Application of Microwave Irradiation for Preparation of a KOH/Calcium Aluminate Nanocatalyst and Biodiesel

Nayebzadeh, Hamed; Saghatoleslami, Nasser; Tabasizadeh, Mohammad

doi:10.1002/ceat.201600466

Cited by 25 publications

(8 citation statements)

References 42 publications

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“…The BET surface area of the samples increased from 17.85 cm −1 at F/O ratio of 0.5-40.96 cm −1 at F/O ratio of 1.5. The increase could be due to the nourmous amount of exhausted gas and the long combustion time during catalyst preparation [25]. However, a further increase in F/O ratio caused an excessive increase in reaction temperature and time, thereby removing crystals from the support lattice, as seen in XRD analysis results [31].…”

Section: Bet-bjh and Acidity Analysesmentioning

confidence: 99%

“…SO 3 H-ZnAl 2 O 4 solid acid catalyst was in the esterification reaction, and the highest FAME yield was achieved (94.59%) at 60 °C, 1.5 wt % of catalyst, 9 MFR [23]. Although the properties of MgO/MgAl 2 O 4 [24] and KOH/calcium aluminate nanocatalysts [25] were thoroughly studied in the transesterification reaction, to the best of our knowledge, no study has been performed on the activity of cobalt aluminate (CoAl 2 O 4 ) as support in the esterification reaction.…”

Section: Introductionmentioning

confidence: 96%

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Fabrication of nanosized SO42−/Co–Al mixed oxide via solution combustion method used in esterification reaction: effect of urea-nitrate ratio on the properties and performance

et al. 2019

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Recently, mixed metal aluminate as a highly active, stable, and reusable nanocatalyst was extremely used in chemical reactions such as esterification. The preparation of the samples via a simple, rapid, and cost-effective method is one of the main problems on the front of the industrial application of these materials. For this purpose, the solution combustion method (SCM) was assessed for the fabrication of spinel CoAl 2 O 4 , and the effects of fuel-to-oxidizer (F/O) ratio on crystalline structure, surface functional groups, surface area, morphology, and porosity were analyzed. The activity of the samples, which was impregnated by the sulfate group was evaluated in the esterification reaction. Morphology and texture properties of the samples indicated the crystallinity, surface area, and pore diameter of CoAl 2 O 4 were enhanced by increasing the F/O ratio. It can be related to increasing the combustion reaction time and temperature. However, at F/O ratios above two, due to limited diffusion of oxygen into the reaction medium, the reaction terminated immaturely. Sulfated cobalt aluminate fabricated at F/O ratio of two was successfully synthesized in nanoscale with same particle size. Moreover, it did not show impurity in its structure that is related to the ability of the combustion method for the fabrication of pure nanocatalyst. Evaluation of the catalytic activity of the SO 4 2− /CoAl 2 O 4 nanocatalysts in the esterification reaction confirmed the results of physicochemical studies. For instance, the sample prepared at F/O ratio of two presented the highest conversion (96.7%) at methanol/oleic acid molar ratio of nine, catalyst amount of 3 wt. %, and reaction temperature and time of 120 °C and 4 h, respectively. In addition to preserving its activity for four runs (conversion > 85%), its activity was simply recovered upon regeneration by sulfate group, making it a promising alternative for industrial production of biodiesel.

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Section: Bet-bjh and Acidity Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Fabrication of nanosized SO42−/Co–Al mixed oxide via solution combustion method used in esterification reaction: effect of urea-nitrate ratio on the properties and performance

et al. 2019

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“…Although the effect of fuel type and other variables on the structure and properties of calcium aluminate fabricated by the MCS method has been studied with our previous work (Nayebzadeh et al, 2016(Nayebzadeh et al, , 2017a, further studies can be performed to obtain a sample with the highest activity and stability. Other parameters such as fuel-to-oxidizer, or fuel ratio (FR), microwave irradiation output power, water content in precursor, and pH of the solution have influence on the properties of the final product synthesized by the MCS method (Rosa et al, 2013;Hashemzehi et al, 2020a).…”

