Browsing by Author "von Blottnitz, Harro"

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    Open Access
    A prospective comparative lifecycle assessment for green and grey hydrogen production and utilisation in the South African context
    (2022) Mbaba, Ongezwa; von Blottnitz, Harro; Fadiel, Ahjum
    Green hydrogen has gathered increasing interest as a medium in the transition to a carbonneutral economy, with several large, export-focused projects currently under development in Southern Africa. However, the environmental implications of hydrogen production and utilisation are not well understood. To address this challenge, a comprehensive literature review for hydrogen production and utilisation lifecycle assessment studies was conducted, and two prospective comparative lifecycle assessments are presented for green and grey hydrogen production and utilisation in the South African context. The first LCA aims to quantify the environmental impacts of producing green hydrogen, relative to grey hydrogen, and determine the production route with the least environmental impacts. The scenarios investigated for hydrogen production are water electrolysis powered by wind, solar PV or concentrated solar power, steam methane reforming, and water electrolysis powered by a 2040 grid electricity mix. Furthermore, the impacts of three available electrolysis technologies; viz. polymer electrolytic membrane (PEM), alkaline, and solid oxide electrolysis were compared. The second LCA aims to compare two systems of utilisation for the green hydrogen that would be produced in South Africa to determine the option where the highest level of decarbonisation could be achieved. The application considered for the assessment is the fuelling of heavy-duty truck transportation. The systems considered are local utilisation for fuelling heavy-duty trucks and hydrogen exportation to Germany also to fuel heavy-duty trucks. These two systems were expanded to include conventional fuel utilisation, making the functional units of the systems equal and thus the systems comparable. SimaPro was used to conduct the two LCAs, and the ReCiPe 2016 midpoint method was used for the lifecycle impact assessments. Grid-powered water electrolysis is found to have the highest potential impacts across most impact categories, even for the case of the significantly decarbonised 2040 grid mix, with SMR second. Solar PV-powered electrolysis leads to the highest potential human non-carcinogenic toxicity impact caused, by the supply chains of PV panels. Wind-powered water electrolysis is the least impactful option across most categories. However, it has the highest potential human carcinogenic toxicity impact among the renewable production options, though it is less than half compared to the value for non-renewable hydrogen production. This toxicity is caused by the supply chains of wind turbines. Considering optimal electrolyser utilisation, combined wind and solar PV-powered electrolysis is the best option. When comparing the water electrolysis technologies, PEM electrolysis leads to the highest environmental impacts. The energy input for production dominates all the impacts. In terms of utilisation, the environmental impact reductions achievable by the export case outweigh the environmental impact reductions achievable by using the green hydrogen locally, across all impact categories. The highest level of decarbonisation is achieved by replacing the most environmentally harmful fuel; South African coal-based diesel used to fuel heavy-duty trucks. The results of the first LCA confirm that green hydrogen is indeed significantly less environmentally impactful compared to grey hydrogen, but with one hotspot for each of the PV and wind-powered electrolysis, which require attention by project developers. The environmental impacts of all the production scenarios are dominated by the energy required for the production processes. The main finding for the second LCA is that local hydrogen utilisation for heavy-duty truck transportation leads to a larger environmental benefit compared to hydrogen exportation in the case of usage for heavy-duty truck transportation in another country. The highest level of decarbonisation is achieved by displacing South African coal-based diesel first.
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    Open Access
    An exploration of lived experiences of 11 resettled families in Mazabuka district, Zambia, by a Nickel mine project
    (2019) Tumbama, Lewis; von Blottnitz, Harro; Donovan, Elspeth
    Mining-induced displacements and resettlements are a global phenomenon. However, how these are done and the implications that they have on the displaced and resettled are shaped by micro, local level dynamics. These include existing regulations, socio-economic and cultural situations of communities involved, level and type of compensations offered to the communities, among others. These shape how communities live the experiences of being displaced and resettled, as more powerful companies with financial resources seek out mining opportunities. For communities that are displaced and resettled, this process becomes a socio-economic one as change of place has implications on people’s ability to access resources on which they depend. This may lead to a transformation of their livelihood assets in the short and long term, which requires changing of their livelihood strategies. Zambia is endowed with natural resources, and the mining sector is the mainstay of the country’s economy. In particular, Zambia ranks among the top 15 producers of copper in the world. The government of Zambia (GRZ) gives mining licenses to companies that in return, pay royalties in form of taxes that support the government’s development programs nation-wide. Therefore, mining is said to be in the broader interest of the nation (GRZ, 2006). This means that the rights to the access and use of land by a particular group of people, individuals or ethnic grouping will be superseded by an economic undertaking that is seen as having a broader development interest of the nation. This includes economic activities such as building bridges or hydro-electric plants, road construction, building economic zones and mining. In Zambia, below ground surface mineral rights belong to the state. Given the global nature and scope of mining induced displacements and resettlements, micro-level dynamics easily remain invisible. In Zambia, research in lived experiences of displaced and resettled communities remain sparse and often unpublished. The aim of the research was to explore the psychological and socio-economic implications for the displaced and resettled households by a Nickel Mining Company in Mazabuka, southern Zambia. Families were purposively sampled and interviewed. Positive and negative lived experiences emerged from the interviews and have been presented as themes. Improved access to services; increased employment opportunities; improved production and acquisition of productive assets; and guaranteed security of land tenure and improved quality of houses were the positive lived experiences of resettled families. Negative lived experiences were: poor quality of soils; loss of locational advantage; emotional depression; discontinuation of gardening activities; and inability to buy drugs for livestock. The findings revealed that despite the cultural homogeneity of the sampled families, lived experiences after resettlement were different based on socio-economic situation of households. This was determined by who the head of the household was, literacy levels and family labour availability, because agriculture is the main livelihood activity. This research used a qualitative single case study approach to understand the ‘how, what and why’ of the lived experiences of the resettled families. It sought to respond to three related research questions: i) Did loss of access manifest in the studied case, and if so, how? What are the psychosocio-economic implications of the Munali Nickel mining-induced displacement and resettlement; ii) What characterizes the livelihoods of resettled families following the establishment of the Munali Nickel Mine, which assets were positively or negatively affected by resettlement and compensation; and iii) What are the coping mechanisms of the displaced and resettled communities following the establishment of the Munali Nickel Mine? The results of this research indicate that the level of compensation paid to resettled family cannot make up for what communities give up so that mining activities can start. Cultural values and the sense of belonging, for example are not compensated for when these are the factors that ensure psychological well-being of communities. Compensation and fulfillment of development promises were‘delayed and not necessarily denied.’ Access to education and health facilities was not achieved until nearly 10 years later, partially attributed to frequent closures of the mine that prevented the mine from honouring its promises in time. The uncertainty in the operations of the mine, loss of access to livelihood strategic resources was unsettling and created a sense of anxiety among resettled community members. While access to schools and clinics as physical assets was facilitated following resettling, the resettled community was not wholly part of the mining operation to the level that ensured human capacity development. For a highly technological undertaking as mining, resettled households could not benefit from any knowledge transfer. Furthermore, interviewed households reported increased distance to the tarred road; loss of sources of livelihood to closure of the mine, and loss of business opportunities in resettlement site; sub-standard houses with leaking roofs and cracks, as well as non-uniformity in compensation; inadequate grazing land; reduced agroproduction due to water logging in the fields and poor soils; scarcity of firewood; and nonreinstatement of churches, among negative experiences that they have lived. Coping with the experiences of ‘delay but not denial of access’ and a ‘mixed bag’ of changes to different asset classes was differential based on age, sex and household composition that determined the level of available labour in the household.
