Sustainable development is described by the World Commission on Environment and Development as ―development that meets the needs of present without compromising the ability of future generations to meet their own needs‖. Sustainability assessments are an integrative process and framework for effective integration of social, economic and ecological considerations in significant decision-making processes. Sustainability is incorporated into South African legislation such as the Constitution of the Republic of South Africa (1996), the National Environmental Management Act (Act 107 of 1998), as well as Environmental Impact Assessment (EIA) Regulations. Despite the existence of such legislation, the challenge lies in the effective implementation of the EIA process, which has been identified as a useful tool in striving towards achieving sustainable development. This research uses Gibson‘s eight sustainability principles and Gaudreau and Gibson‘s sub-criteria to develop a case specific set of sustainability criteria for coal fired power stations in South Africa. The energy generation sector is a major source of social and environmental impacts. Coal power stations contribute to environmental degradation such as reduced air, water and land quality. This industrial process impacts on the environment and therefore needs to strive towards sustainable development by considering these criteria during the EIA process. The set of case specific sustainability criteria for power stations was then used to evaluate the EIA developed for Medupi Power Station in South Africa in order to assess, the extent to which sustainability was considered in the EIA process. The key finding is that sustainability is incorporated into South African legislation hence no change in legislation is required. Despite the existence of legislation, the challenge lies in the fact that is it not always effectively implemented. The EIA process is seen as a tool that can effectively deliver sustainability outcomes. However this process is not effectively utilised. In order for the EIA to consider sustainability the focus needs to be on the following criteria: Intragenerational Equity; Precaution and Adaptation for Resilience; as well as Immediate and Long term Integration, as these were recognised as weaknesses after the evaluation process. The recommendation is also to develop a set of case specific sustainability criteria for other large industries that have significant environmental impacts. / MSc (Environmental Management), North-West University, Potchefstroom Campus, 2015

Conventional concentrating solar power (CSP) plants typically have a very high levelised cost of electricity (LCOE) compared with coal-fired power stations. To generate 1 kWh of electrical energy from a conventional linear Fresnel CSP plant without a storage application, costs the utility approximately R3,08 (Salvatore, 2014), whereas it costs R0,711 to generate the same amount of energy by means of a highly efficient supercritical coal-fired power station, taking carbon tax into consideration. This high LCOE associated with linear Fresnel CSP technology is primarily due to the massive capital investment required per kW installed to construct such a plant along with the relatively low-capacity factors, because of the uncontrollable solar irradiation. It is expected that the LCOE of a hybrid plant in which a concentrating solar thermal (CST) station is integrated with a large-scale supercritical coal-fired power station, will be higher than that of a conventional supercritical coal-fired power station, but much less than that of a conventional CSP plant. The main aim of this study is to calculate and then compare the LCOE of a conventional supercritical coal-fired power station with that of such a station integrated with a linear Fresnel CST field. When the thermal energy generated in the receiver of a CST plant is converted into electrical energy by using the highly efficient regenerative Rankine cycle of a large-scale coal-fired power station, the total capital cost of the solar side of the integrated system will be reduced significantly, compared with the two stations operating independently of one another for common steam turbines, electrical generators and transformers, and transmission lines will be utilised for the integrated plants. The results obtained from the thermodynamic models indicate that if an additional heat exchanger integration option for a 90 MW (peak thermal) fuel-saver solar-augmentation scenario, where an annual average direct normal irradiation limit of 2 141 kWh/m2 is considered, one can expect to produce approximately 4,6 GWh more electricity to the national grid annually than with a normal coal-fired station. This increase in net electricity output is mainly due to the compounded lowered auxiliary power consumption during high solar-irradiation conditions. It is also found that the total annual thermal energy input required from burning pulverised coal is reduced by 110,5 GWh, when approximately 176,5 GWh of solar energy is injected into the coal-fired power station’s regenerative Rankine cycle for the duration of a year. Of the total thermal energy supplied by the solar field, approximately 54,6 GWh is eventually converted into electrical energy. Approximately 22 kT less coal will be required, which will result in 38,7 kT less CO2 emissions and about 7,6 kT less ash production. This electricity generated from the thermal energy supplied by the solar field will produce approximately R8,188m in additional revenue annually from the trade of renewable energy certificates, while the reduced coal consumption will result in an annual fuel saving of about R6,189m. By emitting less CO2 into the atmosphere, the annual carbon tax bill will be reduced by R1,856m, and by supplying additional energy to the national grid, an additional income of approximately R3,037m will be due to the power station. The annual operating and maintenance cost increase resulting from the additional 171 000 m2 solar field, will be in the region of R9,71m. The cost of generating 1 kWh with the solar-augmented coal-fired power plant will only be 0,34 cents more expensive at R0,714/kWh than it would be to generate the same energy with a normal supercritical coal-fired power station. If one considers that a typical conventional linear Fresnel CSP plant (without storage) has an LCOE of R3,08, the conclusion can be drawn that it is much more attractive to generate electricity from thermal power supplied by a solar field, by utilising the highly efficient large-scale components of a supercritical coal-fired power station, rather than to generate electricity from a conventional linear Fresnel CSP plant. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

