SPA – Offline tar analysis

  • Rapid sampling  less than 1 minute in a gasification process. The sampling is simple and reliable with high reproducibility. We provide you with instructions  for improved sample quality. Only 100 ml of sampled gas is required.

  • Detection range: The SPA method is able to detect tar compounds with a boiling point up to 400°C, which is generally sufficient for most gasification applications. Verdant offers other compound analysis methods for those cases when extended range or sensitivity is required

  • VCT offers services in providing with kits and instructions for SPA tar sampling as well as chemical analysis of collected SPA samples. For more information, a quote or ordering

Sampling Kit

  • Gas-tight 100 ml syringe.
  • SPE tubes (Supelclean LC-NH2, 500 mg 3 ml, Art. No: 57014 from Sigma Aldrich).
  • Cannula (injection needle) 1.6×40 mm and plugs to seal SPE tubes after sampling.
  • SPA sampling procedure.

 

Method principle:

Solid Phase Adsorption (SPA) method is a offline tar sampling method originally developed by the owners of Verdant Chemical Technology. The SPA method is able to detect tar compounds with a boiling point up to 400°C, which is generally sufficient for most gasification applications.

Analysis procedure:

  1. A gas sample is taken from a with a syringe and adsorbent. The sampling is simple and reliable with high reproducibility, detailed instructions can be provided. Only 100 ml of sampled gas is required.
  2. Tar compounds in vapour phase are trapped by passing a aliquots of the exhaust through a SPE (Solid Phase Extraction) tube i.e a small disposable polypropylene column prepacked with silica based amino phase ( NH2 ) adsorbent.
  3. Since this adsorbent is very polar, phenolic compounds will be strongly retained to non polar aromatic hydrocarbons according to principle ” like adsorbs like “.
  4. Prior to desorption, two internal standards adds to the SPE tube and then eluted by using two solvents system of different polarity and nitrogen gas to separate aromatic and phenolic fractions. Thus allowing identification of both phenolic and aromatic compounds when we run the gas through our Gas chromotagrapherVarian CP-3800 with flame ionization detector (FID).

 

Detectable Compunds

Aromatics:

  • Benzene
  • Toluene
  • m/p-Xylene
  • o-Xylene
  • Indan
  • Indene
  • Naphthalene
  • 2-Methylnaphthalene
  • 1-Methylnaphthalene
  • Biphenyl
  • Acenaphthylene
  • Acenaphthene
  • Fluorene
  • Phenanthrene
  • Anthracene
  • Fluorantene
  • Pyrene

 

Phenolics:

  • Phenol
  • o-Cresol
  • m-Cresol
  • p-Cresol
  • 2,4-Xylenol
  • 2,5/3,5-Xylenol
  • 2,6-Xylenol
  • 2,3-Xylenol
  • 3,4-Xylenol

 

The results reported in µg (µg for each component in the sample = 100 ml of gas).