The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual co...The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual coal in goaf on CO_(2)were studied by the isothermal adsorption test of CO_(2).Then,to accurately calculate the amount of adsorbed CO_(2)within the residual coal in the goaf,the bidisperse diffusion numerical model considering only Fick diffusion was modified in combination with the diffusion mechanisms.The simulation results showed that the modified model can well describe the diffusion behavior of CO_(2)in the residual coal matrix.Finally,the numerical simulation of CO_(2)sequestration in the goaf of abandoned coal mines was carried out,and the influence of different injection well deployment positions and various thicknesses of residual coal on the migration law and storage effect of CO_(2)in goaf was analyzed.The results showed that CO_(2)preferentially flowed into the caving zone with higher permeability.The distribution of CO_(2)streamlines in the goaf was the most dense in the caving zone and the streamlines in the fracture zone were gradually sparse from bottom to top.When the injection well was deployed at the interface of the two zones,the CO_(2)had the best seepage path.The total storage capacity within90 days was 7.702754×10^(6)kg,of which the free state storage capacity in the fracture of the goaf and the adsorbed state storage capacity in the residual coal were 6.611451×10^(6)and 1.091303×10^(6)kg,respectively.When the injection well was deployed in the middle of the residual coal seam in the goaf and the middle of the fracture zone,the total storage capacity at the same time was 7.613508×10^(6)and 6.021495×10^(6)kg,respectively.The coal with different thicknesses remaining at the bottom of the goaf significantly affected the adsorbed state storage,but had little effect on the free state storage.When the thickness of the residual coal seam was 0.20,0.35,and 0.50 m,the adsorbed state storage capacity within 130 days was 4.37623×10^(5),7.65791×10^(5),and 1.093406×10^(6)kg,respectively.展开更多
Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important eval...Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important evaluation parameter.In this study,the concept of whole-process carbon sequestration using coal-based solid waste and CO_(2),including sequential stirring and curing stages,was proposed to evaluate the performance evolution of CS.The results showed that CO_(2) pressure and ambient temperature positively correlated with the CS amount from coal-based SWB.In particular,CO_(2) pressure prevailed in the stirring stage,while the ambient temperature effect was more significant in the curing stage.The CS amounts obtained during the stirring stage alone,the curing stage alone,and two sequential stages ranged from 0.66%–3.10%,3.53%–5.09%,and 5.12%–6.02%,respectively.The functional group and micromorphology analyses revealed that the prevailing mechanism at the CS stirring stage was the stirringdriven gas dissolution-leaching-mineralization reaction,while that at the curing stage was the hydration-driven gas permeation-dissociation-CS reaction.Both were essentially solid-liquid-gas multiphase chemical reactions.The results are instrumental in substantiating the coal-based SWB carbon sequestration evolution patterns and mechanisms and providing data support for waste disposal and carbon emission reduction in the coal industry.展开更多
Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinni...Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinning practices on carbon sequestration and tree stability in a degraded periurban plantation in the Italian Apennines,six years after thinning.Three treatments were compared:(a)moderate thinning from below(-25%biomass),representing the typical practice;(b)intense selective thinning(-35%biomass),representing an innovative approach;and(c)no management as the control.Growth projections were used to estimate carbon recovery for these treatments,based on site-specific models calibrated with real data.The results show that both thinning approaches increased carbon sequestration over time,with the innovative thinning achieving a 7%higher annual carbon sequestration rate than traditional thinning and 8%more than the control.Estimated payback times were9 years for recovering the harvested volume in both thinning approaches,10 years for innovative thinning to surpass traditional thinning,17 years for innovative thinning to surpass the control,and 24 years