Ethanol fermentation in a continuous tower fermentor

Jones, Stephen T.; Korus, Roger A.; Admassu, Wudneh; Heimsch, Richard C.

doi:10.1002/bit.260260717

Cited by 48 publications

(17 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although the results were promising at a dilution rate of 0.2 h −1 in reactors R1 and R2 (r p = 9 g L −1 h −1 in both), when the dilution rate was increased neither reactor was able to retain the biomass. This was in contrast to the seven months stable operation reported by Jones et al [16] for their flocculent mutant and implies that our expansion zone (at the top of R2) was less effective for biomass retention than their settler.…”

Section: Support-free Performancecontrasting

confidence: 90%

“…NCYC 1119 was also tested without support, making use of its cells' ability to adhere to each other (flocculation), as in a tower fermenter [16]. Although the results were promising at a dilution rate of 0.2 h −1 in reactors R1 and R2 (r p = 9 g L −1 h −1 in both), when the dilution rate was increased neither reactor was able to retain the biomass.…”

Section: Support-free Performancementioning

confidence: 99%

See 1 more Smart Citation

Natural immobilisation of microorganisms for continuous ethanol production

Baptista

Cóias

Oliveira

et al. 2006

Enzyme and Microbial Technology

View full text Add to dashboard Cite

Using a growth medium based on cane blackstrap molasses, we compared ethanol production by two strains of Saccharomyces cerevisiae that were immobilized in polyurethane foam cubes in a fluidised-bed fermenter. One strain (NCYC 1119) was adhesive and extremely flocculent, whilst the other strain was not adhesive and only weakly flocculent. The strong flocs of NCYC 1119 caused blockage of the bed, so that stable operation could not be achieved beyond 15 days. Nevertheless, it was able to produce 40 g L −1 ethanol at a rate up to 16 g L −1 h −1 (D = 0.4 h −1 ), although this production period was limited to 192 h. In contrast, the non-adhesive strain was only capable of producing 28 g L −1 ethanol at a rate of 11 g Lat the same dilution rate, even though production continued for 576 h. Despite the conversion of sugars to ethanol not being complete during these trials (up to 47 g L −1 was expected), it was clearly demonstrated that the productivity of the adhesive strain was higher than that of the non-adhesive one. However, further work is required to develop this process into a robust, industrial system.

show abstract

Section: Support-free Performancecontrasting

confidence: 90%

Section: Support-free Performancementioning

confidence: 99%

Natural immobilisation of microorganisms for continuous ethanol production

Baptista

Cóias

Oliveira

et al. 2006

Enzyme and Microbial Technology

View full text Add to dashboard Cite

show abstract

“…Table 2 presents the main equations proposed for g 1 (P) and g 2 (P), which are first approximations of much more complicated effects [10,[28][29][30][31][32][34][35][36][37][38][39][40][41][42].…”

Section: Effect Of Ethanol Concentrationmentioning

confidence: 99%

“…In Table 3, typical kinetic parameter values for ethanol fermentation are presented [10,19,[28][29][30][31][32][34][35][36][37][38][39][40][41]. Table 3 shows large variations in the values of kinetic parameters, demonstrating that these parameters are strongly dependent upon the operational conditions for which they were adjusted, from the culture medium and from the microorganisms used in the fermentation.…”

Section: Effect Of Cell Concentrationmentioning

confidence: 99%

“…The cell viability level in ethanol fermentations with high yeast densities has been reported as being strongly dependentontherateofaerationimposeduponthe system [34], varying from 40% to 90% [10,34,38,71]. Under anaerobic conditions, unsaturated fatty acids are not synthesized and the yeasts become more sensitive to ethanol [72].…”

Section: Loss Of Cell Viabilitymentioning

confidence: 99%

See 1 more Smart Citation

Kinetic Modeling of 1‐G Ethanol Fermentations

Oliveira¹,

Stremel²,

Dechechi³

et al. 2017

Fermentation Processes

View full text Add to dashboard Cite

The most recent rise in demand for bioethanol, due mainly to economic and environmental issues, has required highly productive and efficient processes. In this sense, mathematical models play an important role in the design, optimization, and control of bioreactors for ethanol production. Such bioreactors are generally modeled by a set of first-order ordinary differential equations, which are derived from mass and energy balances over bioreactors. Complementary equations have also been included to describe fermentation kinetics, based on Monod equation with additional terms accounting for inhibition effects linked to the substrate, products, and biomass. In this chapter, a reasonable number of unstructured kinetic models of 1-G ethanol fermentations have been compiled and reviewed. Segregated models, as regards the physiological state of the biomass (cell viability), have also been reviewed, and it was found that some of the analyzed kinetic models are also applied to the modeling of second-generation ethanol production processes.

show abstract

Design of fluidized‐bed fermentors

Andrews

Przezdziecki

1986

Biotech & Bioengineering

View full text Add to dashboard Cite

Designing a fluidized-bed bioreactor requires choosing the best support particle (if any). Effectiveness factors (proportional to reactor volumetric productivity) are derived for flocs, solid spherical supports, porous supports, and adsorbent supports. The derivation demonstrates a mathematical procedure for reducing the diffusion/uptake equations for many components (substrates and inhibitory products) to a single equation, and for identifying the limiting component. With solid supports there exists a film thickness that maximizes the effectiveness, and the design objective is to keep the film near this optimum throughout the bed. This involves consideration of the effect of support particle density and film growth on bed stratification. Other considerations in picking support particles are obtaining reasonable values for bed height and diameter, minimizing mass transfer resistance between liquid and biomass, and preventing surface shear from stripping off the biomass.

show abstract

Ethanol fermentation in a continuous tower fermentor

Cited by 48 publications

References 20 publications

Natural immobilisation of microorganisms for continuous ethanol production

Natural immobilisation of microorganisms for continuous ethanol production

Kinetic Modeling of 1‐G Ethanol Fermentations

Design of fluidized‐bed fermentors

Contact Info

Product

Resources

About