Aalborg Portland: How we developed new type of cement

In 2021, Troldtekt developed acoustic panels based on the new cement type FUTURECEM. The panels absorb more CO2 than they emit during the production stage, and this is due, among other things, to the cement developed by Aalborg Portland.

Cement has many advantages, and at present, these properties are difficult to achieve using alternative binders. In Troldtekt acoustic panels made of cement-bonded wood wool, the cement ensures strength, robustness and durability. The flipside is that cement production emits a lot of CO2.

The launch of FUTURECEM by Aalborg Portland was therefore a groundbreaking development. The new type of cement has the properties of traditional cement – but with a 30 per cent lower climate footprint.

“At Aalborg Portland, we believe that this type of cement is the future, as reflected in the name of the cement,” says Michael Lundgaard Thomsen, CEO of Aalborg Portland.

Photo: Helene Høyer Mikkelsen

Replacing clinker

The high carbon emissions from cement production are explained by the fact that the production process involves heating a number of solids to very high temperatures in a kiln to make cement clinker. The process is also called calcination, and releases the CO2 that is naturally bound in the chalk. For the same reason, the calcination process accounts for just over half of the climate footprint of cement. 

“There’s no way of reducing the footprint from the calcination process, but we can instead try to reduce the amount of cement clinker in the finished cement,” explains Michael Lundgaard Thomsen.

Traditionally, however, it has not been possible to replace much of the clinker without affecting the strength of the cement. In so-called BASIS cement, 15 per cent of the clinker has been replaced with limestone filler, but it is difficult to add more filler without compromising on strength. The same would be the case if clinker were replaced with burnt clay.

“Another challenge with finding replacement materials for clinker is that the alternatives must be available in sufficiently large quantities to guarantee supplies for years to come,” explains Michael Lundgaard Thomsen.

Synergies between limestone and clay

The breakthrough came when Aalborg Portland started to combine limestone filler and burnt clay. Because while it was not possible for the two materials to replace much of the cement clinker content on their own, mixing burnt clay and limestone filler produced quite a different picture:

“The synergies between limestone filler and burnt clay result in a high level of strength,” explains Michael Lundgaard Thomsen.

This means that 35 per cent of the clinker in the cement can now be replaced with limestone filler and burnt clay, and the strength of the cement remains on a par with that of traditional cement.

“Globally, we’re looking at huge deposits of limestone and clay, so with FUTURECEM we have a technology that produces the same strength based on materials that will be in plenty supply in the coming years,” he says.

Alternative fuels and carbon capture

However, Aalborg Portland’s efforts to reduce CO₂ emissions from cement do not stop here. According to its ‘Roadmap for sustainable cement production in Denmark’, the company aims to reduce its emissions by 30 per cent by 2030.

“We want to achieve this partly by developing new types of cement such as FUTURECEM, but also by switching to alternative fuels in our production,” says Michael Lundgaard Thomsen.

By 2050, Aalborg Portland expects to succeed in reducing its climate footprint by an impressive 70 per cent by switching to alternative fuels and modifying its chalk-based cement.

“But even with 100 per cent carbon-neutral fuels, we’re still going to have to look at carbon capture, whereby CO₂ from our production process can be captured and either used for other purposes or stored. However, it’s still early days for this technology,” he says.

Together with Aalborg University and other partners, Aalborg Portland has been granted EUDP funding to explore the potentials of carbon capture.

FACTS: Aalborg Portland’s climate ambitions

  • Aalborg Portland’s ambition is for its cement production to be one of the most sustainable in the world.
  • The company’s plan is described in its ‘Roadmap for sustainable cement production in Denmark’.
  • The vision is to supply carbon-neutral cement by 2030.
  • By 2050, all cement production in Denmark must be carbon-neutral.