Reduction in air pollution using the ‘basa njengo magogo’ method and the applicability to low-smoke fuels

Abstract

The then Department of Minerals and Energy (DME) piloted the top-down Basa njengo Magogo alternative fire ignition method at Orange Farm dur-ing the winter of 2003. In total, 76% of households reported less smoke in their homes, while 67%reported less smoke in the streets after one month of using the method (Palmer Development Consulting, 2003). Work by Nova (Schoonraad & Swanepoel, 2003) in eMbalenhle (actual environ-mental tests) indicated up to a 60% reduction in smoke compared with the conventional method of bottom-up ignition. To support the findings of the environmental studies, the CSIR were appointed by the DME to conduct an experiment under con-trolled laboratory conditions to gather quantitative data on the reduction in particulate emissions asso-ciated with the Basa njengo Magogo method of lighting coal fires. The CSIR was further contracted to assess whether the Basa njengo Magogo technol-ogy was viable with low-smoke fuels.
The experiment was conducted using traditional D-Grade coal in both the conventional bottom-up and the Basa njengo Magogo ignition techniques. Three low volatile fuels were also assessed using the Basa njengo Magogo method namely:

•    Anthracite (volatile content of 10.6%)
•    Anthracite (volatile content of 12%)
•    Low volatile coal (volatile content of 20.8%), from Slater Coal in Dundee.

All four fuels using the Basa njengo Magogo method recorded similar times of between 11 and 13 minutes from ignition to the fires reaching cook-ing temperature. The bottom-up fire for conven-tional D-Grade coal reached cooking temperature after 55 minutes.Particulate emissions from all the Basa njengo Magogo fires were similar and up to 92% lower in particulate emissions than that of the D-Grade coal in the bottom-up fire. SO2 emissions from the two D-Grade coal fires were the lowest and were identical. The highest SO2 emission resulted from the low volatile coal. The method of lighting the fire does not have a significant effect on the SO2 emissions. The Basa njengo Magogo method of ignition uses approximately 1 kg less coal to reach cooking temperature than the traditional bottom–up method. At a cost of approximately R1.00 per kilo-gram of coal, this translates into a cost savings of approximately R30 per month.