
225Refining Processes for Used Oil Recycling to Base Oils or Fuels
Light low-boiling products made up between 3 and 4% w/w of the fed material on a
dry basis and were burned in a thermal destruction unit with heat recovery from the
ue gases. The water content of the used oil feed, which also contained glycols, was
usually in the 4% to 6% w/w range and was recovered by distillation from the asphaltic
fraction from the solvent extraction step of the process, this water being sent to a
waste water treatment plant in tank cars.
Typical analyses of the SN-150 and SN-350 oils from the Sener plant (Angulo
Aramburu 2003) are presented in a table which ...