Abstracts - VGB PowerTech Journal 8/2010

Energy Conversion and CCP Management of EDP

Fernando Caldas Vieira, Carlos Cunha and Arlindo Goncalves

EDP - Energias de Portugal is the main player in the Portuguese energy sector. In the generation branch in Portugal, EDP has an installed capacity of 10,200 MW, from which 1,180 MW are based on coal. In a regular year Sines coal combustion is over 3,700000 tonnes, producing about 360,000 tonnes of fly ash, 35,000 tonnes of bottom ash as well as 210,000 tonnes of FGD gypsum. All quantities of fly ash are sold to the cement and concrete industries. For the use of bottom ash a European Technical Approval was requested for a mix of ground bottom ash and fly ash to produce a specific type of concrete addition.

Extended Operation of the 500 MW Units at Boxberg and Jänschwalde Power Plants - Project B500 of Vattenfall Europe Generation

Gerald Weiß and Günter Lentföhr

Vattenfall Europe Generation AG generates electricity from lignite with a gross installed capacity of 4000 MW in the eight 500 MW units at theJänschwalde and Boxberg plants. Investigations were carried out in 2004/2005 with a view to further optimising the utilisation of the power stations until 2030. The new findings show among others measures for long-term operation. These measures are integrated into the project B500 in the years 2008 to 2014.

Flexibilisation of Thermal Power Generation in Europe - An Essential Element for Climate Protection

Günther Brauner

The European targets for climate protection intend a significant extension of the renewable energy sources (RES) until the year 2020. Under this aspect future scenarios are possible, where RES will temporary reach about 70 % of all generating capacities. From these facts follows that thermal power generation will play an important role for supply security during periods of low generation conditions of RES. So the scheduled energy generation will be more prominent defined by RES and the capacity factors of thermal power stations will shrink to about 25 to 35 % (2,000 to 3,000 full load hours).

Development of Coal Combustion in Europe

Andreas Hugot and Roberta Leotta-Hauer

Coal-based power generation has always been a major pillar of European electricity supply and Europe will continue to rely on coal also in future although public acceptance is often missing concerning coal development, environmental impact and social consequences. The paper describes current and future energy conversion with the coal markets and coal qualities as well as the relation to coal by-products and their utilisation. Future market needs are an additional aspect.

REACH Registration of Coal Combustion Products - Background and Status

Hans-Joachim Feuerborn

On 1st June 2007, the REACH Regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals) became effective. According to REACH, every single manufacturer who wants to market and/or import by-products (CCPs) from the energy industry has to register these substances with the European Chemicals Agency (ECHA) in Helsinki. Since 1st June 2008, CCPs that had not been registered are not to be produced and/or marketed in Europe. Extended deadlines can be applied to pre-registered substances.

Flue Gas Desulphurisation Gypsum as a Raw Material

Jörg Demmich

For decades the use of wet desulphurisation processes with the production of FGD gypsum has been well-proven in the power industry around the globe. In the meantime the European gypsum industry has also adapted with additional investments to the processing of moist, finely divided FGD gypsum. However, it is extremely difficult at this point of time to give any corresponding long-term prognosis on the development of the environment and energy policy with respect to the long-term raw material supplies with FGD gypsum for the gypsum industry. Two very different scenarios are described leading to entirely different results regarding FGD gypsum production in Germany. One of the scenarios expects a substantial extension of renewable energies in Germany. According to that, this would lead to a considerable reduction of FGD gypsum quantities produced at least in Germany.

Environmental and Health Aspects of Coal Co-combustion Ash

Henk te Winkel

Co-combustion is an important aspect of power generation from coal in the Netherlands and additional European countries. It is important that the environmental and occupational health aspects of fly ash are not negatively influenced by co-combustion activities. Since 1993 KEMA has studied the effect of direct co-combustion in more than fifty test series. In these test series secondary fuels were co-combusted in proportions up to 40 % by dry mass.

Characterisation of Coal Ashes with Respect to Slagging in Steam Generators

Bernhard Bonn

For a long time characterisation of coals with respect to their slagging and fouling tendency has been based on parameters that refer to chemical ash composition. These parameters are imprecise when trying to predict the behaviour of unknown coals. A VGB working group tried to extend these parameters by adding boiler parameters thus improving accuracy. No sustainable results have been available yet.

Fly Ash in Hydraulic Road Binders - Long-term Observation on Existing Roads Versus Laboratory Test

Wolfgang Weingart

On nine different test roads in Germany from the years 1983 to 1998, built with fly ash bound base courses, field investigations were carried out. It was verified that suitable fly ash bound mixtures are sufficiently resistant against frost and have a high long-term durability under the prevailing climatic conditions in Germany. The application of European standards for fly-ash bound courses can be recommended in Germany and construction costs can be saved by applying the alternative hydraulically bound base courses.

Easy Workable Concrete with Small-sized Aggregates and High Stability against Segregation - From the Laboratory into Practical Application

Ludger Lohaus and Thomas Gläser

The design concept was developed for a new kind of fly ash-rich fine concretes characterised by a very good workability and high stability against segregation, while at the same time being free from the well-documented problems associated with the conventional sand-rich and sand concretes. The new design concept leads, with the help of fewer mortar tests, to an easily workable concrete with high stability against segregation by using regional typical basic materials the fine concrete with low cement content has significantly favourable fresh concrete behaviours. A concrete witch was composed by the design concept was successful tested in a precast.

Durable Bridge Construction with Fly Ash Concrete

Thomas Eck and Eberhard Schneider

At present, the focus of the research work in the field of concrete is on the durability of especially fly ash concrete. One main topic frequently discussed is the freeze thaw and de-icing salt resistance of fly ash concrete. As a consequence of research work over the last years an extension of the accounting of fly ash for the exposure classes XF2 and XF4, i.e. concrete exposed to freeze/thaw with de-icing salt and moderate or high water saturation, has been achieved in the revision of DIN 1045-2. However, this accounting for the calculation of the water cement ratio is still not allowed for civil engineering structures according the additional technical contract details for engineering concrete (ZTV-ING) of the German road authority with the exception of inner tunnel linings. Investigations regarding the durability of these fly ash concretes of the Saalebrücke Rudolphstein and the Schornbachtalbrücke have been carried out and are described in this article.

New Testing Concepts and Post-weld Procedures Tap Important Optimisation Potential in Plant Construction

Hans Christian Schröder, Peter Gerster and Frank Schäfers

Newly developed testing concepts and innovative procedures for post-weld treatment cut costs. Their application often requires a pragmatic approach to the existing codes and standards. Examples are the TÜV SÜD testing concept "gAte4optimisation" for evaluating the remaining service life of power and process plants, and modern post-weld procedures like hammer peening with "Pneumatic Impact Treatment (PIT)" by PITEC.