The decarbonisation of the cement industry is a major challenge facing sustainable, low carbon development. A number of levers are available along the industry roadmap to net zero to address the 2 key sources of carbon emissions from a cement works;
Traditionally, fossil fuels have been used for the latter, with coal the most widely used kiln fuel across the cement industry. Substituting these fossil fuels with more sustainable Alternative Fuels is one of the key levers to address those emissions. ‘Co-processing’ is a concept which enables both the thermal and mineral matter from the non-recyclable alternative fuel types to be fully recovered and has been taking place for a number of years, however the types and percentage of alternative fuels used can vary between cement plants.
Alternative fuels include:
Our Kinnegad Cement works in the Republic of Ireland opened in 2002 and started using MBM in 2006 with an initial 5% replacement. In the following 10 years, additional alternative fuels were introduced raising this figure to 60% replacement, and by 2021 it had reached a world class 75% replacement rate. For context, in 2020 across the cement plants in the EU 27, the average alternative fuel rate was just over 52%, with the global average lower still at around 16% (2020 global average of world's top 21 cement producers).
When thinking of this in terms of reduction in carbon emissions, it is an equivalent saving of 140,000 tonnes of carbon in 2021 compared to using fossil fuels alone.