for traditional thinning to surpass the control.Additionally,tree mechanical stability improved significantly in both thinning treatments after two years,with further increases observed in the innovative thinning group after six years.These results suggest that selective thinning can accelerate forest recovery and carbon sequestration,especially in areas with high stem density,where it can reduce the negative impacts of tree mortality and deadwood accumulation.However,careful planning is required to mitigate potential short-term stability is sues,particularly in challenging environments(e.g.,windy conditions,steep slopes).Forest management strategies should therefore aim to balance growth,carbon storage,and tree stability,considering both long-term sustainability and local environmental conditions.The findings are particularly relevant for current climate change mitigation strategies,emphasizing that thinning should be carefully tailored to forest type and conditions to maximize benefits in carbon credit generation and sustainable forest management practices.展开更多
Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and ...Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.展开更多
Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and intro...Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and introducing CO_(2)nanobubble technology to improve the performance of cement-fly ash-based backfill materials(CFB).The properties including fluidity,setting time,uniaxial compressive strength,elastic modulus,porosity,microstructure and CO_(2)storage performance were systematically studied through methods such as fluidity evaluation,time test,uniaxial compression test,mercury intrusion porosimetry(MIP),scanning electron microscopy-energy dispersive spectroscopy analysis(SEM-EDS),and thermogravimetric-differential thermogravimetric analysis(TG-DTG).The experimental results show that the density and strength of the material are significantly improved under the synergistic effect of fractal dimension and CO_(2)nanobubbles.When the fractal dimension reaches 2.65,the mass ratio of coarse and fine aggregates reaches the optimal balance,and the structural density is greatly improved at the same time.At this time,the uniaxial compressive strength and elastic modulus reach their peak values,with increases of up to 13.46%and 27.47%,respectively.CO_(2)nanobubbles enhance the material properties by promoting hydration reaction and carbonization.At the microscopic level,CO_(2)nanobubble water promotes the formation of C-S-H(hydrated calcium silicate),C-A-S-H(hydrated calcium aluminium silicate)gel and CaCO_(3),which is the main way to enhance the performance.Thermogravimetric studies have shown that when the fractal dimension is 2.65,the dehydration of hydration products and the decarbonization process of CaCO_(3)are most obvious,and CO_(2)nanobubble water promotes the carbonization reaction,making it surpass the natural state.The CO_(2)sequestration quality of cement-fly ash-based materials treated with CO_(2)nanobubble water at different fractal dimensions increased by 12.4wt%to 99.8wt%.The results not only provide scientific insights for the design and implementation of low-carbon filling materials,but also provide a solid theoretical basis for strengthening green mining practices and promoting sustainable resource utilization.展开更多
The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To c...The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.展开更多
On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.Th...On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.This marks a significant milestone for ONCE in establishing a systematic framework for coastal wetland carbon sequestration research and global collaboration(Figs.1,2).Coastal wetlands are critical transition zones linking terrestrial and marine ecosystems,yet they face severe degradation from anthropogenic land-based activities and sea level rise that propagate impacts to the ocean.As a UN Ocean Decade Program,the Global ONCE Program champions interdisciplinary and cross-regional collaboration to enhance carbon sequestration in the ocean and coastal wetlands through science and innovation.Aligned with the Tartu Declaration on Wetlands that includes resolutions to promote the rights of global wetlands(especially peatlands)and advance the discipline of wetland science based on facts,this initiative addresses key knowledge gaps in land-ocean interactions.The goal is to harness the full potential of coastal wetlands and ocean systems for climate mitigation,thereby laying a scientific foundation for international policy formulation and implementation.展开更多
Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic c...Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic carbon emissions(ACEs)in Shandong Province,China during 2000-2020,and identified the sensitivity factors affecting VCS.The results show that:1)VCS increased consistently from 193.45 million t to 256.41 million t,with high values areas concentrated in the central,northeastern,and southeastern mountainous and hilly regions,while low values were found in water bodies and urban built-up areas.At the city level,Linyi,Yantai,Binzhou,and Jinan experienced the most significant rises-reaching up to 243000 t/yr.At the county level,Pingdu,Qixia,and Yiyuan also showed substantial growth,each exceeding 30400 t/yr.2)Digital Elevation Molde(DEM)was identified as the dominant natural factor influencing VCS distribution,while land use optimization measures,especially afforestation and farmland conversion in sloped terrain,were the primary human drivers of VCS increase.3)Urbanization and carbon neutrality were not mutually exclusive.While urban expansion locally reduced VCS,rural emigration enhanced carbon sinks in surrounding areas,partially offsetting urban losses.This compensatory mechanism supported VCS increases in nearly all cities and 90% of counties.Nevertheless,with ACEs continuing to rise and the offset ratio by VCS declining,achieving carbon neutrality requires regional strategies that integrate with accelerated energy conservation,emission reduction technologies,and energy transition.These findings provide a scientific basis for decomposing carbon neutrality targets across cities and counties in Shandong and a reference for developing localized land use policies in similar regions.展开更多
Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the reg...Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the region and greatly expanded forested areas.Utilizing nearly 30 years of satellite time-series data,we reveal that the region’s enhanced carbon sequestration(3×10^(12) g·C annually)is primarily driven by crucial changes in forest structure and age,occurring alongside a nearly 120%increase in forested land area.We observe that dense forests maintain a rapid growth rate of approximately 2.5%annually for carbon sequestration in the initial years after establishment.However,this growth rate decelerates with increasing apparent forest age.Meanwhile,the densification(modeled as an increasing forest probability)rate of forests reaches its peak growth during the 10-20 year period,sustaining a high annual growth rate of about 1.8%.We also find that improvements in forest structure,particularly the increasing of forest canopy density and apparent forest age coupled with a notable reduction in forest fragmentation,are also the main driving factors for the enhanced carbon sequestration capacity.Based on these findings,we conclude that forest restoration policies in Southwest China have been successful not only in facilitating large-scale forest growth in Southwest China but,more critically,in promoting the structural maturation(e.g.,densification and reduced fragmentation)that is essential for enhancing the region’s carbon sink capacity and its resilience.展开更多
Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.C...Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.展开更多
Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising...Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising solution for addressing these issues.In this study,we investigated the effects of four biochar application rates(no biochar(N)=0 t ha^(-1),low(L)=3 t ha^(-1),medium(M)=6 t ha^(-1),and high(H)=9 t ha^(-1))under film mulching and no mulching conditions over three growing seasons.We assessed the impacts on GHG emissions,soil organic carbon sequestration(SOCS),and maize yield to evaluate the productivity and sustainability of farmland ecosystems.Our results demonstrated that mulching increased maize yield(18.68-41.80%),total fixed C in straw(23.64%),grain(28.87%),and root(46.31%)biomass,and GHG emissions(CO_(2),10.78%;N_(2)O,3.41%),while reducing SOCS(6.57%)and GHG intensity(GHGI;13.61%).Under mulching,biochar application significantly increased maize yield(10.20%),total fixed C in straw(17.97%),grain(17.69%)and root(16.75%)biomass,and SOCS(4.78%).Moreover,it reduced the GHG emissions(CO_(2),3.09%;N_(2)O,6.36%)and GHGI(12.28%).These effects correlated with the biochar addition rate,with the optimal rate being 9.0 t ha^(-1).In conclusion,biochar application reduces CO_(2) and N_(2)O emissions,enhances CH_(4) absorption,and improves maize yield under film mulching.It also improves the soil carbon fixation capacity while mitigating the warming potential,making it a promising sustainable management method for mulched farmland in semiarid areas.展开更多
Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbo...Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbon and pollutant emissions.CO_(2)capture and mineralization represent promising solutions to these issues.This study proposes a sustainable alternative:a novel CO_(2)-carbonated MgO-mixing column that integrates CO_(2)mineralization with soil reinforcement.This approach involves in situ mixing of MgO with deep soil to form columns,which are then carbonated and solidified by injecting captured CO_(2)through gas-permeable pipe piles,achieving both carbon reduction and soil improvement.In this study,CO_(2)-carbonated MgO-mixing columns were comprehensively evaluated to investigate variations in strength,deformation,pH,and CO_(2)sequestration with depth.Two rapid and cost-effective methods to assess its mechanical properties,uniformity,and CO_(2)sequestration capacity are proposed.The results show that the carbonated MgO-treated soil has good strength along the depth direction,with an average unconfined compressive strength(UCS)of 1.02 MPa and a lower pH than that of cement-mixing columns.It also achieves notable CO_(2)sequestration,ranging from 4.88%to 13.10%(average 8.31%),and exhibits good uniformity,as shown by electrical resistivity tests.Needle penetration and electrical resistivity tests could be used to effectively predict the UCS,deformation modulus,and CO_(2)sequestration.XRD,FTIR,SEM,and TG-DTG analyses reveal distinct microstructural differences at various depths,with unhydrated MgO,magnesite,and dypingite/hydromagnesite present in shallow columns,and brucite,nesquehonite,and dypingite/hydromagnesite present in deep columns.These products bind soil particles and fill pores,enhancing the strength of the MgO-mixing column.展开更多
Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that ...Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that significantly impacts permeability,mechanical strength,injection efficiency,and sequestration safety.For this,we tried to explore the key factors driving the swelling of shale upon CO_(2)injection and its subsequent impact on reservoir properties.Utilizing a self-developed high-temperature-pressure gas adsorption apparatus,we measured strain in Jurassic shale at 308 K under constant hydrostatic pressure with helium(He)at 1300 psi(1 psi=6.895 kPa)and CO_(2)at 850 psi.Next,we investigated the influence of CO_(2)concentration on swelling protentional while maintaining constant pressure,uncovering the anisotropic deformation in relation to pressure.It shows that CO_(2)adsorption induces significant swelling in shale,following a Langmuir-type pressure relationship.Deformation is more pronounced perpendicular than that parallel to the bedding plane.At low pressure,vertical swelling is 2.28 times greater than the horizontal;while at high pressure,the vertical compression is 31.26 times greater than the horizontal.It seems that the anisotropic swelling enhances permeability predictions during CO_(2)injection.Mixed gases under constant compression can prompt gas desorption,stress redistribution,and alterations in pore structure,amplifying He compression effect.The strain induced after replacing CO_(2)with He exceeds that from pure He injection.The asynchronous response of CO_(2)-induced swelling and mechanical compression can precipitate crack propagation and fracturing.Overall,anisotropic swelling from CO_(2)adsorption changes pore structure and permeability,affecting fluid flow and storage.Considering CO_(2)concentration and anisotropic characteristics in reservoir modeling is essential for optimizing injection strategies and enhancing reservoir efficiency.展开更多
Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical char...Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO_(2)injection.The main results show that 4 d of ScCO_(2)treatment caused 50.47%–80.99%increase in load–displacement deformation and 26.92%–76.17%increase in creep depth at peak load,accompanied by 55.01%–63.38%loss in elastic modulus and 52.83%–74.81%reduction in hardness.The degradation exhibited biphasic kinetics,characterized by rapid surface-driven weakening(0–2 d),followed by stabilized matrix-scale pore homogenization(2–4 d).ScCO_(2)preferentially dissolved carbonate minerals(dolomite),driving pore network expansion and interfacial debonding,while silicate minerals resisted dissolution but promoted structural homogenization.These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes.The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO_(2)enhanced coalbed methane recovery.展开更多
Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,...Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,unreasonable CO_(2)-EOR strategies,encompassing well placement and well control parameters,will lead to premature gas channeling in production wells,resulting in large amounts of CO_(2) escape without any beneficial effect.Due to the lack of prediction and optimization tools that integrate complex geological and engineering information for the widely used CO_(2)-EOR technology in promising industries,it is imperative to conduct thorough process simulations and optimization evaluations of CO_(2)-EOR technology.In this paper,a novel optimization workflow that couples the AST-GraphTrans-based proxy model(Attention-based Spatio-temporal Graph Transformer)and multi-objective optimization algorithm MOPSO(Multi-objective Particle Swarm Optimization)is established to optimize CO_(2)-EOR strategies.The workflow consists of two outstanding components.The AST-GraphTrans-based proxy model is utilized to forecast the dynamics of CO_(2) flooding and sequestration,which includes cumulative oil production,CO_(2) sequestration volume,and CO_(2) plume front.And the MOPSO algorithm is employed for achieving maximum oil production and maximum sequestration volume by coordinating well placement and well control parameters with the containment of gas channeling.By the collaborative coordination of the two aforementioned components,the AST-GraphTrans proxy-assisted optimization workflow overcomes the limitations of rapid optimization in CO_(2)-EOR technology,which cannot consider high-dimensional spatio-temporal information.The effectiveness of the proposed workflow is validated on a 2D synthetic model and a 3D field-scale reservoir model.The proposed workflow yields optimizations that lead to a significant increase in cumulative oil production by 87%and 49%,and CO_(2) sequestration volume enhancement by 78%and 50%across various reservoirs.These findings underscore the superior stability and generalization capabilities of the AST-GraphTrans proxy-assisted framework.The contribution of this study is to provide a more efficient prediction and optimization tool that maximizes CO_(2) sequestration and oil recovery while mitigating CO_(2) gas channeling,thereby ensuring cleaner oil production.展开更多
CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as...CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.展开更多
The iron and steel industries generate large amounts of unavoidable CO_(2)emissions as well as considerable quantities of slags.More than one-half of the emitted CO_(2)is produced in blast furnaces during ironmaking,a...The iron and steel industries generate large amounts of unavoidable CO_(2)emissions as well as considerable quantities of slags.More than one-half of the emitted CO_(2)is produced in blast furnaces during ironmaking,and thus it is meaningful to use blast furnace slags to capture CO_(2)while addressing the byproducts and flue gas of ironmaking.Mineral carbonation of slags is a promising route to achieve carbon neutrality and effective slag utilization.To exploit slag more effectively and capture CO_(2)in flue gas,an in-depth investigation into the carbonation of blast furnace slags generated with different cooling methods was conducted.The effects of the solid–liquid ratio and introduced CO_(2)concentration on carbonation were determined.The CO_(2)uptake capacity of air-cooled slag(0.04 g/g)was greater than that of water-quenched slag.The CO_(2)uptake capacities of the two slags were comparable with those of slags in previous works,indicating the potential of the two slags for CO_(2)sequestration and utilization even with low-energy input and this fact suggests that this process is feasible.展开更多
