Engineers face increasing pressure to manage and utilize waste (whether of animal, human or municipal origin) in a sustainable way. We suggest that a solution to the problem of organic waste in rural communities lies in their being able to convert it to biogas technology. This would offer smallholders and farmers a long-term, cheap and sustainable energy source that is independent of the national electricity grid. However, although the technology involved in making biogas from waste has already been fully developed, there are obstacles impeding its adoption. First, there is a general ignorance about this source of energy among the very people who can most benefit from using it. Second, at present, South Africa has no regulatory framework to support the installation of biodigesters. The research focused on the current gap between knowledge and need. The two objectives were raising general awareness of the many and varied benefits that biodigestion can offer, especially to rural communities, and demonstrating how it works. Using science events as a platform, the team introduced the concept of biodigestion, its functioning and uses, to their audiences, and then invited informal responses, which were recorded. The second stage, the case study, entailed the setting up of a small-scale (10 m3) household biodigester in the Muldersdrift community in Gauteng, South Africa. It was put into operation, using fresh cow dung as the feed. Members of the community were invited to watch every step of the process and afterwards were asked to participate in a more formal survey, which sought their opinions on whether biodigestion offers a power source the individual farmer could (and would) use. The results presented in this paper were derived from a comparison of the ‘before-and-after-installation’ responses of the persons interviewed. We found that the members of the Muldersdrift community who had been involved in both phases of the case study (explanation followed by experience of a hands-on educational example) had become more willing to adopt the technology. The results justified our contention that, to ensure a greater adoption of biogas technology in South Africa, it is necessary to provide targeted communities with educational programmes and exposure to pilot plants.

This research explains the conversion of waste tobacco stalks into nitrocellulose to try to recover as much chemical potential contained in the biomass material as possible. Simple pioneering experiments were conducted using pulping tobacco stalks with a moisture content of 10.17 wt% and the soda pulping method being applied to produce cellulose pulp. The cellulose pulp was bleached using calcium hypochlorite to produce a dry white lignin-free pulp, which was subjected to nitration. The mixture used was 67% nitric acid and 98% sulphuric acid, and the acid ratio was varied between 3:7 and 7:3 v/v. Nitration time was varied between 5 and 25 min. This process produced nitrocellulose with all the various conditions. The nitrocellulose obtained with nitrogen content between 11 – 11.5% v/v was characterized using its solubility in acetone. An optimum nitrating mixture of 1:1 v/v with a nitration time of 5 min was used to produce nitrocellulose from tobacco stalks using soda pulping. The results show a great potential for tobacco farming countries to reduce their nitrocellulose import bill using this process.

A fundamental understanding of the precise reduction reaction pathway of cobalt-based catalysts is a crucial piece of knowledge in terms of the Fischer–Tropsch Synthesis (FTS) reaction. The use of hydrogen (H₂) as the reduction agent results in a two-stage reduction of cobalt tetraoxide (Co₃O₄) to cobalt oxide (CoO) and then to metallic Co. The objective of the present work is to apply the Thermodynamic Attainable Region (TAR) to cobalt catalyst reduction using H₂ so as to gain better insight regarding the thermodynamics of reduction reaction. TAR space diagrams suggest that complete Co₃O₄ reduction is feasible through two reaction pathways. Thus, the observed AR results suggest that the temperature programmed reduction’s (TPR) first reaction peak may be attributed to direct reduction of Co₃O₄ → Co and/or reduction to an intermediate compound Co₃O₄ → CoO. The second peak is a result of the reduction of either of the cobalt oxides to Co (Co₃O₄ → Co or CoO → Co).