The role of H3PO4in the preparation of activated carbon from NaOH-treated rice husk residue

RSC Advances ◽  
2015 ◽  
Vol 5 (41) ◽  
pp. 32626-32636 ◽  
Author(s):  
Yaxin Li ◽  
Xian Zhang ◽  
Ruiguang Yang ◽  
Guiying Li ◽  
Changwei Hu
Keyword(s):  

H3PO4promoted the decomposition of some species to form CO2and reacted with PBTRHR to form PH3.

2021 ◽  
Vol 21 (2) ◽  
pp. 318
Author(s):  
Ilesanmi Osasona ◽  
Ujiro Bestow Kanuhor

The world is clamoring for green synthetic modes of scientific and technological operations. From this point of view, an attempt was made to prepare activated carbon from rice husk using aqueous bitter leaf extract and a mineral acid (H2SO4) separately. The surface characteristics and the adsorption properties of the activated carbons from both methods were compared. The effects of adsorption variables on the adsorption of Zn(II) by bitter leaf extract activated carbon (RHAC1) and H2SO4 activated carbon (RHAC2) were conducted through batch studies. The morphological characterization revealed RHAC1 to be fibrous, more porous and contained finer particles than the chemical-activated counterpart. The role of hydroxyl and carbonyl groups in the adsorption of Zn(II) was pivotal. The optimum pH values for the adsorption of Zn(II) by both samples was 7. The adsorption kinetics and equilibrium isotherm obeyed Elovich and Freundlich models respectively while the evaluated Langmuir qmax were 71.47 and 67.12 mg g–1 for RHAC1 and RHAC2 respectively. The thermodynamic parameters revealed that the process was endothermic and spontaneous at all evaluated temperatures. Therefore, bitter leaf aqueous extract, as an activating agent for carbon production, could serve as a better or close substitute for the less environment-friendly H2SO4.


2021 ◽  
Vol 1034 (1) ◽  
pp. 012075
Author(s):  
Purnami ◽  
ING. Wardana ◽  
Sudjito ◽  
Denny Widhiyanuriyawan ◽  
Nurkholis Hamidi

2021 ◽  
Author(s):  
Petar Djinović ◽  
Janez Zavašnik ◽  
Janvit Teržan ◽  
Ivan Jerman

AbstractCeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested in propane oxidative dehydrogenation using CO2. Complete oxidation of propane to CO and CO2 is favoured by lattice oxygen of CeO2. The temperature programmed experiments show the ~ 4 nm AC supported CeO2 crystallites become more susceptible to reduction by propane, but less prone to re-oxidation with CO2 compared to bulk CeO2. Catalytic activity of CeVO4/AC catalysts requires a 1–2 nm amorphous CeVO4 layer. During reaction, the amorphous CeVO4 layer crystallises and several atomic layers of carbon cover the CeVO4 surface, resulting in deactivation. During reaction, V2O5 is irreversibly reduced to V2O3. The lattice oxygen in bulk V2O5 favours catalytic activity and propene selectivity. Bulk V2O3 promotes only propane cracking with no propene selectivity. In VOx/AC materials, vanadium carbide is the catalytically active phase. Propane dehydrogenation over VC proceeds via chemisorbed oxygen species originating from the dissociated CO2. Graphic Abstract


2019 ◽  
Vol 5 (2) ◽  
pp. 383-396 ◽  
Author(s):  
Anna Patrícya Florentino ◽  
Ahmed Sharaf ◽  
Lei Zhang ◽  
Yang Liu

Methanogenesis and enrichment of microorganisms capable of interspecies electron and/or hydrogen exchange was investigated with addition of granular activated carbon (GAC) to batch anaerobic digesters treating vacuum collected blackwater with high ammonia concentration.


2014 ◽  
Vol 486 ◽  
pp. 159-169 ◽  
Author(s):  
Pankaj Raizada ◽  
Pardeep Singh ◽  
Amit Kumar ◽  
Gaurav Sharma ◽  
Brijesh Pare ◽  
...  

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