Production of low cloud point distillates

摘要

Systems and methods are provided for producing at least one low sulfur distillate fuel product with improved low temperature properties. A potential distillate fuel feed is initially hydrotreated to reduce sulfur and nitrogen levels in the feed to desired amounts. The hydrotreated effluent is then fractionated to form several fractions, including a light diesel/distillate fraction and a heavy diesel fraction. The heavy diesel fraction is then dewaxed to improve the cold flow properties of the heavy diesel fraction. The dewaxed heavy diesel fraction can be combined with the light diesel fraction, or the dewaxed heavy diesel fraction can be fractionated as well. Optionally, the heavy diesel fraction is dewaxed under conditions effective for producing a dewaxed fraction with a cloud point that is less than or equal to the cloud point of the light diesel/distillate fraction.

主权项

1. A method for producing distillate products, comprising:
hydrotreating a feedstock under effective hydrotreafing conditions; passing at least a portion of the hydrotreated feedstock into a first separate volume of a divided wall fractionator; fractionating the at least a portion of the hydrotreated feedstock at a cut point of at least about 260° C. to form a heavy diesel fraction and a first light diesel fraction, the heavy diesel fraction being withdrawn from the first separate volume of the divided wall fractionator; dewaxing the heavy diesel fraction under effective dewaxing conditions to produce a dewaxed heavy diesel fraction having a cloud point of about −10° C. or less; passing the dewaxed heavy diesel fraction into a second separate volume of the divided wall fractionator; and fractionating the dewaxed heavy diesel fraction to form at least a heavy diesel product withdrawn from the second separate volume, the fractionation further producing a second light diesel fraction, wherein the first light diesel fraction and the second light diesel fraction form a combined light diesel fraction that is withdrawn from a common volume of the divided wall fractionator.