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    Open Access
    An investigation of the potential and the limitations of small-scale biogas in urban Africa
    (2019) Naik, Linus; von Blottnitz, Harro
    Continuing urbanisation in Sub-Saharan Africa provides many development challenges including; energy provision, waste management and sanitation. On-site biogas has the potential to provide renewable energy to meet primary energy needs, whilst also addressing waste management and possibly sanitation. In urban settings, up to 50% of the municipal waste in urban can comprise organic waste which typically remains an untapped energy source, while the total waste volume continually increases with population growth. Whilst some countries (including Ethiopia and Uganda) have support via national government and/or foreign investment for biogas deployment, their focus is on rural biogas for agricultural waste, not urban biogas for municipal waste. This thesis investigates the case for small-scale biogas as a technology to assist sustainable urban development through understanding factors which will ensure operational success to safeguard investment. The factors investigated were productivity, stability and the need for remote monitoring. The research was divided into three distinct phases which occurred chronologically. The first phase was observational and developmental, in which one biogas unit in a semi-controlled environment was monitored. Some initial insight into the factors which caused instability (in this case, the addition of simple carbohydrates) as well as two methods of mitigation of instability (namely addition of lime and a cessation of feed) were noted for future investigation. Also, in this phase, a mobile phone application, called the “Biogas Monitoring Tool” was developed and refined, accompanied by a monitoring methodology to collect information on measured variables which were considered to inform productivity and stability of small-scale biogas units. Of the variables mentioned, the laboratory method of evaluation of two in particular (pH and temperature) was replaced with more practical and rudimental measuring techniques. The appropriateness of the replacements was statistically analysed, evaluated and found to be acceptable for the intended purposes. The second phase of research involved the widespread rollout of the Biogas Monitoring Tool developed in the first phase. The platform was used to gather data from ten small-scale biogas units across southern Africa to further investigate and analyse the factors which affected the productivity and stability of smallscale biogas units. Readings of pH, burn time, pressure, mass and type of feed were captured through the Biogas Monitoring Tool over twelve months. The analysis showed episodes of instability of biogas units linked to changing feeding regimes of simple carbohydrates, organic loading rates as well as changes in feed ratios/frequency. In terms of productivity of the biogas units, seasonal fluctuations in the five units which were monitored over the winter months was evident, as well as potential underutilization of biogas produced. Furthermore, it was noted that there was better utilisation of gas for institutional installations compared to domestic installations. It was also shown that in five of the biogas units, the stability of the unit had an influence on the quality of gas produced, and it was indicative that it had an influence on the quantity of gas produced. For the third and final phase of research, theories developed from insight gleaned in second phase were tested on one biogas unit in a controlled environment. There were three sets of experiments conducted on this unit which had a pre-determined feeding regime. Also, the biogas stove was burned daily until the biogas ran out, to quantify the productivity of the biogas unit. Firstly, a stepwise addition of the organic fraction of municipal solid waste was introduced into the feeding regime. In this case, it was demonstrated that the organic fraction of municipal solid waste can in fact be the sole feed-stock for biogas unit, with the proviso that there was appropriate knowledge support which includes quick mitigation strategies for periods of instability. Secondly, the effect of pre-treatment of the organic fraction of municipal solid waste was investigated. It was found here that the pre-treatment did appear to improve the stability of the biogas unit, a consideration which may be significant for potential widespread adoption of the technology. Finally, the effect of temperature on gas production was confirmed and quantified, with higher average temperatures showing higher gas production. In conclusion, it was found that all the small-scale units which formed part of this research showed episodes of instability. When considering this technology for energy provision for urban development, there are important considerations around feedstock variability by way of feed type, volume, and frequency affect the stability of these unit. With reference to productivity, it was shown, not only that temperature naturally does affect gas production, but also that the productivity is linked to the stability. Furthermore, it was deemed that the type of setting (institutional versus domestic) was in fact more significant than the ambient temperature or the feeding regime when considering gas use and gas utilisation as indicators of productivity. Finally, with regard to knowledge support via remote monitoring, it was shown that simple and practical measurements were able to provide insight into factors which affected productivity and stability of small-scale biogas units. The final phase further utilised the remote monitoring tool to actively manage the operation of the biogas unit and quickly mitigate instability. Thus, small-scale biogas has the potential to be adopted as technology for energy provision in urban development. The limitations of the application are that waste-based biogas would meet only an portion of the total energy requirement in any particular urban area and that based on the findings of this research, all units are subject to periods of instability. There are various mitigation strategies for instability, some of which involve active management, which may be supplied remotely.
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    Open Access
    An update on the process economics of biogas in South Africa based on observations from recent Installations
    (2019) Nagel, Brigette Mariana; von Blottnitz, Harro
    This dissertation investigates, in the context of South Africa (SA), the process economics of energy from biogas, and hence the financial viability establishing a biogas plant in the absence of a formal incentivisation programme. Firstly, the study set out to establish an improved understanding of the costs associated with the technology. Data on the capital- and running costs of existing biogas plants in SA were sourced by means of stakeholder interviews, and compared with published data on similar plants in countries where the biogas sector is more mature. Two biogas usage pathways were evaluated: biogas-to-electricity through a Combined Heat and Power (CHP) system, and biogas-to-biomethane. Regression analysis was carried out on the observed costs, and this was used to predict future costs. A capacity-cost factor of 0.68 for biogas-to-electricity and 0.57 for biogas-tobiomethane was obtained. Statistical hypothesis testing revealed that the values are significantly smaller than 1, which indicates that economies of scale are observed in both cases. A Lang factor of 1.81 was determined, based on cost data from 20 medium- to large scale biogas plants in South Africa. Operational and Maintenance costs were determined to vary between R2.6 – R4.6 per Nm3 biogas produced where significant feedstock sorting and/or transport costs are present and R0.3 – R1.4 per Nm3 biogas produced where minimal feedstock sorting and/or transport costs are present. It was observed that energy can be recovered from biogas plants at a Levelised Cost of Energy (LCOE) of 0.5 – 2 R/kWh in SA, which corresponds with the range of 1.8 – 2.8 R/kWh documented internationally, even though the LCOE in SA is generally lower that what is observed abroad, especially at plant capacities greater than 1 MW. Based on a financial analysis, a positive Net Present Value (NPV) for a medium-cost CHP plant where only electricity is utilised as income stream is possible from 0.3 MWe upward, with greater returns at higher plant capacities. For a biomethane plant, a positive NPV can be attained at plant capacities of 4 MWeq and higher. A comparison on the financial benefits of two different biogas usage pathways revealed that a biomethane plant has greater potential profitability than a CHP plant at capacities greater than 5 MWeq, whereas at smaller capacities, a CHP plant would yield better returns. The most attractive investment scenario evaluated was a 6 MWeq biomethane plant, where a Return on Investment (ROI) of 18% could be attained with a payback period of 8 years for a plant lifetime of 20 years. However, a risk analysis making use of Monte Carlo simulation revealed that such a project will only have an 91% chance of obtaining a positive NPV, which is below the set benchmark of 95%. Considering the high up-front capital investment associated with a large scale biogas project, it is anticipated that the financial risks associated with such a project would be too high to merit investment at current conditions in South Africa. This could, however, be mitigated if an additional income stream could be established in the form of an incentive, subsidy, grant, or alternatively a waste treatment gate-fee or fertiliser sales income. Lastly, if electricity and fuel prices in South Africa continue to increase at the rate observed over the past two decades, the business case for a single-income-stream biogas plant will become increasingly attractive and profitable in the near future.
