Pyrolysis tar conversion

A process for producing a hydroprocessed steam cracker tar (“SCT”), the process comprising:

• (a) providing an SCT having a temperature T1≤350° C. and a reactivity RT≥28 Bromine Number units (“BN”), the SCT having a density at 15° C. ≥1.10 g/cm3 and viscosity at 50° C. ≥1000 cSt, wherein at least 70 wt. % of the SCT has a normal boiling point of at least 290° C.;
• (b) establishing a predetermined reference reactivity RRef≤18 BN;
• (c) carrying out either
• (i) conducting away at least a portion of the SCT or hydroprocessing at least a portion of the SCT under Mild Hydroprocessing Conditions, or
• (ii) producing a treated SCT by carrying out one or more of
• (A) one or more thermal treatments of at least a portion of the SCT by heating from T1 to a temperature THS, and maintaining the SCT at a temperature of at least THS for a time tHS of at least 10 minutes to produce a treated SCT, wherein THS is at least 10° C. greater than T1 and THS is in the range of 300° C. to 360° C. and tHS of ≥5 minutes, and
• (B) combining at least a portion of the SCT with a second SCT;
• and
• following steps (A) and/or (B) determining an RT of the treated SCT, and comparing RRef and the RT of the treated SCT, and
• (I) when RT of the treated SCT exceeds 12 BN, carrying out step (c)(i) or repeating steps (c)(ii)(A) and/or step (c)(ii)(B), or
• (II) when RT of the treated SCT does not exceed RRef, then conducting the treated SCT to step (d);
• and
• (d) hydroprocessing the treated SCT, the hydroprocessing being carried out under Standard Hydroproces sing Conditions in the presence of (i) a utility fluid, (ii) at least one catalyst, and (iii) a treatment gas comprising molecular hydrogen to produce a hydroprocessor effluent comprising hydroprocessed SCT, wherein the Standard Hydroprocessing Conditions include a temperature ≥200° C., a pressure ≥8 MPa, a weight hourly space velocity (“WHSV”, tar basis) ≥0.3 hr−1, and a molecular hydrogen consumption rate (tar basis) in the range of from 270 S m3/m3 to about 534 S m3/m3.