L4 Bubble and Drops in Technical Equipment

Räbiger, Norbert; Schlüter, Michael; Mersmann, Alfons; Dahl, Hans Detlef

doi:10.1007/978-3-540-77877-6_89

Cited by 2 publications

(6 citation statements)

References 30 publications

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“…In addition to biological impact factors such as growth, hydrocarbon concentration, and solvent compatibility (Jackson et al 2017(Jackson et al , 2020Kleinert and Griehl 2021), the process of in situ extraction or "milking" of B. braunii is mainly influenced by the effective extraction time, i.e., the time each culture suspension particle remains in contact with the solvent, and the phase boundary, the area between solvent and culture suspension created for the transfer of extracellular hydrocarbons (Räbiger et al 2010). In the in situ extraction process used for this study by Griehl et al (2015), the culture suspension is dispersed in the solventcontaining extraction column by a nozzle.…”

Section: Discussionmentioning

confidence: 99%

“…In the in situ extraction process used for this study by Griehl et al (2015), the culture suspension is dispersed in the solventcontaining extraction column by a nozzle. Depending on the applied volume flow, the solvent properties, and the diameter of the nozzle, a temporally determined amount of culture suspension particles (drops of culture suspension containing several colonies of B. braunii) with a characteristic diameter was generated either by periodic particle formation or by jet disintegration in the solvent (Räbiger et al 2010). Depending on the particle properties, the solvent height, and the total volume of extracted culture suspension, the culture suspension droplets pass through the solvent in a certain time (effective extraction time).…”

Section: Discussionmentioning

confidence: 99%

“…Considering a periodic formation of the primary particles at the outlet of the disperser, d P was calculated by iteratively solving Eq. 4 (Räbiger et al 2010), where F η is the viscous force (Eq. 5), F T is the inertial force (Eq.…”

Section: Calculation Of the Extraction Coefficientmentioning

confidence: 99%

“…10. Therefore, the culture suspension particle-related Reynolds number ( Re P ), the viscosity ( K ), and the density ( K ) of the continuous (solvent) phase as well as the culture suspension particle diameter ( d P ) are required (Räbiger et al 2010) For the calculation of Re P , the Archimedes number Ar (Eq. 11) and the liquid key number K F,Δρ (Eq.…”

Section: Calculation Of the Extraction Coefficientmentioning

confidence: 99%

“…As both principles generally belong to the category of liquid-liquid extractions, the phase transition of the long-chain hydrocarbons from the culture suspension to the solvent is influenced by the dispersion of the culture suspension in the solvent using either a stirrer (mixer-settler) or a nozzle (column extractor). The aim of dispersion is thus to generate the highest possible phase interface and the longest possible effective extraction time (Räbiger et al 2010;Schlüter 2018). For the in situ extraction of long-chain hydrocarbons from B. braunii, solvents such as n-hexane, n-heptane, or n-dodecane with a non-polar character are required (Moheimani et al 2014;Griehl et al 2015;Jackson et al 2017).…”

Section: Introductionmentioning

confidence: 99%

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In situ extraction (milking) of the two promising Botryococcus braunii strains Showa and Bot22 under optimized extraction time

Kleinert

Griehl

2021

J Appl Phycol

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In situ extraction or “milking” of microalgae is a promising approach to reduce downstream costs in order to produce low-value substances such as lipids from microalgae in an economical way. Due to its ability to secrete high amounts of long-chain hydrocarbons to an extracellular matrix, the green microalga Botryococcus braunii is suitable for the process of in situ extraction as the cost intensive steps of harvesting, dewatering, and cell disruption could be omitted. Based on a previous study investigating various B. braunii strains in terms of growth, lipid accumulation, and solvent compatibility, the B. braunii strains Showa and Bot22 (both B race) were identified as potential candidates for the process of in situ extraction. In order to prove the suitability of these two strains for the process of in situ extraction, this study first determined the optimal extraction time using short-term in situ extraction over 7 days at different starting biomass concentrations of 1.5 and 2.5 g L−1. Furthermore, both strains were treated applying the optimal extraction time in long-term in situ extractions for 30 days to confirm the results from the short-term extractions. The results indicate a strain-dependent optimal extraction time of 300 min day−1 for strain Showa and 200 min day−1 for strain Bot22. During long-term in situ extraction for 30 days, hydrocarbon productivity was 16.99 mg L−1 day−1 (10.53 mg gDW−1 day−1) for strain Showa and 14.53 mg L−1 day−1 (10.48 mg gDW−1 day−1) for strain Bot22. Furthermore, a direct correlation between hydrocarbon productivity achieved by in situ extraction and the hydrocarbon concentration in the biomass of the respective strain could be established. It could be shown that the consideration of the effective extraction time and the phase boundary area is required to calculate an extraction system independent value for the comparison of different extraction setups.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Calculation Of the Extraction Coefficientmentioning

confidence: 99%

Section: Calculation Of the Extraction Coefficientmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

In situ extraction (milking) of the two promising Botryococcus braunii strains Showa and Bot22 under optimized extraction time

Kleinert

Griehl

2021

J Appl Phycol

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Noninvasive Differential Pressure Technique for Bubble Characterization in High-Temperature Opaque Systems

Sun

Parkinson

Agbede

et al. 2020

Ind. Eng. Chem. Res.

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A novel analytical tool incorporating a differential pressure transducer (DPT) to measure bubble frequency and size in a simple, noninvasive, nonhazardous, and nonoptical-based technique was presented and validated. Bubbles measured in de-ionized water by an upward facing quartz nozzle and helium gas flow rates up to 50 mL min–1 ranged from 3.75 to 4.29 mm, with bubble size deviations of 3–8% from the literature correlations considered. The DPT technique was applied to two high-temperature systems, molten tin and molten LiCl–KCl (59–41 mol % LiCl–KCl), over 400–700 °C using a u-tube quartz injector. For a 50 mm nozzle tip submersion depth in molten tin at 600 °C, preheating stages and bubble frequency measurements were used to demonstrate that the inlet gas temperature at the point of bubble formation, typically assumed at the temperature of the melt, was not in equilibrium and additional gas preheating was required. Calculated surface areas from the bubble diameters obtained from literature correlations and the measured DPT results in molten tin at 600 °C showed a maximum deviation from literature correlations of 7.57%. This highlights the accuracy of the DPT applied across a wide range of fluid properties and temperature ranges and its applicability for bubble characterization in applications concerning the kinetics of gas bubble–liquid reactions or mass transfer at the bubble–liquid interface.

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L4 Bubble and Drops in Technical Equipment

Cited by 2 publications

References 30 publications

In situ extraction (milking) of the two promising Botryococcus braunii strains Showa and Bot22 under optimized extraction time

In situ extraction (milking) of the two promising Botryococcus braunii strains Showa and Bot22 under optimized extraction time

Noninvasive Differential Pressure Technique for Bubble Characterization in High-Temperature Opaque Systems

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