Fig. 1

Stage-wise separation scheme and its simplification. a Representation of the three-stage separation scheme for extracellular products; b simplification of the separation scheme for superstructure generation based on product properties (solubility, density, physical state, volatility and intended use). Abbreviations: solubility in water [insoluble (NSL) or soluble (SOL)], density with respect to water [heavy (HV) or light (LT)], physical state [solid (SLD) or liquid (LQD)], relative volatility with respect to water [volatile (VOL) and non-volatile (NVL)], and intended use [commodity (CMD) or specialty (SPC)]