The investigation of heavy residua's hydrogenation indifferent supercritical systemⅡ.The asphaltene to maltene conversion of heavyresidua

摘要

The hydrogenation of heavy residua (AR, FS, VR1, VR2) in different supercritical media (H2, H2+N2,H2+tolene, H2+water) has been investigated. The higher conversion of asphaltenes to maltenes (e.g. reduced HI)obtained in different supercritical media means the lighter products produced. The highest conversion ofrnasphaltenes to maltenes for four residua is in H2+toluene supercritical system. With comparing in supercriticalrnH2+water system, almost the same highest conversion is obtained. The maximum conversion of residua in differentrnsupercritical system follows the order: H2+toluene≈H2+water ＞H2+N2 ＞pure H2, in the same system thernmaximum conversion of different residua follows the order of FS＞VR1 ＞AR ＞VR2. There is not much changernin the elemental composition; Only slight increases are observed in the H/C ratios of the hydrogenation products.rnWithin the narrow changes observed for each feedstock, H/C ratios of the products increase in the order H2, H2+N2,rnH2+toluene as a function of different fluids used in the hydrogenation experiments. Low net hydrogen uptakes canrnbe attributed to the dealkylation reaction which accompany the hydrocracking of asphaltenes, as indicated by thernreductions in the asphaltene contents after hydrogenation. The results of liquid chromatography and 1H-NMRrnanalysis are the evidences for the dealkylation reactions