Ohorongo Cement (PTY) Ltd received its first consignment of coal early last week, when 30 000 tons of coal was offloaded in Walvis Bay. International shipping and logistics firm Grindrod shipped the coal from Maputo in Mozambique to Namibia’s main harbour, from where the coal will be transported via rail to the Ohorongo plant located close to Otavi in the Otjozondjupa region.
Ohorongo requires the coal to fire the kiln in which the raw materials limestone, shale, marl and iron are burned to produce clinker at temperatures exceeding 2000 degrees Celsius. To produce the targeted cement quantities of the first year of production, a total of approximately 70 000 tons of coal will be consumed during the course of the next 12 months.
With cement production to commence shortly, this ship ment was eagerly awaited by Ohorongo’s production team. Dr Jürgen Hilger, plant manager of the Ohorongo plant confirmed that construction work on the plant is almost complete. Hilger said: “My team is keen to produce highest quality cement and we are currently preparing everything for production.”
According to Managing Director Hans-Wilhelm Schütte , Ohorongo is analysing ways to gradually replace coal with alternative fuels so as to reduce use of coal and thereby fossil carbon emissions. Schütte indicated that from the start Ohorongo planned to use alternative fuels to replace coal and the Ohorongo plant was specifically designed to provide for this option.
Schütte indicated further: “To confirm that our plant is running at the performance specified by our main contractor Polysius, during the first six to twelve months of production we will only use pure coal in our rotary kiln. After that, we plan to follow the example of our mother company who has replaced more than 80% of coal with alternative fuels such as plastics, municipal waste and even animal carcasses. At this point, we are especially investigating the use of wood chips as coal replacement.”
Mr Tobias Konzmann, project manager of the alternative fuels project, is positive that in the long run thebulk of coal burned at the Ohorongo plant will be replaced by more environmentally friendly fuels: “We are looking mainly at the use of wood chips from encroacher bush as coal replacement. Our tests indicate that we can at the very least replace 75 percent of coal with wood chips.”
Konzmann explained that the major advantage of burning woodchips instead of coal is the reduction of fossil CO2 emissions into the atmosphere. Such a replacement of fossil fuels with biogenic fuels translates in the reduction of about 130 000 tons CO2 emission per annum and contributes significantly to the global effort to combat climate change.
Konzmann also pointed out that by using encroacher bush as fuel in the cement production, instead of importing expensive coal, a local resource is utilized for energy. In addition, a further important advantage of harvesting wood-chips is that Ohorongo might just have found a sustainable solution to bush encroachment in Namibia.
The N$2.5 billion plant built by Ohorongo close to Otavi in the Otjozondjupa region will be the most modern plant in Africa, ensuring production of world class cement with least impact on the environment. Through application of best available technology, the plant uses 30 percent less electricity than traditional plants, with minimal dust emissions and significantly reduced water consumption.
