Thermal-oil boilers

Just like your production process, our thermal oil boilers are one of a kind. Our engineers take your requirements and needs as their starting point to design, build and install a solution that fits seamlessly into your existing installation or into an entirely new production line. And once everything is up and running, we don’t just walk away from your thermal oil boiler installation. Our technicians are there for you 24/7.

Discuss your heat demand

When is a thermal oil boiler the right answer to your heat demand?

Thermal oil systems provide extremely stable temperature control for production processes up to 300 °C – often with variations of just a few degrees or less. That precision matters to processes where product quality depends on a constant temperature.

Thermal oil is mainly used for indirect process heating at high temperatures, for example in reactors, ovens, drying installations, heat exchangers and production processes in the chemical, food, plastics and building materials industries.

Callens Thermische Olie leidingen

Key benefits of thermal oil boilers:

  • Flexible in energy source: the thermal oil can be heated with gas, electricity, biogas, hydrogen, syngas or residual streams.
  • Extensive process control: with a precision of no more than 2°C, your end product gets the quality it deserves.
  • Ready for the energy transition: electrification and alternative fuels make it possible to meet your heat demand sustainably, without compromising on operational reliability.
  • No water consumption: as no feedwater is required, there are no costs for water softening, chemicals or condensate treatment either.
  • High energy efficiency: thermal oil remains liquid throughout the heating process. As a result, there are no energy losses through evaporation, condensate or blowdown, as there are with steam systems. This translates into lower energy consumption and lower operating costs.
  • Widely applicable: thermal oil boilers are widely used in the chemical industry, food industry, asphalt and bitumen production, textiles, wood processing and plastics processing, wherever high and stable process temperatures are required.
  • Increased safety: because the system operates at low pressure, the risk of explosions or catastrophic pressure problems is considerably lower than with steam installations.

Which type of thermal oil boiler is the most suitable solution?

The choice of a thermal oil installation is first and foremost determined by your process’s heat demand. But equally important are your:

  • available energy sources
  • consumption profile
  • emission targets
  • energy costs
  • future sustainability plans

Do you prefer conventional fuels, or can you reduce your emissions with alternative ones? Do you have valuable residual streams such as biogas, syngas or another alternative energy source at your disposal? Would you like the flexibility to respond to fluctuations in energy prices?

At the Callens Group, we look at the complete picture so we can propose the thermal oil installation that best matches your current and future needs.

Ask our experts for advice
SOLUTIONS

The Callens Group offers a broad range of thermal oil boilers

From electric boilers to (bio/syn)gas or hydrogen-fired installations: the Callens Group always develops a solution tailored to your heat demand.

With a capacity range from 100,000 kcal/h to 12,500,000 kcal/h, we consistently find the right boiler for every heat demand.

Callens Elektrische TO

Electric thermal oil boilers

Electric thermal oil boilers deliver emission-free process heating at high temperatures. Ideal for companies focusing on electrification with precise temperature control.

Technical range:

  • Power: 100 kW to 30 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Callens Thermische Olie Ashland

Gas-fired thermal oil boilers

Gas-fired thermal oil boilers are the most widely used solution for continuous industrial process heating. They offer high operational reliability, heat up rapidly and come in a broad power range.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Callens Thermische Olie leidingen

Biogas-fired thermal oil boilers

Biogas-fired thermal oil boilers are ideal for businesses that valorize organic residual streams or operate their own digestion installation. Using self-generated biogas, they can produce stable heat, thereby reducing their dependence on fossil fuels.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
Learn more
Callens TO Ashland W 1

Hydrogen-fired thermal oil boilers

Hydrogen-fired thermal oil boilers produce low-carbon process heat at high temperatures. They are a particularly attractive option for companies that have hydrogen available via their own production or an existing hydrogen supply, such as the chemical, petrochemical and steel.industries

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Callens TO Syng 2

Syngas-fired thermal oil boilers

Companies that produce syngas can use it to generate process heat at high temperatures. In doing so, they valorize existing energy streams, reduce their consumption of fossil fuels and lower their energy and waste costs.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Callens Thermische Olie transport

Thermal oil boilers with liquid residual streams

In certain cases, liquid residual streams can be used as fuel for thermal oil boilers. An ideal way to valorize waste streams, limit energy costs and reduce dependence on fossil fuels.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Europal Packaging Blandain 6 ton

Thermal oil boilers in a combined configuration

A combination set-up links two or more boilers that run on different energy sources within a single system. This ensures flexible and reliable heat production that is easy to adapt to changing energy or production needs.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
Learn more
Callens stoom dual fuel 4

Thermal oil boilers with dual-fuel burner

With a dual-fuel thermal oil boiler, a single burner runs on two different fuels. Depending on availability, price or settings, the system automatically switches between, for example, natural gas and hydrogen or biogas, without affecting heat production.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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Callens stoom back up 2

Backup thermal oil boilers

A backup boiler builds in the necessary redundancy, thereby safeguarding the continuity of your production process. A backup thermal oil boiler prevents production downtime during maintenance, breakdowns or peak loads.

Technical range:

  • Power: up to 60 MW
  • Capacity: 100,000 kcal/h to 12,500,000 kcal/h
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A plan on the table, or still very much in the making?

Discuss your challenge

How does a thermal oil boiler reduce CO2 emissions?

Most current-day thermal oil boilers produce process heat generated via natural gas. But this technology works equally well with other energy sources that make more efficient use of the available energy and emit even less CO2.

At the Callens Group, we are happy to think along with you. Our specialists take your specific requirements and operational context as their starting point to work out a thermal oil installation with the lowest possible total cost of ownership, both economically and ecologically.

