The Bobbin and Beaker Vol. 14 No. 4

https://tigerprints.clemson.edu/spec_bobbin/1174/thumbnail.jp

Process intensification in syngas production and cleaning

PhD ThesisThe aim of this work was to develop an intensified syngas cleaning system for different applications of the cleaned gas. The main target of syngas cleaning is the destruction of tars although the removal of heavy metals is also important. The syngas cleaning strategies include water scrubbing followed by further cleaning and moisture reduction, low temperature capture of tars and destruction of tars at high temperatures preferably at the gasifier exit temperature. In the present study, initially a novel downdraft intensive 50kWe air-blown auto-thermal gasifier was used for the gasification of refinery sludge indicating that refinery sludge could be gasified with low levels of tar as a result of catalytic tar cracking during gasification since refinery sludge initially contained large amounts of catalytic rare earth elements. It contained tar and particulate matter of less than 90 ± 6.0 mg/Nm3 and calorific value of 3.71 ± 0.4 MJ/Nm3 (wet gas), which is sufficient for power generation using an internal combustion engine (ICE). Gas composition, tar content and heat content of the produced gas were determined. Results were compared with those obtained with wood chips (reference feedstock). In the development of intensified syngas cleaning systems, we used a model syngas (carbon dioxide) and model tar (crude oil). A new/novel, multi-functional tar removal rig was designed and fabricated. It can be used as a water scrubber or for tar removal under electric field in the absence or presence of biphilic (both hydrophilic to adsorb water and lipophilic to adsorb tars) adsorbents in the form of functionalized PolyHIPE Polymers (PHPs). These PHPs were produced, functionalized and characterized using environmental scanning electron microscopy (ESEM) and surface area analysis (SAA) and then used in the form of packed bed for the adsorption of model tars from model syngas. According to the literature, using the syngas in a power production application, the tar concentration in syngas needs to be less than 100 mg/Nm3 which requires particle and tars reduction efficiencies of 90 % for a satisfactory operation of an Internal Composition Engine (ICE) using syngas produced in a downdraft gasifier. vii Maximum tar removal efficiencies under the prevailing process conditions were: water scrubbing 45.9 ± 4.5 %; adsorption by the sulphonated PolyHIPE Polymers (s-PHP) 61.8 ± 2.5 %; high voltage application with conductive electrodes 97.5 ± 1.5 % at 25kV; and the combination of s-PHP with electric field resulted in 96.7 ± 1.9 % % tar removal efficiency. The advantage of high voltage gas cleaning is that it can be used at high temperatures and that no other material is used as adsorbent which requires regeneration once they are saturated with tar, etc. Finally, another electrical method was designed to crack the model tars using plasma induced catalytic conversion. The results indicate that hydrocarbon profile of crude oil in the model syngas shifted towards low carbon number

An investigation into the improvement of maintenance quality in a production plant through the use of reliability management

Abstract: Extensive research has been conducted on plant reliability maintenance. However, getting the maintenance system in place remains the core of maintenance improvement. The purpose of this research dissertation is to investigate the impact reliability management has within production industries and its role in improving the quality of maintenance. This study will assist management to reflect on the costeffectiveness and influence that the maintenance management system has within the organisation. The study will also contribute to existing knowledge in plant reliability maintenance. It is, therefore, significant for an organisation to establish good management practices and set maintenance as an integral part of their overall plant strategy. The approach that was followed by this research is a mixed method – a combination of quantitative and qualitative. Data collection was carried out through a literature review, observations, a questionnaire, a survey, interviews and from company documentation. An employee questionnaire was prepared and distributed to 25 participants to conduct gap analysis and evaluate the maintenance practices within the observed company. A benchmark study was also performed using an online survey, based on 85 responses from employees in other processing plant industries within South Africa. The empirical study conducted with Company A’s employees (mainly from the maintenance and operation departments) identified possible blunders, which transpired during the reliability management system implementation phase. Based on this sample the results obtained indicated that maintenance is done unnecessarily on the plant on average. The study also found issues regarding maintenance financial planning ineffectiveness, unavailability of spares and lack of skillsets to perform jobs. The online survey revealed that organisations do make use of Computerised Maintenance Management System (CMMS) to facilitate their maintenance. CMMS also has a positive impact on the overall maintenance processes and productivity. The study identified the importance of planning and scheduling shutdowns in advance, as a significant part of the maintenance annual budget and cost reduction. ..M.Phil. (Engineering Management

