Regarding the residue hydrogenation process

In the forum search, enter “residue hydrogenation” to conduct a search, and there are many resources available. Currently, they generally operate for about 1 year, with the longest lifespan being 2 years.

Four hydrogenation processes have been developed for residue hydrogenation: fixed-bed, fluidized-bed, suspended-bed, and moving-bed hydrogenation. In actual production, these processes can be used individually or in combination to meet the requirements of different raw materials and the production of various products. The fixed-bed residue hydrogenation process is characterized by its maturity, ease of operation, relatively low capital investment, relatively low reaction temperature, a residue conversion rate of 20% to 50%, and the unconverted residue can be used as feed for RFCC, as a raw material for coking, or to produce low-sulfur fuel oil. The disadvantage is that the operation cycle is greatly affected by the impurity content in the feedstock, and bed clogging can occur easily; it is generally used for processing residue feedstocks with a (Ni+V) content of less than 150 ppm. The characteristics of the fluidized bed hydrogenation process are: it can process residue feedstocks with a (Ni+V) content as high as 700–800 ppm, it can operate continuously for long periods, and the residue conversion rate ranges from 60% to 90%. The disadvantages are complex processes and equipment, difficulty in operation, and high investment costs for the installation ； Hydrogenated residue is not suitable as an RFCC feedstock; it is usually used as a coking feed or to produce low-sulfur fuel oil. There are currently two commercial technologies for the fluidized bed process: H-oil and LC-Fining. The suspended bed process is a process based primarily on hydrogenative thermal cracking reactions. Research and development in this area have been active since the 1980s, but it is currently mostly at the stage of industrial demonstration or pilot testing. The moving bed process can be used as a pre-reactor system for fixed-bed reactors, with the aim of extending the operating cycle of the fixed-bed reactors. The moving-bed residue hydrogenation process was industrialized in the early 1990s, with Shell’s Bunker technology and Chevron’s OCR technology being the main ones. The normal operating cycle of the device is 1 year, during which the catalyst needs to be replaced. Therefore, crude oil hydrotreating units are generally designed with two series; when one series is shut down for catalyst replacement, the other series can operate normally at reduced capacity, preventing the entire plant from coming to a halt waiting for supplies.

You mentioned whether the 2-year residue hydrogenation process uses a dual-series or single-series setup. What is the actual operating situation of industrial fixed-bed units? Given the current level of catalysts, it’s difficult for a single-series system to operate for more than a year.

The five sets currently in operation domestically are all of the dual-series type.