Surface Characterization of Sulfated Iron Oxide and Its Synthesis of Biodiesel Under Microwave Radiation

Author(s):  
Hong Yuan ◽  
Xiaoqin Ma ◽  
Jie He ◽  
Zhaoyang Dong

AbstractThe solid acid catalysts SO42−/Fe2O3were prepared by impregnation technique, and the preparation conditions were different in calcination temperature, concentration of impregnation solution of H2SO4and impregnation time. The characterization was performed by using Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), Temperature programed desorption of NH3(NH3‒TPD), N2‒BET and microwave absorbing test. As shown by FTIR spectra, the S=O functional group existed in the sample, which was essential for the strong acidity of the SO42‒/MxOytype solid acids. The XRD results indicated that when the calcination temperature exceeded 400℃, iron in SO42‒/Fe2O3transformed from amorphous to crystalline phase. The results from NH3-TPD showed that the prepared sample possessed strong acid and superacid sites. As shown by N2-BET results, the BET surface area of the samples was up to 200m2/g, and their pore size distributions essentially belonged to mesoporous characteristic distribution. The SO42−/Fe2O3solid acid catalysts were used for the transesterification of castor oil under microwave radiation to produce biodiesel. The amounts of FAME in the product were analyzed by high-performance liquid chromatography. The highest yield of product was 65.3 wt.% when the reaction temperature was 65 ℃, alcohol/oil molar ratio was 30/1, catalyst loading was 20 wt.%, the reaction time was 3 h and the power of microwave was 300 w. Furthermore, the reaction results showed that SO42‒/Fe2O3had better catalytic activity under microwave radiation than under conventional heating condition.

2013 ◽  
Vol 291-294 ◽  
pp. 300-306 ◽  
Author(s):  
Hong Yuan ◽  
Qing Shu

Two cesium phosphotungstate-derived solid acid catalysts (Cs2.5H0.5PW12 and Cs0.5H2.5PW12) were prepared. The resulting catalysts were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption and desorption isotherm and temperature programmed desorption of ammonia(NH3-TPD). The Cs2.5H0.5PW12 and Cs0.5H2.5PW12 were respectively used to catalyze the tranesterification of castor oil and methanol for the synthesis of biodiesel with the assistance of microwave. Results shown microwave radiation can greatly enhance the transesterification process when compared with conventional heating method. Cs2.5H0.5PW12 showed better catalyst performance than Cs0.5H2.5PW12. A maximum yield of 90% was obtained from the using of 30:1 molar ratio of methanol to castor oil and 15 wt % mass ratio of catalyst to castor oil at 343 K under microwave radiation after 4h.


2018 ◽  
Vol 36 (8) ◽  
pp. 719-728 ◽  
Author(s):  
Indika Thushari ◽  
Sandhya Babel

Waste utilization is essential and challenging. Utilization of wastes gives environmental, economic, and social benefits. In this study, inexpensive, sulfonated solid acid catalysts were successfully prepared from palm empty fruit bunch (PEFB), coconut meal residue (CMR), and coconut coir husk (CH) waste by a simple protocol. It was found that prepared PEFB–BCS–SO3H, CMR–BCS–SO3H, and CH–BCS–SO3H catalysts have 4.79, 3.75, and 2.80 mmol g-1 acid density and 739.0, 89.77, and 61.49 m2 g-1 surface areas, respectively. Further, the presence of active functional groups on the surface of the catalysts was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Thermal stability of the catalysts was found below 150°C. Results show that biodiesel yield increases with increasing reaction time and methanol loading, when using microwave heating for biodiesel production from waste palm oil (WPO) and prepared catalysts. A maximum biodiesel yield of 95.5% was obtained by PEFB–BCS–SO3H in 60 minutes using 20:1 methanol:oil (molar ratio) at 70°C. CMR–BCS–SO3H and CH–BCS–SO3H obtained 88.7 and 88.5% biodiesel yields in 60 minutes, using 20:1 and 16:1 methanol:oil (molar ratio), at 70 and 110°C, respectively. Even though, the activity of the catalysts decreased during reuse, these are still of interest as the waste biomass of PEFB, CMR, and CH can be used for catalyst preparation and microwave-assisted biodiesel production from WPO.


