Emerging domestic natural gas and helium producer Renergen continues to keep its foot on the gas in South Africa through the development of a zero-emissions solution for cold-chain logistics, in partnership with trailer manufacturer Henred Fruehauf.

The solution uses liquefied natural gas (LNG), which is stored at –162 °C in a truck’s tank and must be brought to an ambient temperature of about 15 °C before being used in the engine.

In getting the gas to an ambient temperature, the cold energy of the gas is transferred to the refrigeration compartment of the truck, consequently providing cooling and reducing the combined greenhouse-gas (GHG) emissions for each truck and refrigeration trailer by up to 96 t/y.

This also results in a reduction of up to 23% on the total fuel bill, compared with trucks using standard refrigeration technology.

The solution, which has been in development for about 18 months, stems from Renergen MD and CEO Stefano Marani and Henred Fruehauf concept manager Eduan Naude’s shared aversion to waste “in any way, shape or form”.

Speaking to Engineering News & Mining Weekly, Marani and Naude describe the solution as “unique”, as it “enables customers to capitalise on the potential for huge savings” financially and environmentally.

Marani says benefits for end-users are twofold: the trucks will use diesel dual-fuel, which is cheaper, while no diesel will be required for the refrigeration component of the trailer.

It is anticipated that the refrigeration solution alone could cut 36 t of carbon dioxide (CO₂) equivalent emissions, and the balance of the 96 t of CO₂ equivalent saved would result from the reduced emissions related to the truck running on diesel dual-fuel.

Marani says end-users will save between R200 000 and R300 000 a year on running costs for each truck, which would formerly have been used to keep the cold-chain logistics running.

Implementing the solution across 100 trucks, therefore, will result in end-users reducing the running costs of their operations by between R20-million and R30-million a year.

“We estimate, conservatively, that you’re saving anywhere from R1.30/km to R1.70/km in your cold-chain logistics, and you’re reducing your total CO₂ emissions from 90 t to 100 t per truck per year,” Marani comments.

About 300 000 trees a year would have to be planted to match the reduction in GHG emissions per fleet of 100 trucks, he reveals.

Local Manufacturing

Naude tells Engineering News & Mining Weekly that the intention is to have the first prototype of the trailer unit trialled and ready to be deployed by mid-2021, with manufacturing soon to follow.

“The intention is to manufacture everything in-house using only South African manufacturers, while limiting equipment imports,” he says, noting that the solution was “specifically designed” for South Africa.

Henred has three local manufacturing plants – in Cape Town, Bloemfontein and Johannesburg – with several others across Africa.

The Cape Town facility will manufacture the LNG trailer solution using a high-speed production line.

Renergen will dispense LNG on the N3 freeway, between Johannesburg, in Gauteng, and Durban, in KwaZulu-Natal, and on the N1 freeway, between Johannesburg and Cape Town, in the Western Cape, as part of a distribution agreement with petroleum refining company Total South Africa.

The announcement of the start of LNG dispensing on the second major transport corridor, the N1, marks a milestone for Renergen in recent weeks.

The LNG filling stations on both these routes will be operational by the start of the third quarter of 2021, says Marani.

Meanwhile, the use of refrigerated trucks along the N1 is what led to the collaboration between Renergen and Henred Fruehauf.

“The innovative collaboration between Renergen and Henred Fruehauf highlights the commitment of both companies to clean energy and showcases what South Africa has to offer the world,” Marani adds.

Renergen’s principal asset is its 100% shareholding in gas company Tetra4, which holds the first and only onshore petroleum production right in South Africa, enabling Renergen to have a first-mover advantage on the distribution of domestic natural gas.

The company’s Virginia gas project, in the Free State, also contains one of the richest helium concentrations (up to 12%) globally.

The natural gas on the site, meanwhile, is very pure, with an average of more than 90% methane, and almost zero higher alkanes, which reduces the complexity of liquefaction. Renergen’s natural gas offers a less carbon- intensive substitute for South Africa’s existing transport fuel, thermal fuel and power.

“We look forward to rolling out this cold-chain solution to our customers across the country and look to other companies globally to begin adopting this innovative technology to reduce the world’s global carbon footprint,” Marani concludes.