Comparison of efficiency of two methods for tar sampling in the syngas

In the present work, a cold solvent trapping (CST) and solid-phase adsorption (SPA) methods for determining concentration of tar compounds have been chosen for comparison. When the cold solvent trapping method is used, the producer gas flows through a series of impingers containing 2-propanol, whereas in a solid-phase adsorption method it passes through two adsorbent cartridges loaded with 500 mg of aminopropyl-bonded silica, and 100 mg of activated coconut charcoal. During the experiment, 52 compounds were identified by the cold solvent trapping method and 48 compounds by the solid-phase adsorption method. The SPA method is more accurate than those using impingers, especially for determining such volatile organic compounds as benzene, toluene, and xylenes, due to the use of a second sorbent, activated coconut charcoal. By contrast, the CST method proves to be more accurate for determining components of heavy tar due to a much larger volume of the sampled gas.