Process Technology for Improved Refinery Crude Diversification Economics

The attractiveness of ebullated-bed hydrocracking as a technology solution for refiners has been enhanced by the recent trend for greater vacuum residue (VR) feed processing flexibility, which leads to improved refinery crude diversification economics. Ebullated-bed hydrocracking is a long-established technology, with improved designs providing conversion of > 85% (540°C+) of very refractive VR feeds with high contaminant metals and Conradson carbon residue (CCR) contents. Since ebullated-bed hydrocracking was commercialised in the 1960s, 16 units have been built. In the last four years, the technology’s popularity has led to another 7 units which are now under construction & startup.

A Customised Approach to Catalyst Development

Ebullated-bed hydrocrackers are highly customised according to a refiner’s specific objectives and there has been a great deal of innovation in the latest grassroots designs. Earlier-generation designs were more closely integrated with downstream fluidised catalytic cracking units and the key products required further upgrading to meet the required specifications. In contrast, the design of newer-generation units features an integrated hydrocracker–high-pressure hydrotreater in the same high-pressure loop. This enables direct production of high-value transportation fuels such as ultra-low-sulphur diesel from VR.

Shell currently operates both types of ebullated-bed unit licensed technologies: Axens’ H-OilRC and Chevron Lummus Global’s LC-FINING technology. Additionally, Shell Catalysts & Technologies has more than 40 years experience in ebullated-bed catalysts and currently supplies customised catalysts to both H-OilRC and LC-FINING units.