368 Refining Used Lubricating Oils
PCB content, which dened when a used oil was considered to be “on-spec” or “off-
spec,” the latter requiring incineration in approved facilities such as industrial fur-
naces or hazardous waste incinerators, which guaranteed a high enough temperature
and residence time to effect the required reactions, coupled with suitable pollution
control methods for the off-gases. The use as a fuel could be after mild processing
such as settling, ltration, and possible blending with fresh fuel oil, or after severe
processing, which included distillation and possibly hydrogenation. The thermal
cracking processes were also reviewed, most of which produced a diesel oil fuel
or marine diesel fuel. The disposal of hazardous ...