Assessing CO2 sources and sinks in and around Taiwan: Implication for achieving regional carbon neutrality by 2050.

Taiwan has pledged to achieve net-zero carbon emissions by 2050, but the current extent of carbon sinks in Taiwan remains unclear. Therefore, this study aims to first review the existing nature-based carbon sinks on land and in the oceans around Taiwan. Subsequently, we suggest potential strategies to reduce CO2 emissions and propose carbon dioxide removal methods (CDRs). The natural carbon sinks by forests, sediments, and oceans in and around Taiwan are approximately 21.5, 42.1, and 96.8 Mt-CO2 y-1, respectively, which is significantly less than Taiwan's CO2 emissions (280 Mt-CO2 y-1). Taiwan must consider decarbonization strategies like using electric vehicles, renewable energy, and hydrogen energy by formulating enabling policies. Besides more precisely assessing both terrestrial and marine carbon sinks, Taiwan should develop novel CDRs such as bioenergy with carbon capture and storage, afforestation, reforestation, biochar, seaweed cultivation, and ocean alkalinity enhancement, to reach carbon neutrality by 2050.

Mineral trapping of carbon dioxide: Rapid hydrothermal synthesis experiments and carbon sequestration potential of dawsonite.

Dawsonite, as a natural CO2 tracing mineral, is intimately associated with CO2 injection and serves as a crucial mineral for geological carbon sequestration. The massive and stable presence of dawsonite in the geological background is a key consideration for CO2 mineralization capture and plays a significant role in identifying CO2 geological burial sites. To investigate the optimal conditions for the rapid synthesis of dawsonite using CO2, we conducted comparative experiments to examine the three primary influencing factors: temperature (100 °C, 120 °C, 140 °C, 160 °C, 180 °C, and 200 °C), pH (8.5, 9, 9.5, 10, and 10.5), and reaction time (6 and 12 h). Through scanning electron microscopy and X-ray diffraction analysis, the optimal conditions for dawsonite synthesis were determined. The experiments revealed that within the pH range of 8.5-10.5 and at temperatures of 100-180 °C, the dawsonite products obtained are consistently pure, which indicates that CO2 can be effectively mineralized and sequestered as dawsonite within these temperature and pH ranges. The synthesis yield increased and then decreased with increasing pH and temperature. At 200 °C, the crystallinity of dawsonite decreased and the content of pseudo-boehmite increased. This suggests that higher temperature conditions are not conducive to the mineralization and sequestration of CO2. Extending the reaction time did not have a significant promoting effect on the quality of the product. The maximum amount of dawsonite synthesis, good dispersion and homogeneity of crystals, and maximum ratio of mineralization of CO2 by dawsonite were achieved at a temperature of 140 °C and a pH of 9.5, indicating that these are the optimal conditions for the hydrothermal synthesis of dawsonite using CO2. Moreover, these are the optimal geological conditions for the mineralization sequestration of CO2 in the form of dawsonite.

Advances in succinic acid production: the enhancement of CO2 fixation for the carbon sequestration benefits.

Succinic acid (SA), one of the 12 top platform chemicals produced from biomass, is a precursor of various high value-added derivatives. Specially, 1 mol CO2 is assimilated in 1 mol SA biosynthetic route under anaerobic conditions, which helps to achieve carbon reduction goals. In this review, methods for enhanced CO2 fixation in SA production and utilization of waste biomass for SA production are reviewed. Bioelectrochemical and bioreactor coupling systems constructed with off-gas reutilization to capture CO2 more efficiently were highlighted. In addition, the techno-economic analysis and carbon sequestration benefits for the synthesis of bio-based SA from CO2 and waste biomass are analyzed. Finally, a droplet microfluidics-based high-throughput screening technique applied to the future bioproduction of SA is proposed as a promising approach.

Formation of Natural Magnesium Silica Hydrate (M-S-H) and Magnesium Alumina Silica Hydrate (M-A-S-H) Cement.

