An ethylene oligomerization system is useful for creating 1-butene from ethylene in the presence of an ethylene oligomerization catalyst. The ethylene oligomerization system includes an internal baffle single pass reactor, a separation system and an exterior motion driver. The exterior motion driver is operable to induce unsteadiness in the flow of the process fluid contained in the internal baffle single pass reactor by transferring motion into the process fluid. An ethylene oligomerization process is useful for creating a refined 1-butene product from ethylene using the ethylene oligomerization system.