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    Restricted
    Biofuel policies in South Africa: a critical analysis
    (Springer, 2012) Letete, Thapelo; von Blottnitz, Harro
    In 2007 the South African government released the country’s National Biofuels Industrial Strategy targeting a biofuels market penetration of 2% of liquid road transport fuels by 2013. Contrary to the international situation, the main driver for the development of a biofuels industry in South Africa is neither the economic threat of increasing oil prices nor mitigation of greenhouse gas emissions, but the need to create a link between the country’s first and second economies. Specifically, the government hopes to stimulate economic development and to alleviate poverty through the promotion of farming in areas previously neglected by the apartheid system. Before the release of this strategy, commercial sugar producers and maize farmers represented the majority of the parties looking to drive the South African biofuels industry. But, two years after its release none of the ventures by these stakeholders have been able to take off, mainly due to the Strategy’s restrictions on the type and source of feedstock as well as on the type of farmers whose participation in the industry would be subsidised. This chapter presents a critical scientific-­based analysis of the implications and results of South Africa’s National Biofuels Industrial Strategy. Firstly an update is presented on the state of the biofuels industry in the country, highlighting the current production statistics and the major investment activities, and how these were affected by the release of the Strategy. Then the ambiguities in the Strategy are outlined and critically analysed with reference to the current state of the biofuels industry in the country. The chapter then concludes with the lessons to be learnt from the South African experience by those African countries which are yet to develop their respective biofuel policies.
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    Open Access
    Carbon intensive but decarbonising quickly? Retrospective and prospective life cycle assessments of South African pome fruit
    (2018) de Kock, Lorren; von Blottnitz, Harro; Russo, Valentina
    The South African economy has in the past been categorised as carbon intensive due to an energy and capital intensive development path and an associated set of economic activities termed the minerals-energy complex. International export markets, specifically the European Union (EU), are systematically applying pressure on imported products with a high carbon footprint through potential trade barriers, border tariffs and consumer lobbying. The objective of this research is to determine whether South African pome fruit has a higher global warming potential (GWP) per kg fruit compared to pome fruit cultivated and packaged in other countries. Following on from this finding, is to determine whether the Greenhouse Gas (GHG) emissions for pome fruit in South Africa are declining, ,as could be expected based upon the declining carbon intensity of the South African economy since 1990 and efficiency improvements in the industry itself. The Attributional Life Cycle Assessment (ALCA) methodology is used to determine the Global Warming Potential (GWP) per kg fruit for multiple boundaries within the value chain, retrospectively for the years 2000, 2010 and prospectively for 2020. The product system boundary includes the farm, packhouse, controlled atmosphere store (CA) and cold store (CS). For the Life Cycle Inventory (LCI), the temporal variations in pome fruit cultivation, packing and storing for the export and local market are taken into account for each of the years studied. Using the single issue characterisation methods – the GHG Protocol and the IPCC GWP 2013 100a – the results for each of the years under study are compared at a value chain, boundary and activity level. The results indicate that the baseline GWP result for South African pome fruit in the year 2000 was relatively high compared to similar international LCA research on apples and pears during this period. However, the results for the years 2010 and 2020 clearly indicate a sustained decline in relative GHG emissions of South African pome fruit according to the GWP indicator result per kg fruit and the normalised results for the industry. It is clear that there has been an increase in eco-efficiency in a number of farming and agro-processing practices since 2000 which correlates to the declining CO2e emissions in the boundaries and value chain of South African pome fruit. The carbon intensity and efficiency of the pome fruit value chain is also determined for each year using the kg CO2e per kg fruit and the industry revenue for a specific year (ZAR 2010 adjusted for PPI). The findings support the hypothesis that the carbon intensity of the pome fruit industry has indeed declined since the year 2000. This decline in carbon intensity represents a relative decoupling of CO2e emissions from economic growth of the industry from 2000 to 2020.
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    End-of-life in South African product life cycle assessment
    (2018) Rodseth, Clare Josephine; von Blottnitz, Harro; Notten, Philippa
    Life cycle assessment (LCA) is a tool specifically developed for quantifying and assessing the environmental burden of a product across its entire life cycle, thus providing powerful support for sustainable product design. There exists a geographical imbalance in the adoption and distribution of LCA studies, with a notably poor penetration into developing countries, resulting from a lack of technical expertise, reliable data, and an inability to engage with the key issues of developing countries. These challenges are particularly prevalent in waste management. The limitations in current LCA capacity for representing product end-of-life, coupled to the disparity in waste management practices between developed and developing countries means that LCA is currently unable to accurately model product end-of-life in South Africa. This means that, for imported products designed on the basis of LCA, the upstream impacts may be accurate, while the end-of-life is not. Therefore, to improve the use of LCA as a tool to support sustainable product design, there is a need to develop life cycle datasets and methods that accurately reflect the realities of waste management in developing countries. The objectives of this dissertation are to (i) identify the current shortcomings of existing LCA datasets in representing the end-of-life stage of general waste in a South African context, and (ii) propose modifications to existing datasets to better reflect the realities of waste management in a South African context and extract lessons from this for use elsewhere. To meet these objectives, research was undertaken in three main stages, with the outcome of each stage used to inform the development of each subsequent stage. The first stage aimed to establish the status quo with regards to general waste management in South Africa. This investigation was informed through a desktop review of government and other publicly available reports, supplemented by field work and stakeholder engagements. These results formed the basis for the second stage: a review of LCA capacity for representing product end-of-life in the South African context. The review of datasets was limited to those contained within SimaPro v8.3 and was undertaken with the aim of understanding the extent to which current datasets are capable of representing South African waste management practices. Finally, three cases of existing LCA datasets were explored. This included testing modifications that could be made in an attempt to improve their applicability to the South African reality. In South Africa, a major limitation in developing a quantified mapping of waste flows lies in the paucity of reliable waste data and the exclusion of the contribution of the informal sector in existing waste data repositories. It was estimated that South Africa generates approximately 12.7 million tonnes of domestic waste per annum, of which an estimated 29% is not collected or treated via formal management options. For both formal and informal general waste, disposal to land (landfill and dumping) represents the most utilised waste management option. Landfill conditions in South Africa range from well-managed sanitary landfills to open dumps. Considering only licensed landfill facilities, it is estimated that large and medium landfill sites accept the majority of South Africa’s general waste (54% and 31% respectively), while the balance is managed in small (12%) and communal (3%) sites. Considering the quantity of informal domestic waste enables a crude estimation of household waste distribution between different landfill classes. In this instance, while the majority of waste (40%) is still managed in large formal landfill sites, an appreciable quantity (26%) is managed in private dumps. Within SimaPro v8.3 landfill disposal is best represented by the sanitary landfill datasets contained within the ecoinvent v3.3 database. SimaPro preserves the modular construction of the ecoinvent dataset, meaning that various generic modifications to these datasets can be made, such as the elimination or addition of burdens, redefinition of the value of a burden, or substitution of a linked dataset. Practically, such modifications are limited to process-specific burdens. However, wastespecific burdens are of greater significance in the life cycle impact assessment (LCIA) result of a landfill process. Waste-specific emissions are generated using the underlying ecoinvent landfill emission model. The current model structure allows for the parametrisation of waste composition in addition to landfill gas (LFG) capture and utilisation efficiencies. However, besides the incorporation of a methane correction factor to account for the effect that various site conditions have on the waste degradation environment, the extent to which the existing