Untersuchungen zur Alkalireinigung von Heißgasen für Anlagen mit Kohlenstaub-Druckfeuerung

Combined Cycle Power Systems with Pressurized Pulverized Coal Combustion are the most sufficient way to increase the efficiency in coal utilization. Therefore it can make a positive contribution to reduction of CO2-Emission and protection of resources. Alkali metals, released during combustion at temperatures above 1600 °C, can cause hot corrosion of gas turbine materials in contact with the hot flue gas. That's why a hot gas cleanup related to alkalis is indispensable. Silicate melts like coal ash slags have a high alkali retention. Thus it was investigated how far the sorption potential of a boiler slag can be improved by polymerizing additives (Al2O3, SiO2 and TiO2). Boiler slags as well as synthetic slags with a reduced number of components (Al2O3-SiO2-CaO-Na2O) were studied. Synthetic slags were mixed under structural considerations to achieve rheological properties similar to boiler slags. Vaporization investigations by Knudsen effusion mass spectrometry were carried out to determine the activities of alkali species in the samples. A relationship between structural and thermodynamic properties has been determined. Since the alkali retention of coal based slags is insufficient for a hot gas cleanup, different technical and synthetic aluminosilicate materials were investigated by annealing experiments and mass spectrometry. Promising alkali sorption in the relevant temperature range (1250 - 1450 °C) only takes place by forming glasses or melts. Therefore the glass forming system Al2O3-SiO2-Na2O has been optimized. Best alkali sorption was achieved with a Al2O3/SiO2-ratio of 1/8. Finally, thermodynamic calculations were done to compare the corrosion potential of a hot gas cleaned on basis of this work with the corrosion potential of light fuel oil. The cleaned hot gas achieved better results.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2003

Author dc:creator

• Willenborg, Winfried

Contributors dc:contributor

• Singheiser, Lorenz

• info:eu-repo/classification/ddc/620
• Kombinationskraftwerk
• Kohlenstaubfeuerung
• Druck
• Heißgasreinigung
• Alkaliverbindungen
• Adsorption
• Adsorbens
• Kohlenschlacke
• Ingenieurwissenschaften
• Druckkohlenstaubfeuerung
• Alkalireinigung
• alumosilikatische Gläser

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-120986%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:59176