Abstracts - VGB PowerTech Journal 4/2010

Further technical subjects: Development Perspectives of Lignite-based IGCC-Plants with CCS

Dietmar Keller and Marcus H. Scholz

In 2006, RWE Power began the development of a coal-based, low-CO2 demonstration power plant, with CO2 separation, transportation and storage systems. The power plant technology selected for use was a gas-and-steam process with an integrate system for the gasification of coal. Under optimal conditions, the first power grid synchronisation is planned for late 2015. Investigations are performed on the power plant, in order to analyse the available technologies of individual process facilities, evaluate the results, and develop a consistent overall concept that can be optimised both technically and economically.

SCR DENOX Trends 2009

Joakim Reimer Thogersen and Hans Jensen-Holm

In Denmark, CO2 reduction is achieved to a large degree by replacing coal-fired power plants with wind power, biomass, waste and natural gas. The increasing use of biomass and other problematic fuels, such as certain inferior types of coal and fuels with high concentrations of arsenic, has implications for the operating life of SCR catalysts. This inhibition by a wide range of factors will be presented, and measures for overcoming it will be discussed.

SCR Catalyst Management - More than 20 Years of Experience

Herwig Maier

For more than 20 years, in accordance with what was then new legislation, SCR systems have been operating in Germany to minimise NOx emissions. By the early 1990s, the retrofitting process had more or less been completed throughout Germany. This also resulted in new challenges for the plant operators as they sought to implement an efficient catalyst management system. Various technologies are now available, and different philosophies of catalyst management have become established. The focus is on the objective of combining optimal performance with the most economical operation possible.

Cold Flue Gas Discharge in the Maasvlakte Power Plant 1 and 2

Hans-Joachim Tietze

E.ON Benelux operates the Maasvlakte hard coal power plant in Rotterdam, with two systems each delivering 540 MW. Due to new environmental protection regulations, both generating units had to be fitted with denitrification systems by 2007. In this context, the retrofitting to allow wet chimney discharge constituted an economic necessity. The retrofitting work and the effect of the wet chimney operation mode on the existing plant components will be described.

Online Emission Measurement at Large Combustion Plants

Erich Polzer

The CEN TC 264 was tasked with developing normative regulations for ensuring the monitoring of  emission limited values at refuse incineration plants within the European Union. This was based on corresponding specifications from the European Union regarding measurement inaccuracies and technical experience and regulations for working with continuously operational monitoring systems. Directive EN 14181 summarises the regulations intended to ensure uniform procedures in online emission measurement technology within the European Union.

Requirements on Flue Gas Cleaning Under Oxyfuel Conditions

Daniel Kosel and Heike Meyer

CCS technologies for power plants and industrial processes also place new requirements on familiar and proven systems. For the process of flue gas desulphurisation, the Vattenfall coal-fired plants typically use wet scrubbers based on limestone. This technology is now also to be used for oxyfuel power plants. As regards the flue gas purification system, it must be noted that CCS technologies, and particularly the oxyfuel process, significantly increase the performance requirements for the purification system. Operating results from the Vattenfall oxyfuel research facility at 'Schwarze Pumpe' have shown that these new requirements can be met.

Fluoroplastic Materials for Pressure Tubes in Flue Gas Heat Exchangers under Corrosive Conditions of Flue Gas Desulfurisation Plants

Gabriele Gottschalk-Gaudig, Siegfried Broda, Frank Adamczyk and Klaus Kreilos

Since the 1980s, power plants have been required to have flue gas desulphurising plants. For the cooling of flue gases to below the acid dew point and subsequent reheating, corrosion-resistant gas-gas heat exchanger systems had already been developed at this time by what is now Babcock Borsig Service GmbH (BBS). The best results were achieved using 100 % plastic piping as a vital component. In addition to the development of the plastic heat exchangers and the differences in design relative to alternative models, the various types of fluoroplastics will be discussed, and in particular the difference between PFA and PTFE.

Investigations of Aqueous Multi-component Amine Systems as Scrubbing Solutions for Separation of CO2 from Flue Gases

Anke Schäffer, Kevin Brechtel and Günter Scheffknecht

Alongside IGCC and oxyfuel technology, amine gas treatment offers an option for separating CO2 from power plant flue gases. The process has already proven itself in the chemical industry, from both technical and economic perspectives, and is suitable for the retrofitting of power plants. A disadvantage of the system is the high energy demand for regeneration, which can reduce the power plant efficiency by up to 13 %. Within the context of a COORETEC project, IFK is monitoring amongst other things the development of new treatment solutions, which could reduce the extent of the efficiency loss by improving solvent properties.

Temporary Needs for Water Demineralisation in Large Power Plants

Guillaume Kalfon

Water demineralisation plants, used to obtain fully demineralised water from spring water, drinking water or rain water, form a major component of every steam turbine power plant. Continuous 24-hour availability is of considerable importance here. In the event of non-availablility of the stationary plant, a mobile plant can be used to avoid operational downtime. For this purpose, the mobile plant must have the best available technology for the demineralisation process, the distribution, the design and the administration of the production and regeneration settings.

The Mechanism of Mercury Separation in Wet Flue Gas Cleaning Systems

Margot Bittig, Dieter Bathen and Bernhard Pieper

The effects of various parameters on the mercury separators in a flue gas treatment system will be discussed. For the first time, the ratio of ligand concentration to the concentration of divalent mercury in the treatment fluid will be brought into the discussion, and the effects of various ligands will be examined. The significance of the results and the model developed for absorptive flue gas treatment will be demonstrated. Optimisation suggestions will be derived, both for existing plants and for planned facilities.

Long-term Experience with Maleic Acid in a Hard Coal-fired FGD Unit

Niels Ole Knudsen

The addition of adipic acid to increase the gas cleaning efficiency of lime water in brown coal power plants is the state-of-the-art approach. In hard coal power plants, functional considerations mean that adipic acid is used less frequently. In Block 3 of the Nordjyllandsværket hard coal power plant, maleic acid was used over an 8-year period with great success, improving the desulphurisation capacity and simultaneously reducing operating costs. The greatest advantage of maleic acid as opposed to adipic acid is its exceptional biological stability in the flue gas desulphurising plant.

Filtration with High Efficiency Fibres in Coal-fired Boiler Applications

Florin Popovici

Modern filter media based on polymer fibre materials. Chemical properties of the base material and filtration performance are the major selection criteria. Composite materials can combine the positive characteristics of the respective base materials, if combined appropriately. The filtration properties of multilobal P84 (polyimide) fibres and trilobal Procon (PPS polyphenylenesulphide) fibres will be compared to those made from standard PPS fibres. An evaluation was also completed in a test stand specially designed for the purpose. Examples from power plants in South Africa will be presented.