Abstract: 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 Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions.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.

Abstract: Waste lubricating oil is reprocessed into commercially usable diesel fuel and naphtha by thermocracking. A thermocracker unit is fired with sludge removed from the principal pool of oil 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 Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions.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.