Thesis (MDF)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Coal export mines in the Mpumalanga Highveld region of South Africa generate growing volumes of discard coal estimated to be in excess of a billion tonnes. It presents a significant pollution hazard. Discard coal has a usable carbon content that can be used in the generation of power through the application of fluidized bed combustion technology. The objective of this study was to evaluate its potential as an economically viable fuel source for generation of electricity at the Witbank coalfields. This study was motivated by advances in fluidized combustion technology and significant changes in the South African electricity market in recent years. A holistic approach was adopted considering regulatory policy, market, technical, environmental and economic factors in the use of discard coal as an alternative fuel source. The policy and regulatory environment was assessed from the perspective of the private sector as project developer and the most likely source of funding, given government’s funding constraints. An evaluation of the future pricing structure of electricity, energy resource mix, demand growth, future development of the coal market, production of discard coal and the cost of coal was conducted. Levelised cost of electricity methodology was used to conduct the economic feasibility for comparison with the cost of Eskom’s pulverised coal technology for its new power stations. The study found that generating electricity from discard coal presents a significant commercial opportunity as its levelised cost of electricity was found to be lower than Eskom’s levelised cost of electricity for its new power stations. Plant sizes of 125 MW to 1 000 MW were considered. For plant capacities of about 500 MW and larger, the cost of electricity was found to be competitive with the current average electricity price taking into account the cost of transmission/distribution and interest charges. This is on condition that the electricity is sold to Eskom or wheeled through Eskom’s grid and sold to third parties. Otherwise, plant capacity will be limited to the maximum demand from large local users, which is expected to be considerably less than 500 MW. Currently there is no regulatory certainty on wheeling mechanisms and charges and it is an area where major policy development is required. The development of a project could be hampered by policy uncertainty and because of Eskom’s monopoly position as single buyer. The favourable results and findings of the economic evaluation conducted during this study warrant further detailed feasibility studies.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology, 2016 / Natural organic matter if not removed from water used for electricity generation has dire consequences that affect the long term plant health. The main problem is that organic matter at higher temperature and pressure disintegrate into smaller organic acids and carbon dioxide. This causes the cycle water and steam to be acidic and this can result in corrosion of the plant. The raw water from the Komati (Arnot power station) and Usutu (Kriel power station) scheme were analysed to determine the organic profile and seasonal variation. There was a noticeable variation in the quality of the water with an increase in DOC during rainy season. The water was found to be containing hydrophobic as well as hydrophilic molecules that could be quantified with a liquid chromatography organic detector (LC-OCD). Current water treatment processes employed at the two stations, Arnot and Kriel, has demonstrated the capability of removing organics to just over 50 percent at the pre-treatment section. The water treatment plant includes demineralisation plant that was able to produce water that met Eskom’s target specifications of less than 250 ppb DOC values. Qualitative and quantitative analysis of the steam-condensate water was done by use of an ion chromatography method. The determined organic anions were found to be acetates, formats and lactates.