TARA (Caesalpinia spinosa): the sustainable source of tannins for innovative tanning processes

This thesis considers the fruit of the tara tree (Caesalpinia spinosa) as a sustainable source for tanning agents and proposes alternatives to the commercial mineral salts and vegetable extracts to comply with an increasing demand that concerns lower carbon footprint and health safety. Taxonomy of the tree is described and the substances contained in the fruit are chemically characterized in order to justify that tara farm forestry is economically viable and to secure a potential worth. The value chain is fully described from fruit collection in remote Andean regions to the export for the most important leather markets. Although tara tannins have been used in the leather industry and its properties being well known, the experimental part of the work aims to optimize innovative formulations using tara as wet-white pre-tanning agent. Combinations with a selected syntan used for wet white and final article recipes are proposedEsta tesis considera el fruto del árbol de tara (Caesalpinia spinosa) como fuente sostenible de taninos para la curtición del cuero y propone alternativas para las sales minerales y los extractos vegetales como respuesta a la creciente demanda para reducir el impacto medioambiental y la seguridad de los artículos de consumo. Se describe la taxonomía del árbol así como la caracterización de su fruto para justificar la silvicultura como práctica económicamente viable y asegurar su valor y la cadena desde la recolección de los frutos en las regiones andinas hasta la exportación a los mercados más importantes de la industria del cuero. Aunque los taninos de la tara ya se usan para la fabricación de cueros desde épocas remotas y sus propiedades están reconocidas, la sección experimental de este trabajo se orienta a optimizar fórmulas innovadoras utilizando la tara como agente de curtido wet-white. Se proponen fórmulas para artículos finales.Postprint (published version

TARA (Caesalpinia spinosa): the sustainable source of tannins for innovative tanning processes

This thesis considers the fruit of the tara tree (Caesalpinia spinosa) as a sustainable source for tanning agents and proposes alternatives to the commercial mineral salts and vegetable extracts to comply with an increasing demand that concerns lower carbon footprint and health safety. Taxonomy of the tree is described and the substances contained in the fruit are chemically characterized in order to justify that tara farm forestry is economically viable and to secure a potential worth. The value chain is fully described from fruit collection in remote Andean regions to the export for the most important leather markets. Although tara tannins have been used in the leather industry and its properties being well known, the experimental part of the work aims to optimize innovative formulations using tara as wet-white pre-tanning agent. Combinations with a selected syntan used for wet white and final article recipes are proposedEsta tesis considera el fruto del árbol de tara (Caesalpinia spinosa) como fuente sostenible de taninos para la curtición del cuero y propone alternativas para las sales minerales y los extractos vegetales como respuesta a la creciente demanda para reducir el impacto medioambiental y la seguridad de los artículos de consumo. Se describe la taxonomía del árbol así como la caracterización de su fruto para justificar la silvicultura como práctica económicamente viable y asegurar su valor y la cadena desde la recolección de los frutos en las regiones andinas hasta la exportación a los mercados más importantes de la industria del cuero. Aunque los taninos de la tara ya se usan para la fabricación de cueros desde épocas remotas y sus propiedades están reconocidas, la sección experimental de este trabajo se orienta a optimizar fórmulas innovadoras utilizando la tara como agente de curtido wet-white. Se proponen fórmulas para artículos finales

Metilação diferencial de DNA no envelhecimento: exploração in silico utilizando dados de elevado rendimento

