Call number: LD2668 .T4 1979 D65 / Master of Arts

About a quarter of all industrial energy consumption in the US is from distillation to separate chemicals such as carbon dioxide from a natural gas stream. Unfortunately, distillation requires huge amounts of thermal energy, space, maintenance, and costs. Gas separation membranes use 90% less energy than distillation, save significant space, and are relatively simple to maintain. Polymers are the main platform for these membranes, but they are often hindered by an intrinsic trade-off between how fast a gas flows through the membrane (permeability) and how effectively the membrane can separate two or more gases (selectivity). One method of overcoming the permeability-selectivity trade-off is to use polymer-grafted nanoparticles (grafted NPs or GNPs) which chemically graft polymer chains from the surface of nanoparticles. These GNP-based membranes have demonstrated significant gas permeability enhancements relative to its neat analogue with a well-defined transport maximum as a function of graft chain length (MWg). They also have shown gas selectivity improvements up to two orders of magnitude greater than the neat with the addition of small amounts of neat polymer. Recently, we discovered that the preparation methods of these GNP-based membranes strongly affect their gas transport properties. Understanding the effects of preparation methods on nanostructure and, in turn, gas transport properties is critical for the commercialization of these gas separation membranes. This thesis is divided into six chapters that investigate how preparation methods may affect the GNP structure with and without the addition of homopolymer, and how these structural changes may affect gas transport. The main questions we answer in this thesis are: • How does the nanostructure of matrix-free GNPs (i.e., GNPs with no free chains) change with increasing graft chain length? How do these changes affect gas transport? • How do evaporation rate, casting method, film thickness, annealing time, and annealing temperature affect the GNP structure? How are these changes related to gas transport? • How does the structure of matrix-free GNPs change upon addition of small amounts of homopolymer? How might these changes relate to gas transport? Chapter 2 presents the experimentally-based model of a multi-GNP system that changes in structure between different regimes of MWg. We discover these changes are energetically driven and suggest different layers of the polymer brush have varying favorability for transport that yield the observed macroscopic properties. Chapter 3 and 4 explores the effects of evaporation rates, casting methods, and annealing temperatures on localized GNP packing with a micro-focused SAXS beam and on global GNP packing with pair-wise distribution functions, respectively. We find that evaporation rates show no effect, but melt-pressing a solution-cast GNP film causes greater disorder with a broader distribution of interparticle spacings whereas annealing a GNP film to higher temperatures reduces disorder. Chapter 5 explores the effects of annealing temperatures, annealing times, film thickness, and MWg’s on the interparticle spacings of GNP thin films. Chapter 6 presents the localized GNP packing on several series of GNP “blends” (i.e., adding small amounts of homopolymer to GNPs), showing that GNP blends increasingly swell with added homopolymer fractions compared to their parent GNPs in all studied cases. Most notably, the addition of short chains to a GNP with MWg below the transport maximum swell similarly to that of the loading of a matrix-free GNP with solvent. This suggests these short chains also act akin to a loaded solvent, isotropically filling the GNP free volume pockets. The Conclusions and Future Work chapter details what questions were answered in this thesis and which questions were only partially answered. We then discuss suggestions for future experiments to ascertain the relationships among preparation method, nanostructure, and macroscopic gas transport.

