Browsing by Author "Von Blottnitz, H"

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    Open Access
    A cleaner production assessment of the ultra-fine coal waste generated in South Africa
    (2007) Reddick, J F; Von Blottnitz, H; Kothuis, B
    The South African coal mining industry is currently disposing of about 10 million tons of ultra-fine coal (<150 µm) per year. Once discarded, these sulphur-containing ultra-fines contribute to several environmental problems. As part of a project initiated by the Water Research Commission to investigate the use of Cleaner Production (CP) in the mining industry, a study was carried out to determine whether a CP approach could be used to identify opportunities to reduce this coal waste, and to determine which of these opportunities would be most feasible. In order to do this, a CP assessment was conducted at three case study collieries in the South African Witbank coalfield. Mass-balancing and sampling, followed by laboratory characterisation tests and site surveys, were used to determine the quantity, quality and sources of the ultra-fine coal at the three collieries. Literature reviews, brainstorming sessions and interviews then followed to generate the CP options. An environmental, economic and technical feasibility assessment was then prepared for each option, to determine the most viable interventions for implementation. A number of opportunities were identified through the assessment. By preventing coarser coal from being discarded with the ultra-fine coal, the quantity of coal disposed of could be decreased at all three collieries, and by up to 24% in one case. Increasing the crusher top size would reduce the amount of coal that is milled to less than 150 µm, so that less is wasted. The ultra-fines that have already been disposed of on slurry dams can be completely reclaimed and converted into a valuable product, which can be sold as power station feedstock. The newly processed ultra-fines could be beneficiated using flotation and exported together with the coarser coal. The results of the assessments thus suggested that workable CP opportunities to reduce ultra-fine coal wastage exist at the sites investigated, and that their feasibility is colliery-specific. The associated financial benefits of the proposed options suggested that CP is a realistic approach to addressing environmental problems.
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    Open Access
    Converting plant biomass to fuels and commodity chemicals in South Africa: A third chapter?
    (2003) Lynd, L R; Von Blottnitz, H; Tait, B; De Boer, J; Pretorius, I S; Rumbold, K; Van Zyl, W H
    There have been two distinct chapters in the history of converting cellulosic biomass to fuels and commodity chemicals in South Africa. The first chapter, fromthe late 1970s to the early 1990s, involved some of the most active research and development efforts of their kind anywhere in the world. Thereafter, during the second chapter, there has been very little activity in the field in South Africa while there has been an unprecedented awakening to the potential of biomass conversion elsewhere. This paper considers the rationale and possible benefits of a potential third chapter based on a revitalized effort on biomass conversion in South Africa. Such an enterprise would build on the country's large biomass production potential, strong technical capability in yeast biotechnology, a well-developed research and development infrastructure in biological processing, and expertise derived from the largest non-petroleum hydrocarbon processing industry in the world. Substantial societal benefits could be realized that address critically important national needs, including the utilization of sustainable resources, industrial development, and improved balance of payments. Moreover, establishing a modern biomass processing industry in South Africa appears to represent one of the largest potential sources of rural employment identified to date.We propose steps to realizing these benefits.
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    Open Access
    Converting plant biomass to fuels and commodity chemicals in South Africa: A third chapter?
    (2003) Lynd, L R; Von Blottnitz, H; Tait, B; De Boer, J; Pretorius, I S; Rumbold, K; Van Zyl, W H
    There have been two distinct chapters in the history of converting cellulosic biomass to fuels and commodity chemicals in South Africa. The first chapter, fromthe late 1970s to the early 1990s, involved some of the most active research and development efforts of their kind anywhere in the world. Thereafter, during the second chapter, there has been very little activity in the field in South Africa while there has been an unprecedented awakening to the potential of biomass conversion elsewhere. This paper considers the rationale and possible benefits of a potential third chapter based on a revitalized effort on biomass conversion in South Africa. Such an enterprise would build on the country's large biomass production potential, strong technical capability in yeast biotechnology, a well-developed research and development infrastructure in biological processing, and expertise derived from the largest non-petroleum hydrocarbon processing industry in the world. Substantial societal benefits could be realized that address critically important national needs, including the utilization of sustainable resources, industrial development, and improved balance of payments. Moreover, establishing a modern biomass processing industry in South Africa appears to represent one of the largest potential sources of rural employment identified to date.We propose steps to realizing these benefits.