Natural gas boilers coming to the fore

As environmental protection pressures increase globally and the quality of coal being supplied to the local market decreases, Johannesburg-based gas reticulator Egoli Gas and one of its technology partners Steam Generation Africa are confident that interest in natural gas as an alternative fuel for boilers will increase in South Africa.

Egoli Gas currently services more than 7 500 customers – including domestic users and central water-heating operators, as well as commercial and industrial businesses – with natural gas from chemicals and petrochemicals company Sasol. The gas is stored at a secure facility in Langlaagte, in Gauteng, and reticulated at Egoli Gas’ Cottesloe premises to end-users. Steam Generation Africa is one of the integral partners in this process, supplying the natural gas boilers required by Egoli Gas’ clients.

Steam Generation Africa MD John Rundle notes that heat recovery boilers are a key area of development in the quest to reduce the release of harmful emissions into the atmosphere. This drive to reduce the environmental impact of industrial processes was advanced internationally in 2015, when the European Union passed a Medium Combustion Plant Directive (MCPD), which was transposed into the national legislation of all member States by the end of last year.

The MCPD limits the release of certain pollutants into the air that result from the burning of traditional fuels at medium combustion plants, which are commonly used in electricity generation and in the provision of heat and steam for industrial processes, as well as those used in residential heating and cooling.

To meet the MCPD requirements, Steam Generation’s UK-based partner introduced a low nitrogen oxide and low noise burner and boiler to international markets last year. “Although this has been manufactured to meet European regulations . . . this cleaner technology will work its way into the local market . . . as companies seek to enhance their efficiencies, reduce their environmental impact and retain their reputations in a competitive global market,” says Rundle.

He explains that the single pass, heat recovery steam-generator range is designed to match commercially available gas engines. The boilers are designed to maximise heat recovery within a compact footprint and each boiler is supplied as a package, fully insulated and clad, complete with valves and pipework to ease site installation. Optional equipment, such as bypass dampers, ductwork and control interface modules, are also available. The standard frame design is between 400 kW and 4 300 kW engines.

The company also offers a composite boiler that is constructed to incorporate heat recovery features and the standard natural gas burner all in one, providing a combined heat power option that provides substantial cost savings. A range of control and auxiliary plant solutions are, moreover, available to support the range.

“The main challenges to promoting natural gas in South Africa are its current price, the difficulty in convincing coal users to convert to using it and the limited distribution network of pipelines currently available. Interest in natural gas and the boilers that are designed to maximise the benefits of the fuel is, however, growing.”

Rundle notes that a key growth opportunity lies in promoting heat-recovery steam boilers that use natural gas generators, combining heat and power, and electrical and thermal energy. The installation of flue gas economisers onto new and existing gas-fired boilers can also increase efficiency and produce significant fuel cost-savings.

Steam Generation completed the supply and installation of two new natural gas boilers, together with flue gas economisers, for a client in Johannesburg in November. Steam Generation Africa will also install a new 5 000 kg/h dual-fired boiler for a client with an existing coal-fired boiler by April.