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 our 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 TTS 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 Hydroprocessing 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.

A hydrocarbon conversion process;

• the process comprising:
• (a) providing a first pyrolysis tar, a second pyrolysis tar, and a pyrolysis tar composition wherein (i) at least 70 wt. % of each of the first and second pyrolysis tars has a normal boiling point of at least 290° C., and (ii) at least the first pyrolysis tar contains free radicals;
• (b) isolating a sample from the first pyrolysis tar and measuring a reactivity RT of the sample;
• (c) comparing RT to a predetermined reference reactivity RRef, wherein,
• (i) when RT is less than or equal to a predetermined reactivity RRef, carrying out the hydroprocessing of step (d);
• or
• (ii) when RT exceeds RRef,
• (A) combining at least a portion of the first pyrolysis tar and at least a portion of the second pyrolysis tar at a blend ratio (wt. % of first pyrolysis tar :
• wt. % of second pyrolysis tar) >0 to produce a pyrolysis tar composition,
• (B) isolating a sample from the pyrolysis tar composition and measuring the reactivity RT of the pyrolysis tar composition sample, and
• (C) increasing the blend ratio and repeating step (c)(ii)(A) if RT exceeds RRef, or carrying out the hydroprocessing of step (d) if RT does not exceed RRef;
• and
• (d) hydroprocessing at least a portion of the first pyrolysis tar of step (c)(i) or at least a portion of the pyrolysis tar composition to produce a hydroprocessor effluent comprising hydroprocessed pyrolysis tar.