M.Ing. (Engineering Management) / South African power demand has been increasing over the past years due to increase in energy consumption from industrial, commercial and residential sectors. In order to meet the growing power demand Eskom Holdings Limited SOC (Eskom) has implemented a number of initiatives such as the energy efficiency programme, power generating capacity increase and refurbishment of the operational coal fired power stations. Energy efficiency initiatives have been designed to encourage residential, commercial and industrial customers to use energy efficient technologies which consume less energy compare to conventional technologies. Power generating capacity increase programme includes construction of new base and peaking generating power plants (such as Medupi, Kusile and Ingula) and return to service of the old generating plants (such as Camden, Komati and Grootvlei). The refurbishment programme or coal refurbishment involves upgrading of operational coal fired power stations with the objective of extending their life expectancy, improve performance and to ensure compliance to latest safety standards...

M.Sc. / This report details the identification of potential sites suitable for both renewable and non-renewable electricity generating technologies in South Africa. Eskom through its Integrated Electricity Planning Process (IEP) determines future-planning scenarios based on demand and supply side options, while considering expected growth in demand for electricity. Site suitability can have a significant influence on the viability of options selected through IEP ...

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / Global 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. / GR2016

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science June 2015 / Lephalale is the home of Matimba, one of Eskom’s coal-fired power stations. Matimba is the biggest power station with a dry cooling system in the world. There are other industries (including coal mines) currently in operation in close proximity to the station. This industrial area is expected to grow as more industrial activities are planned for the following years. These activities will aggravate the levels of air pollution and possibly result in it being a “hot spot” for air pollution. The impact of air quality on health is covered by the National Ambient Air Quality Standards (NAAQS), but the impact of air quality on the terrestrial and aquatic ecosystem is not known. Therefore, this study focuses on the deposition of nitrogen oxides (NOx) (as nitrogen dioxide (NO2)) and sulphur dioxide (SO2) within Lephalale in the Waterberg-Bojanala Priority Area. Additionally, inter-annual variability of NOx and SO2 ambient concentrations and back trajectories of air masses were analysed. The study obtained ambient air quality data and meteorological data from Eskom for the period 2008–2012, while additional meteorological data were obtained from the Agricultural Research Council (ARC) and the South African Weather Service (SAWS). An inferential model was used to estimate the dry deposition flux of SO2 and NOx (as NO2), and the Hybrid Single Particle Langrangian Integrated Trajectory (Hysplit) Model was used to cluster back trajectories of air masses. The results of the seasonal dry deposition velocities of SO2 (0.17 to 0.23 cm/s) and NOx (0.10 to 0.15 cm/s) (as NO2) were higher in summer and lower in winter. They were also within the magnitude of the deposition velocities found in previous studies in the Highveld. The high deposition velocities in summer were attributed to photosynthetically active vegetation, turbulence and solar radiation. However, seasonal dry deposition fluxes of SO2 and NOx were higher in winter across the years. The higher flux values in winter were attributed to higher ambient concentrations of the trace gases. Additionally, the annual dry deposition flux of SO2 ranged between 0.43 and 0.67 kg S ha-1 yr-1, while NOx (as NO2) ranged between 0.84 and 1.05 kg N ha-1 yr-1 over the period studied. The annual deposition flux values found in the current study are lower than those found in previous studies in the Highveld. This difference could be because of the lower ambient concentrations of SO2 and NOx observed in this study. There is an inter-annual variability of the ambient concentrations of SO2 and NOx during the period 2008–2012. However, the difference is not large or statistically significant. The dominant direction of the back trajectories of air masses is east and southeast across all seasons for the entire period of 2008–2012. This lack of seasonal pattern in back trajectories and source regions cannot explain the seasonal changes in ambient concentrations (SO2 and NOx). Hence, climatic factors (e.g. change in weather) or seasonal changes in combustion source intensity must be responsible.

No description available.

