Cement production is an energy-intensive and therefore climate-damaging process, as it requires, amongst other things, cement clinker — a mixture of limestone, clay, quartz sand and iron ore. The clinker is heated to over 1,400°C, releasing large quantities of CO₂.

A cement plant in Tema operates differently. Here, instead of clinker, clay is used, sourced directly from the surrounding area. The material looks similar to clinker on the outside, but where climate impact is concerned, it makes a significant difference. When clay is heated, far less carbon is released compared to clinker. The new plant in Tema is the world's largest facility processing clay in such a way that it can partially replace clinker in cement. The heating of clay takes place at around 800 degrees — considerably lower than for clinker.

The technology is not entirely clean, however. Clay processing also produces emissions, and the cement manufactured here cannot do entirely without clinker either. Nevertheless, the new plant in Ghana will place considerably less strain on the climate than conventional cement plants. The new process is expected to reduce CO₂ emissions by up to 40 per cent. The financial outlay required to retrofit the factory accordingly is also substantial, but the plant's management is confident that it will prove worthwhile. The clinker that is still needed must be imported to Ghana. The partial replacement with far cheaper locally sourced clay favours the economic viability of the process.