Post-combustion capture contactors, where low pressure drop across a tall bed decides the energy penalty.
Carbon capture absorbers handle very large volumes of flue gas at near-atmospheric pressure. Because the driving force is low and the gas volume is high, the columns are tall and wide, and every millibar of pressure drop turns directly into fan power.
That makes structured packing the usual choice: high surface area for mass transfer with the lowest possible resistance to flow. Distribution quality matters more than in most services, because a poorly irrigated bed wastes both height and energy.