The emergence of high-throughput methodologies after the conclusion of the Human Genome Project has brought genomic and epigenomic wide studies to the forefront of current research of biological and biomedical knowledge. Currently, the focus in genetic mutations as primary cause of certain disorders is not so relevant as before, since it was demonstrated that epigenetic mechanisms are involved in cellular programming and gene regulation providing adaptive variants of a given gene to a changing environment with an association to cellular differentiation. The research in the DNA methylation field has already revealed essential facts as the existence of methylation in CpG islands and alternative contexts that influence gene expression in tissue-specific manner. The influence of lifestyle choices in aging processes has also been related to methylome variations. And, in the case of cancer, the cooperation of epigenetic and genetic information is essential to understand the progress of cancer development as well as the silencing of key regulatory genes. An overall hypomethylation in cancer genome leads to oncogene activation whereas hypermethylation in specific regions is associated with silencing of tumour suppressor genes. For that reason, the research for new therapeutic approaches to cancer and aging is a current issue of the scientific community that work in the epigenomic field. In order to contribute to the study of mammalian epigenomes during lifespans, this research focused on the usage of public databases datasets to further investigation about DNA methylation across aged individuals in order to extract tissue-specific markers related with healthy aging. The validation of results was made through the usage of samples, form healthy individuals with good or bad cognitive performances, available in iBiMED. In both situations the genes ELOVL2 (cg16867657) and FHL2 (cg06639320) were identified as good markers of ageO aparecimento de metodologias de sequenciação de elevado rendimento após a conclusão do Projeto do Genoma Humano foi um avanço fundamental para a pesquisa biológica e biomédica na área da genómica. Embora as mutações genéticas tenham sido durante décadas o foco principal na causa de certas desordens, atualmente demonstrou-se que os mecanismos epigenéticos estão envolvidos na programação celular e na regulação genética, providenciando variações adaptativas do mesmo gene a um determinado ambiente e possuindo ainda uma associação direta com a diferenciação celular. O desenvolvimento científico no campo da metilação de DNA revela atualmente factos essenciais na biologia molecular, como a existência de metilação nas ilhas CpG e em contextos alternativos que influenciam a expressão genética nos diferentes tecidos humanos. Para além disso, a influência dos estilos de vida no processo de envelhecimento já demonstrou estar relacionada com o estado do epigenoma, nomeadamente com as variações no metiloma humano. No caso do cancro, a cooperação dos fatores genéticos e epigenéticos é essencial para a compreensão do desenvolvimento desta patologia no organismo humano nomeadamente através do silenciamento de genes reguladores essenciais. Uma hipometilação global no genoma do cancro conduz geralmente a uma ativação de oncogenes enquanto que hipermetilações localizadas estão associadas com o silenciamento de genes supressores de tumores. Por estes motivos, o desenvolvimento de novas terapias para o cancro ou o envelhecimento torna-se um tópico de interesse pela comunidade científica da área da epigenómica. Com o objetivo de desenvolver estes temas e melhorar a determinação de variações globais no epigenoma humano, esta investigação desenvolveu-se com base na utilização de dados de bases de dados públicas de indivíduos saudaveis de forma a extrair marcadores de metilação diferenciada em variados tecidos ao longo do envelhecimento saudável. O projeto foi validado através da utilização de amostras saúdaveis e de indivíduos com boas ou más performances cognitivas disponíveis no iBiMED. Em ambas as situações os genes ELOVL2 (cg16867657) e FHL2 (cg06639320) foram identificados como bons marcadores da idade dos indivíduosMestrado em Biotecnologi

Chemistry in the market place

This book is an expanded version of the first edition of Chemistry in the Market Place. It is a work of high seriousness but its 'flavour' is perhaps best captured in the words of its author as he describes the circumstances of its beginnings: {u2018}over three glasses of cool, artificially coloured, artificially foam stabilised, enzyme clarified, preserved, gassed, amber fluid{u2019} two colleagues and he came to realise that consumers needed some {u2018}real{u2019} chemistry, chemistry that would help them to make sense of the arguments that rage about various aspects of consumer products, particularly those of safety and efficacy. The thrust of the book is towards the product and the chemistry needed to understand it, rather than towards chemistry illustrated by the product. Its scope is wide and includes chemistry in the laundry, the kitchen, the garden, the boudoir, the medicine chest. It also deals with motor cars, the accidental poisoning of children, and carcinogens. It is extensively illustrated with plates, figures, and tables, and contains practical experiments for its users. The book will be welcomed by high school, college and adult education lecturers who are interested in creating courses in consumer chemistry. Concerned consumers will also benefit greatly from the information the work contains, regardless of their knowledge of chemistry. Home economics teachers will find that it forms a perfect complement to their existing texts. It is, in short, an important, practical, hook on a highly significant subject