Section: Introductionmentioning

confidence: 99%

Influence of Fuel to Oxidizer Ratio on Microwave-Assisted Combustion Preparation of Nanostructured KOH/Ca12Al14O33 Catalyst Used in Efficient Biodiesel Production

et al. 2020

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In this study, the microwave-assisted solution combustion method was utilized for the fabrication of Ca 12 Al 14 O 33 as support and the amount of urea was assessed as an important parameter during synthesis of the sample. Synthesized Ca 12 Al 14 O 33 with different fuel amounts was impregnated by KOH and used in the biodiesel production process with canola oil under microwave irradiation. The results presented that the crystallinity, crystalline size, specific surface area, and elemental composition of the final nanocatalysts are affected by the fuel amount. Moreover, during impregnation of potassium components, the structure of support was interestingly transformed from CaAl 2 O 4 to Ca 12 Al 14 O 33 structure due to the incorporation of potassium in an alumina lattice and more diffusion of calcium cations into a support lattice. On the other hand, when the amount of fuel passed the optimum amount (2 times the stoichiometric amount), the crystallinity was reduced due to the formation of high amounts of smoke during combustion and prevention of the entry of air (oxygen) into the system. The results of the microwave-enhanced transesterification reaction confirmed the results of the analyses that the conversion of 94.5% was obtained using an optimum sample at 450 W, 12 molar ratios of methanol/oil, 4 wt.% catalyst, and 60 min reaction time. According to the stability of the optimum sample [at least three times (>75%)], along with its unique mesoporous structure, uniform dispersion of potassium components, and high basicity sites, it can be considered as a comparable solid base nanocatalyst for biodiesel production.

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“…According to Table 2, a 12:1 molar ratio of methanol/oleic acid is quite enough for achieving a good conversion. The conversion decreased by excess methanol over 12 molar ratios of methanol/oleic acid due to occupation of catalyst's pores, decreasing the active sites and deactivation of the catalyst and increasing the separation problem [23,48]. The effect of catalyst loading on the conversion was evaluated with various catalyst loadings over the range of 1-5 wt%.…”

Section: Optimization Of the Esterification Reaction Conditionsmentioning

confidence: 99%

“…The acidic or basic strengths are quoted as being stronger than the weakest indicator that exhibits a color change, but weaker than the strongest indicator that produces no color change. Finally, benzene carboxylic and n-butylamine solutions were used to measure basicity and acidity of the samples, respectively [9,23].…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Influence of calcination temperature on the activity of mesoporous CaO/TiO2–ZrO2 catalyst in the esterification reaction

2018

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In the present study, the effect of calcination temperature on the structure and performance of mesoporous CaO/TiO 2 -ZrO 2 catalyst fabricated by sol-gel method used in the esterification reaction was assessed. Then, CaO/TiO 2 catalyst was also synthesized via the same method to evaluate the effect of zirconia cations on its properties and activity. The samples were characterized by X-ray Diffraction (XRD), Fourier transmittance infra-red (FT-IR), Brunauer-Emmett-Teller (BET)-BarrettJoyner-Halenda (BJH), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analyses. Moreover, Hammett indicator method was utilized to assess the acidity and basicity of the samples. It was found that zirconium was clearly incorporated in CaO/TiO 2 lattice and transformed that from amorphous phase to crystalline structure. In addition, the basicity and acidity of CaO/TiO 2 was clearly increased by zirconia loading. Evaluation of the samples' activity presented that CaO/TiO 2 catalyst exhibit no activity in the esterification reaction, while all CaO/TiO 2 -ZrO 2 catalysts showed high ability to convert oleic acid to its ester. Moreover, the catalyst calcined at 400 °C showed the highest activity in the esterification reaction with desirable properties such as high crystallinity, acidity, basicity and surface area along with well-distribution of particle size and pore size. The best catalyst converted around 90% of oleic acid to ester at optimized conditions of 150 °C, 12:1 molar ratio of methanol/oleic acid, 3 wt% of catalyst for 4 h of reaction time. Moreover, the sample was successfully used for five runs without significant reduction in activity that makes it a suitable choice as a catalyst for industrial applications.

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Application of Microwave Irradiation for Preparation of a KOH/Calcium Aluminate Nanocatalyst and Biodiesel

Cited by 25 publications

References 42 publications

Fabrication of nanosized SO42−/Co–Al mixed oxide via solution combustion method used in esterification reaction: effect of urea-nitrate ratio on the properties and performance

Fabrication of nanosized SO42−/Co–Al mixed oxide via solution combustion method used in esterification reaction: effect of urea-nitrate ratio on the properties and performance

Influence of Fuel to Oxidizer Ratio on Microwave-Assisted Combustion Preparation of Nanostructured KOH/Ca12Al14O33 Catalyst Used in Efficient Biodiesel Production

Influence of calcination temperature on the activity of mesoporous CaO/TiO2–ZrO2 catalyst in the esterification reaction

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