Thesis (MCom)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Worldwide, energy has been, and continues to be, key to economic development. However, the current global consensus is that energy-related carbon dioxide emissions would, at current rates, put the world onto a potentially catastrophic trajectory which could lead to global warming of 5 degree Celsius or more compared to pre-industrial times. There is a critical need for a low-carbon development or a move away from conventional fossil fuels energy sources. This study explores impacts of policies that South Africa developed in order to champion sustainable energy strategies based on energy efficiency and non-conventional energy sources, including renewable energy. The mining sector, because of its energy-intensive nature, was chosen. In order to achieve this objective three approaches were carried out: (i) a critical review of literature on energy efficiency (EE) and renewable energy (RE) ; (ii) two case-studies that demonstrate the impacts of the policies; and (iii) action research on a sample of mines using survey questionnaire and interviewing. The research results show that the need to have security in energy and the need to be competitive and grow revenue are significant in deciding to carry out EE and RE initiatives in the mining sector. The results also show that safety followed by production are the priorities and are accompanied by a range of other demands, such as cost reduction and legislative requirements. It is, therefore, within this context that EE and RE initiative will always be carried out in the mining sector. The research concludes that, under the current market framework, South African EE and RE policies are not as effective as hoped they would be. The research, therefore, recommends that a percentage of the mines’ revenue could be dedicated to EE and RE initiatives. In addition, South Africa needs to come up with a new type of productive endeavour that would lead to less extractive industries, including mines. / AFRIKAANSE OPSOMMING: Energie is, was en sal wereldwyd altyd die sleutel wees tot ekonomiese ontwikkeling. Nieteenstaande, word dit wereldwyd aanvaar dat die huidige energie opwekking se koolstofdioksied vrystelling moontlik kan lei tot aardverwarming van 5 grade Celsius of meer wanneer vergelyk met word met pre-industriële tye. Daar is ‘n kritiese behoefte aan lae koolstofdioksied vrystelling ontwikkelings of ‘n beperking van konvensionele fossielbrandstof energiebronne. Hierdie studie analiseer die impak van die Suid Afrikaanse beleid wat ontwikkel is om volhoubare energie te bevorder wat effektief en onkonvensioneel is, insluitend hernubare energie. Die mynsektor, as ‘n groot verbruiker van energie, vorm die kern van die studie. Die studie is voltooi in drie fases naamlik: (1) kritiese oorsig van die literatuur oor energiedoeltreffendheid (EE) en hernubare energie (RE); (2) twee gevallestudies wat die impak van die beleid bevestig; en (3) praktiese navorsing deur middel van vraelyste en persoonlike onderhoude met seker myne. Die navorsing bevestig dat die behoefte aan bestendige energie teen kompeterende pryse wat die mynsektor in staat stel om inkomste te groei ,‘n beduidende invloed het op die besluit om EE of RE inisiatiewe te onderneem. Die resultate bevestig verder dat beroepsveiligheid en produksie uitsette die eerste prioriteite vir die myne is. Dit word verder beinvloed deur kostebesparings en wetlike vereistes. Enige EE en RE inisiatiewe wat onderneem word sal in hierdie konteks plaasvind. Die navorsing kom tot die slotsom dat, onder huidige marktoestande, Suid Afrika se EE en RE beleid nie so effektief is as waarop daar gehoop is nie. Die navorsing beveel derhalwe aan dat ‘n persentasie van myne se inkomste geoormerk moet word vir EE en RE inisiatiewe. Verder meer , Suid Afrika moet strewe na tipes produksie wat minder natuurlike grondstowwe onttrek, insluitend die myne.

M.A. (Environmental Management) / The Small Micro Medium Enterprise (SMME) sector plays a critical role in the economy of South Africa by reducing poverty and providing employment. South Africa has about 6 million SMMEs that employ more than 61% of citizens and contribute about 37% to the Gross Domestic Product (GDP). The growth and development of the sector over the years has however been compromised and threatened by the shortage of electricity and increasing electricity tariffs. Whereas large companies can manage to afford the adoption of energy efficiency measures in order to reduce energy costs, SMMEs have limited resources and may therefore struggle to afford energy efficiency adoption. However, there is a lack of scientific documentation about energy efficiency adoption amongst manufacturing SMMEs (M-SMMEs) in South Africa. The purpose of the research is to therefore assess the state of energy efficiency adoption amongst M-SMMEs, despite the challenges they experience. To achieve this research goal, the study surveyed and characterised the extent of energy efficiency adoption and also unveiled the drivers and barriers to energy efficiency adoption. Data were collected by means of surveys, making use of questionnaires. A sample of 30 firms was selected for the research. Almost all (96%) firms perceived EE as an opportunity. However, only 50% had adopted EE measures. Key drivers to adoption included the motive to reduce production costs, mitigate the impact of increasing electricity prices, gain competitive advantage and payback period. The gap between EE perception and adoption was caused by several barriers like the lack of finance, skills and time. Among non-adopters, 60% indicated their willingness to be trained in EE. The study therefore recommends improved capacity building through workshops for M-SMMEs.

