4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item Co-gasification of Coal and Solid Waste to Hydrogen Enriched-Syngas in a Fixed Bed Gasifier(University of the Witwatersrand, Johannesburg, 2020-10) Ozonoh, Maxwell; Daramola, Michael O.; Oboirien, Bilainu O.The economic growth of every nation around the globe is centred on energy. Energy can be harnessed from different sources using different conversion systems, but such systems should be sustainable. Liquid fuels such as petroleum and solid fuels (e.g. coal & biomass) are largely used for energy production. Energy recovery from these fuels is usually carried out using thermal chemical processes such as combustion, pyrolysis, and gasification systems. Out of the three technologies, gasification is considered the most attractive based on its efficiency and other qualities. In the gasification process, syngas is produced. It is necessary to produce syngas of high quality such as hydrogen-enriched syngas. Hydrogen-enriched syngas can be used in fuel cells, gas turbines and engines for electricity production. This type of gas burns with little gaseous emissions to the atmosphere, but its production is dependent on the type of fuel and process conditions, and energy conversion system employed. In South Africa, around 95 % of electric power production comes from coal, and the current reserve is projected to last not more than a century [8]. Secondly, the coal is fast depleting and generates a lot of gaseous emissions (e.g. CO2, NOX & SOX) that pose a huge threat to the environment. The emission of the aforementioned gases is a very serious issue in South Africa. Presently, some Carbon Capture and Storage (CCS) projects are on-going in the country, although the CCS is not the fuse of this study. The gasification of biomass waste and coal could assist in gaseous emission reduction. Similarly, large amounts of agricultural wastes (e.g. sugarcane bagasse, corn cob & pine saw dust) and other solid waste such as tyre are in abundance in SA. It is detailed in chapter 2. Majority of the wastes are disposed indiscriminately, hence resulting in environmental pollution. Importantly, the solitary gasification of biomass is very expensive considering the prices of biomass. Besides that, biomass produces large amount of tar hence, resulting in operational difficulties in the gasifier and end user facilities. In this study, co-gasification of coal and solid wastes is considered as a crucial alternative to addressing the aforementioned problems. Particularly, the feedstocks used for this study were coal, biomass (corn cob (CC), pine sawdust (PSD), sugarcane bagasse (SCB)) and waste tyre (WT) and were pre-treated by drying, milling, sieving, and torrefaction (coal was not torrefied). The fuel samples were blended with coal at different ratios as detailed in the thesis and used for the study. For the torrefaction process, the most viable torrefaction process conditions and feedstock were determined, while the torrefaction process model for the feedstocks were developed, using Response Surface Methodology (RSM) and Artificial Neural Network (ANN), respectively. The Performance efficiency of gasification systems was evaluated using experimental data obtained from a few gasifiers (e.g. entrained, fluidised, and fixed bed) operated at varied experimental conditions using blends of feedstocks (e.g. biomass, coal, waste tyre etc.). A backpropagation Levenberg Marquardt (L-M) and Bayesian Regularisation (BR) algorithms of ANN model with Multiple Input- Multiple Output (MIMO) and Multiple Input-Single Output (MISO) layer networks were considered. The results of the MIMO and MISO layer networks obtained from the L-M algorithm were better than that of BR algorithm which is in affirmation with some of the results found in the literature. For model result improvement, Input Variables Representation Technique-by-Visual Inspection Method (IVRT-VIM) and Output Variables Representation Technique-by-Visual Inspection Method (OVRT-VIM) were developed from the study. Estimation of the gaseous emissions and profits from biomass, tyre, and coal fired co-gasification CHP Plant using Artificial Neural Network (ANN) was carried out for 20-year investment period using South Africa (SA) and Nigeria as cases studies via Artificial Neural Network (ANN). Higher profits were obtained from South African feedstocks than that of Nigerian feedstocks due to cheaper price of SA coal WFO and WOFC, but the gaseous emissions (CO, NOX, & SO2) from the Nigerian fuels were lower than that of SA because of differences in compositions of the fuels. The potentials of biomass torrefaction in terms of profitability in a co-gasification CHP plant for a 20-year-investment period was carried out using blends of Coal + SCB, Coal + CC, and Coal + PSD with coal-to-biomass ratio of 50:50, 71:29, and 80:20, respectively. The two financial cases mentioned earlier were considered. Four investment terms including: (A) 1st–5th, (B) 5th– 10th, (C) 10th– 15th & (D) 15th– 20th and two operational cost models; with feedstock costing (WFC) and without feedstock costing (WOFC) were employed. An estimated profit of between USD5.9 million - USD6.5 million and USD7.8 - USD7.9 million was earned at the end of investment plan using WFC and WOFC, respectively. The Internal Rate of Return (IRR) was 5 ± 1 %/yr. and 7 ± 4 %/yr. based on South African electricity price of 0.14 $/c kWh, respectively. The parametric effect of process variables during torrefaction of coal/biomass/waste tyre blends using ANN and RSM models were studied. The variables considered were Higher Heating Value (HHV), Enhancement Factor (EF), and Sold Yield (SY). The most effective operating process conditions (in terms of blending