Occurrences of natural magnesium alumina silicate hydrate (M-(A)-S-H) cement are present in Feragen and Leka, in eastern and western Trøndelag Norway, respectively. Both occurrences are in the subarctic climate zone and form in glacial till and moraine material deposited on ultramafic rock during the Weichselian glaciation. Weathering of serpentinized peridotite dissolves brucite and results in an alkaline fluid with a relatively high pH which subsequently reacts with the felsic minerals of the till (quartz, plagioclase, K-feldspar) to form a cement consisting of an amorphous material or a mixture of nanocrystalline Mg-rich phyllosilicates, including illite. The presence of plagioclase in the till results in the enrichment of alumina in the cement, i.e., forms M-A-S-H instead of the M-S-H cement. Dissolution of quartz results in numerous etch pits and negative quartz crystals filled with M-A-S-H cement. Where the quartz dissolution is faster than the cement precipitation, a honeycomb-like texture is formed. Compositionally, the cemented till (tillite) contains more MgO and has a higher loss of ignition than the till, suggesting that the cement is formed by a MgO fluid that previously reacted with the peridotite. The M-(A)-S-H cemented till represents a new type of duricrust, coined magsilcrete. The study of natural Mg cement provides information on peridotites as a Mg source for Mg cement and as a feedstock for CO2 sequestration.

CO2 sequestration in microbial electrolytic cell-anaerobic digestion system combined with mineral carbonation for sludge hydrolysate treatment.

The combination of microbial electrolytic cells and anaerobic digestion (MEC-AD) became an efficient method to improve CO2 capture for waste sludge treatment. By adding CaCl2 and wollastonite, the CO2 sequestration effect with mineral carbonation under 0 V and 0.8 V was studied. The results showed that applied voltage could increase dissolved chemical oxygen demand (SCOD) degradation efficiency and biogas yield effectively. In addition, wollastonite and CaCl2 exhibited different CO2 sequestration performances due to different Ca2+ release characteristics. Wollastonite appeared to have a better CO2 sequestration effect and provided a wide margin of pH change, but CaCl2 released Ca2+ directly and decreased the pH of the MEC-AD system. The results showed methane yield reached 137.31 and 163.50 mL/g SCOD degraded and CO2 content of biogas is only 12.40 % and 2.22 % under 0.8 V with CaCl2 and wollastonite addition, respectively. Finally, the contribution of chemical CO2 sequestration by mineral carbonation and biological CO2 sequestration by hydrogenotrophic methanogenesis was clarified with CaCl2 addition. The chemical and biological CO2 sequestration percentages were 46.79 % and 53.21 % under 0.8 V, respectively. With the increased applied voltage, the contribution of chemical CO2 sequestration rose accordingly. The findings in this study are of great significance for further comprehending the mechanism of calcium addition on CO2 sequestration in the MEC-AD system and providing guidance for the later engineering application.

Advances in microalgae-based carbon sequestration: Current status and future perspectives.

The advancement in carbon dioxide (CO2) sequestration technology has received significant attention due to the adverse effects of CO2 on climate. The mitigation of the adverse effects of CO2 can be accomplished through its conversion into useful products or renewable fuels. In this regard, microalgae is a promising candidate due to its high photosynthesis efficiency, sustainability, and eco-friendly nature. Microalgae utilizes CO2 in the process of photosynthesis and generates biomass that can be utilized to produce various valuable products such as supplements, chemicals, cosmetics, biofuels, and other value-added products. However, at present microalgae cultivation is still restricted to producing value-added products due to high cultivation costs and lower CO2 sequestration efficiency of algal strains. Therefore, it is very crucial to develop novel techniques that can be cost-effective and enhance microalgal carbon sequestration efficiency. The main aim of the present manuscript is to explain how to optimize microalgal CO2 sequestration, integrate valuable product generation, and explore novel techniques like genetic manipulations, phytohormones, quantum dots, and AI tools to enhance the efficiency of CO2 sequestration. Additionally, this review provides an overview of the mass flow of different microalgae and their biorefinery, life cycle assessment (LCA) for achieving net-zero CO2 emissions, and the advantages, challenges, and future perspectives of current technologies. All of the reviewed approaches efficiently enhance microalgal CO2 sequestration and integrate value-added compound production, creating a green and economically profitable process.

Photosynthetic production of α-farnesene by engineered Synechococcus elongatus UTEX 2973 from carbon dioxide.