Enhanced CO_(2)sequestration(ECS)within low-permeable reservoirs during CO_(2)-enhanced oil recovery(CO_(2)-EOR)processes has gained significant interest,primarily driven by the need to mitigate the greenhouse effect ...Enhanced CO_(2)sequestration(ECS)within low-permeable reservoirs during CO_(2)-enhanced oil recovery(CO_(2)-EOR)processes has gained significant interest,primarily driven by the need to mitigate the greenhouse effect caused by excessive CO_(2)emissions.In this work,the in-situ nuclear magnetic resonance(NMR)is applied to investigate the oil production and CO_(2)sequestration within the micropores of low-permeable reservoirs.Additionally,the impact of CO_(2)-water-oil-rock reactions on CO_(2)-EOR and CO_(2)sequestration is studied by analysis of the changes in minerals,pore structures,and wettability of cores by scanning electron microscopy(SEM),X-ray diffraction(XRD),and contact angle measurements with the experiments of CO_(2)-water-oil-rock interaction in the high-temperature and high-pressure(HT-HP)reactor.The results reveal that the residual water saturation(Swr),CO_(2)injection pressure,and the interaction among CO_(2),water,oil,and rock all exerted a considerable impact on oil recovery and CO_(2)sequestratio n.Compared with the oil recovery and CO_(2)sequestration of the two oil-satu rated cores(Core No.2 and Core No.3)after CO_(2)injection,the accumulated oil recoveries of the two cores with S_(wr)=0.5are enhanced by 1.8%and 4.2%,and the CO_(2)sequestration ratios are increased by 3%and 10%,respectively.Compared with the CO_(2)-water-rock that occurred in oil-saturated cores,the CO_(2)-water-rock reaction for cores(S_(wr)=0.5)is more intense,which leads to the formation of more hydrophilic rock on pore surfaces after the reaction,thereby reducing the adhesion work of CO_(2)stripping oil.The oil and water mixtures in pores also inhibit CO_(2)premature breakthrough from cores,therefore expanding the swept volume of CO_(2)in cores.Otherwise,oil recovery and CO_(2)sequestration in small pores of cores are significantly improved with the rise in CO_(2)injection pressure due to the enhanced driving pressure degree and also the improved mutual solubility and mass transfer between CO_(2)and oil.展开更多
Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and indust...Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and industrial processes—are accelerating these changes,which have various detrimental effects on the environment.This review aims to highlight the edapho-climatic requirements of this cactus and the advantages and challenges of its cultivation to mitigate climate change.The prickly pear cactus is a plant with numerous financial and environmental advantages.It needs well-draining,sandy or gravelly soil to avoid root rot and do best in full sun.With a strong tolerance for dryness,they thrive in arid or semi-arid regions with scorching summers and prefer sparing watering.Despite being suited to tropical climates,some species can tolerate freezing temperatures and sporadic frost.Once established,these hardy plants require little care and thrive in nutrient-poor soils,which makes them perfect for xeriscaping or challenging growing environments.Because of its high water use efficiency ratio and low water requirements,prickly pear can be grown in marginally dry and semi-arid areas.The cactus does contribute to the ecological and socioeconomic fight against climate change.For instance,it supports sustainable agriculture,biodiversity preservation,soil restoration,carbon sequestration,and effective water usage.Demarcating dry and semi-arid zones and fostering employment in these areas is beneficial from a socioeconomic standpoint.The prickly pear’s traditional cultural heritage supports its current economic function as a crop that can withstand drought.While ecological threats necessitate balanced management,this adaptability promotes sustainable growth.Innovations in bioenergy and value-added goods build on its historical applications,increasing its socioeconomic advantages and,eventually,its worldwide significance.展开更多
