Pore development during gasification of South African inertinite-rich chars evaluated using small angle X-ray scattering.

Saved in:
Bibliographic Details
Title: Pore development during gasification of South African inertinite-rich chars evaluated using small angle X-ray scattering.
Authors: Coetzee, G. Hennie1, Sakurovs, Richard2, Neomagus, Hein W.J.P.1 hein.neomagus@nwu.ac.za, Morpeth, Leigh3, Everson, Raymond C.1, Mathews, Jonathan P.4, Bunt, John R.1
Source: Carbon. Dec2015, Vol. 95, p250-260. 11p.
Subjects: X-ray scattering, Biomass gasification, Chemical sample preparation, Physics experiments, Particle size distribution, Carbon dioxide
Abstract: Pore development arising from steam and CO 2 gasification of a char, prepared from an inertinite-rich Witbank Seam 4 coal, was investigated using small angle X-ray scattering. The char, ∼75 μm, was gasified to specific conversions (10, 25, 35 and 50%) using two gasification reagents, CO 2 and steam. A novel ratio analysis technique was developed to study the pore development from experimental data. Differently sized pores grow at different rates with the difference not being simply due to gas accessibility. In particular, the pores between 1 and 40 nm in size showed more pore growth than larger or smaller sizes. Steam gasification created a more porous char with increased pore growth of pore sizes between 1 and 40 nm than CO 2 gasification. The pore growth rate of steam was up to a factor 7 times faster than CO 2 , compared at the highest gasification temperatures. For the smaller pores, <1 nm, it was found that the rate of pore generation was slower compared to larger pores, though pore growth was still evident with the critical cross over pore size for CO 2 to be 1 nm compared to 0.6 nm for steam. This may be a direct consequence of CO 2 's greater kinetic diameter. [ABSTRACT FROM AUTHOR]
Copyright of Carbon is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Pore development arising from steam and CO 2 gasification of a char, prepared from an inertinite-rich Witbank Seam 4 coal, was investigated using small angle X-ray scattering. The char, ∼75 μm, was gasified to specific conversions (10, 25, 35 and 50%) using two gasification reagents, CO 2 and steam. A novel ratio analysis technique was developed to study the pore development from experimental data. Differently sized pores grow at different rates with the difference not being simply due to gas accessibility. In particular, the pores between 1 and 40 nm in size showed more pore growth than larger or smaller sizes. Steam gasification created a more porous char with increased pore growth of pore sizes between 1 and 40 nm than CO 2 gasification. The pore growth rate of steam was up to a factor 7 times faster than CO 2 , compared at the highest gasification temperatures. For the smaller pores, <1 nm, it was found that the rate of pore generation was slower compared to larger pores, though pore growth was still evident with the critical cross over pore size for CO 2 to be 1 nm compared to 0.6 nm for steam. This may be a direct consequence of CO 2 's greater kinetic diameter. [ABSTRACT FROM AUTHOR]
ISSN:00086223
DOI:10.1016/j.carbon.2015.08.030