BIO4Africa research publications
The BIO4Africa partners are conducting a wide range of research studies. The objective is to investigate the nutritional potential and functional properties of agricultural waste products and the optimal setup and processing steps for bio-based technologies in local contexts. These findings are then used to optimise the pilot trials at our test sites.
Here you can find an overview of the studies that have been published in international journals to date. Click on the images to view the literature.
Hydrothermal carbonization of Typha australis: Influence of stirring rate
Omar M. Abdeldayem, Md Abdullah Al Noman, Capucine Dupont, David Ferras, Lat Grand Ndiaye, Maria Kennedy. Environ Res. 2023 Nov 1;236(Pt 2):116777. doi: 10.1016/j.envres.2023.116777. Epub 2023 Jul 28. PMID: 37517487.
Abstract
According to existing literature, there are no conclusive results on the impact of stirring on hydrothermal carbonization (HTC); some studies report a significant impact on the product's properties, while others indicate no influence. This study investigates the influence of stirring rate on several responses and properties of HTC products, including solid mass yield, solid carbon fraction, surface area, surface functional groups, morphology, and the fate of inorganic elements during HTC. Waste biomass was introduced as a feedstock to a 2 L HTC reactor, where the effects of temperature (180-250 °C), residence time (4-12 h), biomass to water (B/W) ratio (1-10%), and stirring rate (0-130 rpm) were investigated. The findings of this study conclusively indicated that the stirring rate does not influence any of the studied responses or properties of hydrochar under the selected experimental conditions used in this study. Nevertheless, the results indicated that a low-stirring rate (5 RPM) is enough to slightly enhanced the heating-up phase of the HTC reactor. For future research, it is recommended to examine the impact of stirring rate on the HTC of other types of biomass using the methodology developed in this study.
Reconsidering lab procedures for hydrothermal carbonization of biomass: The impact of pre-drying and stirring
Omar M. Abdeldayem, Capucine Dupont, David Ferras, Lat Grand Ndiaye, Maria Kennedy. Journal of Analytical and Applied Pyrolysis. Volume 179, 2024. 106459, ISSN 0165-2370.
https://doi.org/10.1016/j.jaap.2024.106459.
Abstract
Although industrial hydrothermal carbonization (HTC) uses wet feedstock, lab-scale studies tend to dry the feedstock under the assumption that the rehydration of the feedstock would restore its original properties. To the best of our knowledge, this assumption has not been thoroughly examined at the lab scale; therefore, its investigation is crucial to prevent any discrepancies that might affect the upscaling of HTC. This research aims to examine the effects of pre-drying biomass by comparing it to the use of wet biomass in HTC experiments, employing three different types of biomass (rejected tomatoes, rejected apples, and digestate). Additionally, the study investigates the influence of stirring on pre-dried and wet biomass under the selected HTC conditions. The results indicate a substantial disparity in studied hydrochar properties when using pre-dried biomass compared to wet biomass. For pre-dried biomass, there is a tendency for an increase in mass yield and solid carbon yield in most examined samples (5–10% dry basis) compared to the wet biomass. Regarding functional groups, wet tomatoes and apples exhibit more pronounced peaks than pre-dried samples. Conversely, digestate shows similar spectra across all examined scenarios. The effect of stirring appears insignificant for most of the studied scenarios; nevertheless, it reduced dehydration and decarboxylation reactions during HTC.