Optimizing the spatial pattern of carbon sequestration service is essential for advancing regional low-carbon development,accelerating the achievement of the"dual carbon"goals,and promoting the high-quality ...Optimizing the spatial pattern of carbon sequestration service is essential for advancing regional low-carbon development,accelerating the achievement of the"dual carbon"goals,and promoting the high-quality development of ecological environment.The carbon sequestration capacity within the mountain-desert-oasis system(MDOS),a unique landscape pattern,exhibits significant gradient characteristics,and its carbon sink potential can be substantially improved through multi-scale spatial optimization.This study employed the Integrated Valuation of Ecosystem Services and Tradeoff(InVEST)model to estimate carbon storage and sequestration(CSS)in the Gansu section of Heihe River Basin,China,a representative MDOS,based on land use/land cover(LULC)data from 1990 to 2020.The Patch-level Land Use Simulation(PLUS)model was coupled to simulate LULC and estimate carrying CSS under natural development(ND),ecological protection(EP),water constraint(WC),and economic development(ED)scenarios for 2035.Furthermore,the study constructed and optimized the CSS pattern on the basis of economic and ecological benefits,exploring the guiding significance of different scenarios for pattern optimization.The results showed that CSS spatial distribution is closely correlated with LULC pattern,and CSS is expected to improve in the future.CSS showed an overall increase across subsystems during 1990–2020,but varied across LULC types.CSS of construction land in all subsystems exhibited an increasing trend,while CSS of unused land showed a decreasing trend,with specific changes of 1.68×103 and 3.43×105 t,respectively.Regional CSS dynamics were mainly driven by conversions among unused land,cultivated land,and grassland.The CSS pattern of MDOS was divided into carbon sink functional region(CSFR),low carbon conservation region(LCCR),low carbon economic region(LCER),and economic development region(EDR).Water resources coordination served as the basis of pattern optimization,while the four dimensions—ecological carbon sink,low-carbon maintenance,agricultural carbon reduction and sink enhancement,and urban carbon emission reduction—framed the optimization framework.ND,EP,WC,and ED scenarios provided guidance as the basic reference,optimal benefit,"dual carbon"baseline,and upper development limit,respectively.Additionally,the detailed CSS sub-partitions of MDOS covered most potential scenarios of such ecosystems,demonstrating the applicability of these sub-partitions.These findings provide valuable references for enhancing CSS and hold important significance for low-carbon territorial spatial planning in the MDOS.展开更多
基金Fundamental Research Funds for the Central Universities,Grant/Award Number:2024KYJD1012。
文摘The potential for CO_(2)sequestration in the goaf of abandoned coal mines is significant due to the extensive fracture spaces and substantial residual coal present.Firstly,the adsorption characteristics of residual coal in goaf on CO_(2)were studied by the isothermal adsorption test of CO_(2).Then,to accurately calculate the amount of adsorbed CO_(2)within the residual coal in the goaf,the bidisperse diffusion numerical model considering only Fick diffusion was modified in combination with the diffusion mechanisms.The simulation results showed that the modified model can well describe the diffusion behavior of CO_(2)in the residual coal matrix.Finally,the numerical simulation of CO_(2)sequestration in the goaf of abandoned coal mines was carried out,and the influence of different injection well deployment positions and various thicknesses of residual coal on the migration law and storage effect of CO_(2)in goaf was analyzed.The results showed that CO_(2)preferentially flowed into the caving zone with higher permeability.The distribution of CO_(2)streamlines in the goaf was the most dense in the caving zone and the streamlines in the fracture zone were gradually sparse from bottom to top.When the injection well was deployed at the interface of the two zones,the CO_(2)had the best seepage path.The total storage capacity within90 days was 7.702754×10^(6)kg,of which the free state storage capacity in the fracture of the goaf and the adsorbed state storage capacity in the residual coal were 6.611451×10^(6)and 1.091303×10^(6)kg,respectively.When the injection well was deployed in the middle of the residual coal seam in the goaf and the middle of the fracture zone,the total storage capacity at the same time was 7.613508×10^(6)and 6.021495×10^(6)kg,respectively.The coal with different thicknesses remaining at the bottom of the goaf significantly affected the adsorbed state storage,but had little effect on the free state storage.When the thickness of the residual coal seam was 0.20,0.35,and 0.50 m,the adsorbed state storage capacity within 130 days was 4.37623×10^(5),7.65791×10^(5),and 1.093406×10^(6)kg,respectively.
