published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Recently Michelin has been developing a new airless, integrated tire and wheel combination called the Tweel. The Tweel promises performance levels beyond those possible with conventional pneumatic technology because of its shear band design, added suspension, and decreased rolling resistance. However, many questions remain as to what kind of environmental impact this radical new design will have. The environmental impact of the Tweel will be compared to a current radial tire used on BMWs, but because of the complexity in manufacturing, using, and disposing these tires it is somewhat difficult to compare environmental problems. Currently there are environmental issues all throughout a tire's lifespan from rubber manufacturing emissions to tire disposal, and the rapidly growing method to evaluate all of these points is Life Cycle Analysis (LCA). LCA is the essential tool required by businesses in order to understand the total environmental impact of their products - cradle-to-grave. By considering the entire life cycle of a Tweel from manufacturing, through use and disposal, and comparing it to knowledge of current tires, an accurate assessment of the entire environmental impact of the Tweel will be made. Since the Tweel is currently still in the research phase and is not currently manufactured and used however, there are uncertainties with respect to end-of-life scenarios and rolling resistance estimates that will affect the LCA. Thus, it will be important to consider a range of options to determine which one will have the most environmental benefits while still keeping the strengths of the Tweel design intact.

M.Tech. (Chemical Engineering) / Solid waste management is a growing environmental concern in developing countries such as South Africa. Waste tyres fall under the general solid waste category give rise to land filling, health and environmental challenges. As a result, majority of these waste tyres accumulate in large quantities at landfill sites or end up being illegally disposed in open fields. Thus, sustainable remedial technologies such as pyrolysis which are environmentally friendly must be developed. Pyrolysis offers a number of attractive advantages as a treatment option such as the production of primary and secondary economic valuable products, namely pyrolysis gas, oil, char and steel wires. The objective of this work was the development of a business model which includes costing, procurement, installation, commissioning and operating a batch pyrolysis plant in Gauteng, South Africa. In addition this work assesses the environmental, socio-economic aspects for waste tyre derived products. The study objectives were achieved through literature research, site visits, telephonic and personal interviews as well as questionnaires. An order of magnitude costing method was used for the construction of the pyrolysis business model. The model showed that it is possible to operate and sustain a batch pyrolysis plant with a constant supply of waste tyres in the Gauteng region. This research has also shown that a batch plant with a 12 year life span and a projected payback period of approximately 5 years can be operated. However, an initial capital incentive of R 10 173 075.00 is required which includes the cost of all major equipment, plant assessment costs, building and structure, engineering and construction and other costs such as contingency fees and office utilities. Four major income streams are expected to be core revenues for the business; the waste tyre gate fee, tyre derived pyrolysis oil, carbon black and steel wire. Project evaluation methods such as the Return on Investment (ROI), Return of Assets (ROA) and the Rate of Return (ROR) were in strong agreement with those obtained from literature. In addition, the positive net present value shows that the project is viable. However, a stable and well regulated market should exist for the pyrolysis products.

The research work critically analyzed the factors responsible for imprudent waste tyre management in South Africa. As an approach to determine the complexity of the problem, questionnaires were sent to one hundred and sixty (160) respondents in conjunction with interviews. Perusal of literature and interaction with industry involved in waste tyre processing to further gain knowledge of the problem and possible solutions that can be solicited to address the problem. Findings revealed that, lack of clear, focused legislation that guide the handling, disposal and processing of waste tyres remain the challenge. It is also deduced that recycling of waste tyres can provide economic benefits and opportunities. It is recommended that South Africa develop appropriate legislation that deals with handling, treatment and disposal of waste tyres, develop an incentive programme to set up initiatives as well as developing skilled and capacitated enforcement agency. / Environmental Sciences / M.A. (Environmental Management)

The research work critically analyzed the factors responsible for imprudent waste tyre management in South Africa. As an approach to determine the complexity of the problem, questionnaires were sent to one hundred and sixty (160) respondents in conjunction with interviews. Perusal of literature and interaction with industry involved in waste tyre processing to further gain knowledge of the problem and possible solutions that can be solicited to address the problem. Findings revealed that, lack of clear, focused legislation that guide the handling, disposal and processing of waste tyres remain the challenge. It is also deduced that recycling of waste tyres can provide economic benefits and opportunities. It is recommended that South Africa develop appropriate legislation that deals with handling, treatment and disposal of waste tyres, develop an incentive programme to set up initiatives as well as developing skilled and capacitated enforcement agency. / Environmental Sciences / M.A. (Environmental Management)