Verification and validation of manual measurement method

Furthermore, informative tar measurements (evaporation and GC analysis) were carried out with tar samples from Harboøre and tar measurements were carried out in updraft gas in Harboøre. Gravimetric tar measurements (by evaporation) and gaschromatographic tar measurements (GCMS analyses) have been carried out. In general, polar solvents result in higher tar recoveries than the non-polar. This is especially pronounced for the gravimetric tar determinations for which the difference is significant. The GC tar measurements show a less clear tendency. Process engineer Finn Petersen at Danish Technological Institute has developed a new sampling train that avoids all the mentioned problems. Furthermore, the 'Petersen-column' is very simple to handle. The efficiency of the system was testcd during a temporary test and a tar penetration of 0.26% of the chromatographyable tars was demonstrated which is satisfying. In addition, the ageing of tar samples was examined and further tests were carried out regarding determination of gravimetric tar mass through evaporation. Our conclusions are: 1)The tar penetration through the 'Petersen column' is dependent on the sample flow rate. With a flow rate of approximateIy 3 litre/min, a break through of about 1% was found and more than 90% of the break through cause BTX (benxenc, toulene, xylene). 2) The 'Petersen column' should be preferred to the sampling train with 6 impinger bottles. 3) Either isopropanol or ethanol should be used as a solvent. 4) GC tar analyses should be carried out as soon as possible after sampling, as storage results in a loss of approx. 10%. 5) When determining gravimetic tar it is recommended to evaporate smaller parts of the samples in order to save tune and expenses. When evaporating samples, the relative uncertainty is found to he 3% which is acceptable