Cyanobacteria are the prospective biosolar cell factories to produce a range of bioproducts through CO2 sequestration. Farnesene is a sesquiterpene with an array of applications in biofuels, pest management, cosmetics, flavours and fragrances. This is the first time a codon-optimized farnesene synthase (AFS) gene is engineered into the genomic neutral site of Synechococcus elongatus UTEX 2973 for farnesene synthesis through its endogenous methylerythritol phosphate (MEP) pathway, rendering UTEX AFS strain. Similarly, bottleneck gene(s) of the MEP pathway, 1-deoxy-D-xylulose-5-phosphate synthase (dxs) and/or fusion of isopentenyl diphosphate isomerase and farnesyl diphosphate synthase (idispA) were engineered engendering UTEX AFS::dxs, UTEX AFS::idispA and UTEX AFS::dxs::idispA strains. UTEX AFS::dxs::idispA achieves farnesene productivity of 2.57 mg/L/day, the highest among engineered cyanobacterial strains studied so far. It demonstrates farnesene production, which is 31.3-times higher than the UTEX AFS strain. Moreover, the engineered strains show similar productivity over a three-month period, stipulating the genetic stability of the strains.

Uncovering the Dynamics of Urease and Carbonic Anhydrase Genes in Ureolysis, Carbon Dioxide Hydration, and Calcium Carbonate Precipitation.

The hydration of CO2 suffers from kinetic inefficiencies that make its natural trapping impractically sluggish. However, CO2-fixing carbonic anhydrases (CAs) remarkably accelerate its equilibration by 6 orders of magnitude and are, therefore, "ideal" catalysts. Notably, CA has been detected in ureolytic bacteria, suggesting its potential involvement in microbially induced carbonate precipitation (MICP), yet the dynamics of the urease (Ur) and CA genes remain poorly understood. Here, through the use of the ureolytic bacteriumSporosarcina pasteurii, we investigate the differing role of Ur and CA in ureolysis, CO2 hydration, and CaCO3 precipitation with increasing CO2(g) concentrations. We show that Ur gene up-regulation coincides with an increase in [HCO3-] following the hydration of CO2 to HCO3- by CA. Hence, CA physiologically promotes buffering, which enhances solubility trapping and affects the phase of the CaCO3 mineral formed. Understanding the role of CO2 hydration on the performance of ureolysis and CaCO3 precipitation provides essential new insights, required for the development of next-generation biocatalyzed CO2 trapping technologies.

Progress and Perspectives on Promising Covalent-Organic Frameworks (COFs) Materials for Energy Storage Capacity.

In recent years, a new class of highly crystalline advanced permeable materials covalent-organic frameworks (COFs) have garnered a great deal of attention thanks to their remarkable properties, such as their large surface area, highly ordered pores and channels, and controllable crystalline structures. The lower physical stability and electrical conductivity, however, prevent them from being widely used in applications like photocatalytic activities and innovative energy storage and conversion devices. For this reason, many studies have focused on finding ways to improve upon these interesting materials while also minimizing their drawbacks. This review article begins with a brief introduction to the history and major milestones of COFs development before moving on to a comprehensive exploration of the various synthesis methods and recent successes and signposts of their potential applications in carbon dioxide (CO2 ) sequestration, supercapacitors (SCs), lithium-ion batteries (LIBs), and hydrogen production (H2 -energy). In conclusion, the difficulties and potential of future developing with highly efficient COFs ideas for photocatalytic as well as electrochemical energy storage applications are highlighted.

Exploring the potential of steel slag waste for carbon sequestration through mineral carbonation: A comparative study of blast-furnace slag and ladle slag.

Steel slag is a by-product of steelmaking which has emerged as a potential CO2 sequestration material due to its high reactivity and abundance. This research investigates the use of steel slag waste for the direct capture of carbon from air and its storage through mineral carbonation. Two abundant wastes, blast-furnace slag (BFS) and ladle slag (LS), were tested for their carbon sequestration potential, and the effects of operational parameters such as reaction time between CO2 and slag waste, temperature, liquid-solid ratio, and pressure on CO2 sequestration were determined. Quantitative and qualitative results reveal that much higher CO2 sequestration was achieved using LS compared to BFS after exposure to CO2 for 1 day at room temperature. By increasing the exposure time to four days, levels of CO2 sequestration increased gradually from 2.71% to 4.19% and 23.46%-28.21% for BFS and LS respectively. Increasing the temperature from 20 ± 2 °C to 90 ± 2 °C positively influenced CO2 sequestration in BFS, resulting in an enhancement from 3.45% to 13.21%. However, the impact on LS was insignificant, with sequestration levels rising from 27.72% to 29.90%. Moreover, better CO2 sequestration was observed for BFS than LS when the liquid-to-solid ratio increased from 3:1 to 4:1, whereupon the sequestration potential reached approximately 15% for BFS and 30% for LS at 90 ± 2 °C. Meanwhile, higher pressure reduced the sequestration potential of slag. The results of this study suggest that there is potential for scaling up the process to industrial applications and contributing to the reduction of CO2 emissions in the steelmaking industry.

