Comparing results obtained for ion exchange membranes and resins is complicated by the fact that the ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using the idealized Thomas model. Two dimensionless parameters are used, the relative mass throughput and chromatographic bed number. The relative mass throughput parameter arises naturally from the Thomas solution for ion exchange. The results show that of the two ion exchange materials, the membrane exhibits better performance in terms of capacity and retention of desired sugars. In addition, acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of more economical recovery and re-use of the acetic acid using membrane-based ion exchange.