Sustainability

Climate protection

Emission reduction

Approximately 60-70% of the carbon dioxide emissions from the cement industry are essentially ‘fixed’ as they arise from the de-carbonisation of the limestone, the primary raw material used for the manufacture of cement. Essentially the heating of the limestone causes a chemical reaction resulting in the liberation of CO2 gas. It is widely recognised that there is limited scope to reduce these emissions further. Carbon Capture and Storage (CCS) may offer an opportunity when the technology is developed further. The industry, through CEMBUREAU (European Cement Association) is playing its role with support for ongoing CCS R&D projects.

The remaining 30-40% of the CO2 emissions arise largely from the use of fuel in the clinker manufacturing process.

CMI members have had significant success in reducing their carbon intensity. Over recent years there has been significant investments by the members of CMI in modern energy efficient production facilities. The industry is also following the trend in Europe by substituting imported fossil fuels used in the manufacture of cement with specially prepared alternative fuels sourced in Ireland. In addition, next generation Eco-Efficient CEM II cements, requiring less energy to produce and with a lower carbon footprint have been introduced to the market.

The following programmes form part of an integrated strategy by the industry to tackle the challenges of climate change and to advance sustainable construction practices:
  • Improving energy efficiency
  • Clinker replacement
  • Fossil fuels substitution
Improving energy efficiency
Three of the four cement production facilities have been installed since 2000. The most recent being Irish Cement’s €200 million investment in Kiln 3; a completely new production line in Platin near Drogheda which is one of the most modern and efficient cement plants in Europe.

This puts Ireland in an enviable position throughout Europe for the relatively young ‘fleet’ of cement manufacturing facilities. These facilities benefit from the latest BAT investments, which allow cement production to be undertaken in an energy efficient manner. For example, in Platin vertical roller mills require 30% less energy than traditional cement mills to operate.

Clinker Replacement

Using locally available materials to manufacture Eco-Efficient Cem II cement

The World Business Council for Sustainable Development (WBCSD) and the International Energy Agency (IEA) Cement Technology Roadmap outlines that novel ‘low carbon cements’ are being investigated and that considerable investments are being made to scale up and commercialize some of these possible cementitious materials.

Until they are proven the primary route to de-carbonize cement production lies in expanding the percentages of locally available cementitious materials that are used to replace cement clinker. Production of these Eco-Efficient CEM II cements delivers considerable sustainability benefits.

In Ireland sales of Eco-Efficient CEM II cement now account for some 80% of the total cement volumes sold by the members of CMI. The technical merits and performance of Eco-Efficient CEM II cement is well established in the market following research in Ireland and a long history of use in Europe. 

When the cement industry in Ireland began to address its climate protection responsibilities in 1998, significant investigations were undertaken to determine the best options for improving the sustainbility of cement manufacturing in Ireland. The full range of permitted replacement materials from the European Cement Standard (EN 197) was examined. Each of the CMI members independently concluded that the use of the locally available materials was the real long-term sustainable option:
  • Limestone from the quarries, for the manufacture of CEM II/A-L; Portland-Limestone Cement
  • Fly ash from Ireland's two coal fired power stations, for the manufacture of CEM II/A-V; Portland-Fly ash Cement

Following these extensive investigations these two materials were identified as being the ideal materials to achieve clinker substitution targets in Ireland.

Comparison Table - Clinker Substitution Materials
 LimestoneFly AshBFS
Cementitious propertiesActs as a nucleation site and helps accelerate early stage hydrationPozzolanicLatent hydraulic
Product qualityPermitted under EN 197Permitted under EN 197Permitted under EN 197
Local AvailabilityAvailable at each of the cement production facilitiesAvailable from 2 power stations locallyNot available in Ireland
Plentiful supplyAbundant supplyLimited supplyLimited availability and based on overseas steel production
Security of supplySecureAt riskAt risk
Consistent qualityQuality controlled by the cement manufacturerQuality controlled by power plantQuality controlled by steel plant
Compatible with current production methodsYesYesYes
Cost effectiveYesYesDependent on 3rd party supplier
Previous use of the materialN/ALandfillUsed local to production

Alternative Material

Resource-efficiency in cement manufacturing

The use of virgin raw materials in the cement manufacturing process has been reduced by the use of 'overburden'. Overburden is the soil and stones overlying the limestone deposits. Previous practice in the cement plants was to remove this material and store it elsewhere on-site, but now following testing it can be used as a shale replacement material. Over 200,000 tonnes is processed annually by the industry here. This reduces the requirement for additional quarrying and reduces the road haulage required.