Conventional hydroconversion of residue has been achieved through high pressure, capital intensive processes with significant operating costs associated with maintaining catalyst activity. Despite the usefulness of heterogeneous catalysts in numerous refining processes, their potential for hydroconversion of heavy feeds with high levels of sulfur, nitrogen, resins, asphaltenes and metals is limited.
This paper will introduce a Pseudo-homogeneous Catalyst (PHC) developed for the specific chemistry of heavy hydrocarbon feeds. The term pseudo-homogeneous provides a convenient description of nano-scale unsupported catalyst particles uniformly dispersed throughout the feed. As a result of particle size, nanoparticle suspensions exhibit properties similar to colloidal solutions.
Residue processing using a high performance pseudo-homogeneous catalyst system results in improved cracking and hydrogenation performance at lower process severity. The PHC system in the Heavy Residue Hydroconversion (HRH) process achieves up to 95% residue conversion at pressure below 7.3 MPa, reaction temperatures between 400 - 460 °C, with feed space velocity between 1,0-2,0 h-1; making PHC systems well suited for deep conversion of hydrocarbon residues.
The sustainability profile of the HRH process is improved as residue conversion to liquids is maximized, while up to 95% catalyst is recovered and regeneration within the process.
Pilot plant results from hydroconversion of Athabasca vacuum bottoms using a pseudo-homogeneous catalyst (PHC) system are discussed.