An educational, steady-state model of prepared biomass in a directly heated, air-blown bubbling bed. Prescribed carbon conversion and gas splitting close a simplified C/H/O/N balance. Temperature is an input, not an adiabatic prediction. These are not equipment specifications, operating instructions or validated performance guarantees.
Model assumptions, equations & sources
Feed analyses are illustrative dry-basis presets. Gas contains CO, H₂, CO₂, CH₄ and N₂; outlet water is vapour. Char is modelled as carbon, ash is inert. Tars, higher hydrocarbons, sulfur/chlorine chemistry, gas leaks and media attrition are excluded. Actual gas composition, contaminants and carbon conversion need measurement or a validated reactor model. Gas normal volume: 0 °C, 1.01325 bar. Dry-feed LHV excludes feed moisture and steam utilities.
Wen–Yu estimates Umf for representative spherical bed particles; irregular, polydisperse, reacting mixtures require validation. Bed ΔP is inventory × g / area once fluidized. Gas viscosity uses a simple temperature power law. Bed expansion, conversion and composition trends are authored teaching assumptions. The calculation tab exposes them. A high U/Umf alone does not prove CFB operation.
The cited configurations are background references, not validation of this lab's synthetic presets or numeric model. Some sources describe coal or indirect gasifiers; those operating conditions are not transferred to this air-blown biomass example.
