SPA-method
The Solid Phase Adsorption method (SPA) for tar sampling and analysis was proposed by Brage, Sjöström and Liljedahl in 1997. It is in priinciple a solid phase extraction (SPE) method. In a first step gas from the process is drawn from a sampling port at the plant over an adsorber cartridge. After sampling the cartridge is sealed and taken to the laboratory for further analysis. In most SPA applications the sampled species are removed from the adsorbent by liquid extraction with solvents. A further method making use of different adsorber types and subsequent extraction by controlled thermal desorption was published by Dufour et al. in 2011.
SPA with liquid desorption of the analytes is extensively in use e.g. at the energy research center of the Netherlands (ECN). Here the method has been further adapted and developed. Researchers from Chalmers University published their version of SPA application for sampling in industrial and large scale demonstation plants [Israelsson et al. 2013]. Osipovs recommended in 2008 the use of activated carbon in addition to the originally proposed amino phase to overcome limitations of the volatile mono-aromatic fraction of 'tar'. This was done by several groups meanwhile. A compilation of the current status of this method will be part of an 'gas analysis report' for the IEA task 33 which will be available in mid 2018.
Practical aspects in applying the SPA method
Relevant literature sources
Method introduction
Dufour, A., Masson, E., Girods, P., Rogaume, Y.: Zoulalian, A.: Evolution of aromatic tar composition in relation to methane and ethylene from biomass pyrolysis-gasification. Energy & Fuels, 25 (2011) 4182-4189
http://dx.doi.org/10.1021/ef200846g
Variatons / improvements
Adding a second adsorption stage
Determination of tar compounds by SPA sampling followed by stable isotope dilution analysis
Ahrenfeldt, J., Egsgaard, H., Stelte, W., Thomsen,T., Henriksen, U. B.: The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification. Fuel 112 (2013) 662–680
http://dx.doi.org/10.1016/j.fuel.2012.09.048
Accuracy
Horvat, A., Kwapinska, M., Xue, G., Dooley, S., Kwapinski, W., Leahy, J.: Detailed Measurement Uncertainty Analysis of Solid-Phase Adsorption-Total Gas Chromatography (GC)-Detectable Tar from Biomass Gasification. Energy Fuels 2016, 30, 2187−2197
http://dx.doi.org/10.1021/acs.energyfuels.5b02579
Application
Dufour, A., Masson, E., Girods, P., Rogaume, Y.: Zoulalian, A.: Evolution of aromatic tar composition in relation to methane and ethylene from biomass pyrolysis-gasification. Energy & Fuels, 25 (2011) 4182-4189
http://dx.doi.org/10.1021/ef200846g
Israelsson,M., Seemann, M., Thunman, H.: Assessment of the Solid-Phase Adsorption Method for Sampling Biomass-Derived Tar in Industrial Environments. Energy & Fuels 27 (2013) 7569-7578
http://dx.doi.org/10.1021/ef401893j
Ahrenfeldt, J., Egsgaard, H., Stelte, W., Thomsen,T., Henriksen, U. B.: The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification. Fuel 112 (2013) 662–680
http://dx.doi.org/10.1016/j.fuel.2012.09.048