Fluidised Bed Gasification of Diverse Biomass Feedstocks and Blends—An Overall Performance Study

Abstract

The aim of this work is to investigate the fluidised bed gasification of several pure and blended feedstock prepared in the form of pellets: oak bark, two bark/wheat straw blends (85/15 and 50/50 wt%) and lignin residue remaining from bioethanol production. Gasification conditions were defined to be representative of dual fluidised bed ones (steam gasification at 850 °C, followed by air combustion of the char). The cold gas efficiency (77–81%), gas composition and tar content (0.9–2.3 g/kgdaf) are close for the gasification of bark and the two bark/wheat straw blends. For lignin residue, the cold gas efficiency is lower (71%), and the tar content is 9.1 g/kgdaf. The agglomeration propensity is much higher for lignin residue than for the other feedstock. This was put into evidence with in-bed temperature measurements at different levels, and confirmed with post-test size screening of the bed material particles. The 50/50 wt% bark/wheat straw blend seems to undergo defluidisation in combustion, however followed by refluidisation of the bed. These findings were also well correlated with a predictive model for defluidisation.

A review on the interplay between bioeconomy and soil organic carbon stocks maintenance.

“…In highly efficient processes, the fraction of C in wood-agricultural biomass that ends in the tar is less than 1% [96]. In average, the gaschar yield is 20% DM (Fig 6 , n=25), with reported values from 7% to 28%.…”

Use of CO2 in Pressurized, Fluidized Bed Gasification of Waste Biomasses

“…Here, the bark was blended with straw (85%/15% w/w) to assess the limits of the above-described idea. In previous publications of the Heat-to-Fuel consortium, it is possible to find more details behind the rationale of the selection, thermodynamic deliberations, as well as small-scale laboratory and fluidized bed experiments [27,32,34].…”

Thermodynamic equilibrium approach to predict the inorganic interactions of ash from biomass and their mixtures: A critical assessment

“…The BCWC mixture was prepared by Defoort et al [9], and the BFWF blend was received as a pellet in the work of Valin et al [27]. The other mixtures were formed manually.…”