====== 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 =====

Video Blogs in correlation with the Report on gas analysis Methods compiled for  the IEA Bioenergy task 33 compiled by TNO, Netherlands.

[[https://www.youtube.com/channel/UCjZQMdEdmaDzNCScS6ckINw/featured|videos on the sampling, sample preparation and analysis]]


===== Relevant literature sources =====
==== Method introduction ====

  * Brage, C., Yu, Q., Chen, G., Sjöström, K.: Use of amino phase adsorbent for biomass tar sampling and separation. Fuel, 76 (1997) 137-142 \\ [[http://dx.doi.org/10.1016/S0016-2361(96)00199-8]]

  * 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 ==

  * Osipovs S.: Sampling of benzene in tar matrices from biomass gasification using two different solid-phase sorbents. Anal Bioanal Chem (2008) 391:1409–1417 \\ http://dx.doi.org/10.1007/s00216-007-1809-7

  * Osipovs, S.: Use of Two Different Adsorbents for Sampling Tar in Gas Obtained from Peat Gasification. Int. J. Environ. Anal. Chem. 2009, 89, 871−880. \\ http://dx.doi.org/10.1080/03067310802592755

== 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 ====

  * Brage, C., Yu, Q., Sjöström, K.: Characteristics of evolution of tar from wood pyrolysis in a fixed-bed reactor. Fuel, 75 (1996) 213-219\\ [[http://dx.doi.org/10.1016/0016-2361(95)00260-X]]

  *  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\\
 
  *  Osipovs, S.: Comparison of efficiency of two methods for tar sampling in the syngas. Fuel, 103 (2013) 387-392 \\ http://dx.doi.org/10.1016/j.fuel.2012.05.021.
 
  *  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


===== Further sources of information =====
 - [[http://www.gas-analysis-webinars.org/?q=node/9|Gas Analysis Workshops]] Berlin 2011 and Milan 2012