Opinion - 09/December/2020

Electrification is driving sustainability in cement and mining

The cement and mining industries recognise their need to decarbonise, and the rapidly falling price of renewables-generated electricity is making this decision easier, says Thomas Schulz, CEO at FLSmidth

The views expressed are those of the author and do not necessarily reflect the position of FORESIGHT Climate & Energy


The renewable energy industry is relying on cement and mining sectors to clean up their activities

The first step on the journey for mining and cement is to replace fossil-fuel driven equipment and solutions with electric power. But for this to make a significant difference, the electricity needs to come from a renewable energy source, such as solar, wind or hydro. Electrification, therefore, makes the most sense in regions and countries where there is sufficient access to renewable energy or where there is a strong ambition of establishing it.

Mining sites and cement plants are dependent on a reliable and stable energy supply. If certain pieces of equipment, especially in the cement industry, suffer even a momentary loss of power, processes often need to be restarted, leading to lost productivity and costly downtime.
But if the electricity supply is sufficient and reliable, the huge energy consumption of these industries (cement contributes 7% of global CO2 emissions) can be replaced by renewable, green power.

Further down the line, new opportunities will emerge that allow for the replacement of fossil fuels in the combustion processes required for cement production—these processes are responsible for 37% of cement’s CO2 emissions. We need to drive a change in our industries towards greener production.

There is also growing and significant pressure from investors to improve sustainability and sustainable practices. But moving the two industries is not an easy task. Both the cement and mining industries are quite conservative when it comes to making the capital-intense investments and implementations needed to improve sustainability. They can be tough to move and it is difficult to set new targets for achieving carbon neutrality. The industries really need to shift gear. There is, however, a growing understanding in the industries that this is an obstacle we must overcome.

ELECTRIFICATION IN CEMENT

Electrification of cement production is gaining more traction as electricity prices decrease. An obvious example where electricity can be applied is the hot gas generators that do not need very high temperatures. This is something customers are already requesting from FLSmidth, particularly in developing countries.

The Capex & Opex for such applications are more attractive than coal-fired alternatives—we know this from a proposal we made for a Bangladeshi customer who wanted to use solar power to drive their grinding station. But it does not stop there. There are several options for using electrical sources of heat in the preheater and main burner in the cement plant configuration, replacing fossil-fuel driven machinery.

Then there are innovations that look to radically change how cement is produced altogether, such as the electrochemical approach. This is a technology compatible with the advent of renewable power, as it functions as a battery. It captures excess power and converts limestone into hydrated lime through electrolysis.

This is a process demonstrated at laboratory scale, which we are conducting with our academic partnerships. Such a cement plant could be small scale, decentralised, automated, easy to deploy, easy to start-up and shut down. It is a very different approach to making cement and is, in my eyes, a promising alternative or supplement to existing technologies.

 

ELECTRIFYING MINING

Within the mining industry, there are multiple options for driving a green transition through electrification. An obvious place to start is with the giant trucks transporting the minerals or metals excavated from the mines—these are mammoth vehicles with engines that consume large amounts of diesel creating significant emissions.

Our ambition is to eliminate all diesel-driven equipment wherever the conditions allow so we are installing so-called in-pit crushing and conveying systems (IPCC). These large electrified crushers break the minerals and metals from the mine site into smaller parts that can be transported by electrical-driven conveyors rather than diesel trucks. While in surface mine operation on average trucks use more than 60% of the energy because of high dead load to payload ratio and long driving distances without load, belt conveyors use on average more than 80% of the energy input to do what it is supposed to do—transporting the mined material.

No matter what part of the mining and cement operation is electrified, it has to be done on a price-competitive level, compared to conventional, existing solutions. Some countries in Europe and the Americas will accept a slightly increased cost, but in other places this will be a more challenging sell. The test for the engineering community is to innovate and fine-tune electrified solutions that exceed the performance of the existing alternatives across all parameters.

 

IT WORKS BOTH WAYS

But just as mining and cement need electrification in order to reduce emissions, electrification is equally dependent on mining and cement—it works both ways. Cement provides basic infrastructure for grids and also is the main component in the large, stable foundations needed for wind turbines.

Mining is even more central to the equation. To make the green energy transition through electrification a reality, the world needs a massive increase in the minerals needed for wind farms, solar panels, electric vehicles and for battery-based energy storage.

A single 3 MW wind turbine (approximately 150-metres in height) requires 4.7 tons of copper, 335 tons of steel and 1,200 tons of concrete. It also needs 2 tons of rare earth elements for the magnets in the huge generator and 3 tons of aluminium, as well as lesser amounts of zinc and molybdenum. All of this coming from the mining and cement industries.

In this way, it is clear that electrification needs mining and cement and that these industries need electrification as a central tool to bring down emissions. This is a journey we are on together.


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