Improving performance of a gas stripping-based recovery system to remove butanol from Clostridium beijerinckii fermentation

Abstract

The effect of factors such as gas recycle rate, bubble size, presence of acetone, and ethanol in the solution/broth were investigated in order to remove butanol from model solution or fermentation broth (also called acetone butanol ethanol or ABE or solvents). Butanol (8 g L(-1), model solution, Fig. 2) stripping rate was found to be proportional to the gas recycle rate. In the bubble size range attempted (< 0.5 and 0.5-5.0 mm), the bubble size did not have any effect on butanol removal rate (Fig. 3, model solution). In Clostridium beijerinckii fermentation, ABE productivity was reduced from 0.47 g L(-1) h(-1) to 0.25 g L(-1) h(-1) when smaller (< 0.5 mm) bubble size was used to remove ABE (Fig. 4, results reported as butanol/ABE concentration). The productivity was reduced as a result of addition of an excessive amount of antifoam used to inhibit the production of foam caused by the smaller bubbles. This suggested that the fermentation was negatively affected by antifoam.

Corynebacterium glutamicum Tailored for Efficient Isobutanol Production

“…The reason for this behavior remains unclear but might be attributed to isobutanol toxicity for the cells. Cell toxicity might be avoided by integrated product removal by gas stripping with N 2 and product recovery by continuous condensation, which was successfully applied for 1-butanol production with Clostridium beijerinckii (19). Such a process will probably allow the system to maintain its high productivity.…”

Current knowledge on isobutanol production withEscherichia coli,Bacillus subtilisandCorynebacterium glutamicum

“…The negative effect might be overcome by developing an integrated stripping process with nitrogen, which has been successfully applied for 1-butanol production with Clostridia. 15 A significantly reduced Y P/S was observed in the fed-batch fermentations with C. glutamicum Iso7 when compared with the cultivations in shaken bottles. 5 operation of this cycle in C. glutamicum.…”

Life-cycle assessment of corn-based butanol as a potential transportation fuel.

“…The information in this section is based on the research results from Qureshi and Blaschek (2000;2001a, b), Ezeji et al (2004), and Ezeji et al (2005).…”

“…Figure 4 shows the Aspen Plus ® output of the process flowsheet from fermentation to downstream processing. Data for the simulation of fermentation and gas-stripping unit operations are based on the research results from Qureshi and Blaschek (2000;2001a,b), Ezeji et al (2004), and Ezeji et al (2005). Table 2 summarizes the main parameters for fermentation and gas stripping input to the Aspen Plus The downstream processing flowsheet in the simulation is based on the most costeffective flowsheet rigorously generated from an exhaustive list of plausible processing equipment and unit operations, as described in Liu (2003), Liu et al (2004Liu et al ( , 2006, and Heckl et al (2006).…”

“…Liu (2003) presents an exhaustive survey of major research findings on ABE downstream processing. Recent studies have focused on integration of fermentation and product removal through in-situ gas stripping and fermentation gas recirculation (Qureshi and Blaschek 2000;Qureshi and Blaschek 2001a;Qureshi and Blaschek 2001b;Ezeji et al 2004;and Ezeji et al 2005). The latest development includes a DuPont patent (2007) describing a strain that produces butanol from biological feedstocks while minimizing acetone production.…”