Gas-liquid interfacial area have been determined by means of chemically enhanced absorption of CO2 in nitrogen as the carrier gas into DEA as well as DEA-ETG aqueous solutions in a packed bed upflow bubble column reactor with an inner diameter of 156 mm. The influence of the reactor pressure, gas and liquid superficial velocities as well as liquid phase viscosities and packing particles diameter on the interfacial areas, pressure drops, and liquid holdups has been investigated. No distinct pressure influence on the measured interfacial areas is observed, while a dependence on the gas superficial velocities has indeed been found. Results indicate that only in the bed packed with glass spheres of 10 mm diameter may two-phase now in the For smaller particles flow maldistributions are found and pure gas flow in part of the voids is anticipated, simultaneous to regular gas-liquid flow in the other voids.