Relatively scarce VFA concentration in actual fermentation broths hinders their potential exploitation as bio-based substrates. Nanofiltration and reverse osmosis approaches can represent suitable solutions for the concentration of VFAs; thus, dedicated NF and RO membrane-based cross-flow filtration was applied by laboratory pilot-scale plant with the aim of getting scalable results for preliminary feasibility evaluation studies. Experiments dedicated to the obtainment of robust evidences about the role and optimal values of main process parameters were carried out under total recirculation and concentration mode, using multicomponent solutions and different spiral wound membranes. The role of main process parameters (P, pH, membrane type) on process performances has been studied. Furthermore, the collected data was used to develop a semi-empirical model describing the mass transfer of the single VFAs. Finally, process design cases have been evaluated. Scalable experimental data was collected during operational parameter screening, which allowed defining pH as a key process parameter. The screening was followed by the development of a semiempirical model useful for NF/RO process design and simulation. Indeed, the model was used as to evaluate the concentration performances when utilizing (A) only RO modules or (B) RO + NF modules. Best overall economic performances were observed for the latter process configuration.