Examination of deposits caused by light tar

The aim of the project is to identify critical constituents for formation of the carbonaceous deposits, to characterise the deposits by a variety of physical and chemical techniques, and by direct motor tests to establish a correlation between gas quality and operating characteristics. The chemical experiments will be performed using a continuous flow system in the temperature range 600-850 deg. C. It is expected that the relative rates for formation of carbonaceous deposits from individual compounds as well as authentic light tar can be established. The deposits will be characterised in detail by GC/MS, PY/GC/MS, TGA, FTIR, ESC, SEM and AFM. Direct motor tests will be made with fuels closely mimicking the gas produced by updraft gasifiers and added critical constituents. The formation of desposits will be evaluated and compared to the operating experinece gained at Harboøre plant. In addition, special emphasis will be paid to the emissions of aromatic hydrocarbons, which may specifically relate the tar constituents of the fuel