model can be adapted to represent alternative landfill conditions is limited. This is particularly true in the case of leachate generation and release. Although adaptation that incorporates the effect of climatic conditions on waste degradability and emission release is possible, this requires a high level of country-specific data and modelling expertise. Thus, the practicality of such a modification within the skills set of most LCA practitioners is questionable. Further limitations in the existing modelling framework include its inability to quantify the potential impacts of practices characteristic of unmanaged sites such as open-burning, waste scavenging, and the presence of vermin and other animal vectors for disease. Analysis of the LCIA results for different landfill scenarios showed that regardless of either the deposited material or the specific landfill conditions modelled, the time frame considered had the most pronounced effect on the normalised potential impacts. Regardless of landfill conditions, when long-term leachate emissions are considered, freshwater and marine ecotoxicity impacts dominate the overall potential impacts of the site. This result implies that if landfill disposal is modelled over the long-term, the potential impacts of the process has less to do with site-specific conditions than it does to do with the intrinsic properties of the material itself. Given the ensuing extent of degradation that occurs over the time frame considered, the practise of very long-term modelling can equalise landfills that differ strongly in the short-term. In terms of product design on the basis of LCA, the choice of material can be more strongly influenced by the time frame considered than the specific landfill scenario. From a short-term perspective, for fast degrading materials the impacts incurred from leachate emissions and their subsequent treatment are of lesser importance than those arising from LFG. From a long-term perspective by contrast, leachate emissions have a significant effect on the LCIA result. Investigation into the effect of reduced precipitation on the LCIA result showed that the exclusion of leachate emissions lowers the potential impacts of a number of impact categories, with the most substantial quantified reduction observed in the freshwater and marine ecotoxicity impact categories. This result implies that for dry climates, the long-term impacts of landfilling could be significantly lower than when compared to landfill under temperate conditions, with the potential impacts of the waste remaining locked-up in the landfill. Given quantified findings on South Africa’s dependence on both formal and informal disposal, and the variation in landfill conditions across the country, it can be concluded that LCA results for the impacts of products originating from global supply chains, but consumed and disposed of in South Africa, will be inaccurate for the end-of-life stage if modifications to end-of-life modelling are not made. The findings from this dissertation provide the basis for i) a crude estimate of ‘market shares’ of different disposal practises and ii) guidelines for parameterisation of material specific emission factors, in particular for shorter term emissions, focused on LFG and leachate emissions.
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    How the sustainability transition in energy is transforming the built environment of South African cities
    (2019) Kluger, Martin; von Blottnitz, Harro
    South Africa is undergoing a sustainability transition (ST) in its energy sector as part of its broader move towards a lowcarbon future. Past studies of the nascent ST using a multi-level approach have already proven obsolete after strong resistance from the incumbent energy regime almost derailed the fledgling renewable energy (RE) industry. After initially going to ground and contracting, the industry re-emerged strongly in South Africa’s cities, mostly in the form of rooftop solar photovoltaic (PV) systems. This study applies an integrated approach utilizing the Multi-level Perspective (MLP) to trace the current ST trajectory, whilst employing the Technology Innovation Systems (TIS) framework as a focal lens, recently adapted to the follower country context, to empirically investigate system development in the solar PV TIS. A survey was conducted to assess the drivers and challenges facing consumers of solar PV technology in cities, the results indicating that the rapid growth in distributed embedded generation (EG) was sparked by recent tax incentives and not the introduction of Feed-in Tariffs (FIT) offered by city municipalities. Whilst the RE sector and solar PV market have grown through consumer demand for EG, they still face resistance from the existing energy regime, needing further development in policy and regulation in order for South Africa’s ST to support a more complex web of distributed and embedded generation, mostly underpinned by RE technologies.
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    Inclusion of leakage into life cycle management of products involving plastic as a material choice
    (2020) Chitaka, Takunda Yeukai; von Blottnitz, Harro
    The accumulation of plastic waste in the natural environment has been a major environmental concern for many decades. However, the environmental impacts associated with leakage are not taken into consideration under current life-cycle based approaches, despite packaging being a major application area of life cycle assessment. Furthermore, there is limited quantitative information on the leakage propensities and rates of different products. This presents a critical limitation during the life cycle management (LCM) of products destined for regions where they are likely to be dumped or littered. This thesis investigates the feasibility and influence of using product specific leakage rates as a proxy indicator for potential marine environmental impacts, to inform the life cycle management of products in which plastic is a material choice. In particular, it explores whether a realistic understanding of leakage rates, differentiated by major use, may facilitate the development of effective interventions to mitigate the growing problem of marine plastic pollution. This entails the quantification of leakage rates for selected plastic items identified as highly prone to leakage based on a series of beach surveys. The potential influence of providing such specific knowledge is investigated via the exploration of current LCM practices for plastic products employed by key value-chain actors in the plastics industry. In addition, the life cycle management of three key items identified as problematic (straws, cotton bud sticks and beverage bottle lids) is explored via a case study approach. Beach accumulation surveys are often used to estimate plastic flows into the marine environment. Thus, two series of beach surveys were conducted across five beaches with varying catchment area characteristics in Cape Town, over two periods in 2017 and 2018 – 2019 respectively. Daily accumulation rates varied across all sites ranging from 38 – 2962 items.day-1 .100m-1 during the first sampling period and 305 – 2082 items.day-1 .100m-1 during the second. Plastic was the major contributor accounting for 85.6 – 98.9% of all items by count. Despite the variations in litter accumulation rates and composition, there was significant commonality in the items which were identified as major contributors. The top 12 most prevalent and abundant identifiable plastic items accounted for 43 – 66% during the first sampling period, and 41 – 73% during the second. Ten of these items were prevalent during both periods, eight of which were associated with food consumed on-the-go, including beverage bottle lids, polystyrene food containers, single sweet wrappers, snack packets and straws. This indicates that the high litterability of these items was consistent across catchment areas and sampling periods. Furthermore, when ratioed to waste generation, items found to be major contributors were found to have significantly higher leakage rates in comparison to less prevalent items. The increasing concern surrounding plastic pollution has pressured value-chain actors to review their approaches to the life cycle management of plastic products. This has led to the development of strategies focussed on plastic packaging which were not commonplace across all companies. However, these strategies are not necessarily aimed at mitigating plastic pollution but are more broadly concerned with sustainable product design, emphasising design for recycling and supporting recycling activities at end-of-life as part of their extended producer responsibility. Thus, the extent to which these strategies address plastic pollution is limited. Furthermore, value-chain actors reported varied approaches to product prioritisation for intervention which are often not grounded in empirical evidence but instead based on anecdotes and limited logic. This may be attributed to a lack of reliable product-specific information surrounding plastic pollution. Such approaches have the potential to prioritise products ii which are not major contributors to marine pollution in lieu of those that are. Interventions targeted towards products that were identified as prone to leakage, including straws and cotton bud sticks, were catalysed by consumer pressure and societal expectations at large. Ultimately, this thesis demonstrates the need for product-specific knowledge on leakage to facilitate responsible and effective life cycle management of products involving plastic as a material choice. Furthermore, it has demonstrated the feasibility of providing such information through the use of leakage rates. Leakage rates have the potential to play an important role in product life cycle management, allowing for the identification of products which are highly prone to leakage into the environment. Thus, their integration into LCM practice has the potential to facilitate the development of targeted strategies to address plastic pollution.
