginia Tech have worked over the past decade to develop a novel separation process that simultaneously removes both mineral matter and surface moisture from fine coal particles. The first stage of the process uses immiscible non-polar liquids, such as straight chain hydrocarbons, to selectively agglomerate fine coal particles in an aqueous medium. The agglomerates are then passed second stage of processing where mild agitation is used to disperse and fully engulf hydrophobic coal particles into the non-polar liquid and to simultaneously reject any residual water and associated hydrophillic minerals entrapped in the agglomerates. The non-polar liquid, which has a low heat of evaporation, is then recovered by evaporation/condensation and recycled back through the process. The research work described in this document focused on the engineering development of this innovative process using batch laboratory and continuous bench-scale systems. The resulting data was used to design a proof-of-concept (POC) pilot-scale plant that was constructed and successfully demonstrated using a variety of fine coal feedstocks. / Ph. D.

No / Mechanochemical synthesis, i.e., reactions conducted by grinding solid reactants together with no or minimal solvent, has been demonstrated as an excellent technique for the formation of both organic and inorganic compounds. Mechanochemistry is viewed as an alternative approach to chemical synthesis and is not always considered when developing manufacturing processes of fine chemicals. Here, recent advances are highlighted regarding mechanochemical synthesis, by utilizing a well‐developed continuous technique – extrusion, and the advantages it offers to further support its use in the manufacturing of these chemicals. To put this work into context, it is shown how extrusion plays a vital role for manufacturing in the food, polymer, and pharmaceutical industries, and how the research carried out by these respective industrialists provides great insight and understanding of the technique, with the results being applicable in the chemical industry. The synthesis of metal–organic frameworks (MOFs) is highlighted herein as an excellent example showcasing the advantages that extrusion provides to the manufacture of these materials, one advantage being the exceptional space time yields (STYs) reported for these processes, at three orders of magnitude greater than conventional (solvothermal) synthesis. / EPSRC. Grant Number: EP/L019655/1

L'optimisation des procédés utilisant un substrat bon marché et abondant est considéré comme un facteur affectant le prix de production du 2,3-BD. Les valeurs optimales du pH, du taux d'aération, de la vitesse d'agitation, et de la concentration en substrat (maltodextrine) pour la production de 2,3-BD à partir de maltodextrines par la souche génétiquement modifiée Klebsiella oxytoca KMS005 ont été déterminées par une méthode conventionnellefacteur par facteur ainsi que par l’utilisation de la méthode des surfaces de réponse avec un plan d’expériences de Box-Behnken. Les résultats ont montré que les valeurs optimales de pH, taux d'aération, vitesse d'agitation, et concentration en substrat (maltodextrine) ont été respectivement de 6,0, 0,8 wm, 400tr/min et 150 g/L. Les surfaces de réponses ont permis de montrer que la vitesse d'agitation était le paramètre le plus influent pour la production de 2,3-BD. La mise en oeuvre d’un procédé fed-batch a permis d’obtenir en 78 h une concentration en 2,3-BD de 88,1±0,2 g/L avec un rendement de 0,412±0,001 g/g et une productivité de 1,13±0,01 g/L/h. L’influence des conditions de micro-aération sur la croissance des microorganismes et sur la production de 2,3-BD a été étudiée. En bioréacteurs batch, le transfert d’oxygène a été caractérisé via la mesure kLa en faisant varier le débit d'air et la vitesse d'agitation. La quantité optimale d'oxygène fournie aété évaluée à 9,5 g correspondant à un kLa de 25,2 h-1. Ensuite, un Ensuite, un procédé fed-batch a été étudié avec différentes stratégies de débit d'alimentation en glucose. Les meilleurs résultats ont été obtenus pour un débit d'alimentation constant