Good day,
I am currently troubleshooting a KBR Rose unit, but have been unable to resolve the problems resulting in the DAO CCR content , 8.8 wt % vs target 5 wt%. In addition the pitch softening point is low at 130 oF vs required 160 min.
Solvent used for extraction is butane, with the asphaltene separator operating 600 psi and 257 - 275 oF. On increase of asphaltene separator temperature, its noted that the pitch softening point gets lower indicating more solvent/DAO in pitch,
We are unable to measure the pressure drop across the tower packing to establish if the packing is plugged. However after washing the asphaltene separator with LCO, normal pitch/DAO separation recovery happens for a few hours, followed by abnormal behavior: low pitch softening point, High DAO CCR.
Crude analysis is showing relatively high parrafinic content and low CCR. However the Rose unit operated with the same crude diet in the past without issues.
Would appreciate any help/guidance on this matter. (Note Licensors recommendation have proved futile to address issue)