Kinetics of gasification in a fixed bed reactor with steam-oxygen mixtures

2002 ◽  
Vol 43 (4) ◽  
pp. 249
Author(s):  
M. Conradie ◽  
F.F. Prinsloo
2020 ◽  
Vol 10 (24) ◽  
pp. 8962
Author(s):  
Mohammad Reza Ghaani ◽  
Satoshi Takeya ◽  
Niall J. English

There have been studies on gas-phase promoter facilitation of H2-containing clathrates. In the present study, non-equilibrium molecular dynamics (NEMD) simulations were conducted to analyse hydrogen release and uptake from/into propane planar clathrate surfaces at 180–273 K. The kinetics of the formation of propane hydrate as the host for hydrogen as well as hydrogen uptake into this framework was investigated experimentally using a fixed-bed reactor. The experimental hydrogen storage capacity propane hydrate was found to be around 1.04 wt% in compare with the theoretical expected 1.13 wt% storage capacity of propane hydrate. As a result, we advocate some limitation of gas-dispersion (fixed-bed) reactors such as the possibility of having un-reacted water as well as limited diffusion of hydrogen in the bulk hydrate.


2014 ◽  
Vol 953-954 ◽  
pp. 325-329
Author(s):  
Jin Wei Jia ◽  
Di Yang ◽  
He Long Hui ◽  
Xing Min Fu ◽  
Lu Liu ◽  
...  

The aims of this work were to investigate the influence of feedstock properties of different part of cassava residues (cassava rhizome (CR), cassava stalk (CS) and cassava leaf (CL)) and operating temperatures on the pyrolysis characteristics and the kinetic parameters. Pyrolysis experiments of three selected biomass feedstock were conducted using a fixed-bed reactor. It was shown that the bio-oil yield of cassava stalk reached the maxima at 600°C, and the char yield reduced with the temperature, whereas the gas yield increased with temperature. The cassava rhizome presented higher thermochemical reactivity than the other samples. The activation energy of cassava stalks was 37.57 kJ / mol and that of cassava rhizome (39.42 kJ / mol) increased slightly. The activation energy of cassava leaf (22.85 kJ / mol) was lowest of the three samples.


2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Amit Arora ◽  
Asheesh Kumar ◽  
Gaurav Bhattacharjee ◽  
Chandrajit Balomajumder ◽  
Pushpendra Kumar

Abstract The case for developing novel technologies for carbon dioxide (CO2) capture is fast gaining traction owing to increasing levels of anthropogenic CO2 being emitted into the atmosphere. Here, we have studied the hydrate-based carbon dioxide capture and separation process from a fundamental viewpoint by exploring the use of various packed bed media to enhance the kinetics of hydrate formation using pure CO2 as the hydrate former. We established the fixed bed reactor (FBR) configuration as a superior option over the commonly used stirred tank reactor (STR) setups typically used for hydrate formation studies by showing enhanced hydrate formation kinetics using the former. For the various packing material studied, we have observed silica gel with 100 nm pore size to return the best kinetic performance, corresponding to a water to hydrate conversion of 28 mol% for 3 h of hydrate growth. The fundamental results obtained in the present study set up a solid foundation for follow-up works with a more applied perspective and should be of interest to researchers working in the carbon dioxide capture and storage and gas hydrate fields alike.


2011 ◽  
Vol 233-235 ◽  
pp. 990-998 ◽  
Author(s):  
Dian Hua Liu ◽  
Ding Ye Fang ◽  
Qin Qin Guan ◽  
A Jian Tao

The conventional process for isobornyl acetate synthesis from camphene and acetic acid is a batch process. The purpose of this paper is to synthesize isobornyl acetate in continuous process in a fixed bed reactor. The continuous reaction conditions were studied. The experiment was put into practice under the following conditions: 35-45, camphene/acetic acid feed ratio(wt%) from 1 to 2 and space velocity from 0.6 to 1.8 h-1. A kinetic model was developed which describes the experimental data well. A pilot fixed reactor was simulated by using the kinetic model.


Author(s):  
Frédéric Paviet ◽  
Olivier Bals ◽  
Gérard Antonini

Gasification is an attractive technology for waste thermal treatment. The successful design and modelling of a gasifier requires reliable kinetic data. The purpose of this work is to study the steam gasification kinetics of chars produced by municipal wastes pyrolysis. The municipal solid wastes (MSW) are modelled as a mixture of four organic constituents: paper, wood, plastics, and vegetables. The various char samples are obtained by pyrolysis of each waste constituent, in a fixed bed reactor at 1000°C, in order to minimize their volatile content and thus, to eliminate any subsequent devolatilization of the carbonaceous residues. These chars are used as raw materials in steam gasification experiments. The gasification studies are performed on each char separately, in a tubular kiln at various temperatures (900°C, 950°C and 1000°C) and various vapour pressures (0.2 bar, 0.5 bar and 0.7 bar). The gases produced are analysed by gas chromatography in order to determine the gasification kinetics. The kinetics parameters, with respect to H2O, together with the influence of the char's physical properties are experimentally determined. A kinetic expression for the gasification reaction, based on the random pore model is deduced. It is shown that the char resulting from the pyrolysis of MSW constituents, essentially paper, wood and vegetables have the same gasification kinetics. On the contrary, the plastic char steam gasification kinetic appears to be significantly slower.


2006 ◽  
Vol 116 (3) ◽  
pp. 179-186 ◽  
Author(s):  
Hong Liu ◽  
Guanzhong Lu ◽  
Yanglong Guo ◽  
Yun Guo ◽  
Junsong Wang

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