Modeling of a Biobutanol Adsorption Process for Designing an Extractive Fermentor

Abstract

For curbing the severe inhibition and toxicity of 1-butanol in a fermentor, which stand as one of the major hurdles on the way to commercialization of biobutanol production processes, an extractive fermentation process that can remove metabolites during the ferementation can be an effective solution. Among various separation techniques, adsorption using poly-(styrene-co-divinylbenzene) adsorbent resin is an effective and energy-efficient technique that holds much promise. In this paper, we have investigated the adsorption-and-desorption characteristics of the fermentation metabolites to aid the design of a new fermentation process equipped with an in situ or ex-situ butanol recovery capability. Specifically, the Langmuir equation and Ideal Adsorption Solution theory (IAST) have been used for developing an adsorption isotherm model, based on which a kinetic model of the adsorption process is developed. For the parameter estimation of the adsorption model, experiments have been carried out with a batch type slurry adsorption process processing a multiple-component mixture containing acetone, ethanol, 1butanol, acetic acid, and butyric acid. It is subsequently confirmed that the adsorption model developed with data from the experiments using the model broth adsorption can accurately predict the adsorption behavior of the actual fermentation broth. To ensure the practical applicability of the adsorption process, desorption experiments of the adsorbent resin have also been performed. It is found that approximately 95% of the adsorbates on the adsorbent can be recovered using 140 °C steam with the steam-to-adsorbent mass ratio of 1. This study on the adsorption-and-desorption characteristics is expected to contribute to designing a large-scale extractive fermentor for biobutanol production.

Ex situ product recovery and strain engineering of Clostridium acetobutylicum for enhanced production of butanol

“…The adsorption experiments to construct equilibrium isotherms were performed in 100 mL of 50 mM phosphate buffer (pH 6.0) containing 5 g of an adsorbent and various concentrations of each solute (0-20 g/L) at 37 • C in a water bath with agitation at 150 rpm, as described previously [21]. After 1 h of equilibration, concentrations of each solute (i.e., acetone, ethanol, butanol, acetate, and butyrate) in the aqueous phase were measured using GC.…”

Atomistic simulations of the structure of highly crosslinked sulfonated poly(styrene-co-divinylbenzene) ion exchange resins

“…55,56 The apparent density decreases with increasing N scl while, in opposition, the porosity increases with N scl . Comparison of the  a values calculated for CGA-N scl /0 microstructures with the experimental measure 30 ( a = 0.97 g/cm 3 ) indicates an excellent agreement for CGA-2/0 ( a = 0.97 g/cm 3 ) and a significant underestimation for CGA-34/0 ( a = 0.77 g/cm 3 ). Nevertheless, the porosity predicted for CGA-2/0 (= 22.9%) is lower than the experimental value (= 31.7%).…”

“…This is evidenced in Figure 5, which shows the temporal evolution of the apparent density ( a ) for representative HGA-145 and HGA-357 microstructures. As it can be seen, the  a values of the relaxed structures are around 1.25-1.28 g/cm 3 , representing an overestimation close to 30% with respect to the experimental value (Table 1). These high density values are due to the homogeneous topology of the resin that is motivated by the own HGA algorithm.…”

“…w/w butanol was of 0.96, 0.98 and 0.96 g/cm 3 , respectively. These values are practically identical to that obtained in absence of butanol, indicating that the alcohol provokes the swelling of the resin.…”

“…removal of organic pollutants, removal of toxic metals, ions exchange processes), [1][2][3][4][5] hydrogen storage, 6,7 hydrometallurgy, 8, chromatography 9,10 and separation of biomolecules. 11,12 In addition, the utilization of P(S-DVB) resins as catalyst in a number of industrial processes is also quite important, as they offer potentially much higher capacity for the supported functionality than the conventional inorganic carriers.…”