双亲催化剂作用超稠油水热裂解降黏机理研究

合成双亲催化剂,200℃与超稠油反应后,降黏率达96.26%。通过气相色谱仪、元素分析仪、分子量测定仪、红外光谱仪及核磁共振波谱仪对反应前后稠油的物化性质进行分析。结果表明,反应后稠油胶质与沥青质含量减小,稠油分子量下降,沥青质分子量降低幅度最大;稠油及其重质组分的氢碳原子比增加,硫的含量减小。稠油发生水热裂解反应的同时,存在沥青质的聚合反应,沥青质的裂解在降黏反应中起到了关键的作用;双亲催化剂促进了水热裂解反应,同时抑制了聚合反应;双亲型催化降黏剂携带的具有活性催化功能的离子协同高温水作用于分子中的C-S、C-N、C-O、C-C及C=S、C=O、C=N、C=S等键,使其发生系列链的断裂、加氢、开环、成环、脱硫等反应,促进了稠油黏度的降低,稠油及其重质组分的氢碳原子比增加,稠油的品质得到一定程度的改善。

Mechanism for reducing the viscosity of extra-heavy oil by aquathermolysis with an amphiphilic catalyst

Amphiphilic catalyst was synthesized and used in the aquathermolysis of extra-heavy oil to reduce its viscosity. The catalyst exhibits good performance in the aquathermolysis at 200℃ and the viscosity is reduced by 96.26% for the extra-heavy oil. The chemical and physical properties of heavy oil both before and after reaction were investigated by gas chromatography (GC), fourier transform infrared spectra (FT-IR), elemental analysis (EL), molecular weight analysis (VPO) and nuclear magnetic resonance (NMR). The results indicated that the content of resin and asphaltene is decreased and the average molecular weight of heavy oil and asphaltene is reduced after the catalytic aquathermolysis. The H/C ratio of heavy oil, resin and asphaltene is increased. The amount of sulfur in the heavy oil is also decreased after the treatment. A series of polymerization reactions take place in the course of aquathermolysis; the amphiphilic catalyst may depress the polymerization reactions while enhance the aquathermolysis. The pyrolysis of asphaltene plays a very important role in the viscosity reduction. During the aquathermolysis, many reactions such as pyrolysis, hydrogenation, ring opening, ring closing and desulfuration concerning C－S, C－N, C－O, C－C, C=S, C=O, C=N and C=S bonds are involved, which attributes to the reduce of viscosity and improvement of the heavy oil quality.