This article first appeared in The Edge Malaysia Weekly on June 17, 2024 - June 23, 2024

Cement is a critical ingredient in the making of the modern world. It is the key component of concrete, which is used to construct buildings, bridges, roads, tunnels and many other structures that make cities liveable.

But it also takes a toll on the environment. Other than the impact of mining limestone, cement manufacturing is the third-largest cause of man-made carbon emissions, according to the United Nations Climate Technology Centre and Network. In Malaysia, cement production was the highest contributor (27.76%) to emissions in the industrial processes and product use category in 2019.

The path to decarbonisation, however, is challenging. The cement industry is called a hard-to-abate sector because the solutions to net-zero emissions are currently either too expensive or unfeasible. The demand for green cement is also slow in coming.

Regardless, cement players are taking note of the global trend towards lower emissions.

The main strategy to reduce emissions from the cement sector is using alternative fuels to power the kiln, which must be heated to over 1,400°C to facilitate the chemical reactions that turn limestone into clinkers. The energy required to fire the kiln — oftentimes, from burning coal — is a major source of emissions for the industry.

“Instead of relying solely on coal, we burn a variety of alternative fuels. Our Bukit Ketri plant in Perlis can utilise up to 60% of alternative fuels, although this depends on the availability of such fuels,” says Hannah Lyana Lee Abdullah, head of strategy and transformation at Cement Industries of Malaysia Bhd (CIMA), the second-largest cement manufacturer in Malaysia. CIMA is owned by UEM Group Bhd.

“We initially started using paddy husks in 2007 because Perlis [has a lot of paddy fields]. But it’s seasonal and paddy is only harvested two to three times a year, so it’s not sustainable. Down south at our Negeri Sembilan plant, we shifted to palm kernel shells and empty fruit bunches in 2014, enabled by an alternative fuel combustion system from NEDO (New Energy and Industrial Technology Development Organization), though these are becoming difficult to source as well because they are used to heat boilers and countries like Japan are importing them,” says Hannah.

Following this, the company began using industrial waste such as shredded tyres and used rubber gloves from its own factories as alternative fuels.

After going through the rotary kiln, the limestone is converted into clinkers, which are cooled in a separate chamber. A lot of heat is lost during this whole process, so CIMA invested RM120 million in a waste heat recovery system to capture the heat and turn it into electricity for self-consumption.

Construction of the system began in March 2022 at the Negeri Sembilan plant, and it is expected to reduce energy consumption by 30% and Scope 2 emissions by 20% once it is operational, according to the company.

The chemical reaction in the kiln is the other major source of emissions in cement production. To reduce these emissions, CIMA focuses on maximising efficiency, says Hannah. Another strategy is to add alternative feedstock like pulverised fly ash — a waste material from power plants — at the final cement grinding stage to reduce the clinker-to-cement ratio.

CIMA also adds gypsum repurposed from waste materials, instead of the conventional natural gypsum. Using waste materials does not compromise the quality of the cement, says Hannah. On the contrary, it gives the cement special properties.

“If you use materials like fly ash, it reduces the heat of hydration [for mass concreting], so there is less risk of thermal cracks. That’s why our cement is widely used in major infrastructure projects like the mass rapid transit, light rail transit, tunnel linings and the second Penang bridge. It also offers improved resistance to the acidity of seawater,” she adds.

Materials derived from waste are also added into the limestone mixture at the beginning of the process where typically, shale, laterite or iron ore and sand are introduced. Some examples are ceramic waste and solar waste, which is obtained from the wastewater from solar photovoltaic panel manufacturing plants.

The challenge is, again, in obtaining sufficient and consistent supply of alternative raw materials.

“For green cement to truly capture the mainstream market, systemic changes are required. This is where government support, through policies and incentives that encourage the use of sustainable materials, and industry-wide collaborations play a pivotal role,” says Hannah.

All these efforts have helped CIMA achieve lower carbon emissions per tonne of cement produced than the benchmark set by McKinsey & Co and CIDB Malaysia, according to the company. Some of its products have also obtained green certifications from SIRIM and the Singapore Environmental Council.

However, since CIMA is not a public-listed company, these figures are not made public.

It is aiming to achieve net-zero emissions by 2050 and has identified six strategic pillars to do so. These efforts could set CIMA apart and align it with global trends. It just recovered from a period of financial losses in the financial year 2022.

“After successfully navigating through Covid-19 and post-pandemic challenges, we are now in a stronger position to map out our trajectory for future growth. Looking ahead, it is crystal clear that the future is in sustainability,” says Khor Khai Nee, acting CEO of CIMA.

“We are actively incorporating cutting-edge green technologies, implementing strategic updates and expanding our horizons beyond the boundaries of CIMA,” adds its chairman Datuk Zaiviji Ismail Abdullah. “Our aim is not only to drive our growth but also to contribute towards the realisation of Malaysia’s goal of achieving carbon neutrality by 2050.”

Getting to that point will be a challenge for cement companies. The use of renewable energy, alternative fuels and raw materials can only reduce emissions to a certain point, while options such as green hydrogen are currently economically unfeasible.

A popular last-mile decarbonisation lever is carbon capture, utilisation and storage. But the technologies that CIMA has seen so far are not practical to be implemented yet. 

To further reduce emissions from this sector, creating buildings that endure the test of time is key, says Hannah. Concrete can also be used in more sustainable ways. For instance, some of CIMA’s concrete products are reinforced with fibre, which means less steel is required in the structure.

Ultimately, all these efforts come with a cost, and customers may not be willing to pay a premium for it currently. But Hannah observes that customers have been coming to the company for high-performance cement — that happens to also have a lower carbon footprint — with special qualities, even if it is more expensive.

“Our board has always emphasised that the key to driving green initiatives is aligning them with value-added benefits to the product,” she says.

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