Optimizing solid / liquid separation with solvent addition

A process for separating heavy oil from catalyst particles, the process comprising:

• a) providing a composition comprising a mixture of 2-40 wt. % catalyst particles in an initial concentration of heavy oil, wherein the catalyst particles are present as a slurry in a colloidal suspension of heavy oil;
• b) adding a sufficient amount of solvent to the mixture of catalyst particles in heavy oil to break up the colloidal suspension of heavy oil, thereby causing the mixture of solvent and catalyst particles in heavy oil to separate into two phases:
• i) a top phase comprising a portion of the heavy oil and solvent;
• and ii) a bottom phase comprising catalyst particles in a portion of the solvent with a reduced heavy oil concentration of less than the initial heavy oil concentration;
• c) separating the top phase from the bottom phase via gravity separation;
• d) recovering the top phase and the bottom phase as two separate compositions.

A system for separating heavy oil from catalyst particles in a feed stream containing 2-40 wt. % catalyst particles in heavy oil having an initial heavy oil concentration, the system comprising:

• a vessel for:
• a) mixing a composition comprising the mixture of 2-40 wt. % catalyst particles in an initial concentration of heavy oil with a sufficient amount of solvent;
• and b) breaking up the colloidal suspension of heavy oil with the sufficient amount of solvent forming a top phase and a bottom phase comprising catalyst particles in a portion of the solvent with a reduced heavy oil concentration of less than the initial heavy oil concentration;
• means for separating the top phase from the bottom phase and recovering the bottom phase comprising catalyst particles in solvent with the reduced heavy oil concentration;
• a filtration assembly for receiving additional solvent and the bottom phase comprising catalyst particles in solvent with the reduced heavy oil concentration, the filtration assembly having a least a filtration unit employing at least a membrane for removing at least 90% of the heavy oil from the catalyst particles.

A process for separating heavy oil from catalyst particles, the process comprising:

• a) providing a composition comprising a mixture of 2-40 wt. % catalyst particulates in an initial concentration of heavy oil, wherein the composition has an initial particulate settling rate;
• b) adding a sufficient amount of solvent to the mixture of catalyst particles in heavy oil to increase the settling rate by at least 25% and decrease the effective viscosity and density of the continuous liquid phase and separate the mixture and the solvent into two phases:
• i) a top phase comprising a portion of the heavy oil and solvent;
• and ii) a bottom phase comprising catalyst particles in a portion of the solvent with a reduced heavy oil concentration of less than the initial heavy oil concentration;
• c) separating the top phase from the bottom phase via gravity separation;
• d) recovering the top phase and the bottom phase as two separate compositions.