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- Title: Researching the reduction of CO2 emissions
- Author(s): Dr. Martin Schneider, Chief Executive, Verein Deutscher Zementwerke (e.V.), Germany, describes the organisation’s research into how waste fuels and blended cements can form the basis for a continuous reduction of CO2 emissions from cement production.
- Synopsis:
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For over 125 years the Verein Deutscher Zementwerke (e.V.) (VDZ) and its Research Institute have been committed to research for quality and progress in the production of cement and its use in concrete. Even as early as the end of the 19th century, the focus of research activities was on technical questions. For example, the most urgent research projects were devoted to new guidelines for testing and to the influence of the different cement constituents on the performance of cement.
Today, and in the years to come, the Institute’s work covers a much broader range of topics. One of the reasons is that cement producers are challenged more and more by economical and environmental considerations. CO2 emissions from cement production must be further reduced and industrial wastes and by-products must be used to save natural resources and fossil energies. As a consequence, cement and concrete research focuses on alternative materials for clinker production. At the same time, the clinker content in cement must be lowered without undermining the performance and environmental compatibility of market-oriented cements.
- Title: Valorisation of waste in cement kilns
- Author(s): Jean-Marie Chandelle, Chief Executive, CEMBUREAU, the European Cement Association, considers the impact of EU legislation regarding waste on the use of waste as alternative raw materials and fuels in the cement industry, and the strategic response which is being developed by the cement industry.
- Synopsis:
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Fortunately, the demands for improved environmental protection and business requirements for growth do occasionally meet. This is definitely the case for the ‘valorisation’ of waste, a new terminology coined to describe the use of waste as alternative fuels in the cement industry.
To environmental policy makers, the use of waste as alternative fuels offers an environmentally beneficial and safe solution to cope with the huge volume of waste generated by human activity. In years to come, when landfilling is rightly no longer regarded as an acceptable option, the ‘valorisation’ of waste (the most efficient way to recover energy and raw materials from waste) will be on the agenda more than ever.
- Title: Environmental constraints
- Author(s): Eric Knies and Steven Miller, F.L.Smidth, Inc., USA, present their view of the future of cement production under the pressure of increasingly stringent environmental constraints, and explore technological solutions which are being designed to carry the industry into the future.
- Synopsis:
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Over the long term, the current trend of increased stringency of environmental constraints continues to gain momentum, becoming an ever greater consideration for both expansion and continued operation of all industries. The cement industry has responded well, with new technological solutions to keep up with the rising bar for improved levels of environmental compliance and is well positioned to continue to do so in the future. Environmental policy has also introduced opportunities for the cement industry, as a means of acceptable disposal for both hazardous and non-hazardous waste. This paper will provide an overview of how the cement process is most directly impacted and current technological solutions that are envisioned to carry the industry into the future.
- Title: Alternative developments
- Author(s): W. Goetzhaber, Wietersdorfer & Peggauer Zementwerke GmbH, Austria, discusses developments for alternative fuels usage at the company’s clinker manufacturing plants.
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- Title: Secondary Fuel Installation
- Author(s): Anton Secklehner and Lutz Weber, Kirchdorfer Cement Plant, describe the installation of a secondary fuel facility at Kirchdorf, Austria.
- Synopsis:
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Founded in 1888, the Kirchdorfer cement plant is located in Upper-Austria. The plant’s kiln system is a 4-stage preheater including bypass with a grate cooler built in 1962 to produce 450 tpd with 100% coal firing.
This continuous improvement led to a limit of the coal mill. Although it was adapted in 1983, a transition to a mixed firing of coal and natural gas was necessary. Due to its proximity to the centre of Kirchdorf, environmentalism plays a major role in the policy of Kirchdorfer Cement Plant.
- Title: Reducing CO2 Emissions
- Author(s): Robert Novak, Wopfinger Baustoffindustrie GmbH, Austria, outlines two innovative initiatives which help to reduce CO2 emissions and preserve the environment.
