Detection of alkali path in a pilot-scale combustor using laser spectroscopy and surface ionization — From vapor to particles
Journal article, 2023

Alkali species have been under intensive research in thermal conversion applications due to their abundance especially in biomass fuels. Alkali metals, sodium (Na) and potassium (K), are known to cause severe operational problems in combustion units, such as slagging, fouling, and corrosion. In this work, we present a monitoring method to follow alkali behavior from vapor to particles in a pilot-scale reactor. In our approach we combine Tunable Diode Laser Atomic Spectroscopy (TDLAS) for atomic potassium monitoring, Collinear Photofragmentation and Atomic Absorption Spectroscopy (CPFAAS) for KCl and KOH detection, and Surface Ionization Detection (SID) for monitoring of total flue gas and aerosol alkali content. Experiments were carried out in the Chalmers 100 kW oxy-fuel combustion unit that, during these experiments, used propane as fuel. Alkali species were injected as a water solution directly to the flame. In addition, SO2 was used to alter the conditions for alkali species formation injecting it directly to the combustion feed gas. Due to the alkali monitoring system described, we were able to monitor the alkali behavior during nucleation and sulfation processes. The conditions for dimer formation and heterogeneous nucleation were observed when the temperature conditions were changed by lowering the thermal input to the unit.

Potassium

Diagnostics

Sulfation

Alkali

Nucleation

Author

Jan Viljanen

University of Tampere

Chalmers, Space, Earth and Environment, Energy Technology

Dan Gall

Chalmers, Space, Earth and Environment, Energy Technology

Ivan Gogolev

Chalmers, Space, Earth and Environment, Energy Technology

Thomas Allgurén

Chalmers, Space, Earth and Environment, Energy Technology

Klas Andersson

Chalmers, Space, Earth and Environment, Energy Technology

Fuel

0016-2361 (ISSN)

Vol. 343 127900

International collaboration for the development of a two-step selective oxidation process

Swedish Energy Agency (44887-1), 2017-10-02 -- 2021-09-30.

Subject Categories

Chemical Process Engineering

Atom and Molecular Physics and Optics

Other Chemical Engineering

DOI

10.1016/j.fuel.2023.127900

More information

Latest update

3/14/2023