SURFACE ACTIVE PROPERTIES OF CLAY TREATED JET FUELS

Abstract

The effect of water contamination in jet fuels on the adsorbent capacity of Attapulgite clay to adsorb and retain N compounds was studied. The effluent jet fuel showed the presence of N molecules indicating that the clay, contaminated with water, does not retain N compounds. The GC/MS analysis of spent clay indicated that only quinolines were adsorbed and retained on the clay. The interfacial tension (IFT) values measured at the jet fuel/water interface were found to increase with a decrease in basic N content of clay treated jet fuels. Quinolines and pyridines present in jet fuel are surface active and adsorb on the Attapulgite clay, however, in the presence of water some N molecules adsorb at the jet fuel/water interface. Since pyridines were not found on the spent clay, the results indicate that the pyridines adsorb at the jet fuel/water interface. The tendency of pyridines to adsorb at the jet fuel/water interface will lead to their poor retention on the clay. The presence of N compounds and water contamination in jet fuel might lead to inefficient operation of clay treaters. The jet fuels having the IFT value below 40 mN/m were found to contain basic N molecules and have poor stability. The clay treated jet fuels having the IFT values in the range of 42.6–46.2 mN/m were found to have a good stability. The use of IFT measurements at the jet fuel/water interface provides an opportunity to better monitor the efficiency of clay treatment and the quality of jet fuels.