Many by-products from other industries serve as valuable raw materials for Heidelberg Materials. We use these resources as alternatives to finite natural raw materials and fossil fuels in the production of cement. In this way, we are helping to conserve resources and solve the problems associated with waste disposal faced by municipalities and industrial companies near our plants. At the same time, these efforts are also reducing our CO₂ emissions. We want to increase the proportion of alternative fuels in our fuel mix to 45% by 2030. In 2023, the figure was 29.9%. The waste-based biomass used, which accounted for around 13% of the fuel mix in 2023, makes a special contribution here, as it is considered climate-neutral under European legislation. By 2030, we intend to raise this figure to 20%.
Alternative fuels are generally waste that either cannot be recycled in full and would therefore be uneconomical to recycle or can only be incinerated for energy recovery to ensure safe disposal. In this scenario, co-processing in clinker kilns for thermal energy recovery offers a practical alternative, as it not only uses the waste’s calorific value but also embeds its mineral components into the clinker as raw material. The waste is co-processed without any residue in a burning process that meets the same strict emission standards as those set for waste incineration plants. About 90% of our cement plants have environmental management systems. As such, they are subject to regular internal and external audits, which cover toxic emissions and hazardous substances as well as waste.
Reuse in cement plants has proved to be a safe means of recovery, particularly for various types of hazardous waste. The high temperatures of over 1,450 °C and the long incineration period in the kilns ensure that all harmful components are completely destroyed. This has been confirmed by measurements taken by independent state-certified institutes.