Dual Fluidised Bed System

Introduction

This rig, still under construction at time of writing, will be a dual fluidised bed system which converts woody biomass into bio-oils. The pyrolysis bed contains the endothermic reaction which converts the biomass, while the energy required for the reaction is supplied by a combustion bed which burns off solid byproducts of the pyrolysis reaction.

Previous Projects

This section describes some of the previous projects that was done on the level and flow rig to give you an idea of what has been done and where you can find the results obtained. Most important data contained in this section is information about what models were used/developed (if you want to reuse models) and what control strategies were employed (if you want to compare your results to something specific).

Mark Transell, 2011

Controllability Analysis: A full feedback controllability analysis was performed, which gave promising results for the initial design. It appears that the desired operating region is fully contained within the operating envelope, and disturbances can be rejected without saturating the manipulated variables.

Design modification suggestions: Two system modifications were suggested:

• The inclusion of an inert gas line to the pyrolysis bed distributor to aid in startup
  
• Cascading of control loops from temperature to flow controllers
  

Other notes: The system, when constructed, is intended to use the controller tunings outlined in Transell (2011)