Why waste is cement industry’s decarbonization strategy

Moving away from fossil fuels towards a clean, circular economy.

In Summary

•Cement production has historically relied extensively on coal and other fossil fuels to heat cement kilns and create clinker.

•It is prudent for manufacturers to use waste as an alternative fuel in production.

Operations at Bamburi Cement's Athi River plant/FILE
Operations at Bamburi Cement's Athi River plant/FILE

The cement industry is making operational and technological advancements that reduce fuel and process emissions by moving away from fossil fuels towards a clean, circular economy.

At the core of this self-regulating imperative is the resolve to speed up innovation in the cement industry, with the crucial goals of enhancing sustainability and reducing the CO2 footprint.

Cement production has historically relied extensively on coal and other fossil fuels to heat cement kilns and create clinker, the main component of cement, which releases large amounts of greenhouse gases into the atmosphere.

It contributes up to 8% of the planet's energy-related carbon footprint.

According to the International Energy Agency (IEA), the demand for cement is expected to grow globally by 12–23% by the year 2050.

As a result, forward-thinking cement manufacturers have transitioned to alternative energy sources from fossil fuels to reduce the additional carbon footprint,  that is expected with this growth.

Today, we have made investments in circular economy strategies like co-processing, which involves heating cement kilns and producing clinker by burning combustibles made from waste at 1500 degrees centigrade, such as rice husks, waste oils, old tires, and used plastic – through Geocyle Kenya, a waste management company set up by Holcim, the major shareholder of Bamburi Cement

PLC, to recycle waste into energy and use it to process the raw materials for cement plants.

Through co-processing we have become a consumer of non-recyclable waste and by-products from several industries, including power, iron, steel, agriculture, and petroleum – with an unquantifiable multiplier effect on the socio-economic and environment value chain.

For instance, the co-processing of different forms of plastic waste helps the cement industry use less energy and partially solves the problems with trash disposal brought on by urbanization and the ensuing waste management crisis.

We have co-processed over 200,000 tons of waste over the past ten years and 25,000 tons annually in accordance with National Environment Management Authority (NEMA) regulations, assisting cities like Nairobi, which generate over 2,400 tons of waste per day, in managing their waste.

Utilizing rice husks as a fossil fuel substitute for coal in cement kilns helps Kenya's food security and value addition equation address the country's growing reliance on rice.

In order to use the rice husks left behind after milling, we have collaborated with millers in Kirinyaga and Kisumu Counties.

This is both a revenue-generating and environmental solution.

Kenya produces 60 million liters of waste oils annually, which the United Nations Environmental Program defines as hazardous.

We have ensured that waste oil is disposed of safely through our Safe Waste Oil Disposal program with the Petroleum Institute of East Africa.

It is then utilised as an energy alternative in cement manufacturing because of its physicochemical composition, which is more similar to that of liquid fossil fuel.

As living standards rise, the number of car owners in Kenya rises. Old tires are becoming another source of waste.

To assure the secure disposal of used tires that would otherwise end up in landfills or burn in the open such as Dandora dumpsite, creating air pollution; we have worked with fleet and logistics firms to dispose the waste tires by co-processing in a practical and ecological manner in our cement kilns.

Co-processing of condemned cargo in partnership with the Anti-Counterfeit Authority, Kenya Revenue Authority, National Environmental Management Authority and Kenya Bureau of Standard has not only provided a solution for the safe disposal of counterfeit products but a substitute to fossil fuels.

Far from the evidence that links alternative fuels in kilns to better clinker quality, co-processing has substantially contributed to the acceleration of our Net Zero future ambitions through reduction of emissions and sustainable waste management.

In 2021, we co-processed approximately 117,467 tons of reused waste in our industrial operations against our target of 317,000 tons of waste by 2025.

Given the hazards to the environment posed by the cement industry's  reliance on fossil fuels as its main energy source, it is prudent for manufacturers to use waste as an alternative fuel in production.

This will further the sector's efforts to be environmentally friendly.

Importantly, sustainable waste management practices and operations will forge new pathways for the sector’s support of a circular economy in line with the national sustainability agenda.

The writer is Bamburi Cement PLC’s Geocyle Director.

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