| abstract |
The refinery off-gases are purified in the unit in two process steps, the off-gases being first washed in a washing column using stripped absorption oils to remove heavy mercaptans and C-components, while the hydrotreating unit is then used to saturate olefinic hydrocarbons and reduce the content of sulfur compounds. Most preferably, the recycle stripped absorption oil is used to control the temperature of the hydrotreater reactor (s) in units where the stripped absorption oil from the hydrotreater reactor outlet separator is mixed with the reactor feed, thereby cooling the hydrotreater reactor by evaporation. |