The sulfonation of solid acrylonitrile‐butadiene‐styrene, a feedstock that is often used in the 3D‐printing process of Fused Filament Fabrication, and its application in liquid‐solid mass transfer characterization is reported. The ion exchange capacities were assessed experimentally. Simulations of intraparticle diffusion coupled with extraparticle liquid‐solid mass transfer demonstrate that, using the prepared ion exchanger, mass transfer coefficients as high as can be measured. Tubular reactors and spherical particles were fabricated using 3D‐printing and modified with the described procedure to determine mass transfer coefficients for laminar flow in a tubular reactor and laminar flow in a fixed‐bed of spherical particles. These results show high agreement with published correlations and demonstrate the applicability of this cost effective, accurate, and reliable method.