Firstly, both a short mesopore thin plate molecular sieve of Zr‐doped SBA‐15 and a strong organic base of bi‐guanides DIC‐TMG were respectively prepared. Then, the organic bi‐guanides DIC‐TMG was grafted onto the short mesopore thin plate molecular sieve to prepare a highly efficient and stable water‐tolerant short mesoporous organic bi‐guanides strong solid base DIC‐TMG/Zr‐SBA‐15 which was used to catalyze the transesterification of renewable bio‐oils to biodiesel under mild reaction conditions. The prepared DIC‐TMG/Zr‐SBA‐15 was elaborately investigated by XRD, BET, SEM, TEM, FT‐IR and Elemental analysis. The obtained results showed that compared with TMG/Zr‐SBA‐15 and DIC‐TMG/SBA‐15, DIC‐TMG/Zr‐SBA‐15 exhibited the best catalytic activity with 95% of biodiesel yield at reaction temperature 75 °C and catalyst dosage 5 wt%. Especially, unlike some other usually solid metal‐based catalysts, this alkaline organic bi‐guanidines DIC‐TMG supported on Zr‐SBA‐15 support catalyst has certain water‐tolerant. With 1 wt% of water content existed in the reaction system, the biodiesel yield still reached 90%, and after five recycles of the catalyst, the biodiesel yield was still more than 80%.
An ionic liquid-based microwave-assisted extraction method was developed to extract luteolin from peanut shells effectively. A series of hydrophilic 1-alkyl-3-methylimidazolium ionic liquids with different anions (Br À , Cl À and BF 4 À ) and different cations ([C 2 mim] + , [C 4 mim] + , [C 8 mim] + and [C 10 mim] + ) were screened, and [C 10 mim]Br was found to be the optimal extraction solvent. The reason is that when the cations are the same, the hydrogen bonding between Br À and the phenolic hydroxyl group on luteolin is the strongest; when the anions are the same, the carbon chain growth enhances the van der Waals force between the ionic liquid and the luteolin. The concentration of ionic liquid, extraction temperature, liquidsolid ratio and extraction time were optimized by both single factor experiments and response surface methodology. Under the optimized conditions of [C 10 mim]Br concentration 1.00 mol/ L, extraction temperature 85°C, liquid-solid ratio 11.63:1 mL/g, extraction time 12 min, the extraction yield of luteolin reached 80.36 � 0.67%. In addition, compared with conventional solvents, [C 10 mim]Br showed an excellent extraction yield to extracting luteolin from peanut shells .
In order to improve the activity and stability of calcium‐based catalysts, a mixing method with other metal oxides was proposed to increase the interaction among the active ingredients to prevent the active components being leached off. A new Ni/CaO‐MgO catalyst was prepared by a double drop addition co‐precipitation method at alkaline condition around pH 10. The catalyst was characterized by XRD, TG‐TGA, FT‐IR, SEM, TEM, BET and CO2‐TPD. The results showed that Mg2+ had been partly replaced by Ni2+ which coordinated with oxygen octahedron to form strong basic sites at MgO defected lattices. The effect of different Ni addition on the catalytic performance was investigated in the transesterification reaction of renewable bio‐oils to biodiesel. Under the optimal reaction conditions of reaction temperature 120 °C, methanol/oil molar ratio of 27:1, catalyst dosage 5 wt%, the yield of biodiesel reached 97.6% only in 60 minutes of reaction time.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.