The Effect of Residence Time on Biomass Pyrolysis of Several in Different Temperature Nodes

2015 ◽  
Vol 733 ◽  
pp. 280-283 ◽  
Author(s):  
Jian Jun Cai ◽  
Qing Cheng Wang ◽  
Quan Wang

The effect of residence time on biomass pyrolysis is discussed in the paper. Firstly, several typical temperature nodes (573, 873, 1073, and 1273K) are selected as the experimental subjects. Then, the residence time is changed in these temperature nodes. Finally, thermo gravimetric analyzer is used to study the pyrolysis and kinetics characteristics of biomass in different experimental conditions. The results show that extension of residence time is not conducive to biomass mass loss and heat release at 523, 873, 1073, and 1273K. In the several temperature condition that the faster heating rate and the shorter residence time, the more weightlessness is and the phenomenon is more obvious in low temperature. With the increase of the residence time, area and value of the second endothermic peak decreases and the value moves to high temperature zone. When the residence time is not the same value, the biomass pyrolysis can still be fitted for two first-order kinetic equations. At the same time, temperature interval length of fitting curve decreases and further leads to E and A increase.

2013 ◽  
Vol 12 (2) ◽  
pp. 197-205

Sorption of toxic metal ions (Ni2+, Cu2+ and Cd2+) from Hevea brasiliensis bark carbon (HBBC) was carried out at 30±1 °C under various experimental conditions. Effect of various process parameters has been investigated by following the batch adsorption technique at 30 +1°C. The percentage removal increased with decrease in initial concentration and particle size and increase in contact time and dose of adsorbent. As initial pH of the slurry increased, the percentage removal increased, reached a maximum. The adsorption is highly pH sensitive. Adsorption data were modelled with various isotherms and first order kinetic equations proposed by Natarajan-Khalaf, Lagergren and Bhattacharya-Venkobachar and intraparticle diffusion models found to be applicable. Kinetics of adsorption is observed to be first order with Intra- particle diffusion as one of the rate determining steps. The monolayer adsorption capacities of HBBC also studied by Langmuir isotherms. HBBC could be used as low-cost adsorbents in effluent treatment, especially for the removal of metal ions, particular in Ni2+, Cu2+ and Cd2+ ions. It is confirmed by FT-IR studies before and after adsorption.


Author(s):  
Mohamed S. Ibrahim ◽  
Alka Gupta ◽  
Dave Gage ◽  
Justin A. Zeamer ◽  
Ryoichi S. Amano

The design and build of a Thermo-gravimetric analyzer (TGA) is discussed in this paper along with the preliminary data obtained. The TGA was designed for biomass pyrolysis and gasification. In the design it was taken in consideration decreasing the size as possible so as to decrease the area subject to heat losses as possible and to be capable of reaching high temperatures sufficient for both pyrolysis and gasification. The TGA was then tested using carbon dioxide and calculations for the rate of mass converted and conversion rate were carried out.


1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.


2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.


2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously.


Author(s):  
How Wei Benjamin Teo ◽  
Anutosh Chakraborty ◽  
Kim Tiow Ooi

As promising material for gas storage applications, MIL-101(Cr) can further be modified by doping with alkali metal (Li+, Na+, K+) ions. However, the doping concentration should be optimized below 10% to improve the methane adsorption. This article presents (i) the synthesis of MIL-101 (Cr) Metal Organic Frameworks, (ii) the characterization of the proposed doped adsorbent materials by X-ray Diffraction, Scanning Electron Microscopy, N2 Adsorption, Thermo-Gravimetric Analyzer, and (iii) the measurements of methane uptakes for the temperatures ranging from 125 K to 303 K and pressures up to 10 bar. It is found that the Na+ doped MIL-101(Cr) exhibits CH4 uptake capacity of (i) 295 cm3/cm3 at 10 bar and 160 K and (ii) 95 cm3/cm3 at 10 bar at 298 K. This information is important to design adsorbed natural gas (ANG) storage tank under ANG-LNG (liquefied natural gas) coupling conditions.


2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.


2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.


Author(s):  
Adewale George Adeniyi ◽  
Kevin Shegun Otoikhian ◽  
Joshua O. Ighalo

Abstract The steam reforming of biomass pyrolysis oil is a well-established means of producing the more useful bio-hydrogen. Bio-oil has a comparatively low heating value, incomplete volatility and acidity, hence upgrading to a more useful product is required. Over the years, the experimental conditions of the process have been studied extensively in the domain of catalysis and process variable optimisation. Sorption enhancement is now being applied to the system to improve the purity of the hydrogen stream. Lifecycle analyses has revealed that bio-hydrogen offers considerable reductions in energy consumption compared to fossil fuel-derived hydrogen. Also, green-house-gas savings from the process can also be as high as 54.5 %. Unfortunately, techno-economic analyses have elucidated that bio-hydrogen production is still hampered by high production costs. Research endeavours in steam reforming of biomass bio-oil is done with an eye for developing added value products that can complement, substitute (and one day replace) fossil fuels whilst ameliorating the global warming menace.


2020 ◽  
Vol 82 (4) ◽  
pp. 673-682
Author(s):  
Fengqin Tang ◽  
Di Gao ◽  
Li Wang ◽  
Yufeng He ◽  
Pengfei Song ◽  
...  

Abstract Loess is a typical natural mineral particle distributed widely around the world, and it is inexpensive, readily accessible, and harmless to the environment. In this study, loess was modified by surface grafting copolymerization of functional monomers, such as acrylic acid, N-vinyl pyrrolidone, and N,N-methylenebisacrylamide as a cross-linking agent, which afforded a novel loess-based grafting copolymer (LC-PAVP). After being characterized by scanning electron microscopy, thermal gravimetric analysis and Fourier-transform infrared spectroscopy, its adsorption capacity and mechanism of removing lead ions (Pb2+) were investigated. With the study of the optimal experimental conditions, it was demonstrated that the removal rate of Pb2+ by LC-PAVP can reach up to 99.49% in 60 min at room temperature. It was also found that the kinetic characteristics of the adsorption capacity due to the pseudo-second-order kinetic model and the thermodynamics conformed well with the Freundlich model. In summary, as a lost-cost and eco-friendly loess-based adsorbent, LC-PAVP is a good potential material for wastewater treatment.


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