Abstract
This thesis forms part of the third ERA-MIN collaboration between Portugal, Poland, Romania, Argentina, and South Africa under the project Charphite. The overall aim of the Charphite project was to determine if char found in coal ash can be used as a substitute replacement for natural graphite in green energy applications, including direct use of char in the electrocatalytic oxygen reduction reaction and the hydrogen oxidation reaction. Ash is a waste product resulting from the combustion of coal. The landfilling or ponding of ash can lead to serious environmental and health concerns, and therefore the utilisation of ash / certain components in the ash is desired. Literature shows that South African coal ash samples (>50 mill ton ash per annum) contain 0.5 to 8 % carbon in ash (chars) and also a significant amount of unburned carbon is associated with carbonaceous shale containing <10 % carbon and >90 % mineral matter. Char in coal ash has a high degree of structural order and can possibly be used as a substitute for natural graphite. The European Union, the United States, and the United Kingdom have all listed natural graphite as one of their raw critical commodities; hence the project has significant merits. Research on producing synthetic graphite from char in coal ash is scarce, with only a limited amount of papers being published as yet. ..
Ph.D. (Geology)