Improvement of Biohydrogen and Usable Chemical Products from Glycerol by Co-Culture of Enterobacter spH1 and Citrobacter freundii H3 Using Different Supports as Surface Immobilization

Glycerol is a by-product of biodiesel production in a yield of about 10% (w/w). The present study aims to improve the dark fermentation of glycerol by surface immobilization of microorganisms on supports. Four different supports were used—maghemite (Fe2O3), activated carbon (AC), silica gel (SiO2), and alumina (γ-Al2O3)—on which a newly isolated co-culture of Enterobacter spH1 and Citrobacter freundii, H3, was immobilized. The effect of iron species on dark fermentation was also studied by impregnation on AC and SiO2. The fermentative metabolites were mainly ethanol, 1,3-propanediol, lactate, H2 and CO2. The production rate (Rmax,i) and product yield (Yi) were elucidated by modeling using the Gompertz equation for the batch dark fermentation kinetics (maximum product formation (Pmax,i): (i) For each of the supports, H2 production (mmol/L) and yield (mol H2/mol glycerol consumed) increased in the following order: FC < γ-Al2O3 < Fe2O3 < SiO2 < Fe/SiO2 < AC < Fe/AC. (ii) Ethanol production (mmol/L) increased in the following order: FC < Fe2O3 < γ-Al2O3 < SiO2 < Fe/SiO2 < Fe/AC < AC, and yield (mol EtOH/mol glycerol consumed) increased in the following order: FC < Fe2O3 < Fe/AC < Fe/SiO2 < SiO2 < AC < γ-Al2O3. (iii) 1,3-propanediol production (mmol/L) and yield (mol 1,3PDO/mol glycerol consumed) increased in the following order: γ-Al2O3 < SiO2 < Fe/SiO2 < AC < Fe2O3 < Fe/AC < FC. (iv) Lactate production(mmol/L) and yield (mol Lactate/mol glycerol consumed) increased in the following order: γ-Al2O3 < SiO2 < AC < Fe/SiO2 < Fe/AC < Fe2O3 < FC. The study shows that in all cases, glycerol conversion was higher when the support assisted culture was used. It is noted that glycerol conversion and H2 production were dependent on the specific surface area of the support. H2 production clearly increased with the Fe2O3, Al2O3, SiO2 and AC supports. H2 production on the iron-impregnated AC and SiO2 supports was higher than on the corresponding bare supports. These results indicate that the support enhances the productivity of H2, perhaps because of specific surface area attachment, biofilm formation of the microorganisms and activation of the hydrogenase enzyme by iron species.

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Mathematical Modeling of Biodiesel Production under Intense Agitation

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2015-0021 ◽

2016 ◽

Vol 14 (1) ◽

pp. 445-451

Author(s):

Aliakbar Roosta ◽

Jafar Javanmardi ◽

Elham Sadat Behineh

Keyword(s):

Mass Transfer ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Rapeseed Oil ◽

Catalyst Concentration ◽

Biodiesel Production ◽

Transfer Coefficients ◽

Increasing Temperature ◽

Intense Agitation

AbstractIn this study, a new approach is proposed to investigate the kinetics of sunflower oil and rapeseed oil transesterification in the presence of potassium hydroxide. Transesterification is a heterogeneous process which affected by a number of parameters, that are not readily available in the literature, such as mass transfer coefficients, partition coefficients, and specific surface area of the dispersed phase. However, under intense agitation condition, mass transfer restrictions may be neglected, and the two phases are supposed to remain in thermodynamic equilibrium, during the process. Therefore, a model was developed independent of the mass transfer coefficient and specific surface area, which is reliable for the intense agitation condition. According to the results, the model is valid at least for mixing rates over 500 rpm. The results of the model were used to study the effects of temperature, methanol-to-oil ratio, and catalyst concentration on the biodiesel conversion. Biodiesel production rate increases with increasing temperature, although rapeseed oil transesterification is more temperature dependent. The results show that the maximum amount of catalyst concentration is less than 1% (by weight); however, the optimum value depends on the operating temperature. The optimum value of the methanol-to-oil-ratio decreases with increasing temperature. Thus, at higher temperatures, less amount of methanol and catalyst are required, which leads to easier purification of biodiesel.

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The Oxidation of Macroporous Cerium and Cerium-Zirconium Oxide for the Solar Thermochemical Production of Fuels

ASME 2011 5th International Conference on Energy Sustainability, Parts A, B, and C ◽

10.1115/es2011-54160 ◽

2011 ◽

Cited By ~ 2

Author(s):

Luke J. Venstrom ◽

Nicholas Petkovich ◽

Stephen Rudisill ◽

Andreas Stein ◽

Jane H. Davidson

Keyword(s):

