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

Abstract

The initial setting up and preliminary tests on a square‐based spouted bed gasifier at pilot scale (20 kWth) 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.

CFD simulation of a spouted bed: Comparison between the Discrete Element Method (DEM) and the Two Fluid Model (TFM)

“…Spouted Beds (SB) continue to attract interest in recent years for a broad range of applications, mostly related to drying processes, due to the high fluid-solid contact achieved [1]. Spouted beds currently stand out as a promising technology to carry out thermo-chemical reactions such as pyrolysis [2,3], gasification [4,5] and combustion [6,7] of different materials, such as coal or waste products. A Spouted Bed can be described as a conventional fluidisation reactor in which the perforated plate has been replaced by single orifice place, promoting enhanced recirculation of solids with a particular multiphase pattern [8].…”

Production, Characterization, and Evaluation of Pellets from Rice Harvest Residues

“…This suggested that a higher quantity of pellets will need to be processed in order to achieve the same quantitative efficiencies. HHV values were found to be lower than commercial wood pellets for both feedstocks (HHV wood = 19.5 MJ/kg [28]). An increase in these values could be achieved by mixing them with other available residues (HHV persimmon stems = 17.3 MJ/kg [29] or HHV appletrees = 17.2 MJ/kg [30]).…”

Spouted-Bed Gasification of Flame Retardant Textiles as a Potential Non-Conventional Biomass

“…In order to achieve continuous feeding and reach gasification temperature (>700 • C), there is a need to analyze syngas components. For this research, the experiments were performed with a pilot plant designed and built in Biella (Italy) which is capable of having material feeding of 200 g/min to with thermal energy provide about 20 kWth [32], 3D illustration of the experimental setup can be seen in Figure 1. The square-based unit which is the main component of the plant, has a side dimension of 0.2 m and 1.3 m in total, with its base inclined at 60 • angle.…”

“…The prepared pellets are continuously fed in a conical shape hopper of the reactor. From hopper, the pellets go through a rotary valve with a specific feeding rate to the gasifier [32].…”

“…The production of char and its evaluation were not considered in this study. However, operation activities under the regime permits mass balance conclusion over 95% [19,32]. The spouted bed is composed of inert solids to improve energy and mass transfer rates and contains up of 2 kg of silica sand inside the reactor.…”