供氢剂及其前身物在渣油加氢裂化中的作用

对供氢剂及其前身物的化学变化规律以及渣油的裂化反应的分析表明 ,供氢剂与分散型催化剂的协同使用可较大程度地降低渣油的加氢裂化生焦量 ,而裂化转化率略有降低。 3种供氢剂的抑制生焦能力由大到小依次为二氢蒽 ,四氢萘 ,十氢萘。其中 ,二氢蒽是很好的供氢剂。供氢剂前身物与分散型催化剂协同使用也可以起到相同或类似的作用 ,3种供氢剂前身物的抑制生焦能力由大到小依次为蒽 ,菲 ,1 甲基萘。在渣油临氢催化条件下 ,供氢剂前身物能起到与二氢蒽和四氢萘类似的作用 ,催化剂的存在有助于实现供氢剂与多环芳烃的可逆反应。在分散型催化剂存在下外加多环芳烃的催化加氢实验结果说明 ,分散型催化剂在渣油加氢裂化体系中主要起着氢化多环芳烃和稳定自由基两种作用。外加的多环芳烃与外加供氢剂 (尤其是三环以上的芳烃 )起着将气相氢向液相传递的作用 ,催化剂的存在有助于加速这一过程。

Effect of hydrogen donor and precursor of donor on catalytic hydro-cracking reaction of residue oil

Six kinds of different aromatics and two dispersed catalysts can be combined and used in the deep conversion of poor residue. The effects of different aromatic additives and dispersed catalyst on thermal-cracking, hydro-cracking and catalytic hydro-cracking process of Liaohe residue were investigated. There is synergism between dispersed catalyst and H-donor or precursor of donors in catalytic hydro-cracking process of residue, and the synergism helps effectively inhibit coking. Hydro-cracking action of residue combined with catalysts and precursor of donors may achieve the same or similar action with catalysts and donors. The use of more active hydrogen donor combined with the same catalyst could result in more effective inhibition of coking. According to the coking resistance abilities of the three hydrogen donors, dihroanthrene is the best, and tetralin is second, decalin is the last. On the other hand, combined with the same donor, more active catalyst can reach more effective inhibition of coking. In the hydo-cracking system of dispersed catalysts combined with precursor of donors, among the three precursors of anthrene, phanthrene and 1-methy naphthalene, the poly-ring aromatics have the different hydrogenated yields of derived hydro-aromatics by dispersed catalysts. The coking resistance of anthrene is better than that of phanthrene, and phanthrene is better than 1-methy naphthalene. The hydrogenated hydro-aromatics displayed different inhibition of coking in the reaction system of residue.