Technology efficiency and kiln economy
One key driver for the reduction in emissions is the increased efficiency of technology and kiln economy. According to the data, the investments made by the industry have effectively reduced the use of old inefficient technologies, such as wet process kilns, since 1990. The energy intensive nature of the clinker process means that optimised efficiency minimises both CO2 emissions and production costs.
However, the GNR demonstrates there are regional differences in the use of technology. For example, in emerging economies such as India and China, huge investments in new efficient cement capacity in recent years have enabled them to lead the industry in kiln economy. They are now on average more efficient than the cement capacity in the older economies of Europe, the US and the Commonwealth of Independent States (CIS).
The radical improvement in the kiln economy of the Chinese industry between 1990 and 2011 was achieved by investment in new precalciner kilns and the retirement of old shaft and wet kilns.
Increasing use of alternative fuels
Another driver of reduced emissions is the use of alternative fuels. According to the GNR data, the industry has increased its use of biomass and fossil and mixed wastes. While a few plants have been able to replace up to 90% of conventional fuels, average replacement worldwide remains low at 13%. This is in part due to the barriers of availability and difficulty in attaining permits. Although the use of alternative fuels is increasing in Europe, Central and North America, and Japan, the data shows that uptake is still low in major cement production regions such as CIS, China and India.
Reduction in clinker content
Reducing the clinker content of cement by replacing it with other useful minerals is another powerful driver for reducing the industry’s CO2 emissions. The degree of real emissions reductions achieved is dependent on the specific mix used by concrete manufacturers. In many countries, the replacement minerals are added at the concrete mixer rather than at the cement mill.
Some regional variations are apparent in cement clinker contents. Regions with lower clinker-to-cement ratios include Brazil, Central and South America, China, Europe and India. The specific minerals used also vary from region to region, depending on availability. For example, cement plants in regions with strong steel industries tend to use slag in cement production.
Decrease in electricity use
An important driver of reduced indirect emissions is the use of electricity. The GNR data shows that consumption of electricity per tonne of cement has reduced globally by 8% since 1990. As with kiln economy, investment from developing economies has resulted in the development of more efficient plants. For example, modern vertical grinding mills, roller presses, separators and mechanical conveying equipment technologies can reduce electricity use to 90 kWh/t of cement.
The data shows a trend of decreasing electricity use across most regions, particularly those with historically high usage such as the CIS, Middle East and North America. However, regional efficiency comparisons must be made with care, as some regions have significantly different standards that allow lower electricity consumption per tonne of cement, but will require higher cement contents in concrete.
The GNR system provides the cement industry with global and regional performance and emissions data, helping members to understand their own performance compared to the rest of the industry and supporting them in the development of effective mitigation strategies. The 2011 data presents evidence of the progress that the industry has made in reducing CO2 emissions and continued plant efficiency, as well as highlighting continuing areas of focus such as increasing use of alternative fuels, reduced clinker content and industry-wide decreases in the use of electricity. Whilst there are some regional variations, the latest reports demonstrate overall improvements in efficiency and mitigation, as well as growing participation from producers worldwide.
The database is managed by an independent third party service provider. In all, 94% of the data is verified independently at the participating company level, making it a very reliable source of information. It also complies with anti-trust laws, so confidential information on individual companies or plants is not disclosed or made accessible, and is protected by contractual and data security measures. Individual participants may only see reports based on their individual company data or aggregated results.
Benefits for participants
The GNR database helps participating companies to manage their energy and CO2 levels, track kiln technology and fuel selection changes that impact emissions and therefore drive internal performance improvements. Trade Associations get access to verified information from across the industry to support their own research and their discussions about climate and energy policies with their governments. Policy-makers get a clear picture of the cement industry’s emissions, and their underlying drivers, giving them a basis for setting emissions benchmarks and working towards reductions.
Invitation to participate
The CSI has designed the GNR system as an open platform to encourage organisations globally to join and participate, contributing data in order to build the broadest dataset for analysis and use.
Joining the GNR system provides access to state-of-the-art data and analysis of the cement industry’s global and regional performance, allowing participants to benchmark their own performance, track their emissions inventories, and develop sound, data-based responses to company and regional climate management issues.
Part 2 of 2. You can find Part 1 here.
Written by Philippe Fonta, of the WBCSD Cement Sustainability Initiative. This is an abridged version of the full article, which appeared in the September 2013 issue of World Cement. Subscribers can view the full article by logging in.
Read the article online at: https://www.worldcement.com/europe-cis/29082013/new_data_for_cement_industry_shows_reductions_in_co2_emissions_2_210/