11 research outputs found
Characterization of Energy-Rich Hydrochars from Microwave-Assisted Hydrothermal Carbonization of Coconut Shell
Comparative study of biochar prepared from cow dung and sewage sludge and its application as an adsorbent for organic pollutants removal in water
Upgradation of chemical, fuel, thermal, and structural properties of rice husk through microwave-assisted hydrothermal carbonization
The process parameters of microwave hydrothermal carbonization (MHTC) have significant effect on yield of hydrochar. This study discusses the effect of process parameters on hydrochar yield produced from MHTC of rice husk. Results revealed that, over the ranges tested, a lower temperature, lower reaction time, lower biomass to water ratio, and higher particle size produce more hydrochar. Maximum hydrochar yield of 62.8% was obtained at 1000 W, 220 °C, and 5 min. The higher heating value (HHV) was improved significantly from 6.80 MJ/kg of rice husk to 16.10 MJ/kg of hydrochar. Elemental analysis results showed that the carbon content increased and oxygen content decreased in hydrochar from 25.9 to 47.2% and 68.5 to 47.0%, respectively, improving the energy and combustion properties. SEM analysis exhibited modification in structure of rice husk and improvement in porosity after MHTC, which was further confirmed from BET surface analysis. The BET surface area increased from 25.0656 m 2 /g (rice husk) to 92.6832 m 2 /g (hydrochar). Thermal stability of hydrochar was improved from 340 °C for rice husk to 370 °C for hydrochar
Influence of pyrolytic and non-pyrolytic rice and castor straws on the immobilization of Pb and Cu in contaminated soil
An overview of microwave hydrothermal carbonization and microwave pyrolysis of biomass
© 2018, Springer Nature B.V. Biomass utilization has received much attention for production of high density solid fuels. Utilization of cheap and naturally available precursors through environmentally friendly and effective processes is an attractive and emerging research area. Pyrolysis and hydrothermal carbonization (HTC) are well-known technologies available for production of solid biofuel using conventional or microwave heating. Microwave heating is a simpler and more efficient heating method than conventional heating. This study presents a critical review on microwave pyrolysis and microwave HTC for solid fuel production in terms of yield and quality of products. Moreover, a brief summary of parameters of microwave pyrolysis and microwave HTC are discussed. The fuel, chemical, structural and thermal weight loss characteristics of solid fuels produced from different biomass are discussed and compared
Optimization of the conventional hydrothermal carbonization to produce hydrochar from fish waste
Cadmium (II) Adsorption from Aqueous Solutions Using Onion Skins
Staff PublicationThe potential of onion skins for removal of aqueous Cd(II) was investigated. Onion skin
powder was chemically modified using thioglycolic acid to develop a suitable, low-cost, and
efficient adsorbent for the removal of Cd(II) from aqueous solutions. Influences of temperature,
contact time, initial concentration of Cd(II), adsorbent dosage, and pH on the removal of Cd(II)
were probed. Optimal adsorption conditions were found at pH 5 and 4, and at 60- and 30-min
equilibrium time for the modified and native onion skins, respectively. The equilibrium process
was well described by the Freundlich isotherm model. The maximum Cd(II) adsorption
capacities, from the Langmuir model, are 17.86 mg/g (modified) and 21.28 mg/g (native). The
adsorption process followed the mechanism of physisorption. Pseudo second-order rate equation
fitted the kinetic data better than the pseudo first-order rate equation for the two adsorbents.
Thermodynamic parameters, such as standard free energy change (ÎG°), standard enthalpy
change (ÎH°), and standard entropy change (ÎS°), were calculated for adsorption experimental
studies. The results showed that the adsorption of Cd(II) on native/unmodified and modified
onion skins was a feasible process and exothermic under the studied conditions. The Cd(II)
adsorbed was efficiently desorbed from adsorbent using 0.3 M HCl