First LOESCHE seminar focusing on “Alternative Fuels” generated a lot of interest
Over 80 participants, among them cement plant operators, business partners and clients from 20 different countries, listened attentively to the presentations on the topic of alternative fuel technologies at the LOESCHE seminar in Vienna.
Vienna – The first joint seminar of LOESCHE GmbH and A TEC Production and Services GmbH with the special focus on alternative fuels took place from 6th – 8th May 2015 in Vienna, Austria. More than 80 interested participants registered for this.
The future of the alternative fuel sector, the development in the cement and limestone industry with regard to solid alternative fuels and solutions to problems arising from the operation of the combustion process with a high proportion of alternative fuels were presented and discussed during the seminar. There was also a focus on the experiences in the preparation of alternative fuels in the new chain beater mill, the “Rocket Mill”, from A TEC.
After a sightseeing tour through Vienna in a historic tram specifically rented for this purpose and a welcome dinner on the Danube embankment the night before, the seminar programme started on Thursday 7th May with an introduction by Dr Thomas Loesche and the presentation “Step by step towards alternative fuels”, which was excellently presented by Matthias Mersmann.
The current trend towards the global tightening of emission regulations is a sign that this side of the process may also not be neglected and sometimes poses great challenges to the plant operator. These limit values often occur coupled with the use of alternative fuels. Due to the introduction of a new limit value in Germany that comes into effect from 2018, everybody is talking about nitrogen oxides (NOX), which is why they were a focus of the next presentation.
In his presentation “NOX reduction below 200 mg/Nm³”, Dr Stefan Kern from A TEC demonstrated not only the mechanisms of formation of NOX during combustion in cement plants but also the NOX mechanisms of decomposition. This served as a basis for explaining the correct design of a staged combustion in a calciner as an effective measure for reducing the NOX emissions to a low level without using ammonia or urea. Should the NOX value be above the limit after this, a cost-effective SNCR-system can be used, which injects ammonia or urea in small volumes in order to achieve the target value.
Then the ReduDust concept was presented by Dr Ernst-Michael Sipple from Holcim Eastern Europe and Johannes Müllner from A TEC. This involves a full recycling of the bypass dust utilising the “ReduDust” procedure. Initial operational experiences in the Holcim cement plant in Rohožník, Slovakia, show that approx. 4,000 tons of saleable salts can be produced from 20,000 tons of bypass dust annually. The chloric salts that cling to the bypass dust are dissolved in a salt solution and separated from the purified bypass dust (Cl-free) using a filter. After purifying the salt solution, these can be crystallised into KCl and NaCl.
A still very recent project of A TEC for increasing the use of alternative fuel was presented by Mr Harald Durstberger (A TEC) before a short break. His presentation “Calciner modification including a new hot gas chamber by Buzzi Cement Hranice” demonstrated the reconstruction of the cement plant in Hranice, Czech Republic, where A TEC together with the Czech partner Aliacem designed and built a calciner. A TEC was responsible for the engineering and the supply of components here, whilst Aliacem was responsible for the steel construction, heat-resistant lining and the construction work on site. The striking thing here is that the design of the combustion chamber functions without hot meal and thus alternative fuels can be used with a very low quality and a very low calorific value.
A networking coffee break gave all attendees the opportunity to make new contacts and exchange ideas.
The programme continued with a further presentation by Matthias Mersmann, who explained process optimisations for the cement industry through the aixergee GmbH. In his presentation, he explained aixergee’s way of working as well as impressive methods, which illustrate every aspect of the pyro-process through CFD modelling. Optimisation projects coherently completed the overall picture.
Then Mr Georg Lechner from Scheuch explained the latest trends in filter technology. The focus was on Scheuch’s new technology for combined denitrification (De-NOX) and for the removal of CO. This system “DeCONOX” is currently installed in the cement plant in Kirchdorf, Austria. The different process variants of SCR denitrification systems were also explained.
