A Kenyan cement maker is testing whether industrial decarbonisation can be both profitable and replicable across Africa
By Ethical Business Team
The cement industry has a problem it cannot engineer away. Roughly half of its carbon dioxide emissions arise not from burning fuel but from the chemical decomposition of limestone during clinker production, an inescapable consequence of the manufacturing process itself. Global cement manufacturing produces approximately 1.6 billion metric tonnes of COâ‚‚ annually, accounting for roughly 8% of total worldwide emissions. Total emissions from the sector have been rising since 2015, and by 2030 they need to fall by around 20% to stay on course for net zero. Against that backdrop, Africa’s producers are barely visible in the policy conversation, underfunded, under-scrutinised, and frequently absolved of ambition on the grounds of development imperatives. Bamburi Cement, Kenya’s dominant manufacturer, is pushing back against that assumption.
The company operates two cement plants in Kenya, an integrated clinkering and cement facility in Mombasa and a grinding plant in Athi River, and holds a brand portfolio that includes Duracem, Nguvu, Powermax 600, Roadcem and a growing line of eco-labelled green cements. For much of its seven-decade history, Bamburi operated in the shadow of its parent, first Lafarge and then Holcim. In late 2024, Tanzania’s Amsons Group completed a KES23.5bn ($182m) acquisition of a 96.54% stake, separating Bamburi from the Holcim stable. The new owner has moved quickly. In December 2025, Bamburi signed a $250m engineering, procurement and construction contract with China’s Sinoma CBMI Construction Co. to build a 1.6 million-tonne clinker production plant in Kwale County on Kenya’s coast, one of the country’s largest industrial investments in recent years.
That investment carries ESG weight as well as commercial logic. The new facility will use a six-stage pre-calciner system and incorporate emissions-reduction technologies, including the use of alternative fuels such as coconut husks, cashew shells and municipal solid waste. Bamburi’s chief executive, Mohit Kapoor, has described the Kwale plant as central to the company’s strategy to modernise its asset base and reduce exposure to imported raw materials. Commissioning is expected by 2028.
The fuel substitution story
The more immediate measure of Bamburi’s decarbonisation credentials lies in its alternative fuels programme, which has been running for over a decade. The company has substituted heavy fossil fuels with biomass, including rice husks, as well as waste tyres and waste oil. By 2024, it had achieved a 98% alternative fuel substitution rate at its Nairobi grinding plant, a record for its Kenyan operations. That figure is striking by global benchmarks. The average alternative fuel substitution rate across the European cement industry, the most advanced in this respect, remains below 60%.
The savings are not solely environmental. Jane Wangari, Sustainability and Geocycle Director at Bamburi Cement, has observed that biomass costs bear no comparison to heavy fuel oil: “The use of alternative fuels is not only saving the carbon emissions but also saving us money because the cost of biomass, frankly speaking, you cannot equate it to the price of heavy fuel oil. The savings are massive.” The company expects to save approximately KES400m ($3.1m) annually once its solar plants in Mombasa and Nairobi reach full output. Those plants, with a combined capacity of 19.5MW, are designed to meet around 40% of Bamburi’s total power requirements, and according to its 2024 annual report were commissioned at year-end.
Solar and waste-derived fuels address the energy-related share of cement emissions. The harder problem, process emissions from calcination, requires a different approach. Bamburi’s response has been to reduce the clinker factor in its cement blends, substituting pozzolana, blast furnace slag, limestone and gypsum for clinker. The clinker-to-cement ratio fell to 53.3% from 54% in 2021, modest progress but directionally consistent with the trajectory recommended by the International Energy Agency. In late 2025, the company launched DURAPLUS CEMIII/A 42.5N, a blend combining PPC clinker with blast furnace slag that achieves over a 45% reduction in COâ‚‚ emissions relative to ordinary Portland cement. From January 2024, Bamburi ceased producing ordinary Portland cement entirely, accelerating a stated target to reach 100% green products by 2025.
The circular economy dividend
Bamburi’s waste co-processing arm, Geocycle Kenya, launched in 2016 and now forms a distinct revenue and compliance strand within the group. The technology converts industrial and municipal waste into kiln fuel, leaving no residue, an outcome that ordinary incineration cannot match. Over 50,000 tonnes of waste is co-processed by Bamburi every year, and more than 500,000 tonnes has been diverted from landfills and open dumpsites over the past decade. Geocycle co-processes close to 5,000 tonnes of waste tyres at the Mombasa plant annually, eliminating what was previously open-air burning across Kenya’s highway network.
The scale of the waste challenge in sub-Saharan Africa makes co-processing a more consequential intervention here than in Europe. According to the World Bank, more than 90% of waste in sub-Saharan Africa is disposed of in open dumpsites and landfills, owing to the absence of adequate treatment infrastructure. Bamburi’s kilns provide one of the few industrial-scale alternatives in East Africa. In 2019 the company co-processed more than 5,000 tonnes of contaminated imported grain in partnership with the UN World Food Programme, Kenya Ports Authority and the Kenya Bureau of Standards. Across the four years to 2024, Geocycle recycled 385,603 tonnes of waste, with the company targeting a 200% year-on-year increase in waste recycling by 2030.
Ownership, appetite and limits
The transition from Holcim to Amsons raises legitimate questions about the durability of these commitments. Holcim embedded Bamburi’s sustainability agenda within a group-level net-zero architecture, with access to global procurement networks for alternative fuels and verified ESG reporting frameworks. Amsons is an East African conglomerate with fewer of those institutional supports, though it has publicly pledged to maintain Bamburi’s sustainability trajectory. Under Amsons, the company has reached full clinker capacity of one million tonnes, with cement volumes growing in double digits in 2025 and ready-mix output up 40%. It posted a KES865m net profit in the first half of 2025, after a net loss of $6.8m in 2024. Growth brings its own carbon pressures.
Kenya’s macroeconomic context sharpens the tension. Cement consumption is expected to rebound strongly in 2025 and 2026, driven by major infrastructure projects including the Rironi-Mau Summit road and an expanding affordable housing programme. Rising volumes will test whether the efficiency gains embedded in Bamburi’s operations can outpace demand-driven emissions growth. The IEA projects that global cement demand could increase by 12-23% by 2050 relative to 2018 levels, with the sharpest growth concentrated in sub-Saharan Africa and South Asia. Without mitigation, that demand surge would proportionally raise emissions.
The structural limits are also clear. Carbon capture and storage, the technology that the IEA and the Global Cement and Concrete Association consider essential for deep decarbonisation, is not yet commercially deployed at any cement plant outside Europe. Kenya’s infrastructure for COâ‚‚ transport and storage does not exist. For the foreseeable future, Bamburi’s decarbonisation toolkit consists of fuel switching, clinker substitution, renewable electricity and waste co-processing. These are meaningful measures. They are not, by themselves, a pathway to net zero.
What Bamburi does demonstrate is that industrial decarbonisation in an emerging economy need not wait for carbon pricing, regulatory mandates or breakthrough technology. A combination of agricultural biomass, waste tyres, solar power and blended cement formulations has driven measurable Scope 1 reductions while generating cost savings and a viable circular economy business. The Kwale plant will determine whether new capacity can be added without reversing that progress. How that question is answered matters well beyond Kenya: nearly 50% of cement production outside China is now covered by decarbonisation roadmaps, with current efforts focused on emerging markets and developing economies. Africa remains thinly represented in that count.
SDG alignment: SDG 9 (resilient infrastructure and sustainable industrialisation); SDG 12 (responsible production and circular economy); SDG 13 (climate action and emissions reduction).
