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Current schemes for the determination of CO2

World Cement,

The European Committee for Standardization (CEN) has recently published a draft standard for the determination of greenhouse gas (GHG) emissions from stationary sources in energy-intensive industries. It includes a cement-specific part that is based on the Cement CO2 and Energy Protocol of the Cement Sustainability Initiative (CSI Protocol), which is now available in version 3.1. More than 960 cement plants worldwide use the CSI Protocol for monitoring their CO2 emissions and also their energy consumption. Cement plants located in the EU additionally have to report their annual CO2 emissions within the framework of the European Emissions Trading Scheme (EU ETS), phase III of which started in 2013.

The drafted EN standard describes methods for the monitoring and reporting of GHG emissions. It consists of six parts in total: one part on general aspects, and sector-specific parts for each of the five industries involved. Beside the cement sector, these are the lime, steel, aluminium and ferroalloys industries. The final publication of the standard is planned for 2016. CEN also plans to suggest the EN standard as a worldwide valid standard to be published in cooperation with the International Organisation for Standardisation (ISO).

The cement-specific part is based on the CSI Protocol (CSI is part of the World Business Council for Sustainable Development, WBCSD). The EU ETS is focused at plant level and reports the amount of direct GHG emissions (t CO2) of an installation stemming from burning fuels and from the calcination of raw materials. The EN standard additionally formulates key performance indicators (KPIs) at product level, also considering indirect emissions from the consumption of electrical power. Such KPIs demonstrate the specific amount of emitted CO2 or the consumed energy per tonne of a product (e.g. t CO2/t clinker of kWh/t clinker). This means that besides direct GHG emissions, the EN standard also encompasses the monitoring of indirect GHG emissions and energy consumption not only at plant level but also at product level. Furthermore, it enables the comparison of the specific emissions of a product (clinker or cement) over time as well as the comparison with product-specific emissions from other plants.

The standardisation project was funded by the European Commission. It received special attention during a visit by representatives of the Directorate-General for Enterprise during one of the verification plant tests.

EN standard verification project

In 2013 and 2014 a total of four 48-hour field tests in two cement plants were performed to verify the different methods laid down in the cement-specific part of the EN drafted standard. A simple and a complicated test setting were chosen. Whilst in the simple test setting only fossil fuels and conventional raw materials were used, the complicated setting encompassed the use of alternative fuels and raw materials. ECRA participated by providing technical experts for the supervision of the field tests and the evaluation of results.

Basically, GHG emissions can be determined by simplified or more detailed mass balance methods (assessing the amount of all relevant input and/or output materials multiplied with their specific emission factor) or by emission measurements at the stack. The aim of the verification project was to compare five different methods.

  • Input and output mass balance methods proved their general appropriateness for CO2 emission reporting.
  • High reliability was achieved with the detailed output mass balance method. This method relies on precisely determining the clinker output of the clinker calcination process.
  • Stack CO2 emission measurements were subject to relatively high uncertainty attributed to the volume flow reference measurements.
  • The field tests highlighted the importance of appropriate sampling procedures for achieving representative raw material and fuel samples and also that careful scale calibration is of high importance for uncertainty management. Furthermore, the relevance of the different GHG defined in the Kyoto Protocol (besides CO2, e.g. CH4 and N2O) was assessed and showed no significant contribution of non-CO2 GHG.

    CSI Protocol Spread Sheet V3.1

    After the publication of the final ISO-EN standard in 2016 the CSI may potentially adapt its already existing calculation tool for CO2 emissions from cement plants accordingly. Currently, more than 960 cement plants worldwide use the CSI Protocol for internationally harmonised CO2 determination. In December 2013 the CSI published the updated version 3.1 of the CSI Protocol Spread Sheet ( This update implements the correction of two calculation formulas in the Company Sheet and a tool for data transfer to the CSI Protocol Spread Sheet. First companies started to use this updated Protocol version for their 2013 reporting for the GNR (“Getting the Numbers Right”) project. In the past the GNR data had been fundamental for describing the benchmark methodology that was the basis for the EU ETS allocation of emission allowances free of charge.

    First reports within EU ETS phase III

    The third period of the EU ETS started on 1 January 2013. Cement plants have to apply the new requirements laid down in the Monitoring and Reporting Regulation (MMR). European cement plants had to deliver their reports on direct CO2 emissions in 2013 based on new regulations for phase III (2013 – 2020) by the end of March 2014. Compared to phase II, cement plants have to follow more stringent formal regulations, e.g. regarding sampling plans, internal written procedures, the documentation of control activities and the approval of equivalence of plant laboratories compared with accredited laboratories. Furthermore, the implementation of the new harmonised rules meant that in some countries further minor emission sources had to be included which had not been reported before in phase II (e.g. fuels for room heating or emergency power equipment). Just a few weeks before the delivery deadline, a discussion on reporting CO2 from the use of urea arose in some member states. Usually, the CO2 used for producing urea stems from ammonia production plants that already have to report these emissions within their EU ETS report. In such cases, reporting by the cement plan would mean double accounting. Further guidance on this issue is expected to be published this year for 2014 CO2 emission reporting.

    This article was originally published in Newsletter 2/2014 of the European Cement Research Academy and is reproduced by kind permission of ECRA.

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