The relationship between mineral contents, particle matter and bottom ash distribution during pellet combustion: molar balance and chemometric analysis

Abstract

This paper aims to identify the correlation between the mineral contents in agropellets and particle matter and bottom ash characteristics during combustion in domestic boilers. Four agrifood residues with higher mineral contents, namely grape marc (GM), tomato waste (TW), exhausted olive mill solid waste (EOMSW) and olive mill wastewater (OMWW), were selected. Then, seven different pellets were produced from pure residues or their mixture and blending with sawdust. The physico-chemical properties of the produced pellets were analysed using different analytical techniques, and a particular attention was paid to their mineral contents. Combustion tests were performed in 12-kW domestic boiler. The particle matter (PM) emission was characterised through the particle number and mass quantification for different particle size. The bottom ash composition and size distribution were also characterised. Molar balance and chemometric analyses were performed to identify the correlation between the mineral contents and PM and bottom ash characteristics. The performed analyses indicate that K, Na, S and Cl are released partially or completely during combustion tests. In contrast, Ca, Mg, Si, P, Al, Fe and Mn are retained in the bottom ash. The chemometric analyses indicate that, in addition to the operating conditions and the pellet ash contents, K and Si concentrations have a significant effect on the PM emissions as well as on the agglomeration of bottom ash.

Fast pyrolysis and steam gasification of pellets prepared from olive oil mill residues

“…Such behavior may be attributed to the catalytic effect of minerals provided by OMWW after the impregnation process. The role of mineral contents on the gasification of biomass char is well identified in the literature [13], especially for the K element which is has a high catalytic effect [17,18,36] and it is the major mineral component as it is shown in Table 1. Similar investigations were performed by Guizani et al [37] for beech wood chips in the same experimental device.…”

Hydrogen enriched syngas production via gasification of biofuels pellets/powders blended from olive mill solid wastes and pine sawdust under different water steam/nitrogen atmospheres

“…Table 2 shows that inorganic elements (Na, K and Ca) are highly concentrated in the EOMSW, EOMSW-OMWW and PS-OMWW samples. This elevated concentration is not only due to the initial amount of Na, K and Ca in raw material EOMSW but also due to impregnation process when using OMWW (rich of these minerals) [30,31]. It is worth noting that these higher inorganic contents are very interesting of point of view catalytic effect during gasification process [31e33].…”

Assessments of Gaseous and Particulate Matter Emissions from Biomass Combustion and their Effect on Human Health

“…This correlation is linear with a regression factor R 2 = 0.94. Also, in the same context Jeguirim et al [38] have shown a linear correlation between the total PM (g/kg) and K and the sum (K + Na + S +Cl) expressed in g/kg. Furthermore, they found that the correlation with potassium is more strong with a correlation coefficient R 2 = 0.94 than with the sum (K + Na + S +Cl) for which R 2 is equal to 0.88.…”