- Synopsis:
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Wopfinger Baustoffgruppe, also known under the brand name Baumit, with its main production site in Wopfing, Lower Austria, is one of the most traditional yet innovative Austrian lime and cement plants. Numerous procedures and technological developments, for example, the so-called Maerz kiln, come from Wopfing and are some of the most modern, energy saving and innovative technologies available. A unique feature of Wopfinger Baustoffgruppe is the concentration of four production sites for lime, cement, ready-made mortar and facing plaster, in a single location. The company belongs to Schmid Industrieholding, which achieved in 2002 a turnover of E500 million with approximately 2800 employees in 14 European countries.
- Title: Reducing Nox Emissions
- Author(s): Bernardo Arecco, Buzzi Unicem, Italy, looks at how the Barletta plant, Italy, chose to tackle NOx emissions.
- Synopsis:
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The new main burner for the Barletta plant, with five primary-airways, was built in Italy as a C. Greco project. Its main fuel is pulverised petcoke. For heating up the kiln with high viscosity oil it uses a multi-nozzle, annular lance with compressed air aided nebulisation integrated in the burner’s tip.
The burner has been installed on a 1993 Polysius kiln system, 4 m dia. x 55 m with a 3% slope, five-stage preheater tower and grate cooler that produces 2500 tpd of clinker. Its specific consumption is approximately 820 kcal/kg, with 55% of the total heating load at the kiln hood (petcoke) and 45% at the calcinator (petcoke and solid alternative fuel such as plastics, tyres and rubber).
- Title: Cutting NOx: A success story
- Author(s): Yngvar Cramer, jura cement, Switzerland, describes the procedures involved in reducing NOx emissions at the company’s Wildegg plant, and the resulting successes.
- Synopsis:
- jura cement Wildegg belongs to the Swiss JURA-Holding, a company within the CRH group. The plant’s kiln system is a 4-stage Polysius Prepol® MSC (Multi Stage Combustion) calciner with grate cooler and a Lurgi baghouse filter for emission control. The Wildegg plant is located at the border of the Aare River, halfway between the small towns of Aarau and Brugg. The plant acquires its raw materials, limestone and marl, from the Jura mountains just across the river. The plant is situated amidst urban housing areas which is why the company, on a voluntary basis, developed an environmental awareness many years ago, adding a certified ISO 14000 environmental to its ISO 9001 quality management system in 1998. Swiss authorities set the first emission limit for NOx to 1500 mg NOx/Nm3 in 1986. This limit was lowered to 800 mg in 1991. In order to comply with the Swiss national measure plan to lower the overall NOx emissions to the level of 1960, Swiss authorities and Cemsuisse, the Association of the Swiss Cement Industry, signed an agreement in 1998 to gradually lower the total NOx emissions from cement clinker production by 20% until 2010. Swiss environmental emission laws for cement kilns and the agreement to reduce NOx do not differentiate between existing and new kilns as in other European countries. To comply with these stringent Swiss environmental laws, the company had to implement primary and, in the end, also secondary step by step measures to lower emissions.
- Title: Modern Filter Techniques
- Author(s): Theo Schrooten, Intensiv-Filter GmbH & Co. KG, Germany, provides information on the most recent developments in filter techniques for the cement industry.
- Synopsis:
- In all industrial areas legislation demands limited emission values for exhaust gases. These values are continually made more stringent and adapted to the best available technology. This affects the production of cement and clinker as well as peripheral plants in the cement industry. Regulations and guidelines of the European Parliament and their conversion into national legislation (e.g. in Germany: ‘Federal Law of Protection against Emissions’) constantly force producers to install more effective cleaning equipment.
Filtering separators are becoming increasingly important with regard to the separation of dust particles and other pollutants. They replace separators which can not be retrofitted economically and therefore have to be replaced (ESP - Electrostatic Precipitator).
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