Upgrading of Pyrolysis Tar and Flash Bottoms

A process for preparing a low sulfur liquid hydrocarbon product comprising:

• i) blending a first process stream with a utility fluid to reduce the viscosity of the first process stream and obtain a second process stream comprising reduced reactivity, lower viscosity tar;
• ii) removing solids from the second process stream to provide a third process stream comprising a reduced reactivity, lower viscosity tar that is substantially free of solids of size larger than 25 μm;
• iii) pretreating the third process stream to further lower the reactivity of the tar and obtain a fourth process tar stream;
• iv) hydrogenating and desulfurizing the fourth process stream and recovering a total liquid product (TLP);
• v) distilling the TLP and recovering a mid-cut of the distillation products and a heavy bottoms fraction;
• vi) mixing at least a portion of the heavy bottoms fraction with a pre-pyrolysis flash bottoms stream to form a mixed feed comprising 25 wt. % or more of the heavy bottoms fraction and having a weight ratio of heavy bottoms fraction to pre-pyrolysis flash bottoms stream of 0.5 or more, the pre-pyrolysis flash bottoms stream having a T5 distillation point of 400° C. or more;
• and
• vii) desulfurizing the mixed feed to obtain a low sulfur product having a sulfur content of about 1.0 wt. % or less.

A system for producing a low sulfur liquid product, comprising:

• a flash separator having a feed inlet, a lower boiling stream outlet, and a flash bottoms outlet;
• a steam cracker comprising a steam cracker inlet and a steam cracker outlet, the steam cracker inlet being in fluid communication with the lower boiling stream outlet;
• a first fractionation stage comprising a first fractionation inlet, one or more first product outlets, and a tar outlet, the first fractionation inlet being in fluid communication with the steam cracker outlet;
• at least one of a heat soaking vessel and a heat soaking conduit;
• a particle separator comprising a particle separator inlet and a particle separator outlet, the particle separator inlet being in fluid communication with the tar outlet via the at least one heat soaking vessel and heat soaking conduit;
• one or more first hydroprocessing reactors comprising a first hydroprocessor inlet and a first hydroprocessor outlet, the first hydroprocessor inlet being in fluid communication with the particle separator outlet;
• a second fractionation stage comprising a second fractionation inlet, one or more light products outlets, the mid-cut outlet, and a hydroprocessed bottoms outlet, the second fractionation inlet being in fluid communication with the hydroprocessor outlet;
• and
• one or more second hydroprocessing reactors comprising a second hydroprocessor inlet and a second hydroprocessor outlet, the second hydroprocessor inlet being in fluid communication with the hydroprocessed bottoms outlet,
• wherein at least one of the particle separator inlet and the first hydroprocessor inlet is further in fluid communication with the flash bottoms outlet, and
• wherein at least one of the particle separator inlet and the first hydroprocessor inlet is further in fluid communication with the mid-cut outlet.

A system for producing a low sulfur liquid product, comprising:

• a flash separator having a feed inlet, a lower boiling stream outlet, and a flash bottoms outlet;
• a steam cracker comprising a steam cracker inlet and a steam cracker outlet, the steam cracker inlet being in fluid communication with the lower boiling stream outlet;
• a first fractionation stage comprising a first fractionation inlet, one or more first product outlets, and a tar outlet, the first fractionation inlet being in fluid communication with the steam cracker outlet;
• at least one of a heat soaking vessel and a heat soaking conduit;
• a particle separator comprising a particle separator inlet and a particle separator outlet, the particle separator inlet being in fluid communication with the tar outlet via the at least one heat soaking vessel and heat soaking conduit;
• one or more first hydroprocessing reactors comprising a first hydroprocessor inlet and a first hydroprocessor outlet, the first hydroprocessor inlet being in fluid communication with the particle separator outlet;
• a second fractionation stage comprising a second fractionation inlet, one or more light products outlets, the mid-cut outlet, and a hydroprocessed bottoms outlet, the second fractionation inlet being in fluid communication with the hydroprocessor outlet;
• and
• one or more second hydroprocessing reactors comprising a second hydroprocessor inlet and a second hydroprocessor outlet, the second hydroprocessor inlet being in fluid communication with the hydroprocessed bottoms outlet and being in fluid communication with the flash bottoms outlet,
• wherein at least one of the particle separator inlet and the first hydroprocessor inlet is further in fluid communication with the mid-cut outlet.