en glucose de 2 g/h après une phase batch de croissance de 48 heures, et suivie d'une phase batch finale de 40 heures. Il en est résulté une concentration finale de 2,3-BD de 74,7 g/L avec une productivité de 0,64 g/L/h et peu de sous-produits formés (environ 3 g/L d’acide succinique, acétate et éthanol). D’autre part, les résultats issus des expérimentations en bioréacteur de 2 L ont été mis en oeuvre à l’échelle pilote. La production de 2,3-BD de maltodextrine a été réalisée dans des bioréacteurs de 10, 90 et 300 L pour différentes vitessesd’agitation et un taux d'aération fixé à 0,8 vvm.). Une concentration de 2,3- BD de 53,8 g/L et un rendement de 0,40 g/g de sucre consommé en 48 hont été obtenus avec une vitesse d’agitation constante de 295 tr/min en réacteur de 10 L. Pour le réacteur de 90 L, une concentration en 2,3-BD de52,53 g/L et un rendement de 0,43 g/g de sucre consommé ont été atteints en 72 h pour une vitesse d’agitation constante à 130 tr/min. Les meilleuresconditions d’inoculation ont été obtenues pour les précultures en phase exponentielle de croissance (12 h d’incubation) et une DO550 égale à 4 avant transfert dans le bioréacteur de 90 L. Pour le réacteur de 300 L, la concentration en 2,3-BD était de 45,02 g/L pour un rendement de 0,43 g/g de sucre consommé, obtenusaprès 72 h. / An optimization process with a cheap and abundant substrate is considered one of the factors affecting the price of commercial 2,3-Butanediol (2,3-BD) production. The optimized levels of pH, aeration rate, agitation speed, and substrate concentration (maltodextrin)were optimized by a conventional method and Response Surface Methodology (RSM) with Box-Behnken design in which metabolically engineered Klebsiell oxytoca KMS005 utilized maltodextrin to produce 2,3-BD. Results revealed that pH, aeration rate, agitation speed,and maltodextrin concentration at levels of 6.0, 0.8 vvm, 400 rpm, and 150 g/L, respectively, were the optimal conditions. RSM indicated that the agitation speed was the most influential parameter when either agitation and aeration interaction or agitation and substrate concentrationinteraction played important roles for 2,3-BD production. Under interim fedbatch fermentation, 2,3-BD concentration, yield, and productivitywere obtained at 88.1±0.2 g/L, 0.412±0.001 g/g sugar supplied, and 1.13±0.01 g/L/h, respectively, within 78 h. The influence of micro-aerobicconditions on microbial growth and 2,3-BD production was also studied. In batch bioreactors, air flow rate and agitation rate characterized through kLa measurement were tested. The optimal amount of oxygen supply was evaluated at 9.5 g corresponding to a kLa of 25.2 h-1 for cell growth and 2,3-BD production. Then, a fed-batch process was investigated by different glucose feeding rate strategies. Fedbatch with a glucose feeding rate of 2 g/h starting at the end of the growth phase during 48 h, followed by a final batch phase of 40 h was found satisfactory. It resulted in a final 2,3- BD concentration of 74.7 g/L with a productivity of 0.64 g/L/h but few byproducts formed (about 3 g/L including succinate, acetate and ethanol). Validated information in the 2 L bioreactor was further applied in a larger scale production of 2,3-BD with series of bioreactors from 10, 90 and 300 L vessels. Batch experiments were conducted based on various agitation speeds with the fixedaeration rate at 0.8 vvm. As a result, 2,3-BD concentration, and yield were achieved at 53.8 g/L, and 0.40 g/g sugar supplied within 48 h, respectively, under the constant tip speed at 295 rpm using a 10 L vessel. Its concentration of 52.53 g/L and yield of 0.43 g/g sugar consumedwithin 72 h were attained under the condition of the constant tip speed at 130 rpm using a 90 L fermenter. An appropriate seed inoculum condition was found with an optical cell density (OD550) around 4 at the log phase (12 h incubation) prior to transferring of the inoculum into the 90 L fermenter. Under the constant tip speed at 70 rpm, 2,3-BD concentration and yield were obtained at 45.02 g/L and 0.43 g/g sugar consumed in the pilot scale of 300 L bioreactor after 72 h incubation.