Etherification of glycerol with (bio)butanol was investigated in order to obtain glycerol ethers usable as oxygenated additives for diesel fuel. Experiments were carried out using a batch reactor assisted by a tubular water-permselective membrane. A-15 resin was used as solid acid catalyst at a reaction temperature ranging from 70 to 160 degrees C in view of maximizing the glycerol conversion. The water formed during the reaction was continuously removed by recirculation the gas phase through the membrane and this allowed to enhance reactions kinetics reaching both a total glycerol conversion and the formation of poly-substituted ethers not obtainable without the membrane. The alcohol dehydration and self-etherification of glycerol or alkyl alcohols give rise to the formation of several side products at moment hardly to identify. (C) 2015 Elsevier B.V. All rights reserved.