The feasibility of glycerol etherification is investigated, considering olefins, alcohols and ethers as co-reactants. Details are presented for the reaction between glycerol and iso-butene. Simultaneous phase and chemical equilibrium calculations show that large glycerol conversion can be obtained at a good selectivity towards the desired di-ether. The behaviour of the reactor-separation-recycle flowsheet is analyzed, demonstrating that the recycle of the mono-ether has a beneficial effect. About 1 m3 of reactor volume is necessary for producing 1 kmol/h of di-ether, while the recycle rates of glycerol and mono-ethers are kept at small values.