ratio, temperature and torrefaction time: input variables) is of the order: 50:50 at 300 OC and 45 min > 50:50 at 250 OC and 30 min >50:50 at 200 OC and 45 min. Similarly, the most viable fuel follows the order of Coal + Torrefied PSD > Coal + Torrefied SCB > Coal + Torrefied CC and > Coal + Torrefied WT. Coal + Torrefied PSD has HHV of 28.27 % and an EF of 1.41. This corresponded to around 10 % increase in the HHV of the torrefied fuel when compared to the raw fuel and about 25.23% higher than the EF of Coal + Torrefied WT of 1.03. Based on the result of the EF of Coal +Torrefied waste tyre, upgrading of the fuel quality via torrefaction is not recommended. Furthermore, a comprehensive study on tar treatment techniques was carried out using tars produced from biomass and blends of biomass and coal employing biochar based and Ni-biochar based catalysts. Box Behnken Design of Experiment (DoE) method was used. A full quadratic regression model was used to develop a mathematical model for tar treatment based on the feedstocks studied. The Pine Sawdust-Biochar Catalyst (PSD-BC) and Nickel Pine Sawdust-Biochar Catalyst (Ni-PSD-BC) were the most effective in terms of tar treatment and with an average percentage amount of tar conversion of 89.76 and 96.73%, respectively. Ni-PSD-BC was more efficient for tar cracking than PSD-BC, but PSD-BC (waste base) may be more attractive if sustainability and cost effectiveness of precursors are considered. Co-gasification of coal and pine sawdust (PSD) to hydrogen enriched syngas in a fixed bed gasifier was carried out with catalyst (WCAT) at 900 OC and without catalyst (WOCAT), at 700, 800, and 900 OC, respectively. Coal-to-PSD ratio of 1:1 was used, while Nickel-pine sawdust-biochar (Ni-PSD-BC) and pine sawdust-biochar (PSD-BC) were employed as catalysts. The gases produced at 700, 800 & 900 OC using WOCAT cannot be used in fuel cells and gas turbines due to poor quality, while others produced at 900 OC WCAT, can be used in internal combustion engines and gas turbines, but unfortunately, have lower quality to be employed in fuel cells for electricity production. However, the study provides a method of beneficiation of the high ash content South African coal for energy production. The outcome of this study is also instrumental to energy security, efficiency and sustainability as well as waste management in South Africa, Nigeria and other parts of the globe. An assessment of the economic, energy and environmental viability of a 5 MW co- gasification power plant was carried out, using blends of coal and biomass, and two financial cases were considered namely: with feedstock costing (WFC) and without feedstock costing (WOFC). Feedstock profitability in the plant for energy production was evaluated. Equipment consisting was not considered. The power plant used 20,473,451.41 kg, 20,986,049.96 kg, 18,251,806.49 kg, and 15,276,277.85 kg of Coal + SCB, Coal + CC, Coal + PSD, and Coal + WT to produce the 5 MW and 5.56 MW electric and thermal power, annually. Coal + Torrefied PSD was the most profitable of the fuels studied. The use of Coal-to-PSD ratio of 4:1 for the power generation as against Coal-to-PSD blend ratio of 1:1 resulted to an annual loss of about ZAR6, 461,301.77 ($90,458,224.70) and ZAR123,782.47 ($1,732954.58) WFC and WOFC, respectively.Item Customer retention strategies for the prepaid mobile telecommunications sector in South Africa(University of the Witwatersrand, Johannesburg, 2010) Flynn, Teresa; Peters, MarkThis study will propose ways in which companies can focus retention strategies in the local prepaid mobile telecommunications sector. Currently there is little academic literature on this topic, even though in-house marketing research has been done by the operators. The purpose of this research is to investigate the customer retention strategies in the prepaid mobile telecommunications sector in South Africa. This will be done by triangulation of what consumers believe is important in their retention, what the organisations deem as paramount, and what retention experts state are the motivators of retention. Data was collected using both a survey questionnaire for consumers, and through face to face interviews with marketing management at mobile telecommunications operators, as well as independent expert consultants on the topic of customer retention. The findings from this study were that the consumers want to keep the same cell phone number as it is part of their identity. The customer looks at the total offering when considering pricing, and not just certain costs, and prefers a prepaid model as spending is controlled in this manner. Both consumers and management agree that rewards and loyalty programs are seen as a value add, especially where they offer instant gratification. A reliable product is necessary for a consumer to stay with the company, as is accessibility to support and other products. Management realises that the total customer experience across all touch points is a retention enabler, with one really bad experience being enough cause for a customer to churn. The consumer survey indicated that customer service is a driver that all market players need to improve on. An organisation's brand allows a consumer to identify with the firm, and is more a pull factor than a push factor, unless it is perceived as dishonest or unethical. The only time a consumer's demographics came into play regarding customer behaviour was age making a difference was when using a cell phone to access the internet -older age brackets use it sparingly if at all. Although other value added services such as SMS and MMS are used across the board. Companies model consumer behaviour, and base it on data from previous churners