Where the rubber hits the road: AES puts rubber manufacturers on the road to sustainable energy optimization

For decades, South Africa’s rubber has been a key material used in both mining and the automotive sector. As pressure mounts to tackle energy consumption and optimisation, the intervention of Associated Energy Services (AES), a leading operations and maintenance service provider for the steam and boiler sector, could be a game changer.

AES Regional Manager Gauteng Jordan Smith, and Associate Director Operations Ray Lund – who works closely with rubber belt and tire manufacturers in Gauteng and the Eastern Cape respectively – notes that there is a strong push within and between rubber companies to swap fossil fuels for renewable energy sources.

Steam for vulcanization

Steam plays an essential role in vulcanization, an integral process that is central to the production of all rubber products: from tires and conveyor belts that transport raw materials in mining, to sealing components such as gaskets or protective clothing such as wetsuits or rubber boots.

With the application of steam, raw natural and synthetic rubber (which has the consistency of soft chewing gum) is transformed into its final durable – but also elastic – form.

During the production of the tires, the green tire is placed in a mold into which steam is fed under high pressure. This causes the tire to be vulcanized in the curing machine, where the parts are pressed together, giving the tire its final shape sustainable qualities.

Lund notes that tire production involves strict quality and safety requirements: “This means that proper control of the steam and heat energy is required when a tire is cured.”

A pressing system is used to manufacture rubber tires using steam heating, which provides the pressure and temperature necessary to bond and harden the components.

Smith points out that steam is a consistent heat source: “If the steam temperature drops and does not heat all parts of the plates evenly, it will result in a poorly bonded product that will not provide the required strength and durability. If the temperature and pressure are too high, the belt produced will be too brittle,” he explains.

Steaming towards the future

Although rubber production has changed little over the years, the sector now faces many challenges. Ever-increasing cost pressures – coupled with an industry shift towards greener suppliers – have driven the need for innovation.

“Recently, customers have been switching from cyclically heated presses to continuously heated presses where the plates are not cooled and reheated between batches,” Smith explains.

The condensate generated during the production process can also be recycled, sending water and sensible heat back to the boiler house for reuse.

The biggest change – and challenge – remains the replacement of carbon-intensive fossil fuels.

“With several customers across a range of industries already using biomass, we are in strategic discussions with rubber companies considering a switch to different forms of renewable energy. This cannot be avoided – and involves a significant technological shift,” Lund advises.

When sustainability is a challenge

Rubber manufacturers with global parent companies are at the forefront of this transformation, which involves balancing the social governance obligations of a multinational company with South Africa’s often tough economic challenges. Changes must be carefully managed to ensure long-term sustainability and not put businesses at risk.

Lund explains: “A fuel switch will inevitably require substantial capital investment if customers are to run their plants effectively, efficiently and competitively. It takes a large amount of capital investment to realize those gains.”

He points out that the technology needed to efficiently burn biomass can be more expensive overall, adding that as more companies switch to biomass and demand grows, the costs could also rise.

“Unfortunately, there is a perception that because biomass is waste, it must be cheap. However, we usually find that local companies in the rubber sector experience major difficulties due to the required capital investments and associated costs. Because of their global ESG (economic, social and governance) commitments, their international counterparts are more likely to consider workable solutions,” Smith notes.

A phased approach and an impressive track record

Smith and Lund both support a long-term, phased approach that AES typically recommends to rubber sector clients. This starts with the ‘low-hanging fruit’ of faster gains from optimizing the performance of existing plants and processes – ultimately paving the way for a switch to renewables further down the line.

The phased approach has proven successful: AES has a proven track record of delivering substantial improvements in energy optimization and has helped a rubber sector customer reduce its CO² emissions and coal consumption by as much as 11.03 percent – ​​without capital investments.

Smith attributes this to AES effectively utilizing economies of scale, cost-effectively sourcing the right quality coal and maintenance spares, and individually assessing each customer’s site to determine tailored improvements and savings. In addition, well-trained and operationally skilled personnel available 24 hours a day, 7 days a week are crucial for successfully managing power plant improvements.

“We have the expertise to ensure the best design and operation of the steam crosslinking and power plant at our customers’ sites. Many companies are looking for that extra percentage gain in efficiency, and working with AES is an effective way to achieve that improvement,” he says.

With input costs and energy efficiency – and even CO2 emissions tax savings – the rubber sector can make the much-needed transition away from dependence on fossil fuels, Lund continues.

“We want to encourage companies from the rubber sector to optimize their energy consumption through a strategic partnership with AES. We can ensure that they ‘bounce back’ and move towards energy optimization and sustainability,” he concludes.