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    Introducing loop-closure for phosphates into a provincial development strategy: An analysis of overlaps of primary and secondary phosphate processing technologies
    (2018) Vidima, Sizwe; von Blottnitz, Harro; Petersen, Jochen
    Almost 90% of the global phosphoric acid demand can primarily be linked to fertiliser production for application onto agricultural lands (PotashCorp, 2014). To fulfil the phosphate fertiliser demand in South Africa’s arable soils, the country largely relies on the mining and processing of the extensive igneous phosphate ore deposits found in Phalaborwa, Limpopo (DMR, 2008); but this extractive approach to procuring phosphates is not sustainable. Moreover, due to rising phosphate demands and declining ore grades, worldwide phosphate ore reserves are expected to last only approximately 100 - 400 years (Smil, 2000). The intensification of phosphate resource consumption has also resulted in increased phosphate loads in wastewater treatment plant (WWTP) influents thereby exerting pressure on existing treatment systems and potentially, on water ecosystems in which these phosphates end up. Therefore, it is because of the myriad difficulties associated with linear phosphate resource flows that there has been ongoing research on the recovery of phosphate nutrients from wastewater (Durrant, et al., 1999; Levlin and Hultman, 2004; Sikosana, 2015) and sourceseparated urine (Ganrot, 2005; Pronk and Kone, 2009). Consequently, the purpose of this dissertation is to investigate a novel approach to loop-closure through the recovery of urine-bound phosphates. Uniquely, this research considers the subsequent integration of the recovered phosphate into existing primary phosphate processing facilities – stimulated by a process to develop a sub-national minerals beneficiation strategy for the kwaZulu-Natal (KZN) province in South Africa. Not only does the investigation seek to understand the technical potential of reintroducing waste-bound phosphates into the phosphate value chain but it also seeks to understand the potential for the respective contribution into the socio-economic sphere of sustainable development through employment creation. Three research approaches were used in obtaining results in this dissertation. Firstly, flowsheet simulations of Dihydrate phosphogypsum (DH) and Hemihydrate phosphogypsum (HH) producing processes were done. The materials balance simulations included a base case where a secondary phosphate source was not introduced in the process and the case where it was introduced into the processes in the form of struvite recovered from sanitation infrastructure. Secondly, a socio-economic assessment was carried out. This involved a cost analysis of implementing a reverse logistics network that collects urine from non-sewer-served areas, processes it into struvite and transports the struvite into a phosphoric acid complex, such as the one owned by Foskor in Richards Bay. In addition to this, the quantity of jobs was determined. Lastly, interviews and desktop research were used to learn about past experiences in recycling thereby providing insight regarding key considerations when implementing extended producer responsibility schemes. With the assumptions that are detailed in Chapter 3, the results of Chapter 4 reveal that it should be possible, from a technical standpoint, to integrate struvite into existing phosphoric acid generation processes. However, the use of struvite in such a process raises concern in the form of loss of phosphoric acid production if the feed tonnage is kept constant. Furthermore, there is a presence of magnesium in the product acid which has been known to adversely affect the formation of gypsum crystals. Additionally, when using the struvite cost obtained from Sikosana (2015) it can be argued that there is little to no process-related financial benefit in integrating struvite in a phosphoric acid generation complex such as the investigated DH and / or HH processes. The socio-economic analysis showed that implementing a reverse logistics network for the recycling of phosphates would cost 147,000 ZAR per ton of struvite generated whilst creating approximately 9,000 to 18,000 jobs (depending on the approach) in the respective collection, processing and transportation phases in recycling, if urine collection were to be extended to all households in KZN not served by network sewer systems. Furthermore, the study revealed that the funding model in the extended producer responsibility scheme would have to contribute an average of 152,000 ZAR per year, through some form of subsidy, for every job that exists in the network. Critical insight was drawn from the literature study and interviewing process. It was found that the key considerations that need attention when setting up an extended producer responsibility (EPR) scheme include a well-governed and aligned producer responsibility organisation (PRO) to assist the producer in achieving their respective production targets. Secondly, there is evidence that mandatory approaches to EPR funding have been less successful as funding approaches for EPR schemes in South Africa; in fact, the more successful EPR schemes have been voluntary / industry driven approaches. As a basis, the work in this dissertation can be used in influencing future work in the phosphate loop-closure context. It can then be concluded that the return of urine-derived struvite, as a secondary phosphate raw material, into industrial phosphoric acid processing should be technically possible. In doing so, a more circular phosphate value chain could be achieved. The reintroduction of a secondary phosphate source in the HH and DH processes would therefore bring about new work opportunities, and thus the upliftment of the socio-economic status of the individuals involved in the reverse logistics that facilitate struvite supply. It is recommended that technical questions, for example the specifics of how struvite interacts with sulphuric acid, be further investigated from a thermodynamic and reaction kinetics perspective. Also, there is enough evidence to start an expert discussion about the suitability of existing mechanisms that have been accepted and used by industrial producers to give effect to their extended environmental responsibilities, for application in phosphate loop-closure.
