Influence of indirectly heated steam-blown gasification process conditions on biochar physico-chemical properties

Journal article (2022)

Authors

M. Del Grosso Large Scale Energy Storage - Mechanical, Maritime and Materials Engineering
L. Cutz Large Scale Energy Storage - Mechanical, Maritime and Materials Engineering
U. Tiringer Team Peyman Taheri - Mechanical, Maritime and Materials Engineering
C. Tsekos Large Scale Energy Storage - Mechanical, Maritime and Materials Engineering
P. Taheri Team Peyman Taheri - Mechanical, Maritime and Materials Engineering
W. de Jong Large Scale Energy Storage - Mechanical, Maritime and Materials Engineering
Research Group
Large Scale Energy Storage (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2022 M. Del Grosso, L. Cutz, U. Tiringer, C. Tsekos, P. Taheri, W. de Jong
DOI: https://doi.org/10.1016/j.fuproc.2022.107347
More Info
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Published Date

2022

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Process and Energy

Research Group

Large Scale Energy Storage

Abstract

Our work provides a thorough characterization of different biochars produced by a novel 50 kWth Indirectly Heated Bubbling Fluidized Bed Steam Reformer. This study investigates the effect of temperature and gasification agent on the physico-chemical properties of biochars. We combined macro, micro and nano characterization techniques to provide a clear picture of the biochar characteristics, surface functionality and its “inert” nature toward potential applications. Our results demonstrate that indirect gasification is capable of producing carbon-rich biochars (> 92%) with increased porosity (89–198 cm3.g−1), high heating value (28–31 MJ.kg−1 a.r.) and aromaticity compared to the parent biomass. All biochars have lower O/C (0.02–0.04) and H/C atomic ratios (0.09–0.19), similar to anthracite. For the range of tested gasification conditions, air/steam gasification at an equivalence ratio of 0.20 and steam-to-biomass ratio of 1.2 provides the highest biochar yield (7.3%), while maintaining syngas composition optimal. On the other hand, air gasification produces biochars with relatively high content of inorganic elements. Indirectly heated biochars are compliant with the European Biochar Certificate regarding the carbon content, O/C ratio, H/C ratio. Our biochars may provide an improvement in agricultural yield and CO2 adsorption, especially those produced under air/steam gasification conditions. Our novel indirect design not only constitutes a promising development in the field of biomass allothermal gasification but also can help improving gasification circularity through the production of high quality biochar.