Performances of a Y-type structured packing produced by 3D foam-printing for the intensification of gas absorption processes

In this work, we report pilot-scale tests on a new design of Y-type corrugated polylactic acid (PLA) packing (Prototype FT.Y), produced by an innovative additive manufacturing process consisting of a one-step 3D foam-printing process. The design characteristics of the packing and the surface texture of the prototype, which is analyzed with optical measurements, are presented. The performances of the FT.Y packing are characterized and compared with those of a benchmark commercial Mellapak 250Y packing, through experimental tests aimed to estimate pressure drops and mass transfer coefficients. The new packing is also tested for a reference absorption case study, the wet Flue Gas Desulfurization (wet-FGD), for its large application in the process industry and as a lab testing method. The 3D foam printing technology allows for an easy tailor-made design of the packing, providing lower weights and interesting surface properties. These translate in low pressure drops and high mass transfer coefficients, which are comparable or superior to those of the Mellapak 250.Y. Indeed, the FT.Y packing provides high liquid-film mass transfer coefficients, which allows desulfurization efficiencies up to 42 % higher than those expected for the benchmark packing. Beyond the potential manufacturing advantages provided by the 3D-foam printing, the FT.Y packing performances make this unit a valuable alternative for process intensification in absorption and distillation processes, especially in those cases when the liquid-film mass transfer resistance has a relevant role in the process design.