抄録
The effects of solvent properties on the liquefaction of Victorian brown coal were studied using an autoclave with iron oxide/sulfur catalyst under various reaction conditions (temperature: 430°C or 460°C, initial hydrogen pressure: 3, 6, or 12MPa). The solvents used were a recycling solvent (PR-S) and a further hydrogenated solvent (HD-S), a product of hydrogenation with Ni-Mo/Al2O3 catalyst. Results showed that hydrocarbon gas yield and hydrogen gas consumption were lower, and naphtha (b.p.<180°C) yield was higher using HD-S compared with PR-S. At lower hydrogen pressure, the HD-S provided a higher oil (b.p.<420°C) yield than the PR-S, but with more severe conditions (460°C and 12MPa), the PR-S provided the higher oil yield and more hydrogenated heavy products.
The amount of transferred hydrogen to all products was the same in both solvents, and depended only on the reaction conditions, however, the distribution of transferred hydrogen was different. The results suggested that the PR-S worked more effectively as a hydrogen shuttler at severe conditions compared with the HD-S which contained a considerable amount of initial donatable hydrogen. Thus, we can conclude that the overall liquefaction efficiency of such solvents depends on the liquefaction conditions.