Rational design engineering of a more thermostable Sulfurihydrogenibium yellowstonense carbonic anhydrase for potential application in carbon dioxide capture technologies.

Implementing hyperthermostable carbonic anhydrases into CO2 capture and storage technologies in order to increase the rate of CO2 absorption from the industrial flue gases is of great importance from technical and economical points of view. The present study employed a combination of in silico tools to further improve thermostability of a known thermostable carbonic anhydrase from Sulfurihydrogenibium yellowstonense. Experimental results showed that our rationally engineered K100G mutant not only retained the overall structure and catalytic efficiency but also showed a 3 °C increase in the melting temperature and a two-fold improvement in the enzyme half-life at 85 °C. Based on the molecular dynamics simulation results, rearrangement of salt bridges and hydrogen interactions network causes a reduction in local flexibility of the K100G variant. In conclusion, our study demonstrated that thermostability can be improved through imposing local structural rigidity by engineering a single-point mutation on the surface of the enzyme.

Experimental Study on Effects of CO2 Curing Conditions on Mechanical Properties of Cement Paste Containing CO2 Reactive Hardening Calcium Silicate Cement.

Human survival is threatened by the rapid climate change due to global warming caused by the increase in CO2 emissions since the Second Industrial Revolution. This study developed a secondary cement product production technology by replacing cement, a conventional binder, with calcium silicate cement (CSC), i.e., CO2 reactive hardening cement, to reduce CO2 emissions and utilize CO2 from the cement industry, which emits CO2 in large quantities. Results showed that the carbonation depth, compressive strength increase rate, and CO2 sequestration rate increased as the CSC content increased, suggesting that CSC can be applied as a secondary cement product.

Experimental study on characterization of lime-based mineral carbonation reaction and CO2 sequestration.

This paper reports for the first time the use and application of a novel technique in the characterization of mineral carbonation reaction and CO2 sequestration in soil stabilization using flow meters. Soils based on SiO2 with two different sizes were tested. Lime (Ca(OH)2) was used as the reactant. Instant CO2 flow rate (L/min), total CO2 volume (L), temperature (°C), and absolute pressure (kPa) were monitored and recorded for 1 h by flow meters connected to the mold inlet and outlet. It was determined that the mineral carbonation reaction started in the first seconds and ended before the 5th minute. The mineral carbonation is a short-term and potential reaction, and it is not a time-dependent reaction. It is separated from other carbonation reactions with these characteristics. The highest CO2 captured value was obtained in the soil mixed with 5% lime, where fines were not used. The second highest CO2 captured value was obtained in soil mixed with 1% lime, where fines were not used. CO2 captured with 1% lime is more than CO2 captured with 5% lime in the soil containing fines. Accordingly, 1-5% lime can be used in soil carbonation studies. According to the soil properties, the highest CO2 captured and the CO2 efficiency was achieved with the use of 6-7% water by weight.

Microalgal upgrading of the fermentative biohydrogen produced from Bacillus coagulans via non-pretreated plant biomass.

BACKGROUND: Hydrogen is a promising source of alternative energy. Fermentative production is more feasible because of its high hydrogen generation rate, simple operating conditions, and utilization of various organic wastes as substrates. The most significant constraint for biohydrogen production is supplying it at a low cost with fewer impurities. RESULTS: Leaf biomass of Calotropis procera was used as a feedstock for a dark fermentative production of hydrogen by Bacillus coagulans AH1 (MN923076). The optimum operation conditions for biohydrogen production were 5.0% substrate concentrationand pH 9.0, at 35 °C. In which the biohydrogen yield was 3.231 mmol H2/g dry biomass without any pretreatments of the biomass. A freshwater microalga Oscillatroia sp was used for upgrading of the produced biohydrogen. It sequestrated 97 and 99% % of CO2 from the gas mixture when it was cultivated in BG11 and BG11-N media, respectively After upgrading process, the residual microalgal cells exhibited 0.21mg/mL of biomass yield,high content of chlorophyll-a (4.8 µg/mL) and carotenoid (11.1 µg/mL). In addition to Oscillatroia sp residual biomass showed a lipid yield (7.5-8.7%) on the tested media. CONCLUSION: Bacillus coagulans AH1 is a promising tool for biohydrogen production avoiding the drawbacks of biomass pretreatment. Oscillatroia sp is encouraged as a potent tool for upgrading and purification of biohydrogen. These findings led to the development of a multiproduct biorefinery with zero waste that is more economically sustainable.

