scholarly journals Lignin and Cellulose Extraction from Vietnam’s Rice Straw Using Ultrasound-Assisted Alkaline Treatment Method

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ngo Dinh Vu ◽  
Hang Thi Tran ◽  
Nhi Dinh Bui ◽  
Cuong Duc Vu ◽  
Hung Viet Nguyen
Keyword(s):  
Rice Straw ◽  
Ultrasonic Irradiation ◽  
Extraction Method ◽  
Treatment Method ◽  
Alkaline Treatment ◽  
Lignin Extraction ◽  
Ultrasonic Assisted ◽  
Ft Ir ◽  
Ultrasound Assisted ◽  
Modern Analytical

The process of cellulose and lignin extraction from Vietnam’s rice straw without paraffin pretreatment was proposed to improve economic efficiency and reduce environmental pollution. Treatment of the rice straw with ultrasonic irradiation for 30 min increased yields of lignin separation from 72.8% to 84.7%. In addition, the extraction time was reduced from 2.5 h to 1.5 h when combined with ultrasonic irradiation for the same extraction yields. Results from modern analytical methods of FT-IR, SEM, EDX, TG-DTA, and GC-MS indicated that lignin obtained by ultrasound-assisted alkaline treatment method had a high purity and showed a higher molecular weight than that of lignin extracted from rice straw without ultrasonic irradiation. The lignin and cellulose which were extracted from rice straw showed higher thermal stability with 5% degradation at a temperature of over 230°C. The ultrasonic-assisted alkaline extraction method was recommended for lignin and cellulose extraction from Vietnam’s rice straw.

scholarly journals Comparative Study on Conventional and Ultrasound Irradiation Promoted Synthesis of 2,3-Disubstitutedquinoxaline Derivatives

2018 ◽  
Vol 28 (3) ◽  
pp. 141
Author(s):  
Ahmed Mutanabbi Abdula ◽  
Ghazwan Ali Salman ◽  
Hamid H. Mohammed
Keyword(s):  
13C Nmr ◽  
Ultrasonic Irradiation ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Heating Method ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
Ultrasound Assisted ◽  
Good Percentage

A series of ten chalcone-substituted quinoxalines (4a-e), (3a-e) starting from 1-(phenylquinoxalin-2-yl)ethanone and 1-(3-methylquinoxalin-2-yl)ethanone have been synthesized using conventional heating and ultrasound-assisted methods. Furthermore, novel of five quinoxaline derivatives including pyrazoline, isoxazole, pyrimidin-2-one, N-acylpyrazoline and pyridin-2-one moieties were also prepared from the reaction of chalcone compound 4a with different cyclization reagents using the same strategy. The structures of all synthesized compounds were established on the basis of FT-IR, 1H-NMR and 13C-NMR. The ultrasonic irradiation method provide several advantages over conventional heating method, including shorter reaction times (30-90 min.) and good percentage yields (65% - 88%), comparing with conventional protocol (5 to 20 hrs. with 30% to 55% reaction yields).

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

Ultrasound-Assisted Citric Acid Extraction of Zinc in Plateau Red Soil and Tessier Speciation Study

2013 ◽  
Vol 726-731 ◽  
pp. 4464-4467
Author(s):  
Wei Wei ◽  
Xue Jin Zhou ◽  
Yun Tao Gao
Keyword(s):  
Heavy Metal ◽  
Citric Acid ◽  
Manganese Oxides ◽  
Red Soil ◽  
Extraction Rate ◽  
Acid Extraction ◽  
Speciation Study ◽  
Ultrasonic Assisted ◽  
Ultrasound Assisted ◽  
Iron And Manganese

Taking plateau red soil as research object, using the ultrasonic-assisted organic acid extraction the heavy metal zinc in it, and analyze the form of zinc. Results showed that the extraction rate can reach 68%, with the increase of time, the extraction effect of zinc is obviously enhanced in this method. Ultrasonic-assisted citric acid extraction soil can increase the extraction rate of exchangeable, bound to carbonates and bound to iron and manganese oxides relatively.

Ultrasound-Assisted Oxidative Desulfurization of Diesel Fuel in H2O2/Heteropoly Acid/Solvent System

2014 ◽  
Vol 1033-1034 ◽  
pp. 85-89 ◽  
Author(s):  
Guo Xian Yu ◽  
Qian Zhong ◽  
Mei Jin ◽  
Ping Lu
Keyword(s):  
Sulfur Content ◽  
Ultrasonic Irradiation ◽  
Diesel Fuel ◽  
Oxidation Reaction ◽  
Heteropoly Acid ◽  
Oxidative Desulfurization ◽  
Solvent System ◽  
Oxidative Reaction ◽  
Solvent Systems ◽  
Ultrasound Assisted

Ultrasound-assisted oxidative desulfurization (UAODS) of diesel fuel in H2O2/Heteropoly acid/Solvent systems, was investigated. Effects of solvent, catalyst, ultrasound and reaction temperature on the oxidation desulfurization of diesel fuel were investigated. When MPA/oil was 2%wt, methanol/diesel fuel was 20%wt, ultrasound power was 400 W and ultrasound time was 10 min, the sulfur content of diesel fuel was decreased from 211 ppm to 19 ppm. The use of ultrasonic irradiation in H2O2/Heteropoly acid/Solvent system significantly improved the efficiency of the oxidation reaction, and solvent was helpful to make the oxidative reaction happen in the same one phase.

Application of an Ultrasound-Assisted Extraction Method to Recover Betalains and Polyphenols from Red Beetroot Waste

2021 ◽  
Author(s):  
Ganwarige Sumali N. Fernando ◽  
Kelly Wood ◽  
Emmanouil H. Papaioannou ◽  
Lisa J. Marshall ◽  
Natalia N. Sergeeva ◽  
...  
Keyword(s):  
Extraction Method ◽  
Ultrasound Assisted Extraction ◽  
Assisted Extraction ◽  
Ultrasound Assisted
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