Building sustainable industries

Professor John Bunt's work focuses on the coal value chain. (Supplied)

Professor John Bunt's work focuses on the coal value chain. (Supplied)

Building sustainable industries that minimise their impact on the environment, deliver maximum value to the economy and make intelligent use of scarce resources is the focus of three Research Chairs.

Professor Thokozani Majozi’s Chair in Sustainable Process Engineering at the University of the Witwatersrand is approaching this subject from a chemical engineering perspective.

His main focus is on ensuring the efficient use of resources by optimising processes in the design phase of projects.

“We have developed mathematical methodologies that provide minimum resource utilisation targets that are then incorporated into the process and plant designs. Resources in this context typically include energy and water, but extend to carbon and waste water emissions,” says Majozi.

Research conducted by the Chair has used mathematical modelling to explore the efficiencies that can be achieved in power generation plants. He explains that this has consisted of investigations into Integrated Gasification Combined Cycle (IGCC) technology that could substantially improve the output of power plants.

This would have significant advantages for Eskom, because the models indicate that the efficiency of power generation can be pushed from the current 35% to as much as 50% using the same quantity of coal. Eskom currently uses open gas cycle technology in some of its plants, which would benefit from adopting the techniques that his research has shown to be both viable and responsible.

The Research Chair has also been conducting fundamental research into the simultaneous optimisation of energy and water in chemical batch processing plants. Many industries rely on energy- and resource-intensive processes to both heat and cool batch processing production.

The research work has delved into methods that use process integration to optimise the heating and cooling processes and minimise energy consumption and waste water effluent.

Majozi says the outcomes of his research are being applied directly in industry and are expected to impact South Africa’s future competitiveness by applying the optimised designs that place less strain on scarce resources.

The profile of the Chair has also enabled numerous international collaborations that further its depth of study, while building the country’s profile on the international stage.

The Research Chair in Coal Research at North-West University, which Professor John Bunt occupied in 2013, complements this work in that he is investigating the coal value chain and the improvements that can be made in using coal as an energy source.

His research – both fundamental and applied – aims to add value to existing industrial processes, but also to develop innovative new technologies that use catalytic processes which are of global interest.

His research relates to the optimisation of coal resources, including techniques to improve the use of fine coal (previously proven unsuitable for use in coal-fired power generation).

A pyrolysis model has been developed that improves predictions and our understanding of the fixed bed gasification process, which is used  in gasification technologies that produce synthesis gas for liquid fuels and chemicals.

A large part of his current and future research seeks to gain a better understanding of advanced computational chemistry in coal-gas reactions.

In addition, Bunt is looking at the environmental impact of waste from these processes. Apart from investigating cost-effective methods to reduce acid mine drainage, he is researching ways to reduce carbon emissions from coal processes and to add value to waste products generated elsewhere by combining them with waste products from coal gasification.

One exciting area of investigation is into a more affordable way of using fly ash and gasifier ash instead of bauxite in the production of alumina. This would have a considerable impact on industry’s need to import alumina, given the country’s lack of natural bauxite deposits.

Professor Jean-Paul Franzidis at the University of Cape Town is attacking the problem of resource use within the country’s mining industry. Although his Research Chair is titled Minerals Beneficiation, he is concerned less with the narrow definition of value-add than with the entire mining value chain.

He explains that the Chair is investigating both fundamental and systemic research components.

The fundamental research component is concerned with cross-cutting areas that find application across different operations, such as mineralogy, rheology, electrochemistry, computational modeling and particle tracking using radio-active labeling.

The systemic research looks at ways to improve process performance, reduce power and water consumption and waste production, and promote cleaner and safer processing techniques.

The broad scope of this line of work is evident in the field of study that includes mine safety, with the Chair recently graduating its first mine safety graduate.

Franzidis says the Chair has enabled him to grow the scientific and research capabilities available to the industry through graduates’ involvement in this line of work.

A total of 27 post-graduates have thus far graduated through the Chair, with most of them employed in the industry. The majority of these graduates are black and a large number are women.

An important collaboration that has emerged from the Chair’s work is the development of an MPhil programme in Sustainable Mineral Resource Development, in conjunction with the University of Zambia. This programme is not restricted to engineers, and includes additional subjects such as strategic social engagement and environmental stewardship.

Franzidis says the work has also led to co-operation with government structures, including research towards the development of a provincial mineral beneficiation strategy.