Cloud point improvement for partial conversion hydrocracking units

A method of improving the cold flow properties of diesel comprising:

• hydrotreating and hydrocracking a hydrocarbon feed in a hydrocracking zone in the presence of a hydrotreating catalyst and a hydrocracking catalyst under hydrotreating and hydrocracking conditions to provide a reactor effluent comprising a product mixture comprising diesel, kerosene, and naphtha, and unconverted feed;
• separating the reactor effluent in an enhanced hot separator into an overhead vapor stream comprising the product mixture and a liquid bottoms stream comprising the unconverted feed, the enhanced hot separator including a bed of packing, and wherein a stream of hydrogen is introduced into the enhanced hot separator below the bed of packing;
• contacting the overhead vapor stream from the enhanced hot separator with a dewaxing catalyst in a finishing reaction zone to convert a portion of n-paraffins in the product mixture to iso-paraffins;
• separating an effluent from the finishing reaction zone in a high pressure separator into an overhead stream comprising gases and a liquid stream comprising the product mixture;
• and
• separating the liquid stream from the high pressure separator into at least a diesel stream, a kerosene stream, a naphtha stream, and a bottoms stream in a fractionation zone.

An apparatus for improving the cold flow properties of diesel comprising:

• a hydrocracking zone having an inlet and an outlet;
• an enhanced hot separator having a fluid inlet, a stripping gas inlet, an overhead outlet, and a bottoms outlet, the fluid inlet of the enhanced hot separator being in fluid communication with the outlet of the hydrocracking zone, the stripping gas inlet being in fluid communication with a stripping gas source, the enhanced hot separator containing a bed of packing;
• a finishing reactor containing a dewaxing catalyst having an inlet and an outlet, the inlet being in fluid communication with the overhead outlet of the enhanced hot separator;
• a high pressure separator having an inlet, a gas outlet, and a liquid outlet, the inlet of the high pressure separator being in fluid communication with the outlet of the finishing reactor;
• and
• a fractionation zone having an inlet and at least one outlet, the inlet of the fractionation zone being in fluid communication with the liquid outlet of the high pressure separator.