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    Investigation of the applicability of a cleaner production approach to road side catering in urban Africa
    (2018) Niyobuhungiro, Rissa Vénérande; von Blottnitz, Harro
    In urban Africa, informal street food trade is often accompanied by processing activities, including slaughtering, brewing, grilling or cooking. Food and drinks are often prepared on open fires using wood as a fuel. When wood is used as a fuel, it generally emits smoke containing various pollutants. Previous studies showed that limited capital, lack of education and expression are the main barriers to the implementation of new technologies in the informal sector. It has been argued that the use of cleaner technologies, especially those relevant for the energetic aspect of informal production, would provide affordable net benefits to society in terms of public health, climate change mitigation and food security, but without showing how this could be done in a specific case. This thesis investigated whether a cleaner production approach would be beneficial: economically and for health and safety to roadside vendors in an informal context. The study aimed to provide insights as to whether government could show presence in such settings not only as (unwelcome) regulator, but in a supportive way by introducing cleaner and more efficient means of production, mainly clean-burning technologies in the informal food and drinks preparation. The specific objectives of this thesis were to: ➢ Compare the resource usage and pollution loads associated with traditional vs. cleaner methods of informal roadside food and drink preparation; ➢ Establish whether the cost-savings deriving from increased resource efficiency of cleaner methods would be sufficient motivation for producers to adopt these; ➢ Observe and document other constraints to the adoption of cleaner methods of production by attempting to demonstrate resource efficiency gains and emission reductions possible under real conditions of informal food and drinks production. Two cleaner technologies were considered: efficient wood stoves, which are known to have sizeable benefits in terms of reduced fuel wood usage and smoke emissions (though investigated to date mainly in the context of household energy usage), and anaerobic digestion, which can potentially serve simultaneously as receptacle and treatment for organic wastes, and produce biogas to serve fuel needs. This study combined qualitative and quantitative field observations in a case study setting with experimental work to study the biogas production potential of slaughtering waste. The case study location, Nyanga township in Cape Town, served as a representation of the many urban African settings in which roadside catering occurs. Nyanga township has both formal and informal housing. Its population including many unskilled and unemployed people also makes it a good place for informal activities. One common informal economic activity in Nyanga is the production of cooked meals and drinks. This is done on street corners alongside the road around the transport interchange, where many people pass by and vendors provide various services. The cooked meals include roasted lamb, pork and beef. Live chickens are slaughtered and plucked, and also sold whole for home preparation. An African beer known as umqombothi is locally prepared in two processes, with each process involving approximately two hours of cooking using a 230 L drum. In the field work, it was investigated how much wood was used in open fires compared to efficient wood stoves, specifically for the activity of chicken plucking and umqombothi mashing. The respective fuel costs were calculated and the air quality in the street-side workplace were measured in term of levels of particulate matter less than 10 micron (PM10). It was observed in the field that in most cases sheep and chicken slaughter waste was dumped alongside the road. This dumping was due to the lack of slaughtering facilities in the area. Many other reports have stated that the lack of adequate infrastructure in informal settlements is the cause of inappropriate waste dumping. The qualitative observations confirmed that the meat and other cooked meals were prepared using inefficient methods linked not only to the waste of resources but also to waste of money and exposure to polluted air from burning wood. Air quality measurements showed smoke levels near open fires to be about 8 times higher than when using an efficient wood stove. PM10 levels of 4 900 ±1 500 µg/m3 were measured near chicken pluckers using open fires for their hot water, while when using a stove the PM10 averaged 590 ± 130 µg/m3 . Smoke levels near biogas stoves were measured at 310 ±140 µg/m3 . The stoves used in this study reduced the quantity of wood used for plucked chicken production by a factor of 6. This reflected a reduction in energy otherwise wasted around the pot in the inefficient traditional cooking method. Stove use reduced the solid waste as well as the smoke accordingly. If a stove lasted 3 years, the vendors would save an estimated R33 700 on fuelwood in case they used harvested wood, and if wood waste is used, the fuelwood savings over three years would be R6 300. It was estimated that 100 kg of slaughtering waste dumped every day could generate enough biogas for 7 vendors to be provided with enough thermal energy for their catering trades. Based on the experimental work conducted, it was calculated that a digester of a size of 76 m3 would be needed for this amount of slaughtering waste. The main conclusions of the thesis are: • Cleaner technologies, in the form of efficient wood stoves and biogas reactors and stoves, showed significant saving potential in the informal roadside food and drink production processes investigated in Nyanga, Cape Town. • The wood stoves investigated in this study were suitable for chicken plucking (which use 25 L pots) but not for the mashing stage of umqombothi preparation (which is done in 230 L drums). • The use of these stoves resulted in a 6-fold reduction in wood burned, as well as an 8-fold reduction in particulate air pollution in the workplace. These stoves also offered a very fast payback time (of the order of a few weeks) and significant fuel wood cost savings to caterers. • Biogas stoves were the cleanest of the three methods compared and should be affordable to caterers if a reasonably priced gas supply were available, but the biogas reactor installation represents an infrastructure investment that could not be paid for by the caterers. • A biogas intervention would ensure the reduction of slaughter waste, which is often indiscriminately dumped and thus a significant health hazard. The main recommendations of the study are: • Since wood stoves would offer fast payback times for fuel wood using traders, the local economic development section of local government should aim to stimulate and develop local business to provide such stoves to caterers. • While the slaughter waste can be used as a substrate for biogas generation, for it to become available to the vendors, local government should invest in this as a form of urban infrastructure. • Slaughtering facilities should be built for the vendors where the waste can be kept together and may be used by the municipalities or other bodies. • Similar studies in other developing countries are also encouraged, so as to develop the specific insights on the affordability of achieving benefits to society in terms of public health, climate change mitigation and food security worldwide. Enough time should be allocated for research that combines social interactions in the field with scientific measurements.
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    Life cycle sustainability assessment of next generation energy infrastructure in Africa: Is there a case for biohydrogen after biomethane?
