
250 Refining Used Lubricating Oils
circulation rate preferably between approximately 300 and 20,000 standard cubic
feet per barrel (50.6 and 3371 normal m
3
per cubic meter) are also stated.
The product stream from the hydrogenation reactor is mixed with an aqueous scrub-
bing solution where the composition of the scrubbing chemical is chosen according to
the components present in the feed stream to the hydrogenation reactor: if the stream
contains halogenated compounds, the agent chosen would be a base such as calcium
hydroxide, potassium hydroxide or sodium hydroxide to neutralize the acids of hydro-
gen chloride, hydrogen bromide or hydrogen ...