Analysis of Gasifier Samples Collected with a High-Temperature/High-Pressure Cascade Impactor: Electron Spectroscopy for Chemical Analysis, Energy Dispersive X-Ray Analysis, and Scanning Electron Microscopy

Abstract

A particulate sample was collected from the process stream of a low Btu gasifier in a cascade impactor operated at 400°C and 10–12 atmospheres pressure. Stainless steel shim stock was used as collection substrate. The sample, which weighed less than 1 mg, was successfully mounted and examined by ESCA, EDXA, and SEM. The ESCA spectra of the samples and of the blank impactor plates were taken before and after ion etching. The SEM and EDXA data were obtained for samples still on the impactor plate and for a sample transferred from the plate to a carbon, oxygen, and sulphur, but no significant peaks for alkali metals or calcium normally found on the surface of coal combustion fly ash. The EDXA data demonstrated that the core of the particles contained Al, Si, Mg, Ca, and S. Methods of sample manipulation are described.