What 10+ years of carbonisation has taught us

From a simple hearth producing biochar and cooking charcoal for developing markets to advanced carbonisation systems that transform waste into biochar, recover heat and cut carbon emissions, Pyrocal’s Continuous Carbonisation Technology (CCT) has evolved over a decade of development, optimisation and operational learning.

Technical Manager Deric Dignon shares what the team has learnt along the way and how the technology has changed for the better.

Q1. What have the biggest improvements to Pyrocal’s carbonisation systems been over the past ten years?

Answer:

Our CCT systems have a greater operational efficiency, are now fully automated and can run unattended for long periods with built-in safeguards and shutdowns in case of an upset. These changes were driven by customer demand for ‘hands-off’ low labour systems, stricter emissions and contaminant destruction requirements and our desire to develop Australian-made equipment that is one of the best globally.

Most of the system is now dedicated either to heat recovery or emissions control, and the sophistication in these sections has increased significantly in the last five years especially.

Q2. How has the range of compatible feedstocks and Pyrocal’s knowledge base evolved?

Answer:

The range of feedstocks tested at our R&D facility in Toowoomba over the past decade is enormous. Starting with nutshells we expanded to woodchips, cotton gin trash, manures, compost overs, C&D-type materials, grains and multiple biosolids types.

We now have a large body of knowledge on what feedstocks can be successfully processed, what the likely biochar properties would be, the heat recovery performance and emissions levels.

This means if a new client comes with a particular feedstock, we have most likely assessed it or something similar and can advise on project viability and expected outputs.

Q3. How has system uptime improved?

Answer:

Operational uptime and reliability have increase significantly especially as we have a strong handle on one of the biggest causes of downtime: feedstocks. Our team knows which feedstock parameters matter, how to assess them, and how they impact stability and uptime. These critical learnings have come from running our own biochar facility, extensive R&D trials and a long-term commercial operation at our facility for Logan Water.

Q4. How has the way temperature, residence time and oxygen are run changed over time?  

Answer:

The main evolution has been precision of control. We can now deliberately manipulate biochar properties by adjusting operating temperature in the hearth to target the characteristics a customer wants.

Operating temperature in the thermal oxidiser can also be tuned to improve emissions control or increase heat recovery.

The benefits are that you get tailored biochar properties, stronger compliance and efficiency and overall, a more predictable and bankable outcome which supports approvals, business cases and long-term O&M planning.

Q5. For operators, what are the most important things to watch day-to-day?

Answer:

The single biggest factor influencing stability is feedstock characteristics and quality. Operators need to focus on monitoring feedstocks and being aware of any changes which may affect plant behaviour.

Q6. How consistent is Pyrocal’s Terix Biochar quality across different feedstocks and sites?

Answer:

Biochar quality is strongly influenced by feedstock, and some properties are inherent and can’t be changed. Our wide trial base has allowed our team to understand what quality to expect from each material and how far operating conditions can ‘tune’ it.

While quality will differ between sites using different feedstocks, stable operating conditions plus tight automation and control mean each individual system can produce very consistent, high-quality biochar.

Q7. What are the key lessons about integrating our systems into existing plants?

Answer:

Our most hard‑won integration lessons come from biosolids projects, where linking with upstream treatment is critical. The Logan Water facility was the main learning ground here, showing that project success depends heavily on how three sections are configured and integrated:

1. Upstream dewatering
2. Upstream drying
3. The carbonisation system

Configuration of these sections has a major influence on operability and uptime for the whole facility so we aim to be as involved as possible in integrating with upstream processes and applying our Logan learnings to ensure operational flexibility and reliability for new projects.

Q8. Has maintenance ease improved over time?

Answer:

Carbonisation of biosolids is inherently maintenance intensive and running our own system in Toowoomba has given us firsthand insight into where we can improve, with a clear emphasis on making maintenance easy and fast.

We’ve focused on two key areas:

• Components: We’ve redesigned wearing parts in high-temperature zones to be modular, longer lasting and light enough to handle by hand, which makes them quicker and easier to replace.
• Heat exchanger: We’ve added access doors so all heat‑exchange surfaces can be cleaned without disassembly, with a target clean down time of about 30 minutes.

These refinements have made our own lives easier and now flow through to our customers and clients as well.

Q9. What have you learned moving from pilot to full scale?

Answer:

By the time we built the Logan demonstration plant, the technology was already close to full‑scale. The early pilots more than a decade ago bridged that gap, but the big step since has been moving from demonstration to long‑running commercial plants, which now validate performance and feed real‑world lessons back into our R&D and design.

Q10. What practical advice would you give a utility, council or grower before starting a carbonisation project?

Answer:

For biosolids projects:

1. Understand your feedstock.
   • Know what you have, how it behaves, and how consistent it is.
2. Understand what thermal treatment entails.
   • O&M requirements for a thermal process are different from a typical water‑treatment plant.
   • Utilities need to appreciate those differences and what they mean for staffing, skills and maintenance.
3. Understand the value of the biochar and how to maximise it.
   • Be clear on markets, benefits and how you will derive maximum value from the biochar.

With the experience that we have gained, we can assist on all three fronts: feedstock assessment, defining O&M requirements and unlocking the value of the biochar.

For biomass projects:

• The same principles apply (know your feedstock, know the biochar market), plus:
• Heat recovery is a key source of operating efficiency and ROI.
  • Using recovered thermal energy in existing facilities (e.g. pre‑drying) is important to improve project returns.

Q11. What have you learned about the business case?

Answer:

• Biosolids:

The financial benefits are clear (e.g. disposal cost reduction, energy recovery, certainty of outlet), but this alone has not been enough to drive widespread council and utility adoption. Political and regulatory drivers still matter to address the issue of contaminants such as PFAS, pharmaceuticals and microplastics

• Biomass:

The business case is reliant on a secure, low-cost feedstock supply, a clear route to market for the biochar and a use for the heat recovered in the process.

Q12. Why should waste producing organisations and businesses embrace carbonisation now?

Answer:

The benefits are proven; the available feedstocks are finite and increasingly contested, and early movers who lock in supply and markets will be better placed over the long term.

Carbonisation turns regulatory pressure on biosolids and other wastes into disposal certainty plus new revenue streams for biochar and nutrients whose value is likely to rise, while supporting circular-economy goals and higher-value use of organic waste. It’s just better for the planet, people and businesses.

Q13. What makes you proud to be part of the Pyrocal journey?

Answer:

I’m proud to be part of an incredibly innovative team that has solved tough technical challenges and is now operating at the cutting edge of carbonisation globally, all from regional Queensland while ‘punching well above our weight’ on the international stage.

We’re designing and building equipment in Australia, strengthening sovereign manufacturing in a space that would otherwise rely on imports, and delivering real, practical solutions for PFAS, waste disposal and decarbonisation that Australia can be genuinely proud of.