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The world today is facing many energy challenges such as power outages experienced internationally and in South Africa. The demand for energy is constantly increasing and is creating environmental problems such as climate change, which is presently a major concern to society. This study is an attempt to establish how energy saving mechanisms such as the elimination of non-essential power can add economic value within the mining industry. This paper examines the effect of non-essential power and how it could assist companies to reduce their energy consumption, aid local power utilities in a crisis and maintain normal production levels. This research report was based on an investigation for power saving opportunities at a mining company during a power crisis. The paper looks at energy efficiency and the barriers to the adoption of energy savings. Companies in general do not have a structured way of addressing non-essential power saving. Companies are not aware of the value such initiatives could have on corporate responsibility and sustainable reporting. The benefits of energy efficiency and nonessential power on the triple bottom line are not clearly documented in literature. When comparing the impact of non-essential power on the triple bottom line, it became obvious that further research is required in order to prove whether it influences the social aspect. The impact of power generation on the global environment has not been clearly calculated and linked to the value of saving power. The literature review highlighted that companies are focusing on long-term initiatives instead of smaller initiatives, which requires less effort. During the investigation of the mining company, it was found that not much effort was made during the design stages in separating the electrical circuits from non-essential and essential power. The author concludes that switching off non-essential power held economic and environmental benefits for the mining company. The author therefore concludes that switching off non-essential power impacts positively on the economic and environmental part of the triple bottom line. It was found that the elimination of non-essential power is easy to implement with minimum investment and effort. Furthermore, the savings from these initiatives could easily be measured to calculate the return on the investment. / AFRIKAANSE OPSOMMING: Ons kry deesdae al meer te doen met uitdagings soos internasionale en plaaslike kragonderbrekings in die energiebedryf. Die aanvraag vir energie verhoog deurlopend en veroorsaak omgewingsprobleme soos klimaatsveranderinge, wat ‘n groot bekommernis is vir die samelewing. In hierdie studie word gepoog om vas te stel hoe energie besparings meganismes soos die eliminering van nie-noodsaaklike krag ekonomiese waarde kan voeg tot die mynboubedryf. Die uitwerking wat nie-noodsaaklike krag het en hoe dit maatskappye kan help om kragverbruik te verlaag terwyl produksievlakke steeds gehandhaaf word, is hier ondersoek. Plaaslike kragvoorsieners kan ook baat vind hierby in krisistye. Hierdie navorsingsverslag is gebaseer op ‘n ondersoek van krag besparings geleenthede by ‘n mynmaatskappy gedurende ‘n krisistydperk van kragonderbrekings. Die verslag kyk na die doetreffendheid van energieverbruik, asook na die hindernisse wat ondervind word in die inwerkingstelling van energie besparings inisiatiewe. Maatskappye het in die algemeen nie ‘n gestruktureerde metode om die probleem rakende nie-noodsaaklike krag aan te spreek nie. Hulle is nie bewus van die nut wat sulke inisiatiewe kan hê op korporatiewe verantwoordelikheid en volhoubare verslaggewing nie. Die voordele wat energiebesparing en die eliminering van nie-noodsaaklike krag op die ekonomie, gemeenskap en omgewing het, word nie duidelik geboekstaaf nie. Verdere navorsing moet gedoen word om die impak van energiedoeltreffendheid en nie-noodsaaklike krag op die sosiale aspek te bewys. Die uitwerking wat kragopwekking op die globale omgewing het is nog nie bereken en verbind met die waarde daarvan op kragbesparing nie. Die verslag beklemtoon dat maatskappye fokus op langtermyn inisiatiewe in plaas daarvan om te kyk na kleiner inisiatiewe wat minder moeite en tyd sal verg. Die ondersoek by die mynmaatskappy het getoon dat daar nie klem geplaas is op die onderskeiding tussen nie-noodsaaklike en noodsaaklike krag met die installering van die elektriese stroombane tydens die ontwerpstadium nie. Daar is gevind dat die afskakeling van nie-noodsaaklike krag ekonomiese en omgewingsvoordele vir die maatskappy inhou. Daar is tot die slotsom gekom dat die afskakeling van nie-noodsaaklike krag in die algemeen dus ‘n voordelige uitwerking het op die ekonomie en omgewing. Dit is maklik om te implementeer met minimum moeite en belegging. Die besparings deur middel van hierdie inisiatiewe kan ook maklik gemeet word om die opbrengs op die belegging te bereken.

