Conversion of waste oils, animal fats and vegetable oils

摘要

Waste lubricating oil, vegetable oil and animal fat are reprocessed into commercially usable diesel fuel and naphtha by thermocracking. A thermocracker unit is fired with sludge removed from the principal pool of oil or fat undergoing vaporization. The vapors are separated from liquids in a primary distillation tower with precisely controlled heating. Resultant vapors are partially condensed. Resultant liquids flow downward through a secondary distillation tower into a reboiler which is heated by a flue gas bypass with an auxiliary burner. Vapors leaving the secondary distillation tower are partially condensed and resultant fluids are passed to a light ends flash tank. Gases from the flash tank fuel the auxiliary burner. Liquids are collected and stored for selling as naphtha. Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions. Liquids within specification are stored in a diesel storage tank for further use and sale. Off-specification products are stored in a reflux storage tank and are pumped and heated and sprayed downward in the primary distillation tower for washing the tower and for reprocessing in the thermocracking unit. Some light ends are mixed with sludge in a storage tank. The mixture is pumped as sludge fuel to the burner in a fire tube in the thermocracking unit.