Power generation through Waste Heat Recovery for international manufacturer

Case Study

The project

Load shedding, unreliable power supply and increasing electricity costs, all realities that businesses in South Africa must endure, were some of the key factors in a decision made by an international manufacturer to consider generating their own power using natural gas.  

The client believed that Energas Technologies, as a leading supplier of high-end and specialised equipment to the oil and gas industries in sub-Saharan Africa, was the ultimate choice to deliver a complete turnkey natural gas power plant. So why is this?

Our proven ability to offer turnkey solutions was to our advantage and the core competence of Energas is finding and implementing engineering solutions in the energy and natural gas industry. We specialise in solving engineering challenges in collaboration with our long-term consulting partners and trusted equipment suppliers and this team would face a significant challenge with this project.

The challenge

The supply of the required plant would entail the supply and installation of a new gas reticulation pipeline; gas engines (gensets); a new gas-fired steam boiler; a waste-heat boiler which will use exhaust heat from the engines to produce steam; interconnecting piping; a new gas engine building and associated electrical infrastructure. 

The solution

Heat recovery from engine exhaust gas made this a very interesting project. Usually, the heat is discharged into the atmosphere. But the efficiency is significantly increased if the exhaust gas can be used.

The client operated a coal-fired boiler which was replaced with a waste heat steam boiler. When more steam is required than what can be recovered, the additional steam is supplied with gas as a fuel source. The waste heat boiler is a combination boiler; it works by recovering energy from the exhaust heat and also has a gas burner. When the waste heat boiler is being serviced or the engines are not working there is a standby gas boiler to ensure a continuous supply of steam to the plant. 

Additionally, having four smaller engines (4x 500 kW) instead of a single large engine (1x 2 MW) allows for continuous power supply to the plant. When one engine is serviced, the other three can still operate. Or if the plant’s usage is low one or two engines can switch off while the other operates at a higher and more efficient load.

The outcome

The gas pipeline takes gas from a new high-pressure customer metering station which has been installed in a new building that we supplied. The exhaust heat from the engines is used in a waste heat boiler. This free steam will result in a substantial annual saving on the gas bill. 

Projections show that a substantial saving can be realised, compared with importing electricity from the grid, in the first year of operation and the accumulated saving over 10 years, based on inflation and price assumptions, is substantially more than the project value. 

With the equipment offered, we and the supplier can monitor various engine parameters to ensure optimum efficiency of operation. Very few plant operation and maintenance staff are required to oversee the gensets and steam plant. We are convinced that the solutions provided reduce the overall energy cost to the customer, meet environmental requirements and ensure efficient operation. 

You too can benefit

As this case study is a testament to the documented benefits perhaps your businesses should also consider the natural gas energy route. We firmly believe that several industries can benefit from their own power generation with natural gas. It will reduce energy costs and make them more independent from the grid, especially when combined with heat recovery. They can save millions of rands over a few years and ensure that their production is not affected during load shedding. Why should this not be your business?

Arrange a no-obligation consultation with us and start using power generation through Waste Heat Recovery to your advantage too.