Abstract: Lubricant oil comprising a hydrocarbon oil of lubricating viscosity, a sulfurized overbased calcium alkylphenolate detergent-inhibitor having a calcium metal to alkylphenol ratio of at least 2.9:2; and a sulfurized naphthenic base oil-contaning composition having a sulfur content of from 1 percent to 6 percent by weight.

Abstract: Lubricant oil comprising a hydrocarbon oil of lubricating viscosity, a highly overbased alkaline earth metal-containing alkylphenolate detergent-dispersant composition sufficient to impart a total base number to said lubricant oil of at least 10; and a chlorinated sulfurized alkylphenol.

Abstract: A furfural refining unit treates medium sweet charge oil with a furfural solvent in a refining tower to yield raffinate and extract mix. The furfural is recovered from the raffinate and from the extract mix and returned to the refining tower. A system controlling the refining unit includes a gravity analyzer, a refractometer and viscosity analyzer, all analyzing the medium sweet charge oil and providing corresponding signals, sensors sense the flow rates of the charge oil and the furfural flowing into the refining tower and the temperature of the extract mix and provide corresponding signals. One of the flow rates of the medium sweet charge oil and the furfural flow rates is controlled in accordance with the signals from all the analyzers and all the sensors, while the other flow rate of the medium sweet charge oil and the furfural flow rates is constant.