Fundamental aspects of 1-butene oligomerization kinetics were investigated under differential conversion at industrially relevant temperatures and pressures on the zeolite H-beta. An apparent activation energy of 28 kJ mo1(-1) for dimer formation was measured and suggests that dimer formation rates were limited by mass transfer. The result was in apparent contradiction to the rapid, and not mass transfer limited, rate of butene double bond isomerization. The Weisz-Prater criterion for the rate of butene consumption was 0.007, a value smaller than 1, suggests that butene transport in the zeolite micropores was not in control of the rate of either oligomer formation or double bond isomerizatoin. Oligomerization kinetics are rationalized then by a model in which transport of oligomers out of the zeolite crystal is rate controlling. Titration of external acid sites with n-octyltrichlorosilane was used to ensure that rates of formation of either product were not significantly impacted by catalysis on the outside of the zeolite crystallites. (C) 2015 Elsevier B.V. All rights reserved.