Johannes Kornelis Minderhoud

First-stage hydrocracking: process and catalytic aspects

Abstract First-stage hydrocracking is a fixed-bed, catalytic process, which is implemented industrially with the prime objective of reducing organonitrogen, organosulfur and organooxygen compounds from the feedstock, and for lowering the aromatics concentration. Additionally, a part of the feedstock may be cracked. The most difficult step is generally the hydrodenitrogenation (HDN) reaction. The essential factors in HDN, and the consequences for other hydrotreating and hydrocracking reactions, are discussed. Considerable attention is paid to inhibition effects of nitrogen compounds. These effects are not only important from a process point of view, but also influence developments of first-stage hydrocracking catalysts. Recent trends in catalysts are reviewed with an emphasis on those showing improved cracking activity compared to conventional NiMo/alumina systems.

Hydrocracking in the Year 2000 : A strong interaction between Technology Development and Market Requirements

New developments in hydrocracking technology are increasingly guided by the prevailing market conditions and requirements. This necessitates a very good knowledge of local circumstances in the refinery as well as an integrated approach of the various disciplines involved such as catalyst, process, reactor and engineering technology. Some recent developments, illustrated by a case study, are discussed.

On the Stability of Mo 2 N During First-Stage Hydrocracking

An unsupported sample of Mo 2 N has been subjected to a first-stage hydrocracking test. The evolution of the HDS and HDN performance indicated a transformation of Mo 2 N into MoS 2 . This was substantiated by XPS and TEM, the latter technique showing that the transformation is limited to only a few surface layers.