to identify possible churners. Of these, only profitable churners are then recognised for retention campaigns. Retention campaigns are measured for success. The prepaid market makes up 80% of the mobile telecommunications market in South Africa, and the revenue they contribute is approximately 35% of the total. Therefore this customer base should not be neglected or ignored. Due to the demographics of emerging markets, prepaid offerings are the way of the future. The research paper finishes with several recommendations on how to enrich customer retention strategies for the prepaid mobile communication market.Item The influence of Entrepreneurial Capital on the performance of subcontracting SMMEs in Gauteng, South Africa(University of the Witwatersrand, Johannesburg, 2019-03) Rampa, Mmatsatsi; Galawe, JabulileThis study explores the prospect of entrepreneurial capital in stimulating SMME performance. It seeks to investigate the use of non-financial capital (entrepreneurial capital) in SMMEs registered under the CIDB, in the general building sector, and its influence on SMME performance. It unpacks the two dimensions of entrepreneurial capital which are entrepreneurial commitment and entrepreneurial competence. This study is a quantitative research, based on a positivism research paradigm. The survey structured research instrument was collected using Qualtrics. The primary data, with a sample size of 377, was distributed using emails and was consolidated via Qualtrics. The data analysis and interpretation was based on descriptive analysis, correlation analysis, exploratory analysis and multiple linear regression analysis. The study was initially designed to analyse the two dimensions (entrepreneurial competence and commitment) collectively with their antecedents (opportunity, relationship, conceptual, organising and strategic competencies); and (normative, continuous and affective commitment) respectively. The survey findings could not converge into a clear multi-dimensional factor structure for each construct. Hence the analysis could only be undertaken at the dimensions level without breaking them down any further into their sub-sets. Entrepreneurial competence was the only one of the two that emerged as the statistically significant predictor of SMME performance. However, both dimensions had a positive influence with business performance, though entrepreneurial commitments’ influence was weak and not statistically significant. SMME owners/managers should continuously advance and assess their specific entrepreneurial competence in order to positively influence their business performance. Policy makers, training and support programmes should align content to specific entrepreneurial competence.Item Integrated electronic human resource management systems for front- line employees and mine safety performance(University of the Witwatersrand, Johannesburg, 2021) Nyelisani Clement , MufamadiThe South African mining industry heavily relies on manual labour, resulting insignificant risks to lives and production. Competency gaps, human behaviour, andviolations are major contributors to frequent accidents. Despite the implementation ofhuman resource management (HRM) systems, safety and productivity challengespersist, with base metals productivity declining annually by 0.3% from 2013 to 2017.Investing in competencies can enhance overall firm performance, as individualimprovements lead to better team and organizational performance.This study examined the impact of integrated electronic HRM (e-HRM) systems onsafety performance in mining. It explored the relationship between e-HRM practices,employee roles, and mine safety. The research utilized SPSS and PLS-SEM tools tovalidate and analyze data, testing eight hypotheses within a theoretical framework thatincluded performance management, HRM systems, and technological development.The findings showed that ability, opportunity, and motivation significantly and positivelyinfluence e-HRM practices, which in turn enhance employee roles, mine safetyperformance, and sustainable e-HRM systems.Sustainable e-HRM systems were identified as mediators that enhance e-HRMpractices and mine safety performance. However, the study could not substantiate theeffects of employee level, firm age, and industry experience on safety performance.Limitations included the cross-sectional study design and the omission of factors likeleadership and organizational culture. Despite these limitations, the study concludedthat sustainable e-HRM systems improve business success by integratingsustainability plans, ethical data management, and effective technology use, fosteringemployee autonomy and safety.The study suggests further longitudinal and qualitative research to evaluate the long-term sustainability of e-HRM improvements and their impact on safety performance.Comparative studies could also explore different system types and cultural variations,while investigating e-HRM's role in crisis management to reveal strategies fororganizational resilienceItem Business model innovation in South African companies under the changing post-COVID-19 world of work(University of the Witwatersrand, Johannesburg, 2021) Hlabathi, Katekani; Mzyece, MjumoBusinesses that have survived pandemics and other major global disruptions have demonstrated the importance of continually re-evaluating their business models. Implementing business model innovation has been shown to significantly enhance a business's chances of surviving major global disruptions. This study aims to determine how the application of business model innovation, particularly in South African enterprises, has enabled these businesses to survive and remain profitable in a changing work environment, especially