2,4,4-Trimethyl-1-pentene → 2,2,4,6,6-Pentamethylheptane

Participants

Reaction Steps

Isobutanol can be converted to triisobutylene and/or isododecane as illustrated in FIG. 8. FIG. 8 depicts a typical process configuration for converting isobutanol to a higher alkane comprising predominantly 2,2,4,6,6-pentamethylheptane. Isobutanol is preheated and fed via stream 1 to a reaction vessel that contains 2.5% para toluene sulfonic acid operating at 160° C. and 50 psig. A vapor stream is generated and is passed up through a rectification column before being partially condensed and decanted into two liquid phases at 35° C. and 45 psig. The upper phase is organic comprising mostly isobutylene and is returned to the top of the column as reflux while the lower aqueous phase is removed as stream 2. Uncondensed vapors are let down in pressure across a valve and reheated by a steam exchanger to form isobutylene vapor stream 3 that is fed into a tubular oligomerization reactor packed with Amberlyst-15 catalyst in the form of 0.5 mm beads operating at 100° C. and near atmospheric pressure. At a weight hourly space velocity of 1 g isobutylene per g catalyst per hour, 8.6% of the isobutylene is converted to diisobutylene, 81.6% to triisobutylene and 5.8% to tetraisobutylene, while 4% remains unconverted. The reactor effluent stream 4 is flashed in a drum to safely vent off the unreacted isobutylene and the mixed isomers of isobutylene oligomers is pumped via stream 5 to a trickle bed hydrogenation reactor along with an excess feed of hydrogen gas stream 6 sourced from cylinder storage. The conversion of olefins is quantitative and the hydrogenation reactor effluent stream 7 is flashed in a drum to safely vent off unreacted hydrogen gas and produce a liquid product steam 8 comprising predominantly 2,2,4,6,6-pentamethylheptane. Steps for the conversion of isobutanol to triisobutylene and isododecane (2,2,4,6,6-pentamethylheptane) are known in the art, see, for e.g., Alcantara et al., Reactive Funct. Polymers 45:19-27 (2000); Ludwig et al., J. Catalysis 284:148-56 (2011); and U.S. Pat. No. 5,625,109.

Provenance & Evidence