Energy solutions company Novo Energy has launched a R130-million large-scale natural- gas compression facility at the Highveld industrial park, in eMalahleni, Mpumalanga.

CEO Andri Hugo said the facility, which opened earlier this month, would play a significant role in helping to address South Africa’s power constraints, while also reducing carbon intensity.

“South Africa is a coal-based economy, with about 77% of electricity generated from coal and a large portion of transport fuels derived from the same source. Add to that the large percentage of industrial processes that use coal and you have an entire industrial sector built around cheap coal and electricity.

“But we depend heavily on imported resources for our hydrocarbon supply and this has resulted in exposure to international energy supply uncertainty, issues of reliability and price volatility,” he pointed out.

He added that, although South Africa’s gas market was small, accounting for only 3% of the energy mix, the inherent benefits had the potential to change the economy by stimulating economic growth, development stability and job creation.

“Natural gas will play an important role in our energy mix through power generation, thermoindustrial applications and transport and the vast natural-gas discoveries on the continent will provide the key to unlocking our gas economies,” Hugo asserted.

Novo business development manager Justin Austin, meanwhile, said natural gas was the simplest hydrocarbon available, making it suitable as a feedstock for fertilisers, plastics and energy applications.

Natural gas could also be used as a heating fuel for industrial, commercial and residential applications, steam generation and direct heating applications, natural- gas-run vehicles and power generation, he pointed out.

The eMalahleni gas compression station is Novo’s thirteenth – and its largest – such facility.

Austin said the most important application for natural gas going forward would be for power generation in remote locations, especially for remote mines that did not have grid accessibility and were using diesel as an energy source.

The Facility
The eMalahleni plant, which took less than six months to build and will operate 24 hours a day, seven days a week, is a fully automated site with substantial compression capacity and access to very large gas supplies – Sasol’s natural-gas pipeline feeds the plant.

Novo describes the facility as a gas aggregation hub that has a unique configuration of compressors and loading facilities capable of rapidly loading the Novo logistics fleet.

It also has the ability to refuel vehicles on site.

“The site is a national key point, so we eliminate supply interruptions when there is no electricity and a lot of redundancy has been built into the site on all the components from a compression and loading point of view . . . and, because of this, we can always make sure there’s no interruption to our customers should there be equipment failure or anything go wrong. We have also made provision for generator tie-in in the future,” said Hugo.

He added that Novo built this facility to meet the growing demand for compressed natural gas (CNG), as well as to supply customers who were not on an existing gas pipeline.

“As a gas aggregation hub, we can receive gas, process the molecules and manage the logistics of getting the gas to our customers. From mines to bakeries, factories, hospitals or a fleet – we deliver the CNG to our customers’ sites by road. Our gas packs installed on trailers are then fed into either a factory or a fuelling station.

“Many businesses across various industries have never had access to a natural-gas pipeline and have been restricted to the use of coal and refinery products that are dirty and expensive.

“Because of the new infrastructure, we can help them make the switch to natural gas – a cleaner, more sustainable alternative energy [source] that is half the price, and we can distribute gas anywhere in the country.”

Hugo said the gas aggregation hub had been structured to provide flexibility in the future so that the eMalahleni site could receive gas from any other source – not just a pipeline. The company could then distribute to customers in compressed form or even as liquid natural gas.

Through its customised offering and ability to supply CNG to industrial, mining, pharmaceuticals, agricultural, food and transport customers to meet their requirements for heat, steam, power generation and cleaner fuel for transportation, Novo aims to strengthen energy security, revitalise the economy of Mpumalanga and play an important role in environmental-impact reduction.

Compression Process
Gas is supplied to the Novo plant through a pipeline from the gas reticulation network at the old Evraz Highveld Steel plant – where the Highveld industrial park is now located – to an inlet meter station at the Novo compression system.

Thereafter, the gas is compressed to 250 bar with a four-stage reciprocal compressor through a priority filling valve, which fills the buffer storage cylinders in sequence.

The priority valve will also allow the compressor to fill the gas trailer packs up to 250 bar.

The CNG is stored in a buffer storage system so that it can make use of the compression station more efficiently. CNG is stored at high pressure in the buffer storage tank reservoirs.

The buffer storage volume is used for refuelling the lower-volume customers, such as for vehicles, and is designed to be large enough so that the compression equipment requires fewer starts between refuelling.

For truck bay dispensing, gas is drawn from the buffer storage cylinders through the dispenser in sequence. Once the gas trailer pack is connected to the dispenser and the filling starts, the dispenser will automatically draw gas from the buffer storage until the pressure in the gas trailer packs is the same as the buffer storage pressure, at which point the compressors take over to top the gas trailer packs up to 250 bar.

For vehicle dispensing, gas is drawn from the buffer storage cylinders through the dispenser in sequence. Once the vehicle is connected to the dispenser and filling starts, the dispenser will automatically draw gas from the buffer storage until the pressure in the vehicle storage reaches 210 bar. If the storage is insufficient to fill the vehicle to 210 bar, the compressor will come on line and top up the vehicle to the required pressure.