during the COVID-19 pandemic. In this context, business model innovation refers to the creative introduction of new ways of the business providing value to their customers through the products they sell or services they provide. A qualitative study with ten (10) respondents from South African enterprises was conducted to test the proposition that businesses who apply business model innovation in pandemics, such as the COVID-19 pandemic, will survive and become even more profitable. The study was conducted in several enterprises from different industries, using interviews and questionnaires. The study aims to provide a possible framework to be used by businesses during pandemics and to provide a basis for further research on the subject. The study's key findings show that there are both internal and external factors that influence the implementation of an innovative business model. COVID-19 was rated highly as an influence that is top of mind, affecting how firms conducted their businesses today. The study also revealed that customers and stakeholders are key to developing an innovative business model. The limitations of the study relate to the number of respondents and their location. This was a direct effect of the qualitative nature of the study and the physical and other restrictions due to COVID-19; thus, the results may not be widely representative or fully replicable. Nevertheless, overall, the study indicates that business model innovation could give businesses the competitive advantage and the differentiation needed to succeed during times of uncertainty.Item Product innovation strategies that support an organisation’s reset business strategy(University of the Witwatersrand, Johannesburg, 2021) Maithufi, Marang Norah; Mupfawa, ShunguLiterature reveals that many organisations do not have well-communicated innovation strategies, or rarely articulate their innovation efforts to align with business strategies. In addition, research further emphasises that without innovation strategies, different parts of an organisation can find themselves pursuing conflicting priorities even in the existence of a clear business strategy. Organisation A, the case under study, has recently accounced its new refresh business strategy; in order to align itself with the changing business and consumer landscapes. The new business strategy focusses on value delivery through customer-centricity and market-focused businesses. The aim of this study is to ascertain product innovation strategies that can support Organisation A’s new business ambitions. Organisation A produces and markets a wide range of products, including chemicals; both commodity as well specialty chemicals. The products identifed for the study are polymers products, selected due to the unique challenges the products currently face; which include being commodity products at the mature stage of their product lifecycle. Parallel to this, these products have recently endured substantial environmental scrutiny relating to the increasing (polymers) plastics waste footprint in the environment and other externalities, with consumers thus demanding more environmentally sustainable product solutions. For a richer discovery, as well as uncovering perceptions which may influence how innovation is conducted at Organisation A, a qualitative single case study research strategy was pursued, via semi-structured interview schedules with Organisation A’ employees involved in and associated with the development, production, marketing, sales and support of polymers products under study. The study revealed that although innovation is widely acknowledged as important, the perceptions held within the business were that polymers product innovation was not a forefront imperative. This, according to the study participants, manifested as an environment that was unsupportive of product innovation endevours, a business that was overly risk-averse, internally focussed, and considered other categories of innovation such as manufacturing process innovations as more value creating than polymers product innovation efforts. Consequently, only incremental and sustaining product innovation activities that were perceived to not disrupt the business were embraced. Three strategies or opportunity areas are proposed, that Organisation A can explore for its polymers product innovation efforts to support the new business strategyItem The adoption of technology in the Limpopo province agriculture sector(University of the Witwatersrand, Johannesburg, 2021) Kganakga, Khomotso; Larbi, LeeThe fourth Industrial revolution technologies offer us an opportunity to increase competitiveness, as well as an opportunity to overcome weaknesses prevalent in the current agricultural system and the persisting limits of intensive agriculture. The Limpopo province agricultural sector is a major producer of some of South Africa’s agricultural commodities and a competitor in the export markets of agriculture produce. This study seeks to explore the usage and adoption of technology in the Limpopo province agriculture sector. Even though there has been research in the agricultural sector of South Africa in the context of the fourth industrial revolution none has been done in the Limpopo province context. Therefore, this study will attempt to close the knowledge gap by providing more literature on the topic The research strategy adopted for this study is a qualitative interview research approach. The finding of this research indicates that role players in agricultural sector of Limpopo have embraced the use and adoption of technology within the sector, this adoption of technology has helped the industry to be competitive internationally, however the introduction of technology within