Open AccessA new technique for real-time measurements of potassium and sodium aerosols based on field-reversal surface ionization
Author(s) -
D. Gall,
Charlotta Nejman,
Thomas Allgurén,
Klas Andersson,
Jan B. C. Pettersson
Publication year - 2021
Publication title -
measurement science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.48
H-Index - 136
eISSN - 1361-6501
pISSN - 0957-0233
DOI - 10.1088/1361-6501/abe130
Subject(s) - alkali metal , potassium , ionization , sodium , aerosol , analytical chemistry (journal) , ion , thermal ionization , combustion , materials science , field desorption , desorption , lithium (medication) , chemistry , environmental chemistry , adsorption , electron ionization , medicine , organic chemistry , metallurgy , endocrinology
A new method for real-time measurements of potassium and sodium containing aerosol particles is described and verified. The method is based on surface ionization technique and may be used to explore the alkali chemistry related to high temperature chemistry processes. The measurement device is a further development of the simple and cost-effective surface ionization detector previously used for online alkali measurements in combustion and gasification research. The discrimination between sodium and potassium is possible due to differences in their surface desorption kinetics and facilitated by rapidly reversing the field potential between the ion source and the nearby collector. The instrument is evaluated in a series of laboratory experiments using size-selected alkali salt particles containing KCl, NaCl, K 2 SO 4 , Na 2 SO 4 , KNO 3 and NaNO 3 . The filament temperature was found to be a key influencing factor in order to optimize the strength and Na–K deviation of the observed ion current. The ability to simultaneously report absolute concentrations of Na and K makes the instrument attractive for solid fuel conversion of alkali-rich fuels such as low-grade biomass and to explore behavior deviations of Na and K in high temperature processes.