Ask our experts for advice
Scandinavian Tobacco 2x Viessmann 2 T 13b 1

Electrification of thermal oil boilers

Electric thermal oil boilers generate high process temperatures without producing direct emissions. Connect them to green electricity and the indirect emissions disappear too.

What’s more, they operate efficiently and are known for their high efficiency, precise temperature control and easy integration into an electrified production environment.

Flexible heat solutions

A thermal oil boiler in a combination set-up or with a dual-fuel system allows you to quickly switch between different energy sources. In practice, the system switches between, say, electricity, natural gas, biogas or hydrogen without interrupting heat production. A smart solution for anyone looking to flexibly respond to fluctuating energy prices.

Alternative fuels

Biogas, hydrogen, syngas and liquid residual streams open up new ways to produce process heat with a smaller ecological footprint.

The optimal choice depends on availability, fuel quality, investment costs, emission requirements and operational reliability. Thanks to our technology-independent approach, we recommend a solution that is tailored to your production process and energy context.

Integration of residual energy

Industrial sites often have heat sources that are underused. Integrating this residual energy into a thermal oil installation can significantly lower your total energy consumption.

This way, you increase the efficiency of your production process, reduce demand for primary energy and take an important step toward a more sustainable heat supply.

Working with the Callens Group means peace of mind, reliability and certainty

A thermal oil boiler is an investment for decades. That is why it pays to choose a partner that offers you the right solution and provides you with the service needed to guarantee lasting performance. You’ll find that combination at the Callens Group.

At the Callens Group, you have a single point of contact for your entire steam project: from the first analysis to installation, including service and maintenance. This keeps the process clear and reduces the need for separate coordination between different parties.

The Callens Group is not tied to a single brand, manufacturer or technology. This allows us to select the solution that is technically and economically the most attractive for each project. To do so, our engineers take account of energy prices, grid capacity, water quality, emission targets, available space and total cost of ownership to provide you with a solution that integrates perfectly into your production environment.

With more than 120 service and maintenance specialists, the Callens Group has one of the largest service teams. Preventive maintenance, interventions, remote monitoring and an extensive stock of spare parts ensure that your steam installation remains maximally available and that unplanned downtime is kept to a minimum.

Department of Technology

The Department of Technology is the Callens Group’s innovation center. Here, new developments in heat technologies are assessed for their technical feasibility and their added value for industrial applications. Only proven technologies ultimately find their way to customers.

With 13 locations across Belgium, the Netherlands and France, we combine the benefits of an international group with the proximity of local teams. This allows us to act quickly.

Projects with thermal oil boilers

IMG 2718
Thermal technology Thermal oil boilers Gas-fired

Solution to highly diverse heating needs

Output2 x 5,200 kW
Operating regime250 - 290 °C
IMG 20190306 165335502
Thermal technology Steam boilers Gas-fired +2

Steam and thermal oil ingeniously combined

Capacity300 kg/h
Power195 kW 
Operating pressure0,5barg 
Tekst LHS WPT PRJ10513 Guardian Luxguard
Thermal oil boilers Gas-fired Thermal technology

Thermal oil puts the heat on glass in the autoclave

Output1.920 kW
FuelNatural gas
FAQ

Questions?
We have the answers.

A thermal oil boiler is an industrial heating installation that heats thermal oil and circulates it through a closed circuit. The oil ensures uniform heat transfer to reactors, drying installations, ovens, heat exchangers and other industrial processes. Boilers of this kind operate at high temperatures (up to 300 °C) and at relatively low pressure.

Thermal oil boilers are used for process heating in sectors such as the chemical industry, the food industry, plastics processing, wood processing, asphalt and bitumen production, coating lines and drying installations. They are particularly suited to processes that require a stable heat supply at temperatures up to around 300 °C.

Sizing takes account of the required thermal output, the desired process temperature, peak loads, operating hours, future expansions and the characteristics of your production process. Correct sizing ensures optimal energy efficiency and avoids both over and under-capacity.

CO2 emissions can be lowered through electrification, the use of biogas or hydrogen, alternative fuels, heat recovery or the integration of hybrid systems. Which solution is the most attractive will depend on the available infrastructure, heat consumption and your company’s sustainability ambitions. Discuss the options with us!

Thermal oil boilers can generate high temperatures in a stable way using natural gas, biogas, hydrogen, syngas, liquid residual streams and electricity. Dual-fuel and combination set-ups, which use several energy sources, are also an option. The most suitable choice will depend on energy prices, fuel availability, emission targets and process requirements.

Depending on the installation’s design and the heat transfer oil used, thermal oil boilers can reach temperatures of up to around 300 °C. This makes them a suitable solution for industrial processes where conventional hot water systems cannot deliver temperatures that are sufficiently high.

Both thermal oil boilers and steam boilers are used for industrial process heating, but each has its own field of application.

A thermal oil boiler is especially attractive when high and stable process temperatures are required, typically up to 300 °C. Because thermal oil remains liquid at these temperatures, the system can operate at relatively low pressure. This simplifies the installation and limits the need for water treatment, condensate recovery and other peripheral equipment.

A steam boiler, on the other hand, is often the better choice when steam is needed in the production process directly or when heat has to be transported quickly over greater distances.

Discuss your question with our specialists!

Regular maintenance is essential for the safe and efficient operation of the installation. In addition to inspections of burners, pumps, safety components and control technology, the quality of the thermal oil must also be periodically checked. Preventive maintenance helps prevent downtimes and extends the service life of your installation. More information about service and maintenance.

Discuss your challenge or project with our experts

Would you like to explore which solution is suitable for your specific project?

Our engineers are happy to think along with you, from initial exploration to concrete engineering.

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