Editor's Choice


The thermal combustion balancing act

April 2025 Editor's Choice

From carbon taxes to export tariffs, cost containment to security of supply and sustainability, companies are under increasing pressure to switch to greener fuel sources. Associated Energy Services (AES) warns that this pivotal change has some potentially serious knock-on effects.

For commercial director, Dennis Williams and projects director, Gavin Evezard, legal drivers and corporate head office decisions may initiate the process, but a fuel source switch needs to be case-specific. The plus side to this is that carefully considered upgrades, such as the kind which AES manages for its clients, will result in more effective combustion and better fuel efficiency. They will also enhance productivity and even relationships with communities in areas surrounding clients’ operational sites, ultimately future-proofing their energy plant. However, options must always be logistically and financially viable.

Williams and Evezard note that global commitments made by South Africa in terms of climate change tend to centre on ‘big business’ rather than on companies further down the supply chain, which are typically under immense pressure to contain costs and manage risk. These businesses are constantly juggling the demands of various stakeholders – government, investors, employees and even decision makers at a multinational level – but will ultimately have to confront the thermal combustion and fuel source conundrum head-on.

Not all biomass is created equal

Because of the low energy density of biomass, it ironically often emits more CO2 per ton of steam than some conventional fossil fuels. “The use of biomass − timber for example − generates a higher tonnage of CO2 per unit useful energy than coal does, and this is a function of fuel quality (composition, moisture content) and overall thermal efficiency. However, it has been accepted that the carbon in biomass derives from photosynthesis, so it has been removed from the atmosphere and is not CO2 stored in the earth as coal or oil, and it is deemed to be carbon neutral,” Williams explains.

Evezard also notes that the potential opportunity for a switch to biomass is region-specific so there is not a ‘one size fits all’ approach when switching to greener fuels. Technology selection based on the biomass available is critical.

Furthermore, space requirements for storing the more bulky biofuels present an added complication, as does long-term supply and pricing, together with the potential logistics costs associated with their long-distance transportation.

“For industrial thermal applications, the operational cost of a biomass plant may be similar or slightly higher than for a fossil fuel plant. Having said that, the capex required to install that equipment is significantly higher than for an equivalent fossil fuel plant. The maintenance costs are also greater, because of the need for physically larger furnaces and boilers, and more materials handling equipment is required to move four to five times more fuel volume when compared to an equivalent fossil fuel plant,” he continues.

The bigger picture

Alternatives to biomass also come with their challenges. While the capital cost of converting to liquid natural gas (LNG) is lower, accessibility is questionable and the energy costs are high. More cutting-edge options such as green ammonia, green hydrogen and transferring solar and wind energy into a tangible fuel pool are some way down the track. Those looking to change need to consider what is available now.

Overall, Williams says that AES is fuel-agnostic and always aims to operate a plant as efficiently as possible: “Inefficient thermal combustion and energy plant operation has a negative impact on resource use and emissions. Our involvement results in a ‘more output for less input’ approach. A key starting point for clients to consider is that they get a 100% saving for every unit of energy that their process plants do not need to consume. Energy auditing is a good starting point.”

Evezard adds that companies can also look at some ‘low-hanging fruit’ or very accessible energy savings by addressing the issue of equipment that is not insulated, the scheduling of how heat is used, and operational equipment which is not in production and on standby for days or hours.

However, it is sustainable sourcing of biomass which remains the greatest challenge. Locally, large paper companies have installed massive energy plants, impacting on the availability of biomass in significant parts of the country. Consequently, clients who secure their biomass supply early are most likely to benefit, leaving latecomers to find other options.

In addition to monitoring technology and supply developments, AES can leverage its almost 30 years of experience in implementing thermal combustion solutions to provide the best one for each client’s business.

“We are in a unique position, where our substantial collective experience on projects and operations can provide a client with a technical solution and capex offering. We furthermore guarantee the project outcomes when it comes to performance, efficiency, output and emissions. At the same time, we can provide clients with a steam and boiler operations and maintenance service level agreement with ongoing performance guarantees,” concludes Williams.

For more information contact AES, +27 21 532 3381, [email protected], www.aes-africa.com




Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

What’s driving the IE3 motor revolution?
WEG Africa Editor's Choice
The International Efficiency 3 (IE3) motor standard will soon become South Africa’s legal minimum standard, mandating that local suppliers offer more efficient electric motors. What is driving this change, and how does it affect the many industries that rely on these modern electric workhorses?

Read more...
Unlocking the smart factory
ElectroMechanica Editor's Choice Motion Control & Drives
At ElectroMechanica, we recognise that transitioning to smart automation isn’t just about adopting new technology; it’s about solving real challenges. Labour shortages, rising costs and downtime due to outdated machinery make digital transformation essential for long-term competitiveness.

Read more...
Case History 197: Bad reboiler temperature control.
Michael Brown Control Engineering Editor's Choice Flow Measurement & Control
It is very important that reboiler temperature controls operate well in petrochemical refineries, or the product quality can really suffer. I was asked to check such a control in a refinery where they were having problems with one of these controls.

Read more...
The future of industrial automation: fieldbus and industrial networking
LAPP Southern Africa Editor's Choice
As a global leader in integrated solutions in the field of cable and connection technology, LAPP recognises that fieldbus and industrial networking technologies are pivotal in shaping the future of manufacturing and production processes.

Read more...
AI-driven innovations with CCTV and cyber security
RJ Connect Editor's Choice Fieldbus & Industrial Networking
The fast progress of artificial intelligence (AI) and video analytics is redefining the rail surveillance landscape. Advancements have bolstered proactive event detection, predictive maintenance and enhanced situational awareness.

Read more...
Loop signature 27: SWAG tuning of simple integrating processes.
Editor's Choice
The chief control engineer of one of the largest petrochemical refineries in South Africa once sent me an email after a course at his plant. He wrote that he had found the section on SWAG tuning of simple integrating processes one of the most informative of the whole course.

Read more...
Harnessing industrial AI agents for reliable automation
Editor's Choice IT in Manufacturing
The excitement around generative AI (GenAI) has been undeniable, promising wide-ranging changes across industries. However, for those of us in the world of industrial control and automation, the realities of implementing these powerful technologies are a little more nuanced.

Read more...
Futureproof your industrial network security with OT-centric cyber security
RJ Connect Editor's Choice
To achieve digital transformation, industrial operators must first address the daunting task of merging their information technology (IT) and operational technology (OT) infrastructure. In this article, we focus on the importance of strong OT network security and provide some tips on how to strengthen cybersecurity for industrial operations.

Read more...
The symbiotic relationship between OEMs and SIs
Schneider Electric South Africa Editor's Choice System Integration & Control Systems Design
While businesses tend to turn directly to original equipment manufacturers OEMs or vendors when embarking on IT projects, the role of the SI as a key facilitator and partner cannot be overstated.

Read more...
Case History 196: Unstable condensate level control.
Michael Brown Control Engineering Editor's Choice Level Measurement & Control
The operators in a petrochemical refinery were having great trouble in trying to stabilise the condensate level in a vessel, and this was adversely affecting other loops downstream. Several unsuccessful attempts had been made to retune the controller.

Read more...