466033 Adsorptive Recovery of Biobutanol in Vapor Phase
Monday, November 14, 2016: 4:55 PM
Cyril Magnin II (Parc 55 San Francisco)
Extended Abstract: File Not Uploaded
The depletion of oil reserves and the increasing costs for crude oil have attracted the attention of sustainable and more environmentally-friendly alternatives for petroleum based fuels and chemicals. Biobutanol, produced by ABE (acetone, butanol and ethanol) fermentation of renewable feedstocks (biomass), is a promising candidate as renewable platform molecule. A typical ABE fermentation generates a mixture of acetone, butanol and ethanol with a total concentration of 2 wt% (3:6:1 ratio, respectively) diluted in water . However, high separation costs due to the presence of other co-products and low final concentration prevents biobutanol to become a viable competitor to other biofuels [2,3]. Adsorption has been identified as an energy-efficient technique. In previous work, we have already proposed ZIF-8 and SAPO-34 as shape selective materials for the recovery of butanol in liquid phase conditions [4,5]. No attention has been paid yet to the recovery of acetone, ethanol and butanol from the head space of the fermenter, in spite of a significant amount of these relatively volatile organics in the vapor phase.
In this work, a selection of relevant zeolites and MOFs (with hydrophobic/ hydrophilic properties, shape/non-shape selective, potential kinetic selectivity…), was applied for the vapor phase separation and recovery of butanol in the headspace of the fermentation chamber. Working in vapor phase offers several advantages; ABE concentrations relative to water vapor are higher, adsorbents don’t suffer from stability issues (aqueous conditions and low pH) and no clogging or fouling problems due to microbial cells and inorganic salts.
Separation performance was tested in dynamic conditions by performing vapor phase breakthrough experiments, where the effect of composition, humidity of the vapor stream, contact time and total pressure on selectivity was investigated. The effect of water on the adsorption of the organics could be minimized by using very hydrophobic materials. Adsorbents with complementary selectivity were identified; the combination of different materials in sequential columns with alternating adsorption and desorption steps allows to obtain butanol in very high purity and recovery. Dynamic process simulations have been performed for this multicolumn recovery process, accounting for the complex multicomponent equilibria of the different adsorbents (including favorable, unfavorable and sigmoidal isotherms). Such simulations allow to identify the optimal combination of materials to maximize product selectivity and recovery.
 D. Antoni, V.V. Zverlov, W.H. Schwarz, Appl. Microbiol. Biotechnol. 77 (2007) 23-25.
 T.C. Ezeji, N. Qureshi, H.P. Blaschek, Chem. Rec., 4 (2004) 305-314
 C. Dellomonaco, F. Fava, R. Gonzalez, Microb. Cell Fact. 9 (2010) 3
 J. Cousin Saint Remi, T. Rémy, V. Van Hunskerken, S. Van der Perre, T. Duerinck, M. Maes, D. De Vos, E. Gobechiya, C.E.A. Kirschhock, G.V. Baron, and J.F.M. Denayer, ChemSusChem 4 (2011) 1074-1077.
 J. Cousin Saint Remi, G. Baron, J. Denayer, Adsorption 18 (2012) 367-373.