Mineral Carbonation of Biomass Ashes in Relation to Their CO₂ Capture and Storage Potential

Abstract

Short-term stored, long-term stored, and weathered biomass ashes (BAs) produced from eight biomass varieties were studied to define their composition, mineral carbonation, and CO 2 capture and storage (CCS) potential by a combination of methods. Most of these BAs are highly enriched in alkaline-earth and alkaline oxides, and the minerals responsible for CCS in them include carbonates such as calcite, kalicinite, and fairchildite, and to a lesser extent, butschliite and baylissite. These minerals are a result of reactions between alkaline-earth and alkaline oxyhydroxides in BA and flue CO 2 gas during biomass combustion and atmospheric CO 2 during BA storage and weathering. The mineral composition of the short-term stored, long-term stored, and weathered BAs is similar; however, there are increased proportions of carbonates and especially bicarbonates in the long-term stored BAs and particularly weathered BAs. The carbonation of BAs based on the measurement of CO 2 volatilization determined in fixed temperature ranges is approximately 1−27% (mean 11%) for short-term stored BAs, 2−33% (mean 18%) for long-term stored BAs, and 2−34% (mean 22%) for weathered BAs. Hence, biomass has some extra CCS potential because of sequestration of atmospheric CO 2 in BA, and the forthcoming industrial bioenergy production in a sustainable way can contribute for decreasing CO 2 emissions and can reduce the use of costly CCS technologies.

CO2 capture and storage by carbonation of biomass ashes

“…Their formation is a result of both solid-gas and solid-liquid reactions between alkalineearth and alkaline oxyhydroxides and CO 2 during biomass combustion, as well as post-combustion hydration, hydroxylation and carbonation of some minerals by moisture and CO 2 in the air through storage of BAs. It was found that the mineral composition of the short-term stored, long-term stored and weathered BAs is similar; however, there are increased proportions of carbonates and especially bicarbonates in the long-term stored and weathered BAs (Vassilev et al, 2021). The DTA, TG, DSC and evolved CO 2 data show the complete decomposition of carbonates in BAs according to the endothermic effects and mass losses at 600-900 °C (Vassilev et al, 2021).…”

“…It was found that the mineral composition of the short-term stored, long-term stored and weathered BAs is similar; however, there are increased proportions of carbonates and especially bicarbonates in the long-term stored and weathered BAs (Vassilev et al, 2021). The DTA, TG, DSC and evolved CO 2 data show the complete decomposition of carbonates in BAs according to the endothermic effects and mass losses at 600-900 °C (Vassilev et al, 2021). An example of this decarbonation is illustrated herein for long-term stored and weathered PPA in Fig.…”

“…The chemical composition of BAs is highly variable as the contents of oxides fluctuate in large ranges, particularly for SiO 2 (1-90%), CaO (1-63%), K 2 O (4-50%), SO 3 (1-28%), Na 2 O (0.1-14%), and MgO (Vassilev et al, 2021). The phase-mineral composition of BAs (Table 1) consists mainly of inorganic amorphous matter, carbonates and bicarbonates, and to a lesser extent, silicates, chlorides, hydroxides, phosphates and sulphates, plus some char.…”

“…2021.82.3.192 at ambient conditions for 4 months; before their characterization. Methods such as light microscopy, powder X-ray diffraction (XRD), differential-thermal (DTA) and thermo-gravimetric (TG) analyses, as well as differential scanning calorimetry (DSC), evolved CO 2 profiles and chemical analyses were used (Vassilev et al, 2021).…”

The Utilisation of Solid Fuels Derived from Waste Pistachio Shells in Direct Carbon Solid Oxide Fuel Cells

“…On the one hand, the individual inorganic phases that comprise the mineral residue can influence the operating parameters of the DC-SOFC. Within the operating temperatures (800-850 • C) of the DC-SOFC, decomposition of the alkali carbonates CaCO 3 or MgCO 3 to MgO and CO 2 may occur [38,39]. The presence of CO 2 , MgO, and CaO can facilitate the solid fuel gasification process in the anode chamber in the DC-SOFC [40].…”