Highly active CoMo HDS catalyst for the production of clean diesel fuels

Abstract

supported CoMo catalysts with a chelating agent and phosphorus for the hydrodesulfurization (HDS) of diesel fractions were prepared. The activity measurements with the prepared catalysts were carried out with straight-run light gas oil feedstocks in a pilot plant under industrial hydrotreating conditions. As a result, Cosmo Oil Co., Ltd. developed a new CoMoP/ HY-Al 2 O 3 catalyst, C-606A, which had three times higher HDS activity than the conventional CoMoP/Al 2 O 3 catalyst. Commercial operations to produce ultra-low sulfur diesel (ULSD) with C-606A have successfully demonstrated its high performance and high stability. This catalyst has an extremely high activity, which enables to achieve <10-ppm sulfur in products in diesel hydrotreater designed to produce 500-ppm sulfur diesel fuels. Mo K-edge EXAFS, TEM and FT-IR of adsorbed NO were performed to investigate the nature of the active sites on the developed catalysts. The results showed that the new catalyst has multiple layers of MoS 2 slabs and the edges of MoS 2 are mainly occupied by Co-Mo-S phases. XPS and FT-IR were used to investigate the sulfiding behavior of Co and Mo in the formation process of the active sites during sulfidation. The results showed that addition of carboxylic acid to the impregnation solution postponed the sulfidation of Co at low temperatures, thereby increasing formation of the Co-Mo-S phase.

Formation of active sites and hydrodesulfurization activity of rhodium phosphide catalyst: Effect of reduction temperature and phosphorus loading

“…as the Co chemical vapor deposition technique [4,5] and the addition of citric acid [6] or phosphorus [5,7,8], have been widely investigated.…”

Conversion of heavy gasoil into ultra-low sulfur and aromatic diesel over NiWRu/TiO2–γAl2O3catalysts: Role of titanium and ruthenium on improving catalytic activity

“…The oil refining industry has been forced to produce cleaner fuels and operate their units more efficiently to meet with strict environmental restrictions imposed by government agencies, and to convert more heavy feedstocks to satisfy fuels demand in the regional markets and to improve their profit margins. The Environmental Protection Agency (EPA) developed heavy duty highway diesel fuel standards which came into force from 2008, which required a 90% emission reduction from 500 ppm S heavy duty vehicle standards [1][2][3].…”

“…To fulfill these requirements, oil companies have been making important capital investment for modernizing their refineries through the acquisition of new technologies, supporting research projects for the development of new catalytic materials and optimizing their operations for producing gasolines and diesel fuels having very low level of sulfur and aromatic compounds. A maximum of 50 ppm S and 20 v% aromatic compounds in fuels is currently permitted in most of mature markets and countries in way of development [1][2][3]. The National Environment Agency (NEA) defined Ultra-Low Sulfur Diesel (ULSD) as diesel fuels with 50 ppm S. However, in some states in the US and countries in the European Union (EU), Japan, South Korea and South Africa, a maximum limit of 10 ppm S were established.…”

Highly Active HDS Catalyst for Producing Ultra-low Sulfur Diesel Fuels

“…The sulfur level in the E.U. has already been reduced to 50-ppm sulfur in 2005, and will be fully implemented to 10-ppm by 2009. For the production of ULSD fuels, Cosmo Oil Co. Ltd. successfully developed a new CoMo HDS catalyst [5][6][7][8][9]. This developed catalyst, C-606A, has three times higher HDS activity compared with the conventional CoMoP/ Al 2 O 3 catalyst, which enables \10-ppm sulfur content in products using a commercial diesel hydrotreater designed to produce 500-ppm sulfur diesel fuels.…”

“…After impregnation, this catalyst was air-dried only without calcination. The new catalyst preparation method could increase the formation of the active sites, Co-Mo-S structure, and provide more highly active Co-Mo-S Type II [8].…”