沥青质在渣油加氢催化剂中的扩散受阻

Hindered Diffusion of Asphaltene in Residue Hydrotreating Catalyst

以甲苯为溶剂,研究了沥青质在不同孔径的渣油加氢催化剂中的扩散受阻情况。结果表明:沥青质聚集体在渣油加氢催化剂中处于受阻扩散状态,不同孔径催化剂中的扩散受阻情况不同;扩散受阻因子F(λ)可以较好地表征沥青质在渣油加氢催化剂中的扩散受阻情况;扩散受阻因子随催化剂孔径的变化非常明显,催化剂孔径越小,沥青质聚集体扩散时受阻作用越严重,扩散受阻因子F(λ)值越小。此外,扩散受阻因子还与沥青质在溶液中的初始质量分数、催化剂的曲折因子等有关。

The hindered diffusion of asphaltene in residue hydrotreating catalysts with different pore sizes was studied by employing toluene as the solvent.The results show that asphaltenes in residue hydrotreating catalyst are at hindered diffusion states,and it is strongly depending on the pore size of the catalysts.We found that the hindered diffusion factor(F(λ))describes such hindered diffusion well.F(λ)changes significantly with the change of the pore size.The smaller the pore size is,the more hindered effect is,and the smaller the value of F(λ)is.Moreover,it is found that F(λ)is also related to the initial mass fractions of asphaltene in the solution and the tortuosity factor of catalysts.