M.Sc. / The increased demand for electricity in South Africa is expected to exceed supply between 2004 and 2007. Electricity supply options in the country would be further complicated by the fact that older power stations would reach the end of their design life beyond the year 2025. In light of this and considering the long lead times required for the commissioning of new plants, new power supply options need to be proactively investigated. The environmental impacts associated with coal-fired generation of electricity have resulted in increased global concern over the past decade. To reduce these impacts, new technologies have been identified to help provide electricity from fossil fuels. The alternatives considered are gas-fired generation technologies and the Integrated Gasification Combined Cycle (IGCC). This study attempts to document and understand the environmental aspects related to gas-fired and IGCC electricity generation and evaluate their advantages in comparison to conventional pulverised coal fired power generation. The options that could be utilised to make fossil fuel electricity generation more environmentally friendly, whilst remaining economically feasible, were also evaluated. Gas-fired electricity generation is extremely successful as electricity generation systems in the world due to inherently low levels of emissions, high efficiencies, fuel flexibility and reduced demand on finite resources. Associated benefits of a Combined Cycle Gas Turbine (CCGT) are lower operating costs due to the reduced water consumption, smaller equipment size and a reduction in the wastewater that has to be treated before being returned to the environment. A CCGT plant requires less cooling water and can be located on a smaller area than a conventional Pulverised Fuel (PF) power station of the same capacity. All these factors reduce the burden on the environment. A CCGT also employs processes that utilises the energy of the fuel more efficiently, with the current efficiencies approaching 60%. Instead of simply being discharged into the atmosphere, the gas turbines’ exhaust gas heat is used to produce additional output in combination with a Heat Recovery Steam Generator (HRSG) and a steam turbine. Furthermore, as finite resources become increasingly scarce and energy has to be used as wisely as possible, generating electricity economically and in an ecologically sound manner is of the utmost importance. The clean, reliable operation of gas-fired generation systems with significantly reduced noise levels and their compact design makes their operation feasible in heavily populated areas, where electricity is needed most. At the same time, energy can be consumed in whatever form needed, i.e. as electricity, heat or steam. The dependence of the South African economy on cheap coal ensures that it will remain a vital component of future electricity generation options in the country. This dominance of coal-fired generation in the country is responsible for South Africa’s title as the largest generator of carbon dioxide (CO2) emissions on the continent and the country could possibly be requested to reduce its CO2 emissions at the next international meeting of signatories to the Kyoto Protocol. Carbon dioxide emissions can be reduced by utilising gas-fired generation technologies. However, the uncertainty and costs associated with natural gas in South Africa hampers the implementation of this technology. There are currently a number of initiatives surrounding the development of natural gas in the country, viz. the Pande and Temane projects in Mozambique and the Kudu project in Namibia, and this is likely to positively influence the choice of fuel utilised for electricity generation in the future. The economic viability of these projects would be further enhanced through the obtaining of Clean Development Mechanism (CDM) credits for greenhouse gases (GHG) emissions reduction. Alternatively, more efficient methods of generating electricity from coal must be developed and implemented. IGCC is capable of achieving this because of the high efficiencies associated with the combined cycle component of the technology. These higher efficiencies result in reduced emissions to the atmosphere for an equivalent unit of electricity generated from a PF station. An IGCC system can be successful in South Africa in that it combines the benefits of utilising gas-fired electricity generation systems whilst utilising economically feasible fuel, i.e. coal. IGCC systems can economically meet strict air pollution emission standards, produce water effluent within environmental limits, produce an environmentally benign slag, with good potential as a saleable by-product, and recover a valuable sulphur commodity by-product. Life-cycle analyses performed on IGCC power plants have identified CO2 release and natural resource depletion as their most significant positive lifecycle impacts, which testifies to the IGCC’s low pollutant releases and benign by-products. Recent studies have also shown that these plants can be built to efficiently accommodate future CO2 capture technology that could further reduce environmental impacts. The outstanding environmental performance of IGCC makes it an excellent technology for the clean production of electricity. IGCC systems also provide flexibility in the production of a wide range of products including electricity, fuels, chemicals, hydrogen, and steam, while utilizing low-cost, widely available feedstocks. Coal-based gasification systems provide an energy production alternative that is more efficient and environmentally friendly than competing coalfuelled technologies. The obstacle to the large-scale implementation of this technology in the country is the high costs associated with the technology. CDM credits and by-products sales could possible enhance the viability of implementing these technologies in South Africa.