    (2018) Masilela, Phumlani; von Blottnitz, Harro
    The recovery of energy in the form of biomethane gas from inexpensive biodegradable organic wastes is starting to become a cornerstone of green economy investments. It is possible that such installations could serve as a precursor for the infrastructural development of a hydrogen economy, since biogas processes can be modified to produce hydrogen instead of methane. It is unclear whether such a change would improve or worsen the environmental, social, and economic performance of such waste-to-energy installations. Earlier studies show that the dark fermentation process for biohydrogen production faces several challenges such as low yield and slower production rate. Furthermore, it is unclear whether the biohydrogen production technology offers potential benefits in terms of ecological and socioeconomic sustainability. This study explores the usage of Life Cycle Sustainability Assessment (LCSA) to investigate next generation energy options to support green economies in Africa. LCSA has been advocated by the United Nations Environment Programme (UNEP) to consider the evaluation of all environmental, social and economic negative impacts and benefits in decision-making processes towards more sustainable products throughout their life cycle. This thesis uses LCSA for comparing biomethane versus biohydrogen produced from organic wastes in three settings: agro-industrial processing, represented by brewery wastewater; urban, represented by the organic fraction of municipal solid waste (OFMSW); and rural, represented by cattle manure. In each setting, two end-uses of both fuels are considered, viz. electricity generation (combined heat and power (CHP) systems vs. fuel cell (FC) systems), and as vehicle fuel (compressed natural gas (CNG) vehicles vs. fuel cell (FC) vehicles). According to published information on biogas yields of the substrates (i.e. brewery wastewater, OFMSW, and cattle manure), biomethane achieve a significantly higher energetic yield than biohydrogen estimated at 9.0, 10.5, and 9.7 MJ/kg of volatile solids (VS) for the case of biomethane, and at 4.8, 1.4, and 0.9 MJ/kg of VS in the case of biohydrogen, for the three substrates respectively. This difference in energetic yields significantly impacts on all further sustainability performance of the fuels. Nevertheless, an LCSA comparison was constructed, combining environmental and social life cycle assessment with a life cycle cost calculation to present the overall sustainability performance index of the results. The results show that for the urban setting (exemplified by OFMSW), the application of biomethane in CHP systems provides the highest sustainability performance index (SPI) value estimated at 1.90, while that of vehicle operations in CNG vehicles stands at 1.83. For biohydrogen, the recovery of energy from brewery wastewater in the agro-industrial setting (exemplified by brewery wastewater), the application of biohydrogen in the FC systems commands the SPI value of 1.75, but the vehicle operation in the FC vehicles records a much lower performance value of 0.90. The results clearly indicate that the biomethane technology for the electricity generation offers the most sustainable performance outcome when compared with the biohydrogen technology for the electricity generation which stands at 1.90 and 1.75, respectively. In the case of vehicles operations the application of biomethane in the CNG vehicles records much higher sustainability performance index value when compared to FC vehicles which stands at 1.83 and 0.90, respectively. In the agro-industrial settings the application of the biomethane in the electricity generation systems is equal that of the application of the biomethane in the vehicle operations in the CNG vehicles, which stand at 1.73. In the case of the urban settings the application of biomethane in the electricity generations provides higher sustainability performance index value when compared to the vehicle operations in the CNG vehicles which records the value of 1.90 and 1.83, respectively. In rural settings (exemplified by cattle manure) the application of biomethane produced from cattle manure in CHP systems records high SPI value of 1.75, but application in the CNG vehicles records the SPI value estimated at 1.68. The outcomes of the study thus show that the generation and use of biomethane in all selected settings promises a better sustainability performance, when compared to biohydrogen. Agro-industrial settings, in particular, seem to be very well suited for biohydrogen production, and there is no strong case for the application of biohydrogen technology in both the urban and rural settings. It is observed that the life cycle cost performance is significantly influenced by the application of the fuel (i.e. either in electricity generation, or as fuel for vehicles), and not only by the type of technology implemented (i.e. anaerobic digestion vs. dark fermentation process). Clearly, decision making for implementation of a particular technology requires a sound decision on the demand of a particular fuel type, end application of the fuel and also the type of the technology implemented. It has been reported that the energetic efficiencies in fuel cells for electrical energy generation has reached the efficiency of approximately 80%. The results of this study demonstrate that biohydrogen application for electricity generation seems to be promising for application in agro-industrial settings. This setting has access to skilled technicians required for the operating of the biohydrogen production technology, and also the economic power for the implementation of the biohydrogen technology. Often the implementation of the biomethane technology in the agro-industrial settings is to advance economic savings that result from the installations of the biogas digester. Thus, the private sector can either directly or indirectly play a crucial role in the research and development for the next energy generation infrastructural development. The social aspects need to be considered when analysing the potential role of different energy technologies for sustainable development. Actually, people are accustomed to infrastructural development of biogas installation in rural areas when compared to the biohydrogen technology. The social performance in such settings is faced with serious challenges regarding the level of education among the people and availability of human capacity in terms of skill development for the implementation of the proper infrastructural development. In rural areas, there is a need to effectively pay attention to various stakeholders. It has been reported that in certain instances the energy generation technology can come to a halt if proper stakeholders and community leaders are not well informed about the plan to implement new energy generation technology. This thesis thus demonstrates how UNEP’s call to consider environmental, social and economic dimensions of new developments can be interpreted, with a special focus on technological advancement in energy production systems. The energy sector in Africa faces enormous twin challenges of making a leading development contribution whilst respecting environmental sustainability imperatives. This thesis provides realistic solutions and advice for policy development of implementation of renewable technological options in three types of African settings. In respect to the development of the methodological approach for assessment of energy production systems, this study specifically contributed through developing a stakeholder analysis. The stakeholder analysis presents the framework for mapping of relevant impact indicators across the three dimension of sustainability analysis, for the production of gaseous energy carriers from organic wastes. The approach shows how different participating parties, such as government, companies primarily in the energy sector, end users (domestic users), and non-governmental organizations (NGOs) can collaborate and clearly understood impacts in the three dimension of sustainability. Furthermore, this developed stakeholder analysis within the context of LCSA has a role to play in the policy development by creating awareness between government, energy users and energy companies during energy technological innovations. The stakeholder analysis developed in this study was shown to help determine the social indicators within the context of LCSA. In summary, while hydrogen may soon be applied as an energy carrier in practice, this thesis shows that as long as biohydrogen yields remain much lower than biomethane yields, there is no strong case for admitting biohydrogen technology in both urban and rural settings. At the moment it remains possible that biomethane infrastructural development could serve as a precursor for the infrastructural development for the biohydrogen technology in the agro-industrial settings.
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    Reducing the carbon footprint of the University of Cape Town: an energy systems approach
    (2024) Gabin, Matthew; von Blottnitz, Harro
    Universities are uniquely positioned to play a significant role in forging pathways to a sustainable future. As many of society's challenges are reflected in university systems, these can serve as useful testing grounds to inform interventions, such as emissions reduction strategies. As the University of Cape Town (UCT) has committed to several environmental sustainability goals, this dissertation investigates greenhouse gas emissions reduction pathways for UCT through an energy systems approach by constructing an energy systems simulation model to represent the institution's various proposed decarbonisation plans. The research built on UCT's series of carbon footprint reports and its proposed sustainability plans, focusing on electricity usage which required detailed data collection. This involved engaging with multiple stakeholders at different levels in order to construct an energy systems model on the LEAP (Long-range Energy Alternatives Platform) software. This dissertation specifically uses the LEAP model to conduct a scenario analysis on UCT's emissions reduction plans, while considering the drivers of the institution's energy demand. This dissertation assesses three scenarios and their impacts with regards to UCT's Scope 2 emissions: Scenario 1 studies the impact of the national grid decarbonising, Scenario 2 the impact of on-site electricity generation from solar power and, Scenario 3 the impact of implementing energy-efficiency measures to reduce the institution's overall energy demand (where each scenario is built on its predecessor). The results of the study found that the institution relies heavily on the national grid decarbonising to reach its sustainability commitments. Expected decarbonisation of the national grid could result in the institution's Scope 2 emissions being reduced by 7.5% by 2030 but accelerating thereafter for a reduction of 91.4% by 2050 (relative to 2019 emissions). In comparison, Scenario 2 would result in the institution's Scope 2 emissions being reduced by 15.1% by 2030 and growing to 97.6% by 2050 (relative to 2019 emissions). Finally, Scenario 3 would result in the institution's Scope 2 emissions being reduced by 24.5% by 2030, and by 97.9% by 2050 (relative to 2019 emissions). This dissertation found that, with the current proposed decarbonisation scenarios, that UCT is able to significantly reduce its Scope 2 emissions, but the window for meaningful own action is short-term as much of the expected reduction post 2030 is GBNMAT001 END 5069W iii from measures not implemented by the institution itself. A leading university should be leading, and not lagging society. The insights from this study have demonstrated the impact of scenario analysis on informing emissions reduction planning and importantly, provide a strong foundation in the amalgamated data sets on which future modelling work can be built.