the sector has bought about some level of uncertainty regarding job securities for some. Technology will continue to advance and bring about change in society and its environment, those in business who chose to ignore this fact and continue with obsolete practices are at the risk of finding their own businesses one day. The provincial government too has role to play in advancing awareness and developing policiesItem Adoption of locally developed Metal Additive Manufacturing Technology: Evaluation of South Africa’s manufacturing industry’s readiness(University of the Witwatersrand, Johannesburg, 2021) Sono, Oscar James Hendrick; Wotela, Kambidima; George, JamesPresently, Metal Additive Manufacturing (MAM) has progressed to the stage where the manufacture of components for industries such aerospace, energy, automotive and medical industries, are possible to a high degree of reliability. The South African government has invested substantially on the technology’s advancement through various government entities, publicly funding the research and development programmes and infrastructure developments. Yet the adoption of the technology remains slow, contrast to the USA and other European countries. Therefore, this thesis sought to explore the readiness of South Africa’s manufacturing industry to adopt locally developed MAM technologies. This was undertaken by employing a quantitative research approach, in which a cross- sectional design survey was used to conduct the interrogation, guided by innovation diffusion theories, particularly DOI. The study applies descriptive analysis to determine the current state of MAM adoption and the level of awareness about the technology within the industry. Backward multiple regression was used to determine if cost, organizational capability, and potential job loss have an impact on the adoption of the technology within the industry testing the three hypotheses. The results indicated that the state of MAM adoption within the manufacturing industry was low, with only three machines owned/leased, and potential adopters that are likely to uptake the technology, believing it can bring value-add to their organisations. These potential adopters are familiar with awareness programmes driving MAM campaigns. On the other hand, they also indicated reasons they believed would lead to non-uptake of the technology, the non-adopters did too, with cost of material being the leading constraint. Furthermore, results of tested hypotheses inferred a causal relationship between the adoption of MAM technology and the variables, and the impact was significant on its uptake or non-uptake. However, it was important to note that the sample size was low to take a conclusive stance, hence the researcher recommends a continuation of the studyItem Feasibility Study of a Digital Platform for sharing household equipment and resources for a fee in Gauteng(University of the Witwatersrand, Johannesburg, 2021) Nkomo, Greaterman; Totowa, JacquesThis research seeks to investigate the feasibility of a digital sharing application that connects the supply and demand for everyday household components. The research methodology that was used in this study was the qualitative methodology, using interviews. Twelve interviews were conducted via video conferencing using Zoom and Microsoft Teams and all the participants were from the Johannesburg region in Gauteng. The research findings were that the participants had some assets that were not being utilized and they are willing to list them in a sharing application to make extra income. The research revealed that the key motivation for utilizing the digital sharing application is the economic benefits associated with participating, either through saving money by renting the tools instead of purchasing every tool that they may need to complete a project or to make extra money by sharing their tools for a fee or to save money. The research shows that people are open to utilizing digital sharing applications if the application meets certain standards such as having up to date information; secure and easy to use. The household equipment that people are willing to share include garden tools; toolbox kits; laundry equipment; outdoor furniture; picnic tables and many more. Based on this research, there is a market for a digital sharing application that focuses on the everyday household componentsItem A needs assessment of outsourcing information technology and business services to rural areas in South Africa(University of the Witwatersrand, Johannesburg, 2020) Ramagondo, Vhumbani; Louwrens, JessicaThe purpose of this study was to investigate the perception of South African organisations on the rural outsourcing of their Business Processing and Information Technology services. This study is based on a questionnaire survey conducted on South African organisations. The goal of this survey is to determine the perceptions of people concerning the attractiveness of potentially outsourcing their services to rural areas. Results of the study show a negative perception towards the attractiveness of rural outsourcing. The results also highlighted the factors that are contributing to this negative perception of rural outsourcing. The findings of this study have several implications for the viability of a rural outsourcing market in South Africa. The results also provide both potential rural outsourcing suppliers and clients with an assessment of the potential of rural outsourcing business processing outsourcing (BPO) and information technology outsourcing (ITO). The study also makes a valuable contribution to the outsourcing industry by identifying the business process and information technology services that are most suitable for rural outsourcing