Processes for the direct alkylation of ethylene with isobutane or isopentane using a highly active ionic liquid alkylation catalyst are described. Ethylene is sent to a high-temperature alkylation reactor loop, and C.sub.3, C.sub.4, and C.sub.5 olefins are routed to a low temperature alkylation reactor loop. In each reactor, the olefins are contacted with an excess of isobutane or isopentane in the presence of a highly active ionic liquid catalyst. Portions of the reactor effluent streams are fed to a common downstream catalyst separation and product fractionation sections. The remainder of the reactor effluent is recycled back to the respective alkylation reactor.

An isoalkane alkylate base oil and a process to make an isoalkane alkylate base oil having a VI higher than 90, comprising: a. selecting an isoalkane feed containing at least one isoalkane and an olefin feed containing at least one linear olefin such that a combined carbon number of the isoalkane feed and the olefin feed is from 20 to 60; and b. alkylating the isoalkane feed with the olefin feed in the presence of an acidic alkylation catalyst under alkylation conditions to make the isoalkane alkylate base oil having the VI higher than 90; wherein the isoalkane alkylate base oil has a kinematic viscosity at 100° C. from 2 to 30 mm.sup.2/s, a pour point less than 0° C., and a bromine index less than 2000 mg Br/100 g.

An isoalkane alkylate base oil and a process to make an isoalkane alkylate base oil having a VI higher than 90, comprising: a. selecting an isoalkane feed containing at least one isoalkane and an olefin feed containing at least one linear olefin such that a combined carbon number of the isoalkane feed and the olefin feed is from 20 to 60; and b. alkylating the isoalkane feed with the olefin feed in the presence of an acidic alkylation catalyst under alkylation conditions to make the isoalkane alkylate base oil having the VI higher than 90; wherein the isoalkane alkylate base oil has a kinematic viscosity at 100° C. from 2 to 30 mm.sup.2/s, a pour point less than 0° C., and a bromine index less than 2000 mg Br/100 g.

An alkylate base oil of biological origin and a process to make an alkylate base oil comprising: a) hydrogenating a farnesene to make a farnesane comprising from zero to less than 5 wt % unsaturated molecules; and b) alkylating the farnesane with one or more C6 to C43 olefins in the presence of an acidic alkylation catalyst to make the alkylate base oil having a kinematic viscosity at 100° C. from 3 mm.sup.2/s to 20 mm.sup.2/s.

An alkylate base oil of biological origin and a process to make an alkylate base oil comprising: a) hydrogenating a farnesene to make a farnesane comprising from zero to less than 5 wt % unsaturated molecules; and b) alkylating the farnesane with one or more C6 to C43 olefins in the presence of an acidic alkylation catalyst to make the alkylate base oil having a kinematic viscosity at 100° C. from 3 mm.sup.2/s to 20 mm.sup.2/s.

Processes for treating effluent streams in alkylation processes are described. One or more process streams rom HF alkylation processes, H.sub.2SO.sub.4 alkylation processes, or ionic liquid alkylation processes can be thermally oxidized in a thermal oxidation system. The thermal oxidation system can replace at least one of the caustic wash unit, the neutralization unit, and the acid gas treatment unit.

Processes for treating effluent streams in alkylation processes are described. One or more process streams rom HF alkylation processes, H.sub.2SO.sub.4 alkylation processes, or ionic liquid alkylation processes can be thermally oxidized in a thermal oxidation system. The thermal oxidation system can replace at least one of the caustic wash unit, the neutralization unit, and the acid gas treatment unit.

Processes for treating effluent streams in alkylation processes are described. One or more process streams rom HF alkylation processes, H.sub.2SO.sub.4 alkylation processes, or ionic liquid alkylation processes can be thermally oxidized in a thermal oxidation system. The thermal oxidation system can replace at least one of the caustic wash unit, the neutralization unit, and the acid gas treatment unit.

A process to make an isoalkane alkylate base oil, comprising: a. oligomerizing an olefin feed having a carbon number from 3 to 6 using a metallocene catalyst to make an unsaturated olefin oligomer; and b. alkylating an isoalkane feed with the unsaturated olefin oligomer in the presence of an acidic alkylation catalyst, and without any addition of hydrogen, to make an alkylate product comprising the isoalkane alkylate base oil having a kinematic viscosity at 100° C. greater than 10 mm.sup.2/s, a VI higher than 80, and a bromine index less than 1000 mg Br/100 g.

A process to make an isoalkane alkylate base oil, comprising: a. oligomerizing an olefin feed having a carbon number from 3 to 6 using a metallocene catalyst to make an unsaturated olefin oligomer; and b. alkylating an isoalkane feed with the unsaturated olefin oligomer in the presence of an acidic alkylation catalyst, and without any addition of hydrogen, to make an alkylate product comprising the isoalkane alkylate base oil having a kinematic viscosity at 100° C. greater than 10 mm.sup.2/s, a VI higher than 80, and a bromine index less than 1000 mg Br/100 g.