Inclusive greenhouse gas budget assessment in turfs: From turf production to disposal of grass clippings.

Globally, greenhouse gas (GHG) reduction is a serious concern. To evaluate whether turfs serve as a GHG sink or source, GHG budget assessments for life cycle are required. However, previous studies have only focused on the use of turfs. To bridge these gaps in literature, this study investigated GHG (CO2, N2O, and CH4) emissions from the disposal of grass clippings and soil GHG fluxes in turfs. Additionally, GHG budgets in the turf production phase were assessed. Finally, inclusive GHG budgets from turf production to disposal of grass clippings for four turf uses (soccer stadium, golf course, office, and urban park) were assessed. Grass clippings were disposed in three forms (incineration, leaving as-is, and biochar). We found that GHG emissions from incineration and leaving 1 t-fresh weight (FW) of grass clippings were 0.711 and 0.207 t-CO2e, respectively. Contrastingly, the GHG emissions from the biochar yield from 1 t-FW of grass clippings were -0.200 t-CO2e. Further, annual soil GHG fluxes in newly established Zoysia and Kentucky bluegrass turfs were calculated at 0.067 and 0.040 tCO2eï½¥ha-1ï½¥yr-1, respectively. As the turf grass in production fields sequester large amounts of CO2, GHG budgets in turf production phase were estimated at approximately -20 t-CO2eï½¥ha-1ï½¥yr-1. Inclusive GHG budget assessment from turf production to disposal of grass clippings showed that turfs only in the urban parks served as a GHG sink and this ability was comparable to CO2 sequestration in forests. To enhance the ability of GHG sinks and to promote changes from a GHG source to GHG sink, our study revealed the importance of reduction of GHG emissions from energy and resource uses (especially fertilizers and gasoline) for turf management.

Enhanced sequestration of CO2 from simulated electrolytic aluminum flue gas by modified red mud.

The aluminum industry is facing severe economic and environmental problems due to increasing carbon emissions and growing stockpiles of red mud (RM). RM is a strongly alkaline, high-emission solid waste from the alumina industry with potential for CO2 sequestration. However, the effectiveness of RM carbon sequestration is poor, and the mechanism behind it is not well understood. In this study, the effect of microwave and tube furnace activation of RM on CO2 sequestration in alumina was first investigated at different temperatures. The result showed that the CO2 sequestration capacity of unmodified RM (URM) was only 14.35 mg/g at ambient temperature and pressure, and the CO2 sequestration capacity could be increased to 52.89 mg/g after high-temperature activation and modification. Besides, high-temperature activation and modification will effectively improve the carbon sequestration capacity of RM. The carbonized RM was characterized by FT-IR, SEM, XRD, laser particle size, TG-DSC, and pH measurements. In addition, the mechanism of RM capturing CO2 was also proposed, which shows that CO2 was finally sequestered in the RM as CaCO3. The change in particle size distribution and the mineral phase in the RM indicated that high-temperature activation modification positively affects the application of RM to the sequestration of CO2. This study can provide a promising technology for the low-carbon and green development of the aluminum industry, as well as achieving the waste treatment and utilization objective.

Bioelectrocatalytic CO2 Reduction by Mo-Dependent Formylmethanofuran Dehydrogenase.

