由沈北-大庆减压渣油制备微晶蜡及其表征

Preparation and characterization of microcrystalline wax from Shenbei-Daqing vacuum residue

为探讨从沈北-大庆减压渣油生产高熔点微晶蜡的可能性,对其进行了丙烷、异丁烷溶剂脱沥青,以脱沥青油为原料,通过溶剂精制、溶剂脱蜡脱油制得微晶蜡。采用气相色谱、凝胶渗透色谱、红外光谱和核磁共振氢谱等分析手段,对微晶蜡的碳数分布、分子量分布及分子结构进行了表征。所得微晶蜡的滴熔点满足80号-85号微晶蜡要求,微晶蜡潜质量分数约为10%;轻脱沥青油所得微晶蜡的碳数分布在23-68;微晶蜡的数均分子量为1200-1600,氢碳原子比在1.95-1.98变化;微晶蜡的主要组成是含长碳链的饱和烷烃,异构烷烃约占70%,含少量环烷环结构,不含芳香环。微晶蜡的平均分子结构可看作是带不同长度与个数的长侧链的含1个或2个环的环烷烃。

To probe the possibility of producing microcrystalline wax with high melting point from Shenbei-Daqing vacuum residue, the residue was first deasphalted through a series of solvent deasphalting procedures with propane and butane to obtain deasphahed oil （ DAO）, and then the microcrystalline wax was prepared from DAO by solvent refining and dewaxing. The carbon number distribution, average molecular weight, composition and structure of microcrystalline wax were determined by GC, GPC, FT-IR and ^1H-NMR. The melting points of microcrystalline wax samples meet the demands of 80# to 85# commercial products. The potential content of microcrystalline wax is about 10% in Shenbei-Daqing vacuum residue. The carbon number of the light microcrystalline wax ranges from 23 to 68. The number average molecular weight ranges from 1200 to 1600 and H/C atom ratio from 1.95 to 1.98. The microcrystalline wax is dominated by paraffins of long chains; of them about 70% are isoparaffins. There are a small amount of cycloalkanes and almost no aromatic hydrocarbons in the microerystalline wax. The molecular structure of microcrystalline wax can be regarded as cycloalkanes with 1 or 2 rings and various long alkyl chains.