Abstract: A process for forming a concentrated solution, including distilling in a distillation zone comprised of 10 or more theoretical distillation stages, at a pressure of no greater than 300 mm Hg and a reflux ratio (D/L) of at least 1:1, an amount of an initial solution comprised of tert-butyl hydroperoxide (TBHP) in tert-butyl alcohol (TBA) having a TBHP concentration of up to 60 wt. % and a total impurity content greater than 0.01 wt. %, for a time and under distillation conditions to form a concentrated solution comprised of TBHP in TBA; and separating an overhead distillate from the distillation zone so that the concentrated solution thereafter has a TBHP concentration greater than 60 wt. %, a TBA concentration less than 40 wt. %, a water impurity content no greater than 0.1 wt. % and a total impurity content of no greater than 1 wt. %. Related epoxidation catalyst formation and epoxidation processes are also described.

Abstract: A process for forming a concentrated solution, including distilling in a distillation zone comprised of 10 or more theoretical distillation stages, at a pressure of no greater than 300 mm Hg and a reflux ratio (D/L) of at least 1:1, an amount of an initial solution comprised of tert-butyl hydroperoxide (TBHP) in tert-butyl alcohol (TBA) having a TBHP concentration of up to 60 wt. % and a total impurity content greater than 0.01 wt. %, for a time and under distillation conditions to form a concentrated solution comprised of TBHP in TBA; and separating an overhead distillate from the distillation zone so that the concentrated solution thereafter has a TBHP concentration greater than 60 wt. %, a TBA concentration less than 40 wt. %, a water impurity content no greater than 0.1 wt. % and a total impurity content of no greater than 1 wt. %. Related epoxidation catalyst formation and epoxidation processes are also described.