Massive efforts are invested in developing innovative CO2 -sequestration strategies to counter climate change and transform CO2 into higher-value products. CO2 -capture by reduction is a chemical challenge, and attention is turned toward biological systems that selectively and efficiently catalyse this reaction under mild conditions and in aqueous solvents. While a few reports have evaluated the effectiveness of isolated bacterial formate dehydrogenases as catalysts for the reversible electrochemical reduction of CO2 , it is imperative to explore other enzymes among the natural reservoir of potential models that might exhibit higher turnover rates or preferential directionality for the reductive reaction. Here, we present electroenzymatic catalysis of formylmethanofuran dehydrogenase, a CO2 -reducing-and-fixing biomachinery isolated from a thermophilic methanogen, which was deposited on a graphite rod electrode to enable direct electron transfer for electroenzymatic CO2 reduction. The gas is reduced with a high Faradaic efficiency (109±1 %), where a low affinity for formate prevents its electrochemical reoxidation and favours formate accumulation. These properties make the enzyme an excellent tool for electroenzymatic CO2 -fixation and inspiration for protein engineering that would be beneficial for biotechnological purposes to convert the greenhouse gas into stable formate that can subsequently be safely stored, transported, and used for power generation without energy loss.

A precise microalgae farming for CO2 sequestration: A critical review and perspectives.

Microalgae are great candidates for CO2 sequestration and sustainable production of food, feed, fuels and biochemicals. Light intensity, temperature, carbon supply, and cell physiological state are key factors of photosynthesis, and efficient phototrophic production of microalgal biomass occurs only when all these factors are in their optimal range simultaneously. However, this synergistic state is often not achievable due to the ever-changing environmental factors such as sunlight and temperature, which results in serious waste of sunlight energy and other resources, ultimately leading to high production costs. Most control strategies developed thus far in the bioengineering field actually aim to improve heterotrophic processes, but phototrophic processes face a completely different problem. Hence, an alternative control strategy needs to be developed, and precise microalgal cultivation is a promising strategy in which the production resources are precisely supplied according to the dynamic changes in key factors such as sunlight and temperature. In this work, the development and recent progress of precise microalgal phototrophic cultivation are reviewed. The key environmental and cultivation factors and their dynamic effects on microalgal cultivation are analyzed, including microalgal growth, cultivation costs and energy inputs. Future research for the development of more precise microalgae farming is discussed. This study provides new insight into developing cost-effective and efficient microalgae farming for CO2 sequestration.

Interpretation and Prediction of the CO2 Sequestration of Steel Slag by Machine Learning.

The utilization of steel slag for CO2 sequestration is an effective way to reduce carbon emissions. The reactivity of steel slag in CO2 sequestration depends mainly on material and process parameters. However, there are many puzzles in regard to practical applications due to the different evaluations of process parameters and the lack of investigation of material parameters. In this study, 318 samples were collected to investigate the interactive influence of 12 factors on the carbonation reactivity of steel slag by machine learning with SHapley Additive exPlanations (SHAP). Multilayer perceptron (MLP), random forest, and support vector regression models were built to predict the slurry-phase CO2 sequestration of steel slag. The MLP model performed well in terms of prediction ability and generalization with comprehensive interpretability. The SHAP results showed that the impact of the process parameters was greater than that of the material parameters. Interestingly, the iron ore phase of steel slag was revealed to have a positive effect on steel slag carbonation by SHAP analysis. Combined with previous literature, the carbonation mechanism of steel slag was proposed. Quantitative analysis based on SHAP indicated that steel slag had good carbonation reactivity when the mass fractions of "CaO + MgO", "SiO2 + Al2O3", "Fe2O3", and "MnO" varied from 50-55%, 10-15%, 30-35%, and <5%, respectively.

Methodology for Evaluating the CO2 Sequestration Capacity of Waste Ashes.

The concentration of CO2 in the atmosphere is constantly increasing, leading to an increase in the average global temperature and, thus, affecting climate change. Hence, various initiatives have been proposed to mitigate this process, among which CO2 sequestration is a technically simple and efficient approach. The spontaneous carbonation of ashes with atmospheric CO2 is very slow, and this is why accelerated carbonation is encouraged. However, not all ashes are equally suitable for this process, so a methodology to evaluate their potential should be developed. Such a methodology involves a combination of techniques, from theoretical calculations to XRF, XRD, DTA-TG, and the calcimetric determination of the CaCO3 content. The present study followed the approach of exposing ashes to accelerated carbonation conditions (4% v/v CO2, 50-55% and 80-85% RH, 20 °C) in a closed carbonation chamber for different periods of time until the maximum CO2 uptake is reached. The amount of sequestered CO2 was quantified by thermogravimetry. The results show that the highest CO2 sequestration capacity (33.8%) and carbonation efficiency (67.9%) were obtained for wood biomass bottom ash. This method was applied to eight combustion ashes and could serve to evaluate other ashes or comparable carbon storage materials.