Specific Surface ◽

Production Rate ◽

Surface Area ◽

Cerium Oxide ◽

Specific Surface Area ◽

Zirconium Oxide ◽

H2 Production ◽

Production Rates ◽

Solar Thermochemical ◽

Ordered Porous

The H2 and CO productivity and reactivity of three-dimensionally ordered macroporous (3DOM) cerium and cerium-zirconium oxide upon H2O and CO2 oxidation at 1073K is presented in comparison to the productivity and reactivity of non-ordered porous and low porosity cerium oxide. The production of H2 and CO2 constitutes the second step of the two-step solar thermochemical H2O and CO2 splitting cycles. The 3DOM cerium oxide, with a specific surface area of 25 m2 g−1, increases the average H2 and CO production rates over the non-ordered porous cerium oxide with a specific surface area of 112 m2 g−1: the average H2 production rate increases from 5.2 cm3 g−1 min−1 to 7.9 cm3 g−1 min−1 and the average CO production rate increases from 7.7 cm3 g−1 min−1 to 21.9 cm3 g−1 min−1. The superior reactivity of 3DOM cerium oxide is attributed primarily to the stability of the 3DOM structure and also to the improved transport of reacting species to and from oxidation sites realized with the interconnected and ordered pores of the 3DOM structure. Doping the 3DOM cerium oxide with 20 mol% zirconia further stabilizes the structure and increases the average H2 and CO production rates to 10.2 cm3 g−1 min−1 and 22.1 cm3 g−1 min−1, respectively.

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Glycerol oxidation by fluorinated and platinized Titania

CIENCIA EN DESARROLLO ◽

10.19053/01217488.v12.n1.2021.12417 ◽

2021 ◽

Vol 12 (1) ◽

pp. 135-142

Author(s):

E. Bautista ◽

E.G. Ávila-Martínez ◽

R. Natividad ◽

Julie Murcia Mesa ◽

R. Romero ◽

...

Keyword(s):

Reaction Mechanism ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Detrimental Effect ◽

Visible Region ◽

Electromagnetic Spectrum ◽

Glycerol Oxidation ◽

Glycerol Conversion

In this work, fluorinated and platinized TiO2 was evaluated in the glycerol oxidation. Fluorination led to increase the specific surface area of titania, and platinization treatment led to obtain the highest absorption in the visible region of the electromagnetic spectrum; thus, 0.5 wt.% Pt-F-TiO2 was the best catalyst in the obtention of highest yield and selectivity to glyceraldehyde (GAL). It was also found that 2wt.% of Pt content had a detrimental effect in the glycerol conversion. Fluorination and platinum addition led to modify the reaction mechanism and selectivity.

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Samarium Promoted Ni/Al2O3 Catalysts for Syngas Production from Glycerol Pyrolys

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.11.2.555.238-244 ◽

2016 ◽

Vol 11 (2) ◽

pp. 238 ◽

Cited By ~ 3

Author(s):

Mohd Nasir Nor Shahirah ◽

Bamidele V. Ayodele ◽

Jolius Gimbun ◽

Chin Kui Cheng

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Fixed Bed Reactor ◽

Ni Catalyst ◽

Impregnation Method ◽

Glycerol Conversion ◽

Product Ratio ◽

Syngas Production ◽

Bet Specific Surface Area

The current paper reports on the kinetics of glycerol reforming over the alumina-supported Ni catalyst that was promoted with rare earth elements. The catalysts were synthesized via wet impregnation method with formulations of 3 wt% Sm-20 wt% Ni/77 wt% Al2O3. The characterizations of all the as-synthesized catalysts were carried out, viz. BET specific surface area measurements, thermogravimetri analysis for temperature-programmed calcination studies, FESEM for surface imaging, XRD to obtain diffraction patterns, XRF for elemental analysis, etc.. Reaction studies were performed in a stainless steel fixed bed reactor with reaction temperatures set at 973, 1023 and 1073 K employing weight hourly space velocity (WHSV) of 4.5×104 mL g-1 h-1. Agilent GC with TCD capillary column was used to analyze gas compositions. Results gathered showed that the BET specific surface area was 2.09 m2.g-1 for the unpromoted Ni catalyst while for the promoted catalysts, was 2.68 m2.g-1. Significantly, the BET results were supported by the FESEM images which showed promoted catalysts exhibit smaller particle size compared to the unpromoted catalyst. It can be deduced that the promoter can increase metal dispersion on alumina support, hence decreasing the size of particles. The TGA analysis consistently showed four peaks which represent water removal at temperature 373-463 K, followed by decomposition of nickel nitrate to produce nickel oxide. From reaction results for Sm promotion showed glycerol conversion, XG of 27% which was 7% higher than unpromoted catalyst. The syngas productions were produced from glycerol decomposition and created H2:CO product ratio which always lower than 2.0. The H2:CO product ratio of 3 wt% Sm promoted Ni/Al2O3 catalyst was 1.70 at reaction temperature of 973 K and glycerol partial pressure of 18 kPa and suitable enough for Fischer-Tropsch synthesis. Copyright © 2016 BCREC GROUP. All rights reservedReceived: 22nd January 2016; Revised: 1st February 2016; Accepted: 17th February 2016How to Cite: Shahirah, M.N.N., Ayodele, B.V., Gimbun, J., Cheng, C.K. (2016). Samarium Promoted Ni/Al2O3 Catalysts for Syngas Production from Glycerol Pyrolysis. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2): 238-244 (doi:10.9767/bcrec.11.2.555.238-244)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.555.238-244

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