Preliminary tests for the thermo-chemical conversion of biomass in a spouted bed pilot plant

The initial setting up and preliminary tests on a square-based spouted bed gasifier at pilot scale (20 kW(th)) have been investigated. The novel plant is composed of: a squared-base spouted bed unit, a feeding system to regulate the biomass mass inflow, an air pump, a clean-up system, and an online gas chromatograph analyzer to assess the quality of the produced gas. The profile of temperatures along the reactor has been monitored with different thermocouples during experimental tests. The start-up process has been optimized to reduce the time to achieve stationary conditions. Two different materials (wood pellets and prunings from apple trees) have been tested at different feeding rates. Wood pellets were used to validate the performance of the spouted bed reactor and afterwards, residues of prunings from apple trees were validated as a suitable potential feedstock for energy recovery purposes. In addition, a representative sample of char from wood pellet gasification has been collected and characterized. In particular, the properties of specific surface area, pore size, and pore distribution have been measured by the Brunauer-Emmett-Teller method. The obtained outcomes represent one of the few available results in literature using a square-based spouted bed reactor for the gasification of biomass at pilot scale.