Method and process to maximize diesel yield

A process for upgrading a refinery feedstock derived from one or more hydrocarbon cracking operations that is a complex mixture rich in C5 to C14 olefinic compounds and aromatic compounds boiling in the range of from 15° C. to 250° C., the process comprising:

• a. introducing the feedstock and excess hydrogen gas into a hydrogen mixing zone to produce a liquid hydrocarbon feedstock containing dissolved hydrogen and excess hydrogen gas;
• b. flashing the liquid hydrocarbon feedstock containing dissolved hydrogen in a flashing zone to separate a single-phase reactant of liquid hydrocarbon feedstock containing dissolved hydrogen from a stream of excess hydrogen;
• c. introducing the single-phase reactant of liquid hydrocarbon feedstock containing dissolved hydrogen recovered from the flashing zone into an alkylation unit in the presence of at least one catalyst having Lewis acid and/or Brønsted acid activity;
• d. maintaining the olefins and aromatics in contact with the catalyst in the alkylation unit for a time and under predetermined conditions so that substantially all of the aromatic compounds in the original feedstock are alkylated by the olefinic compounds in the original feedstock to produce an alkylated product having a higher boiling temperature range,
• whereby the alkylation occurs as a two-phase reaction;
• e. recovering an alkylated product stream from the alkylation unit;
• f. passing the alkylated product stream to a fractionation zone to separate middle distillates from the alkylated product stream;
• and
• g. recovering a middle distillate product stream.