Suspension bed heavy oil hydrocracking

 Suspension bed (also known as slurry bed) heavy oil (residual oil) hydrocracking is the process of thermal cracking and hydrogenation reaction which heavy oil (residual oil) fractions are generated under high temperature and high pressure under the condition of coexistence of hydrogen and fully dispersed catalyst (and/or additives).The technology was first invented by Friedrich Bergius for which he won the Nobel Prize in 1931.Since the primary conversion rate of this technology can reach 95% or even higher.The raw material can be extremely poor quality residual oil or even a mixture of coal and residual oil.The processed products are naphtha, diesel oil, wax oil, etc. with very low sulfur content.And the total liquid yield is greater than 100%.Therefore, in the era of high oil prices, this technology has become an excellent choice for maximizing resource utilization and has developed rapidly.

Most of the earliest suspended bed hydrogenation technologies are used solid powder catalysts.After the reaction under high temperature, high pressure, and hydrogen, the solid catalyst remains in the unreacted residue accounting for about 5% to 10% of the total reaction feed and is discarded.The catalyst used in this stage has low activity but low price.For example, the amount of natural iron-based materials loaded on lignite and clay generally accounts for a few percent of the feed which the injection concentration is high and cannot be recycled.After the 1980s, with the increasingly stringent requirements for environmental protection, it is hoped to reduce the amount and difficulty of handling residues containing solid catalyst powder.So the suspended bed hydrocracking technology using homogeneous catalyst came into being.Homogeneous catalyst with high activity and low injection volume (hundreds of μg/g).It can not be separated from unconverted oil, which not only meets the requirements of environmental protection, but also solves the problem of catalyst wear in the reaction system.Homogeneous catalysts include oil-soluble organometallic catalysts and water-dispersed catalysts, which are basically Mo and Ni-based, expensive but recyclable.