Countries and governments around the world have accepted the scientific argument on the prevalence and the possible effect of global warming and climate change on the environment, world economy and ultimately human life (Nhamo, 2011). Amongst all industrial corporations, the mining industry is the biggest environmental polluter due to its extractive nature and energy intensive operations. However because of its economic importance, it cannot be abandoned, instead it needs to find a win-win situation, where it continues to succeed but minimizes environmental damage. This thesis aims to examine the possible impact of clean technology on the sustainability of South African gold mining sector. Specifically, the study aims to determine the drivers behind the move towards clean technologies and methods, identify challenges and opportunities associated with this transition at Harmony Gold’s Kusasalethu mine. This was achieved through using Kusasalethu as a case study to which investigations of the effectiveness of clean technology and methods were carried out. The case study was multidimensional; exploring the effect of clean technology on energy consumption, greenhouse gas emission (GHG), water consumption, cyanide management and Kusasalethu’s financial performance. While the case study was largely qualitative it involved quantitative data analysis that had to be triangulated with other data sources and data gathering instruments to achieve legitimacy. This meant that the study had to adopt the mixed research methods. The instruments used included; key informant interviews, and document analysis, structured questionnaire and a set of open ended questions that served as interview guide. The qualitative data were analyzed by means of coding, descriptions, typologies, taxonomies and visual representations, whilst quantitative data were processed through Microsoft Excel to generate various forms of descriptive statistics. The findings indicate that resource consumption (energy, water, cyanide) depends on the mine design and gold output rate. Clean technology implementation at Kusasalethu helped the mine reduce energy consumption and GHG emissions. However scope 2 (indirect GHG emissions associated with energy consumption) is also determined by coal production technologies and methods used by coal mines. Although data on Kusasalethu water and cyanide management and related technologies was not available, the aggregate data for all Harmony Gold mines indicated higher annual water and cyanide consumption during 2010 and 2012. In terms of Kusasalethu’s financial performance and clean technology adaptation, acquisition of clean technologies increased capital expenditure temporarily. However, the positive effects of the clean technology transition and implementation minimized operational cost and increased operational profit greatly. Although adopting clean technologies calls for increased capital expenditure, this study reveals that this expenditure pays off in lower operation costs for the mine and the environment benefits through lower GHG emission. However, clean technologies are yet to impact significantly in lowering water and cyanide consumption levels as they do with energy consumption. The study concluded that clean technology and methods played a positive role on Kusasalethu’s environmental impact and financial performance by reducing energy consumption and GHG emissions. Though, more need to be done in terms of water and cyanide management. / Environmental Sciences / M. Sc. (Environmental Management)

Countries and governments around the world have accepted the scientific argument on the prevalence and the possible effect of global warming and climate change on the environment, world economy and ultimately human life (Nhamo, 2011). Amongst all industrial corporations, the mining industry is the biggest environmental polluter due to its extractive nature and energy intensive operations. However because of its economic importance, it cannot be abandoned, instead it needs to find a win-win situation, where it continues to succeed but minimizes environmental damage. This thesis aims to examine the possible impact of clean technology on the sustainability of South African gold mining sector. Specifically, the study aims to determine the drivers behind the move towards clean technologies and methods, identify challenges and opportunities associated with this transition at Harmony Gold’s Kusasalethu mine. This was achieved through using Kusasalethu as a case study to which investigations of the effectiveness of clean technology and methods were carried out. The case study was multidimensional; exploring the effect of clean technology on energy consumption, greenhouse gas emission (GHG), water consumption, cyanide management and Kusasalethu’s financial performance. While the case study was largely qualitative it involved quantitative data analysis that had to be triangulated with other data sources and data gathering instruments to achieve legitimacy. This meant that the study had to adopt the mixed research methods. The instruments used included; key informant interviews, and document analysis, structured questionnaire and a set of open ended questions that served as interview guide. The qualitative data were analyzed by means of coding, descriptions, typologies, taxonomies and visual representations, whilst quantitative data were processed through Microsoft Excel to generate various forms of descriptive statistics. The findings indicate that resource consumption (energy, water, cyanide) depends on the mine design and gold output rate. Clean technology implementation at Kusasalethu helped the mine reduce energy consumption and GHG emissions. However scope 2 (indirect GHG emissions associated with energy consumption) is also determined by coal production technologies and methods used by coal mines. Although data on Kusasalethu water and cyanide management and related technologies was not available, the aggregate data for all Harmony Gold mines indicated higher annual water and cyanide consumption during 2010 and 2012. In terms of Kusasalethu’s financial performance and clean technology adaptation, acquisition of clean technologies increased capital expenditure temporarily. However, the positive effects of the clean technology transition and implementation minimized operational cost and increased operational profit greatly. Although adopting clean technologies calls for increased capital expenditure, this study reveals that this expenditure pays off in lower operation costs for the mine and the environment benefits through lower GHG emission. However, clean technologies are yet to impact significantly in lowering water and cyanide consumption levels as they do with energy consumption. The study concluded that clean technology and methods played a positive role on Kusasalethu’s environmental impact and financial performance by reducing energy consumption and GHG emissions. Though, more need to be done in terms of water and cyanide management. / Environmental Sciences / M. Sc. (Environmental Management)