溶剂萃取恢复渣油加氢转化催化剂活性的研究

催化加氢处理是渣油裂化加工的重要技术，但焦炭和金属在催化剂上的沉积将降低催化剂的活性。采用溶剂萃取法除去工业失活催化剂上沉积的焦炭和金属的研究结果表明，用四氢呋喃、吡啶和喹啉这3种含杂原子的有机强溶剂常温萃取催化剂，其去除焦炭能力很弱，而且会因这些溶剂的强吸附作用污染催化剂；盐酸洗涤能有效去除催化剂表面的钙、铁沉积层，但不能去除焦炭；低芳香性的加氢瓦斯油在400 C、H2压力为10MPa、反应1h的条件下可部分去除催化剂上的焦炭，但不具备强的氢化焦炭作用；1,2,3,4-四氢化萘因具有供给原子氢的能力，可以有效地氢化和去除催化剂上的焦炭。一旦除去一定量的焦炭或金属化合物沉积物，失活催化剂的加氢脱硫活性将得到恢复。

REACTIVATION OF RESIDUE HYDROCONVERSION CATALYST BY SOLVENT TREATMENT

Catalytic hydro-processing is an important technology for residue oil upgrading, but the catalysts are easy to be deactivated due to the deposition of coke and metals on the catalyst surface. Burning off the coke from spent hydro-processing catalyst might cause structure collapse of the catalyst, and thus the investigation of using various solvents to extract the spent catalyst was carried out. Test results showed that extraction with heteroatom containing strong organic solvents, such as tetrahydrofuran, pyridine and quinoline, could not remove coke from the spent catalyst, besides surface contamination might happen due to the strong adsorption. Washing with dilute HCl acid could effectively remove calcium and iron deposits from the surfaces of catalyst pellets, yet it had little effect on removing coke. Using hydrotreated gas oil as solvent, under the conditions of a reaction temperature of 400 C, a hydrogen partial pressure of 10 MPa and a reaction time of 1 h, a portion of coke deposits could be removed yet without the function of hydrogenating coke. Tetralin, a hydrogen donor, exhibited good function of removing coke from spent hydro-processing catalyst. As soon as the deposits of coke or/and metals were partially removed from the spent catalyst, the HDS activity of said catalyst was enhanced.