Patent ID: 8269049

Claim:
A method of fabricating diethylene-glycol tert-butyl ether (DEGtBE) using isobutylene (IB = ) and diethylene glycol (DEG), comprising steps of: (a) obtaining DEG and IB = to be mixed in a reactor together with a catalyst of an acidic cation exchanged resin to obtain a glycol ether mixture, wherein said reactor has a reaction temperature between 30 and 150 Celsius degrees (° C.) and a reaction pressure between 15 and 500 pounds per square inch (psi); wherein said catalyst has a mole ratio of acidity to IB = ([H + ]/IB = ) between 0.01 and 1.00; and wherein said DEG has a mole ratio to IB = (DEG/IB = ) between 0.5 and 10.0; (b) processing said glycol ether mixture through a first stage of vacuum distillation then a second stage of vacuum distillation, said first stage being a low vacuum water extraction distillation to separate octane and a byproduct of diethylene-glycol di-tert-butyl ether (DEGDtBE), wherein said first stage has a pressure between 50 and 500 torr and a temperature between 50 and 150° C.; and wherein water added in said first stage has a weight ratio to said glycol ether mixture between 0.1 and 5.0, said second stage being a high vacuum distillation to separate un-reacted DEG and a product of DEGtBE, wherein said second stage has a pressure between 0.1 and 10 torr and a temperature between 50 and 150° C.; and (c) recycling said byproduct of DEGDtBE separated in said first stage into said reactor to process a transetherification with said DEG, wherein said DEGDtBE has a weight ratio to said DEG between 0.002 and 1.0.