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    Resource intensity trends of ferrochrome production in South Africa
    (2020) Dlamini, Reuben Mkhuleko; von Blottnitz, Harro
    South Africa owns more than 70% of the world's known chromite reserves. Chromite has historically been the most feasible source of chromium suitable for ferrochrome production, which in turn is an essential raw material for stainless steel production. Stainless steel has a myriad of applications in modern society. The South African ferrochrome industry was developed on the foundation of abundant raw material; historically cheap electricity and labour; and investment into industry research and infrastructure. The industry, like other mineral industries, has made a significant contribution to the socio-economic development of South Africa. The South African government, through the Department of Mineral Resources, has drafted a mineral beneficiation strategy that is focused on developing the downstream industry to leverage the abundant mineral resource for prolonged and increased benefit to the South Africa. Yet while the ferrochrome and stainless-steel value chains have been identified as strategic, their mining and processing is resource intensive and a significant contributor to emissions that have the potential of causing environmental degradation. In order to have meaningful engagement between stakeholders, there must be reliable information. This has resulted in the development of sustainability indicators to facilitate engagement. Of the various types of sustainability indicators, resource intensity, which is the ratio of the resource used to the unit product, was selected for this study. This was because resource intensity trends can be used to show the effects of environmental constraints quantitatively and qualitatively, such as ore grade and the effects of technological innovation on processing a mineral resource. In this way, decisions can be made regarding the environmental impacts and the technology required to mitigate these. From a review of similar studies, it was found that approach for a similar included gathering data from mining company reports and, where possible, collaborating with companies. These data were then compiled to identify trends showing whether industries have improved in certain aspects. The causes of those variations were also reported in conjunction with the trends. In certain instances, expert insights were used to support the investigations. Most studies found that ore grades gradually decline, which increases input into the industry. However, technology improvements and improved process improvements have the potential to mitigate the effects of these declining ore grades. This observation informed the development of the hypothesis for this study, which is that process and technology improvements could avert an increase in resource input when an ore grade declines. The methodology adopted for this study included compiling resource intensity trends from publicly available sources over the period 2007-2017 (and on one occasion data were shared by a ferrochrome producing company), mapping major industry projects over this period, and conducting interviews with eight industry experts to verify trends and establish the impact of technology choice in relation to observed resource intensity trends. It was assumed that the quality of the data was uniform and of a sufficiently high quality for comparison and analysis. Although ore grade trends could not be obtained, it was inferred that ore grade is decreasing. This is due to increased usage of Upper Group 2 (UG2) seam chromium concentrate, which has a lower grade than the conventional higher ore grade, Lower Group 6 (LG6), or Middle Group 1 and 2 (MG1/2) seam ore. Moreover, the chrome source raw material quality used in ferrochrome production was found to be improving with the advent of pelletising and sintering technology, which makes it possible to use UG2 ore. This technology increases the durability of the ore, which also improves the efficiencies. This has led to the development of industrial symbiosis, whereby platinum group metal (PGM) producers generate UG2 tailings, which are sent to co-located ferrochrome producers to produce chromium concentrate. Chromium concentrate forms part of the raw material to produce sintered pellets which are used to produce ferrochrome. Electricity intensity was also observed to decrease over time due to improvements in process energy integration. The increased application of closed furnaces allows the use of flue gas from smelting for combustion to generate electricity and heat transfer of the hot gas to be used to heat up other process streams. The addition of a prereduction increased energy efficiency, in addition to improving ore efficiencies, collectively reduced the electricity requirements. Furthermore, the increased use of chrome sintered pellets has contributed to the decline in electricity intensity. Water intensity trends could not be conclusively determined due to evolving water accounting. It was inferred that if the water accounting remained constant from when it was reported to change, the water intensity was also decreasing. This has been attributed to increased water efficiency investments such as increased paving of water canals to increase recycling. Reductant intensities could not be confirmed as there were insufficient data to draw the trends and consequently review them. It was mentioned that new Glencore proprietary furnace technology has reduced the requirement of expensive coke reductant. The impetus of most of these projects was remaining profitable. The continual increase in the price of electricity in South Africa has propelled ferrochrome producers to reduce their electricity usage, as electricity accounts for up to 50% of ferrochrome production costs (Pan, 2013). Legal compliance has also motivated some technology implementations. For instance, in preparation for the carbon tax, manufacturers reduced their electricity use and started to increase the combustion of carbon monoxide off-gas from smelting for electricity production and other applications such as heat integration and prereduction. There has also been an increase in awareness of climate change and greenhouse gases, and the need for more responsible and sustainable mineral processing. The public perception of a company can significantly affect its profitability, with environmental protests affecting operations and consequently profits.
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    Stakeholder collaboration and learning during the concept design phase of an urban biogas project
    (Energy Research Centre, University of Cape Town., 2010) Melamu, Rethabile; Boyd, Anya; Wlokas, Holle L; Roden, Brett C; Austin, Greg; von Blottnitz, Harro
    Anaerobic digestion (AD) of organic matter to produce biogas is a waste management option for waste streams high in organic matter which are unsuitable for thermal treatment. In Africa, the implementation of this technology is slow compared to developed countries, more so in the urban areas in contrast with rural areas. An understanding of factors behind the low rate of implementation of this technology is needed. As a response to this challenge a research group at the University of Cape Town (UCT) set-up a multi-disciplinary team to implement a biogas digester on the UCT campus as a demonstration project. This paper aims at documenting notes on stakeholder collaboration and learning during the concept design phase to implement an urban biogas project. One of the findings of the project thus far is that a significant proportion of time needs to be dedicated to establishing key stakeholders and decision makers. Education, training and good relationship with stakeholders and the technology provider were also found to the important in the concept design of the project.
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    The TCLP and its applicability for the characterization of worst case leaching of wastes from Mining and Metallurgical operations
    (Elsevier, 1999) Cohen, Brett; Lewis, Alison; Petersen, Jochen; von Blottnitz, Harro; Drews, S C; Mahote, S I
    Laboratory batch extraction tests, such as the Toxicity Characteristic Leaching Procedure (TCLP), are widely used to classify industrial solid wastes destined for disposal in landfills. Whilst the ease and speed of such tests makes their use an attractive option, it is also immediately clear that the physical and chemical mechanisms dominating in such tests do not bear much resemblance to those expected in a landfill situation. Neither can tests of such short duration be expected to identify long term effects which, if present, are likely to dominate leachate generation behaviour once the waste is disposed. This paper discusses the mechanisms involved in leaching. A series of tests on a metallurgical waste (an EAF dust) is reported which aimed to identify the appropriateness of the TCLP in characterising worst case leaching for this type of material. The results are discussed together with some more theoretical aspects of leaching to assess the applicability of the TCLP for wastes from the mining and metallurgical operations. It is concluded that some of the physical and chemical parameters defining the TCLP require some flexibility in order to create adequate worst case scenarios for each particular waste material.