Processes to produce poly alpha-olefin trimers

A process to produce a poly alpha-olefin (PAO), comprising:

• introducing a first group of one or more alpha-olefins and a first catalyst system comprising a metallocene compound into a continuous stirred tank reactor or a continuous tubular reactor under first reactor conditions, wherein the alpha-olefin is introduced to the reactor at a flow rate of about 100 g/hr or more, to form a first reactor effluent comprising PAO dimer comprising at least 96 mol % of vinylidene and 4 mol % or less of trisubstituted vinylene and disubstituted vinylene, based on total moles of vinylidene, trisubstituted vinylene, and disubstituted vinylene;
• and
• introducing the first reactor effluent, a second group of one or more alpha-olefins and a second catalyst composition comprising an acid catalyst into a second reactor under second reactor conditions to form a second reactor effluent comprising PAO trimer,
• wherein the PAO dimer in the first reactor effluent comprises, based on total moles (100 mol %) of vinylidene, disubstituted vinylene, and trisubstituted vinylene in the PAO dimer in the first reactor effluent:
• 98 mol % or more vinylidene, and up to 2 mol % of trisubstituted vinylene, and/or disubstituted vinylene.

A process to produce a poly alpha-olefin (PAO), comprising:

• introducing a first group of one or more alpha-olefins and a first catalyst system comprising a metallocene compound into a continuous stirred tank reactor or a continuous tubular reactor under first reactor conditions, wherein the alpha-olefin is introduced to the reactor at a flow rate of about 100 g/hr or more, to form a first reactor effluent comprising PAO dimer comprising at least 96 mol % of vinylidene and 4 mol % or less of trisubstituted vinylene and disubstituted vinylene, based on total moles of vinylidene, trisubstituted vinylene, and disubstituted vinylene;
• and
• introducing the first reactor effluent, a second group of one or more alpha-olefins and a second catalyst composition comprising an acid catalyst into a second reactor under second reactor conditions to form a second reactor effluent comprising PAO trimer,
• wherein the metallocene compound is represented by the formula:
• wherein:
• each of R1, R2, and R3 is independently hydrogen or a substituted or unsubstituted linear, branched, or cyclic C1-C20 hydrocarbyl or silylcarbyl group;
• each of R4 and R7 is independently a substituted or unsubstituted linear, branched, or cyclic C1-C30 hydrocarbyl or silylcarbyl group;
• each of R8, R9, R10, R11 and R12 is independently a hydrogen, or a substituted or unsubstituted linear, branched, or cyclic C1-C20 hydrocarbyl, silylcarbyl, or germanyl group, or optionally at least three of R8, R9, R10, R11 and R12 are not hydrogen;
• each of R13, R14, R15, R16, R17, and R18 is independently hydrogen or a substituted or unsubstituted linear, branched, or cyclic C1-C20 hydrocarbyl or silylcarbyl group;
• M is a group 3, 4 or 5 transition metal;
• each X is independently a halogen, a hydride, an amide, an alkoxide, a sulfide, a phosphide, a diene, an amine, a phosphine, an ether, or a C1-C20 substituted or unsubstituted linear,
• branched, or cyclic hydrocarbyl group, or optionally two or more X moieties together form a fused ring or ring system;
• and
• m is an integer equal to 1, 2, or 3.