Optimum solids concentration for solids suspension and solid–liquid mass transfer in agitated vessels

Bong, Eng Ying; Eshtiaghi, Nicky; Wu, Jie; Parthasarathy, Rajarathinam

doi:10.1016/j.cherd.2015.05.021

Cited by 31 publications

(35 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is worth noting that in the stirred tank reactors, the volumetric gas–liquid or liquid–solid mass transfer coefficient has been reported first to increase with an increase of the solid or catalyst loading and then to decrease after reaching a maximum. 55 , 56 Thus, there might exist an optimal solid catalyst amount to ensure the desired mass transfer rate and reaction performance.…”

Section: Results and Discussionmentioning

confidence: 99%

Optimization of Biodiesel Production over Chicken Eggshell-Derived CaO Catalyst in a Continuous Centrifugal Contactor Separator

Fayyazi

Ghobadian

Bovenkamp

et al. 2018

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Solid calcium oxide (CaO) catalyst was prepared via the calcination of chicken eggshells as an environmentally friendly waste resource and incorporated in a continuous centrifugal contactor separator (CCCS) for intensified biodiesel synthesis. Biodiesel or fatty acid methyl esters (FAME) were produced via the transesterification of sunflower oil (containing 5 wt % tetrahydrofuran as a cosolvent) with methanol under 60 °C and separated from the glycerol and catalyst phases continuously in the CCCS. The influence of reaction parameters on biodiesel production was well modeled by response surface methodology. At an oil flow rate of 9 mL/min, an alcohol to oil molar ratio of 11:1, and a weight hourly space time (defined as the catalyst weight over the oil mass flow rate) of 0.050 h, an optimized FAME yield of 83.2% with a productivity of 638 kgFAME/(m3reactor·h) was achieved. CaO catalyst was reused without significant activity loss for at least four cycles.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Optimization of Biodiesel Production over Chicken Eggshell-Derived CaO Catalyst in a Continuous Centrifugal Contactor Separator

Fayyazi

Ghobadian

Bovenkamp

et al. 2018

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Determination of the mass transfer coefficient for S:L extraction Mass transfer has been widely studied in S:L systems, although principally for first-order coefficients. [24][25][26] As the mass transfer coefficient obtained in this study is of the second-order; the correlation has been adapted as follows (Eq. 2):…”

Section: Methodsmentioning

confidence: 99%

Phosphorus recovery from organic waste for its agronomic valorization: technical and economic evaluation

Fernández‐Delgado

Amo-Mateos

Cubero

et al. 2021

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

BACKGROUND: The present work investigates the use of municipal mixed waste compost (MMWC) residue for phosphorus (P) recycling from a technical, economic, and environmental perspective. The study aims to obtain liquid extracts rich in P from MMWC with a low heavy metals content, suitable for their subsequent precipitation in the struvite form. The effect of inorganic (sulfuric/nitric) and organic (oxalic/citric) acids at different molarities and temperatures was studied using technical analysis. The preliminary economic analysis allows the costs of the extraction section for the optimal extraction strategies to be estimated and compared.RESULTS: Based on the multilevel factorial design, the P extraction optimization shows that sulfuric acid 0.5 M and 30 °C provided the highest P extraction yield, 94.2%. However, oxalic acid 0.1 M and 30 °C is the best choice to maximize the P extraction yield, while also minimizing the heavy metals concentration, reaching a P recovery of 2.5 g P/kg. The extraction kinetics for all tested acids were satisfactorily modelled using a second-order model (r 2 > 0.99). The preliminary economic analysis, estimated for a P extraction pilot plant of 100 kg h −1 of MMWC, noted that sulfuric acid 0.5 M provided the lowest total investment cost (130 000 €) and a minimum sale price of theoretical struvite at 4.96 €/kg. CONCLUSION: MMWC is a promising raw material for P recycling as fertilizer due to an appreciable P concentration (7 g P/kg), which can be used together with other residues rich in P to obtain an economical and sustainable extraction process.

show abstract

“…Among them, the solid/ liquid mixing procedure is applied to many unit operations, [1][2][3] such as crystallization, adsorption, solid catalytic reaction, and polymerization in order to maximize solid/liquid mass transfer and reaction rates by preventing particles from depositing on a vessel bottom. [4][5][6][7] Thus, not only cloud height above 10 mass percent particle concentration but also completely suspended rotation speed were investigated by impeller mixing with baffles. [8,9] The reaction rate was moderately increased above the completely suspended rotation speed.…”

Section: Introductionmentioning

confidence: 99%

Suspension pattern and rising height of sedimentary particles with low concentration in a mechanically stirred vessel

et al. 2020

View full text Add to dashboard Cite

In this study, the effects of impeller rotation speed, off-bottom clearance, blade angle, types of solid and liquid, etc., on the suspension pattern of sedimentary particles and particle rise height in liquid were investigated with a hemispherical vessel without baffles under low particle concentration. The transition conditions of suspension pattern between regimes I and II, and regimes II and III, were observed visually, and their non-dimensional equations were expressed with an acceptable correlation by varying the above operation factors a great deal. Here, regime I is stagnation of particles on a vessel bottom, II is partial suspension, and III is complete suspension in liquid. The non-dimensional equation of the maximum particle rise height was also successfully obtained. The combination of the non-dimensional equations of transition and maximum particle rise height permitted us to determine the adequate solid/liquid mixing operation conditions without collision of particles with device parts.

show abstract

Optimum solids concentration for solids suspension and solid–liquid mass transfer in agitated vessels

Cited by 31 publications

References 20 publications

Optimization of Biodiesel Production over Chicken Eggshell-Derived CaO Catalyst in a Continuous Centrifugal Contactor Separator

Optimization of Biodiesel Production over Chicken Eggshell-Derived CaO Catalyst in a Continuous Centrifugal Contactor Separator

Phosphorus recovery from organic waste for its agronomic valorization: technical and economic evaluation

Suspension pattern and rising height of sedimentary particles with low concentration in a mechanically stirred vessel

Contact Info

Product

Resources

About