Acetone-butanol-ethanol Recovery Research Articles

Recent innovations for reviving the ABE fermentation for production of butanol as a drop-in liquid biofuel

Butanol is a key microbial product that provides a route from renewable carbohydrate resources to a "drop-in" liquid biofuel, broadening its market in the near future. The acceptable performance of butanol as a neat or a blended fuel in different engines both from the technical and environmental points of view has attracted a wide range of research for reviving the old acetone-butanol-ethanol (ABE) fermentation. In this review, recent findings on fuel characteristics of butanol, different generations of substrate for large scale butanol production, and alternative process designs for upstream, mainstream, and downstream operations have been critically reviewed and discussed. In the upstream, studies devoted to designing and optimization of pretreatments based on prerequisites of butanol production, e.g., maximizing cellulose and hemicellulose recovery and minimizing lignin degradation, are presented. In the mainstream, different microbial systems and process integrations developed for facilitating ABE production (e.g., in-situ butanol removal) are scrutinized. Finally, innovations in ABE recovery and purification as "Achilles Heel" of butanol production processes which directly controls the energy return on investment (EROI), are reviewed and discussed.

Assessing the energy requirements for butanol production using fermentation tanks-in-series operated under vacuum

Abstract The acetone-butanol-ethanol (ABE) fermentation from corn stover was considered. We propose, study and optimise, via process simulation (using MATLAB® and Aspen Plus®) the use of fermentation tanks-in-series and in situ product recovery by vacuum evaporation. As the operating time of continuous fermentation processes is usually limited at less than 500 h, shutdown and start-up of the reactors are considered and optimised. A multi-objective optimisation methodology that considers economics as well as the energy requirements of the process was used. The optimal configuration was found to be five fermentation tanks-in-series where the first and the last reactors are operated at atmospheric pressure, and the intermediate vessels are operated under vacuum. The economic potential using this configuration was found to be 45% higher than that of vacuum fermenters operating in parallel (continuous operating mode). Also, the total fuel requirements for ABE recovery and purification system were as low as 7 MJ kg−1 butanol, a reduction of between 4 and 33% when compared to a parallel configuration of batch, fed-batch or continuous fermenters. The energy efficiency of this recovery and reaction system was as high as 74% when co-generation is considered.

Carbonized ZIF-8 incorporated mixed matrix membrane for stable ABE recovery from fermentation broth

Recently, zeolitic imidazolate framework-8 (ZIF-8) has been recognized as one of the most potential doping particles for pervaporation separation of organics because of its unique pore structure and high surface area. However, in this work, ZIF-8-based mixed matrix membrane (MMM) was found to have poor stability in separating acetone-butanol-ethanol (ABE) fermentation broth due to the organic acids caused the degradation of ZIF-8 framework. To improve the stability of ZIF-8-based MMM in practical application, ZIF-8-derived nanoporous carbon (ZNC) was prepared via direct carbonization and used to replace ZIF-8 in MMM. Results indicated the acid-stability, specific surface area and pore volume of ZNC were all remarkably improved compared with those of ZIF-8. The ZNC-based MMM showed high hydrophobicity and good compatibility between particles and polymer. More attractively, during 100 h of continuous operation for ABE recovery from fermentation broth, ZNC incorporated MMM exhibited a stable performance with an average total flux of 1870 g m−2 h−1 and a n-butanol separation factor of 20.

Recovery of butanol from Clostridium beijerinckii P260 fermentation broth by supercritical CO2 extraction

AbstractBACKGROUNDButanol is a superior biofuel to ethanol because of its blend properties and higher energy density. However, its recovery by distillation from the fermentation broth is energy intensive. For this reason, butanol recovery by supercritical CO2 extraction from simulated and actual fermentation broths was studied. Recovery of butanol by this technique has numerous advantages including being environmentally favorable, avoiding use of costly chemicals or membranes, and compatible with the microbial culture.RESULTSFor the model solution extraction process, feed contained 7.00, 12.00, and 1.00 g L−1 acetone, butanol, ethanol (ABE), respectively, to mimic the actual concentrations obtained in the fermentation broth. In the extract phase, butanol concentration obtained ranged from 460.4 to 573.2 g L−1 with butanol selectivities ranging from 128 to 204.8. ABE recovery was also successfully demonstrated using actual fermentation broth of C. beijerinckii P260.CONCLUSIONSupercritical CO2 extraction was successfully used for recovery of all three (ABE) components. Fermentation broth raffinate (feed depleted in ABE after recovery) was also reused for a second fermentation thus allowing process water recycle. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Modeling of single- and multi-stage extraction in the system of water, acetone, butanol, ethanol and ionic liquid

This paper investigates liquid-liquid equilibrium (LLE) in the mixture of acetone, butanol, ethanol (ABE) and water in combination with three hydrophobic ionic liquids:1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [bmim][Tf2N],1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6];and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulphonyl)imide [bmp][Tf2N].To model the LLE, the non-random two-liquid (NRTL) equation was used. The experimental data were taken from the cited work of Kamiński et al. (2014), where the unknown equation parameters had been determined with the help of Matlab programming. In this work, however, Aspen Plus™ software was employed as it readily facilitates further simulations of the extraction step. Different yet similarly accurate sets of the NRTL parameters were obtained. After the model formulation, single-stage and multi-stage extraction processes were simulated and examined in terms of ABE recovery effects.

Bioproduction of butanol in bioreactors: New insights from simultaneous in situ butanol recovery to eliminate product toxicity

Simultaneous acetone butanol ethanol (ABE) fermentation by Clostridium beijerinckii P260 and in situ product recovery was investigated using a vacuum process operated in two modes: continuous and intermittent. Integrated batch fermentations and ABE recovery were conducted at 37 °C using a 14-L bioreactor (7.0 L fermentation volume) containing initial substrate (glucose) concentration of 60 g/L. The bioreactor was connected in series with a condensation system and vacuum pump. Vacuum was applied continuously or intermittently with 1.5 h vacuum sessions separated by 4, 6, and 8 h intervals. A control ABE fermentation experiment was characterized by incomplete glucose utilization due to butanol toxicity to C. beijerinckii P260, while fermentation coupled with in situ recovery by both continuous and intermittent vacuum modes resulted in complete utilization of glucose, greater productivity, improved cell growth, and concentrated recovered ABE stream. These results demonstrate that vacuum technology can be applied to integrated ABE fermentation and recovery even though the boiling point of butanol is greater than that of water.