Investigations into the feasibility of small angle X-Ray scattering for studying porosity development in chars

[摘要] Quantitative descriptions of the surface area and porosity of carbonaceous chars is a key aspect to our understanding of fuel behaviour under gasification conditions. Traditional techniques for characterising porous solids in terms of their surface area and pore size distributions rely on gas adsorption and the interpretation of the resulting isotherms using models specific to the system of interest. Whilst such investigations reveal useful information about the properties of a sample, they come with some practicaland scientific limitations.A small angle X-ray scattering (SAXS) study of some coal chars has been performed to determine is likely usefulness as an alternative to these traditional methods of pore size and surface area determination. The research was intended as a preliminary study of a broad range of chars, both in origin and method ofconversion, in order that the technique can be assessed for its potential application, and so that the most suitable candidate chars can be selected for further study.Results show that while it proves extremely difficult, if not impossible, to extract exact surface area estimates from the data, some inferences about the development in pore structure can be made.Sample selection criteria for further study are recommended. These are the choice of a single source coal (Drayton) with samples covering a wide range of conversions. Samples of an activated carbon with well documented pore sizes should also be included in a follow up study.It is also recommended that all three available camera positions on the SAX/WAX beamline at the Australian Synchrotron be used in subsequent studies in order to minimise errors in their overlapping q ranges.

[发布日期] 2012-03-31 [发布机构] CSIRO

[效力级别] Accelerators [学科分类] 地球科学(综合)