Recovery of volatile products from dilute high-fouling process streams.

As biomass hydrolysis and fermentation technologies approach commercial viability, advancements in product recovery technologies will be required. For cases in which fermentation products are more volatile than water, recovery by distillation is often the technology of choice. Distillation technologies that will allow the economic recovery of dilute volatile products from streams containing a variety of impurities have been developed and commercially demonstrated. Distillation tower and tray designs, along with specialized heat-exchanger designs, allowing for extended processing intervals on solutions containing lignocellulosic residues, organic acids, and inorganic salts concentrations > 100 g/L are in commercial operation. In the case of ethanol, distillation energy consumption efficiencies for processing solutions containing < 40 g/L of desired product can approach demonstrated energy consumption efficiencies for solutions containing concentrations > 120 g/L. These proprietary technologies have been applied individually at commercial scale, and designs have been developed that incorporate the combined technologies with only a marginal increase in capital investment compared to traditional methods.