With several years' efforts, Research Institute of Petroleum Processing (RIPP) has successfully developed Resid Hydrotreating Technology (RHT) coupled with the RHT series catalysts, guard catalysts, HDM catalysts, HDS catalyst and HDN catalyst. RHT catalysts are "Butterfly" extrudate and this unique shape can not only reduce the diffusion distance of the catalyst but also helps maintain a low pressure drop of catalyst bed. By optimizing the combined catalyst system and operating conditions, many sour residues with high contents of metals, sulfur, nitrogen and CCR can be hydrotreaded for producing good quality RFCC feedstocks. For Middle East residue feeds such as Arabian middle AR, Iraq AR and Iranian VR, the sulphur conversion are more than 90%. RHT catalysts can also process effeciently some special residues such as Xinjiang residue, in which metal are mostly concentrated in strong polar compounds in asphaltene and therefore is difficult to hydrotreat for other commercial catalysts.
Stability test for RHT catalysts system was carried out with Iranian AR, a high metal content feed (Ni+V=130ppm). After 9500 hours' test the temperature was far below 415°C which is the usual EOR (end of run) temperature of industrial units. The deactivation rate was only 1.75°C per month during middle deactivation stage. Stability test shows that the RHT catalyst system has very high metal tolerance and can operate for long period.
The RHT catalysts were commercially applied in a vacuum residue hydrodesulfurization unit of SINOPEC Qilu Petrochemical Company in October, 2002. The catalysts are still in running till now. The RHT catalysts show better hydrodemetallation and hydrodesulfurization activities and and the hydrotreated product can meet the quality requirement of RFCC feed.
Owing to the continuous depletion of petroleum resource and the consequent increase in oil price, the full use of heavy residual feedstock is becoming more and more important. Among resid processing methods, fixed bed hydrotreating combined with fluid catalytic cracking processis becoming one of the most attractive processes for deep conversion of resid due to the characterized results of the combined process in good product quality, high yield of liquid products and good environmental effects. Thus research on resid hydrotreating catalysts and process is continuing. With several years' efforts, SINOPEC Research Institute of Petroleum Processing (RIPP) has successfully developed Resid Hydrotreating Technology (RHT) coupled with the RHT series catalysts_guard catalysts, HDM catalysts, HDS catalyst and HDN catalyst. The catalysts were designed to meet the demand of the resid hydrotreating technology. In late 2002, the RIPP's RHT catalysts were successfully put into commercial application and anticipated goals were achieved.
Resid is characterized by its large complex molecule, high viscosity and high impurity contents and therefore is difficult to be hydrotreated using a single catalyst. In order to realize a successful commercial operation, a combined system with a series of catalysts is needed. For resid fixed bed hydrotreating process, the most important consideration is neither the high activities nor long cycle life alone, but a balance of them.
