Hybrid and Mixed Matrix Membranes for Separations from Fermentations

Abstract

Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs) for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s), Greater understanding of the compatibility between the polymer and inorganic phase(s), Improved methods for homogeneously dispersing the inorganic phase.

Electrocatalytic upgrading of itaconic acid to methylsuccinic acid using fermentation broth as a substrate solution

“…2,19,20 Indeed, fermentation processes delivering high-boiling and polar products in aqueous electrolyte-solutions often cause highly demanding and energy intensive separation processes. [21][22][23][24] These challenges make a close integration with further transformation attractive avoiding intermediate product separation. 25 However, despite promising progress in the design of efficient catalysts for a valorisation of biomassderived platform chemicals, few examples demonstrate a direct catalytic transformation of crude fermentation broth.…”

High-flux PIM-1/PVDF thin film composite membranes for 1-butanol/water pervaporation

“…Organophilic pervaporation, for the removal of organics from aqueous solution or for the separation of organic-organic mixtures, is much less well developed, but has attracted much attention in recent years. A promising application area is biobutanol production, where an economic and energy-efficient separation technique is needed to separate the product from the dilute fermentation broth [3][4][5][6][7][8].…”

“…Inorganic membrane materials such as silicalite-1 [20] have also been employed. Improved performance can be achieved with mixed matrix membranes (MMMs) [6], such as PDMS/silicalite-1 [21], PDMS/ZIF-7 [22], PEBA/Zn(BDC)(TED) 0.5 [23] and PIM-1 with graphene-like fillers [24].…”

Nanofiltration and reverse osmosis membranes for purification and concentration of a 2,3-butanediol producing gas fermentation broth

“…[7] Membrane technologies however present an attractive low energy alternative to these methods. [20,21] Nanofiltration (NF) and reverse osmosis (RO) are pressure driven membrane processes that are suitable for the downstream purification and concentration of fermentation products. Examples exist for the purification / concentration of various acidic products from fermentations such as lactate, [22,23] acetate [24,25] and succinate.…”