Nation H(10 and 20%)-on-SiO2 (Aerosil 200) prepd. by impregnation in resp. H2O and MeOH, and for comparison, Amberlyst 35 dry, Nation NR50 and SAC-13, BET surface 65, 125, 45, 0.02 and 200 m(2)/g, resp., were examd. as catalysts in etherification of glycerol (90 degrees C, 17 atm, 6 hrs, glycerol/isobutene 1:5 by moles, catalyst 5%) and esterification of oleic acid (90 degrees C, 6 hrs, acid/isobutene 1:2 by moles, catalyst 7% reactants wt. basis) run with a com. (11.4:28.4:60 w/w) isobutane-1-butene-isobutene fraction. The 10% and the 20% composites had comparable acid strengths (0.18 and 0.21 meq H+/g, resp.), were more active than the ref. catalysts, converted glycerol in 90.5 and 81.2%, resp. (98% selectivity toward tert-Bu ethers) and oleic acid in 50+% each, and gave only 2.4 and 7.8% isobutene dimers in the etherificate.