MRS Advances ◽  
2018 ◽  
Vol 3 (47-48) ◽  
pp. 2865-2873 ◽  
Author(s):  
Shiba Adhikari ◽  
Zach Hood ◽  
Nidia Gallego ◽  
Cristian Contescu

The production of biodiesel by the esterification of oleic acid, as an example of free fatty acid (FFA), was explored by using a new solid acid catalyst derived from lignin, a highly abundant low-cost biomass material. The catalyst was synthesized from lignin-derived carbon fiber by straightforward sulfonation and contains 1.86 mmol/g of sulfonic acid (-SO3H) groups. The catalyst was characterized by a variety of techniques including PXRD, TGA, TPD-MS, SEM, and XPS to understand the surface chemistry and the result of sulfonation. It was found that the sulfonated lignin-derived carbon fiber (CF-SO3H) catalyst was very efficient at esterifying oleic acid at 80 oC in 4 hours, with 10 wt. % catalyst (in terms of oleic acid content) and at a 10:1 molar ratio of methanol: oleic acid with a yield of 92%. Furthermore, the catalyst can be reused with no significant loss in activity after 4 cycles. Hence, synthesizing solid acid catalysts from lignin-derived carbon fiber affords a novel strategy for producing biodiesel via ‘green chemistry’.


Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 237 ◽  
Author(s):  
Katja Vasić ◽  
Gordana Hojnik Podrepšek ◽  
Željko Knez ◽  
Maja Leitgeb

The development of solid acid catalysts, especially based on metal oxides and different magnetic nanoparticles, gained much awareness recently as a result of the development of different nano-based materials. Solid acid catalysts based on metal oxides are promising for the (trans)esterification reactions of different oils and waste materials for biodiesel production. This review gives a brief overview of recent developments in various solid acid catalysts based on different metal oxides, such as zirconia, zinc, titanium, iron, tungsten, and magnetic materials, where the catalysts are optimized for various reaction parameters, such as the amount of catalyst, molar ratio of oil to alcohol, reaction time, and temperature. Furthermore, yields and conversions for biodiesel production are compared. Such metal-oxide-based solid acid catalysts provide more sustainable, green, and easy-separation synthesis routes with high catalytic activity and reusability than traditionally used catalysts.


1992 ◽  
Vol 57 (11) ◽  
pp. 2241-2247 ◽  
Author(s):  
Tomáš Hochmann ◽  
Karel Setínek

Solid acid catalysts with acid strength of -14.52 < H0 < -8.2 were prepared by sulfate treatment of the samples of boehmite calcined at 105-800 °C. Two preparation methods were used: impregnation of the calcined boehmite with 3.5 M H2SO4 or mixing of the boehmite samples with anhydrous aluminum sulfate, in both cases followed by calcination in nitrogen at 650 °C. The catalysts were characterized by measurements of surface area, adsorption of pyridine and benzene, acid strength measurements by the indicator method and by catalytic activity tests in the isomerization of cyclohexene, p-xylene and n-hexane. Properties of the catalysts prepared by both methods were comparable.


Author(s):  
Yutian Qin ◽  
Jun Guo ◽  
Meiting Zhao

AbstractBiomass is a green and producible source of energy and chemicals. Hence, developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded. Metal–organic framework (MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation. In this review, we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites. Then, the methods for the generation and adjustment of corresponding acid sites are overviewed. Next, the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed. Furthermore, based on our personal insights, the challenges and outlook on the future development of MOF-based solid acid catalysts are provided. We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 391
Author(s):  
Lu Liu ◽  
Xiaofei Philip Ye

The feasibility of fabricating better solid acid catalysts using nonthermal plasma (NTP) technology for biobased acrolein production is demonstrated. NTP discharge exposure was integrated in catalyst fabrication in air or argon atmosphere. The fabricated catalysts were characterized by Brunauer–Emmett–Teller surface area analysis, temperature-programmed desorption of ammonia, X-ray powder diffraction and Fourier-transform infrared spectroscopy of pyridine adsorption, in comparison to regularly prepared catalysts as a control. Further, kinetic results collected via glycerol dehydration experiments were compared, and improvement in acrolein selectivity was displayed when the catalyst was fabricated in the argon NTP, but not in the air NTP. Possible mechanisms for the improvement were also discussed.


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