3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item An assessment of the environmental sustainability guidelines and requirements set by international stock exchanges(2017) Urdang, Brandon CraigEnvironmental reporting is largely voluntary for companies, unlike financial reporting which has well set standards for measurement, reporting, auditing and governing laws based on IFRS and GAAP. A driver such as a stock exchange is able to act as a “regulating body” that requires a minimum reporting standard for companies listed on the stock exchange. Stock exchanges have an ethical responsibility to encourage companies listed with them to be environmental stewards to provide investors with responsible investment opportunities. This study provides an understanding of the quality of environmental guidelines presented by international stock exchanges compared to key global environmental concerns. The aim of this dissertation was to assess and compare sustainability guidelines provided by selected stock exchanges, with specific focus on key global environmental concerns. The objectives were (1) to assess the existing environmental reporting requirements of 19 stock exchanges across all continents, (2) to determine how the JSE environmental reporting guidelines compared to those of other stock exchanges, (3) to compare 20 JSE listed companies’ environmental reports based on the presence and quality of data, (4) to compare what companies reported to what the JSE required and (5) to identify possible differences in reporting between the impact levels and industries of companies. A Sustainability Balanced Scorecard (SBSC) was developed by identifying seven key global environmental concerns (resources; biodiversity; water; energy; emissions, pollution and waste; products and services; and supply chain management) that were common themes from the MEA (2005) and UNEP Ecosystem Management policy (2010). A five tier scoring system specific to assessing reporting guidelines and another five tier scoring system specific to assessing company environmental reports were used. Nineteen stock exchange guidelines were assessed to represent both developing and developed countries and all regions (Africa, America, Australasia and Europe). Overall, the stock exchange guidelines addressed the key global environmental concerns rather poorly. There were no differences in the quality of guidelines for stock exchanges that recommended guidelines in developing or developed countries. There were no differences found in the guidelines of stock exchanges operating in different regions. There were differences in the focus on key global environmental concerns by the guidelines. The environmental information reported by twenty companies spanning three impact levels and seven industries was also assessed. The companies in the high and medium impact levels iv reported similarly and better than the companies in the low impact levels. There were differences found in the way companies reported according to the different industries as well as differences in the way companies addressed the key global environmental concerns. Even though the JSE’s developed guidelines did not account for resources and biodiversity, the Global Reporting Initiative (GRI) reporting guidelines that the JSE recommended to their listed companies covered these categories. Companies reported voluntarily on the categories because they may understand the importance of managing resources and biodiversity for the sustainability of their business. Stock exchanges are faced with a variety of companies at different impact levels representing different industries, making it difficult to provide a minimum set of environmental reporting guidelines. Stock exchanges should require companies to report on all key global environmental concerns identified in this study, but should not dictate how the companies report on them. Global environmental reporting standards may be better suited with a global sustainability body like the Global Sustainability Standards Board (GSSB) that is able to provide global standards for all companies. Companies need to change the way that they do business, the benefits of reporting on environmental performance outweigh the risks of not reporting and managing these impacts. Sustainability reporting and best practise today may be the compliance of the future. Stakeholders are increasingly expecting companies to contribute more to environmental sustainability. Companies are essential in building a resilient planet that will be able to feed a growing population that will increase from seven to nine billion people by 2050. Key words: Environmental Sustainability; Johannesburg Stock Exchange; Millennium Ecosystem Assessment; Sustainability Balanced Score Card Approach; United Nations Environment Programme Ecosystem Management PolicyItem Optimization of the synthesis and performance of Polyaspartamide (PAA) material for carbon dioxide capture in South African coal-fired power plants(2016) Chitsiga, Tafara LeonardGlobal climate change is among the major challenges the world is facing today, and can be attributed to enhanced concentrations of Greenhouse Gases (GHG), such as carbon dioxide (CO2), in the atmosphere. Therefore, there is an urgent need to mitigate CO2 emissions, and carbon capture and storage (CCS) is amongst the possible options to reduce CO2 emissions. Against this background, this work investigated the synthesis and performance evaluation of Polyaspartamide (PAA) adsorbent for CO2 capture. In particular, the effect of the presence of water-soluble amines in the amine-grafted poly-succinimide (PSI) (referred to as Polyaspartamide (PAA) adsorbent), was investigated. Methyl Amine (MA) and Mono-Ethanol Amine (MEA) were employed as water-soluble amines and the effect of changes in their concentration on CO2 adsorption capacity was investigated as well. Water-soluble amines were incorporated to allow water solubility of the adsorbent paving the way for freeze-drying to improve the geometric structure (surface area, pore volume and pore size) of the adsorbent. Initially, the PSI was loaded with Ethylenediamine (EDA), forming PSI-EDA. The water-soluble amines were grafted to PSI-EDA, with the EDA added to improve the chemical surface of the adsorbent for CO2 capture. NMR and FTIR analyses were performed and confirmed the presence of MA and MEA amine groups in the PAA, thereby indicating the presence of the grafted amines on the backbone polymer. BET analysis was performed and reported the pore volume, pore size and surface area of the freeze-dried material. It was observed that the physical properties did not change significantly after the freeze-drying compared to literature where freeze-drying was not employed. An increase in adsorption capacity with an increase in MA and MEA concentrations in MA-PAA and MEA-PAA samples was observed. At low amine concentrations (20% amine and 80% EDA grafted), MEA-PAA was observed to exhibit higher adsorption capacity compared to the MA-PAA samples. At high amine (100% amine grafted) concentrations, MA-PAA samples displayed higher adsorption capacity. Three runs were performed on each sample and the results obtained were reproducible. The best adsorption capacity obtained was 44.5 g CO2/kg Ads. Further work was then performed to understand the effects of operating variables on CO2 adsorption as well as the interactive effect using the Response Surface Methodology approach. The experiments were done by use of CO2 adsorption equipment attached to an ABB gas analyzer. A central composite design of experiment method with a total of 20 experiments was employed to investigate three factors, namely, temperature, pressure and gas flow rate. Six regression models were drawn up and mean error values computed by use of Matlab, followed by response surfaces as well as contours, showing the influence of the operating variables on the adsorption capacity as well as interaction of the factors were then drawn up. The results obtained displayed that each of the factors investigated, temperature, pressure and gas flowrate had an incremental effect on the adsorption capacity of PAA, that is, as each factor was increased, the adsorption capacity increased up to a point where no more increase occurred. Adsorption was seen to increase for both an increase in gas flowrate and adsorption pressure to a maximum, thereafter it starts to decrease. A similar trend was observed for the interaction between temperature and pressure. However, the interaction between gas flowrate and temperature was such that, initially as the temperature and the gas flowrate increase, the adsorption capacity increases to a maximum, thereafter, the temperature seizes to have an effect on the adsorption capacity with a combined effect of decreasing temperature and increasing gas flowrate resulting in a further increase in adsorption capacity. It was confirmed that the operating variables as well as the flow regime have an effect on the CO2 adsorption capacity of the novel material. The highest adsorption capacity was obtained in the pressure range 0.5 bar to 1.7 bar coinciding with the temperature range of 10 oC to 45 oC. The interaction of gas flowrate and adsorption pressure was such that the highest adsorption capacity is in the range 0.8 bar to 1.5 bar which coincides with the gas flowrate range from 35 ml / min to 60 ml / min. In conclusion, the best adsorption capacity of 44.5 g / kg via the TGA and 70.4 g / kg via the CO2 adsorption equipment was obtained from 100 % MA grafted PSI.