In the cement industry, in which operators are constantly searching for ways to reduce production and energy costs, there has been a strong movement towards alternative fuels. The combustion of materials like household waste (municipal waste, MSW, RDF) is on the rise and is increasingly replacing traditional fuels such as coal.
Dr Hansjörg Diller from MVW Lechtenberg und Partner informed the delegates in his presentation “What will be the future of alternative fuels” about the current and future trend of using alternative fuels globally, and especially in Egypt and Europe. The participants were presented with several informative figures regarding the market.
After lunch, the interested participants went to the Rohožník cement plant in Slovakia. Here the ReduDust concept, which makes it possible to efficiently recycle 20,000 t/y of bypass dust, was presented clearly and explained in greater depth during the visit of the plant.
In the evening, the guests had the opportunity to review the day at a relaxed dinner on Kahlenberg hill with a view over Vienna.
Michael Suppaner (A TEC) kicked off the second day with his presentation “Ultimate cement kiln process technology”. The presentation gave an overview of the requirements for designing the pyro-process. He also presented in detail the A TEC Post Combustion Chamber (PCC), which has a positive effect on emission reduction (CO, NOX) and through which the performance regarding alternative fuels (and petroleum coke) increases.
Johannes Uttinger from A TEC explained in his presentation the experience of the company with the new chain-beater mill (Rocket Mill), which was first presented at the LOESCHE Symposium in 2014. The many advantages of this mill compared to conventional shredders and cutting mills can, in principle, be summarized into the following aspects. Crushing is possible in one step from < 300 mm to < 15 mm, which is the ideal size for main burner fuel. At the same time as being crushed, the material is dried and inorganic components (ash) are separated. With the crushing technology, a product with a particularly high specific surface area is generated, which has a very positive effect on the ignitability and the burnout. Impressively, it was reported that the mill had already achieved enormous operational cost reductions after just a few weeks in operation, and that the substitution rate of alternative fuels was able to be significantly increased due to the better fuel quality.
The new burner from A TEC GRECO, the FLEXIFLAME EcoPro, which was designed for operation with up to 100 % solid alternative fuels, was presented by Martin Willitsch, A TEC GRECO Combustion Systems Europe. The presentation also gave insight into the combustion phases and processes in the main burner.
The final presentation of the seminar was held by Friedrich Willitsch (A TEC). With the presentation “Mercury emission reduction in cement kilns”, the new system “ExMercury” for reducing mercury emissions was presented.This system was jointly developed by A TEC, Scheuch and the cement factory W&P Weitersdorf. In this system, the mercury cycle in the raw meal / filter dust is broken by treating the filter dust. This dust is heated, which causes the mercury to vaporise. The dust can be reused in the system whilst the mercury vapours are adsorbed by activated carbon. The low energy and minimal activated carbon requirements are a special feature of the system.
This presentation served as a preparation for the plant visit which followed directly thereafter. The participants travelled together by bus to the cement factory of Weitersdorfer & Peggauer GmbH in Carinthia. After a hearty lunch on-site, not only were the operational experiences with the chain- beater mill (Rocket Mill) and the FLEXIFLAME Eco Pro burner presented, but also the “ExMercury” system used for reducing mercury in operation. The interested participants had the opportunity of asking their detailed questions directly to the satisfied cement factory operators and were impressed by the positive operating results.
On the bus journey back to Vienna through the beautiful scenery of Austria, there was plenty of time for further discussion and initial enquiries.
Dr. Thomas Loesche was pleased with the strong interest on the subject of alternative fuels and he himself took some ideas back with him to Düsseldorf.
LOESCHE, specialised in the development and construction of energy-saving combined drying and grinding plants for the cement, steel, ore, power station and industrial minerals industry, is always a step ahead when it comes to environmental topics like CO2 reduction or preservation of primary raw materials.
A TEC, the Austrian pyro-process expert and part of the LOESCHE Group since 2010, extended LOESCHE’s product portfolio in recent years with several specific products in the area of plant optimisation and alternative fuel use.