简介：Gasification is a potentially sustainable and cleaner alternative to combustion of coal and biomass fuels. Gasification processes occur at multiple length scales including endothermic solid-gas reactions at the particle micro-scale (~10 μm) coupled with boundary layer processes (~500 μm) that are linked to the gas phase processes at the reactor scale (~ 10 m). The processes at the particle scale (~500 μm) are governed by diffusion of heat and mass to and from the surface and heterogeneous and homogeneous chemical reactions. Multi-scale computational and experimental studies of gasification in the presence of steam, CO2, and excess hydrogen in presence of a sustainable heat source such as solar radiation can lead to reduced carbon footprint and enhanced sustainability.
An optical diagnostics accessible fixed bed high pressure reactor arrangement (as shown in Fig. 1) for studies of biomass and coal gasification was developed. The high pressure reactor features controlled uniform heating in CO2, steam and hydrogen environments. Diagnostics include microbalance, pressure, temperature and strain gauge transducers, and mid-infrared absorption spectroscopy. Structural and elemental changes in the biomass samples are analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectral (EDS) analysis. Computational studies include development of a spatially resolved model for the gasification of porous materials in gaseous environments using unsteady reaction diffusion equations.