Determination of ions in ash using ion-selective electrodes
Saxena, Divisha (2023)
Saxena, Divisha
2023
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2023081195272
https://urn.fi/URN:NBN:fi-fe2023081195272
Tiivistelmä
The aim of this research work is to evaluate suitability of ion-selective electrodes for determination of Na+, K+, Cl-, CO32- and pH in electrostatic precipitator (ESP) ash samples from a recovery boiler provided by Andritz Oy. The ash composition is an important detail for soot blowing (cleaning) of a recovery boiler and an approximate concentration range of Na+, K+, Cl-, CO32- and SO42- in the ash samples has been provided from Andritz analysis database. K and Cl composition is the most important parameter for the fouling analysis. This research work involves preparation and testing of multi-ion standard (calibration) solutions and PVC membrane-based carbonate-selective electrodes. Commercial ion-selective electrodes are used for Na+, K+, Cl- and pH measurement and a carbonate-selective electrode prepared in our lab was used for estimation of CO32- content in the ash samples. The SO42- content (mass %) is calculated as remaining ions in the solution. Due to the relatively high ion concentrations in the samples, a very low limit of detection is not needed here, while the electrode selectivity and stability (ruggedness) are important. The Na+, K+, Cl-, CO32- and SO42- are always present in an estimated range in the ash samples. This work focuses on the accuracy and precision of ion measurements with ion-selective electrodes.