One-time through hydrocracking process

The invention provides a reverse-type once-through hydrocracking technique to produce clean hydrocracking product and the catalyzer system. Its character: adopting first-cracking after-refining flow, adopting once-through operating mode, and make raw material contact at least two grades of catalyzer to produce clean medium fractional oil and high-quality tail oil. On one hand, it makes full use of double functions of the hydrocracking catalyzer, on the other hand, the whole catalyzer system has high activity to improve the processing ability of the equipment. 本发明提供一种生产清洁加氢裂化产品的反式一次通过加氢裂化工艺及其催化剂系统，其特点是采用先裂化后精制的流程，采用一次通过操作方式，并通过将原料与至少两种级配的催化剂接触，生产清洁中间馏分油以及用于下游装置进料的优质尾油。本发明方法一方面充分利用了加氢裂化催化剂的双功能，另一方面整个催化剂系统活性高，提高装置的处理能力。