Hydroconversion VGO and DAO Process by Axens

Application: An ebullated-bed process H-OilDC is used for hydroconversion (hydrocracking and hydrotreating) of heavy vacuum gasoil and DAO having high Conradson carbon residue and metal contents and low asphaltene content. It is best suited for high severity operations and applications requiring long run lengths.

Description: The flow diagram includes integrated mid-distillate hydrotreating for an ultra-low-sulfur-diesel product. The typical battery limits scheme includes oil- and hydrogen-fired heaters, an advanced design hot high-pressure separator and ebullating pump recycle system, a recycle gas scrubber and product separation and fractionation.

Catalyst in the reactor is replaced periodically without shutdown and, for cases of feeds with low metal contents, the catalyst can be regenerated onsite to reduce catalyst consumption.

Various catalysts are available as a function of the feedstock and the required objectives. An H-OilDC unit can operate for four-year run lengths at constant catalyst activity with conversion in the 20-80% range in once-through mode and to more than 95% in recycle mode with up o 99% hydrodesulfurization.

Operating conditions:
Temperature, °F 750– 820
Hydrogen partial pressure, psi 600 –1,500
LHSV, hr –1 0.5 –3.0
Conversion, wt% 20 –80 in once-through mode

Licensor: Axens.