Mon. Jul 22nd, 2024

Cement plants must reduce their high carbon footprint

Natasha Kumar By Natasha Kumar Mar22,2024

François Legault's government is asking Quebec's four cement plants to propose a plan to reduce greenhouse gases (GHG) by May 1. A complex problem for this sector which emits 15% of all industrial carbon in the province. However, several avenues are already being explored to achieve this objective.

Cement factories must reduce their high carbon footprint

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The Lafarge cement plant located in Saint-Constant, Quebec, emitted 775,000 tonnes of CO2 in 2021.

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“When we talk about GHGs , this is where it happens,” says Gilles Autote, pointing to the ovens of the Saint-Constant cement plant, in Montérégie.

The factory produces nearly 900,000 tonnes of cement per year and operates a limestone quarry on the same site, specifies the Quebec spokesperson for the company Lafarge, a subsidiary of Holcim, the world's leading producer of cement. concrete.

The temperature of the huge metal tubes rises beyond 1400 degrees Celsius during the transformation of limestone into clinker, the main element of standard cement, commonly called Portland cement.

To produce one ton of clinker, nearly 800 kilos of carbon dioxide are released into the air during combustion. This is the main reason why this material has a heavy carbon footprint.

Consequently, it will be difficult for this industry to achieve the carbon neutrality objective set by Quebec in 2050.

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The Saint-Constant cement plant emitted 774,000 tonnes of GHGs in 2021 and, by 2030, it wants to reduce its emissions by 30%. Quite a challenge, recognizes Mr. Autote, while still saying he is optimistic.

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The ovens of the Lafarge cement plant in Saint-Constant.

To achieve this objective, Lafarge has just modified its manufacturing method. Until then, calcined carbon made up more than 70% of the cement composition. In the new recipe, part of the clinker is replaced by raw limestone, which therefore does not need to be heated.

Old Canadian standards required a maximum of 5% limestone in the finished product. The limit now stands at 15%. The cement plant intends to reduce its GHG emissions by 60,000 tonnes starting this year.

To reduce the proportion of clinker, Lafarge already uses other so-called alternative products. Most are industrial residues such as fly ash, a material from coal combustion, or slag, a residue from steel manufacturing.

The ultimate goal, explains Gilles Autote, is to gradually increase the proportion of ingredients with a lower carbon footprint compared to calcined carbon.

But for each modification of the recipe, the challenge is to obtain quality concrete and to gain the trust of sometimes doubtful customers, he explains.

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Gilles Autote, spokesperson for Lafarge in Quebec, and Daniel Vadacchino, director of the Saint-Constant cement plant.

In his laboratory at the University of Sherbrooke, professor of civil and chemical engineering Arezki Tagnit-Hamou is carrying out research to change the composition of cements.

It works with cement manufacturers to adopt new technologies and with the Quebec government to adopt standards accordingly.

According to him, the solutions have been known for a very long time and we must not waste time in responding to the urgency of climate change.

He also observes a paradigm shift and maintains that the carbon footprint of cement is now an essential parameter.

We really need to include reducing CO2 in the game plan.

p>A quote from Arezki Tagnit-Hamou, director of the Concrete Infrastructure Research Center at the University of Sherbrooke

Except that cement plants do not all start from the same point. Some use very advanced technologies, others are very late and, according to him, they should take advantage of this paradigm shift to move towards more innovative solutions.

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Professor Arezki Tagnit-Hamou at the Concrete Infrastructure Research Center from the University of Sherbrooke.

The Ciment Québec plant, located in Saint-Basile, in the Portneuf region, has invested nearly $150 million to modernize its facilities, thanks in particular to a contribution from Quebec of $46 million.

On the other hand, the Joliette cement plant is known for its outdated infrastructure. It is reportedly about to be sold and the new owner will need to invest funds to bring the facilities up to date.

The controversial McInnis cement plant, in Gaspésie, on the other hand, has recent installations, but all sectors combined, it is the Quebec factory which produces the most greenhouse gases, nearly 1.4 million tonnes in 2022.

In an email sent to Radio-Canada, the spokesperson for the McInnis cement plant, Lyse Teasdale, affirms that the company intends to respect the targets imposed by the government and that it will produce a roadmap by May 1.

Like Lafarge, the cement plant is exploring alternative ingredients and has already integrated a greater quantity of raw limestone into 80% of its production.

McInnis is also considering another option: using low-carbon fuels to power his furnaces. The company also plans to request a permit this year to use biomass, a material which would come largely from Gaspé forests.

A promise impatiently awaited for several years, recalls environmental activist Pascal Bergeron, also spokesperson for the Gaspé organization Environnement Vert Plus.

He notes that the use of carbon-neutral alternative fuels could reduce GHG emissions by 10 to 20%.

This would be a marginal gain, but not negligible, according to Professor Arezki Tganit-Hamou, because current fuels are often very polluting.

These are mainly fossil fuels such as oil or coal, but also industrial waste such as used oil, construction residues or tires.

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The Saint-Constant cement plant uses 80% fossil fuels to heat its ovens and 20% recycled industrial products such as tires.

Carbon capture is another option regularly mentioned by the industry. Technologies exist, but profitability is far from assured, according to Mr. Tagnit-Hamou, who expects very high storage and transport costs. This is why he would rather favor reduction at source.

As is often the case in the fight against GHGs, one of the most obvious solutions remains to reduce consumption. This is the crux of the matter, according to the researcher.

He also invites architects and engineers to prioritize models that require a smaller quantity of cement, that is- i.e. slender structures and the use of more efficient concrete.

A point of view shared by Pascal Bergeron. He would like to see the adoption of a concrete exit plan in Quebec. This is the role of politics, he says, and it is the jobthat is not being done at the moment.

If we don't intervene upstream on consumption, we will never solve the problem.

A quote from Pascal Bergeron, spokesperson for the organization Environnement Vert Plus

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Environmental activist Pascal Bergeron.

Moreover, Mr. Bergeron believes that the carbon exchange would already make it possible to force cement factories to reduce their GHG emissions.

The problem, he maintains, is that the Quebec government offered them a special status with very low royalties, the objective being not to penalize them in the face of foreign competition.

With the business model that we are being offered, private business will self-regulate, deplores Pascal Bergeron.

Faced with Quebec's laxity, its expectations are now limited. He regrets that the government is asking cement companies to present their own game plan by May, rather than imposing coercive measures.

Will this do anything? Are there really going to be consequences? he asks. We find this to be quite unconvincing.

In the coming months, Quebec intends to establish thresholds for x27;GHG emissions for cement plants and, in the event of non-compliance, there will be significant financial consequences, assures Mélina Jalbert, press secretary to the Minister of the Environment Benoit Charette.

Quebec is targeting, by 2030, a 37.5% reduction in GHG emissions compared to their 1990 level and carbon neutrality for 2050.

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Natasha Kumar

By Natasha Kumar

Natasha Kumar has been a reporter on the news desk since 2018. Before that she wrote about young adolescence and family dynamics for Styles and was the legal affairs correspondent for the Metro desk. Before joining The Times Hub, Natasha Kumar worked as a staff writer at the Village Voice and a freelancer for Newsday, The Wall Street Journal, GQ and Mirabella. To get in touch, contact me through my natasha@thetimeshub.in 1-800-268-7116

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