复配助剂对渣油悬浮床加氢裂化反应的抑焦作用

以辽河常渣(LHAR)为原料,水溶性催化剂Catl作为悬浮床加氢裂化主催化剂,表面活性剂SAN和SAP以不同质量比(m(SAP)/m(SAN))复配作为助剂进行釜式反应,考察了助剂在渣油中的质量分数为600 μg/g时,m(SAP)/m(SAN)对反应产物分布和生焦率的影响.当助剂的re(SAP)/m(SAN)=1时,其对体系的抑焦作用效果最为显著.因此将m(SAP)/m(SAN)=1的复配物SA作为反应助剂,考察了不同SA用量对加氢裂化产物分布、生焦率和沥青质平均相对分子质量的影响.结果表明,随着SA在渣油中质量分数的增大,生焦率先减小后增大,沥青质含量及平均相对分子质晕先增大后减小,w(SA):300μg/g是变化的拐点.SA对渣油胶体体系中的沥青质具有稳定作用,能抑制沥青质的缔合,阻滞第二液相的出现,使更多的大分子沥青质存在于反应体系中.

THE EFFECT OF COMPOUND ADJUVANT ON COKE FORMATION IN RESIDUE SLURRY-BED HYDROCRACKING

The SAN/SAP compound with a certain ratio of SAN to SAP as adjuvant together with the main catalyst--water-soluble Catl was added into Liaohe LHAR, then the slurry bedcracking reaction of LHAR was carried out at the SAN/SAP compound mass fraction of 600 μg/g.The effects of the mass ratio of SAP to SAN(m(SAP)/m(SAN)) in SAN/SAP compound on the distribution of products and the volume of coke formed in the slurry bed cracking reaction of LHAR were investigated.The results showed that the SAN/SAP compound additive(SA) with m(SAP)/ m(SAN) = l had best performance on resisting coke-formation.With the increase of SA dosage, the coke volume decreased first and then increased, while the average relative molecular mass and mass fraction of asphaltene increased first and then decreased.The inflection point was at the SA dosage of 300 μg/g.It was proved that the SA could stabilize the asphaltene in residue colloidal system, resist the aggregation of asphaltene and keep more asphaltene molecule staying in residue colloidal system.