AFRICA: Ohorongo turns on the heat

The country’s only cement producer, Ohorongo Cement,  received its first consignment of coal last week, when 30,000 tonnes of coal was offloaded in Walvis Bay.  International shipping and logistics firm Grindrod shipped the coal from Maputo in Mozambique. From Walvis Bay to Otavi, the coal will be transported by rail.

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, approximately 70,000 tonnes of coal will be burned during the course of the next 12 months.

With cement production to commence shortly, this shipment 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 to reduce the 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 the bulk 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 invader bush as coal replacement.  Our tests indicate that we can at the very least replace 75% of coal with wood chips.”

Konzmann explained that the major advantage of burning wood chips instead of coal is the reduction of CO2 emissions into the atmosphere.  Such a replacement of fossil fuels with biogenic fuels translates in the reduction of about 130,000 tonnes CO2 emission per annum.

Konzmann also pointed out that by using invader bush instead of importing expensive coal, a local resource is utilised 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.

Ohorongo Cement claims their N$2.5 billion plant near Otavi is 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% less electricity than traditional plants, with minimal dust emissions and significantly reduced water consumption.