基金supported by the National Key R&D Program of China(No.2023YFC3904304)the National Natural Science Foundation of China(No.52304158)Jiangsu Key Laboratory for Clean Utilization of Carbon Resources Research Project(No.BM2024007)。
文摘Underground carbon sequestration(CS)by solid waste backfill(SWB)offers an effective pathway for collaborative disposal of coal-based solid waste and CO_(2),where the amount of carbon sequestration is an important evaluation parameter.In this study,the concept of whole-process carbon sequestration using coal-based solid waste and CO_(2),including sequential stirring and curing stages,was proposed to evaluate the performance evolution of CS.The results showed that CO_(2) pressure and ambient temperature positively correlated with the CS amount from coal-based SWB.In particular,CO_(2) pressure prevailed in the stirring stage,while the ambient temperature effect was more significant in the curing stage.The CS amounts obtained during the stirring stage alone,the curing stage alone,and two sequential stages ranged from 0.66%–3.10%,3.53%–5.09%,and 5.12%–6.02%,respectively.The functional group and micromorphology analyses revealed that the prevailing mechanism at the CS stirring stage was the stirringdriven gas dissolution-leaching-mineralization reaction,while that at the curing stage was the hydration-driven gas permeation-dissociation-CS reaction.Both were essentially solid-liquid-gas multiphase chemical reactions.The results are instrumental in substantiating the coal-based SWB carbon sequestration evolution patterns and mechanisms and providing data support for waste disposal and carbon emission reduction in the coal industry.
基金supported initially by the LIFE FoResMit Project(LIFE14 CCM/IT/000905)。
文摘Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change,leading to a loss of ecosystem services and biodiversity.This study investigates the impact of different thinning practices on carbon sequestration and tree stability in a degraded periurban plantation in the Italian Apennines,six years after thinning.Three treatments were compared:(a)moderate thinning from below(-25%biomass),representing the typical practice;(b)intense selective thinning(-35%biomass),representing an innovative approach;and(c)no management as the control.Growth projections were used to estimate carbon recovery for these treatments,based on site-specific models calibrated with real data.The results show that both thinning approaches increased carbon sequestration over time,with the innovative thinning achieving a 7%higher annual carbon sequestration rate than traditional thinning and 8%more than the control.Estimated payback times were9 years for recovering the harvested volume in both thinning approaches,10 years for innovative thinning to surpass traditional thinning,17 years for innovative thinning to surpass the control,and 24 years for traditional thinning to surpass the control.Additionally,tree mechanical stability improved significantly in both thinning treatments after two years,with further increases observed in the innovative thinning group after six years.These results suggest that selective thinning can accelerate forest recovery and carbon sequestration,especially in areas with high stem density,where it can reduce the negative impacts of tree mortality and deadwood accumulation.However,careful planning is required to mitigate potential short-term stability is sues,particularly in challenging environments(e.g.,windy conditions,steep slopes).Forest management strategies should therefore aim to balance growth,carbon storage,and tree stability,considering both long-term sustainability and local environmental conditions.The findings are particularly relevant for current climate change mitigation strategies,emphasizing that thinning should be carefully tailored to forest type and conditions to maximize benefits in carbon credit generation and sustainable forest management practices.
基金supported by the National Natural Science Foundation of China(grant no.32371866)。
文摘Drought influences carbon fixation by plants.Therefore,elucidating its impact on carbon fluxes in plants at the ecosystem level is crucial for assessing their role in mitigating climate change.Using carbon fluxes and environmental factor data from FLUXNET sites,we analyzed the influence of drought on carbon fluxes,their drivers,time-lag effects,and recovery times across various climatic regions and seasons.Results showed drought significantly decreased gross primary production(GPP),ecosystem respiration,and net ecosystem productivity in arid regions but slightly increased carbon sequestration in humid regions.Summer droughts negatively affected vegetation carbon fluxes,partly offset by the positive impact of spring droughts.Nonforest carbon fluxes were more susceptible to drought effects than forest fluxes.Soil water content(SWC)was the main influence on changes in arid regions,whereas vapor pressure deficit(VPD)dominated humid regions.Decreased SWC and increased VPD reduced carbon sequestration in arid regions but increased it in humid regions.Increased VPD reduced GPP,leading to forest carbon loss,whereas decreased SWC reduced GPP,leading to nonforest carbon loss.The lag time of the drought effects on carbon fluxes was longer in humid regions(19.44 d)than in arid regions(14.71 d).Compared to nonforest areas(16.74 d and 57 d for drought lag and recovery time,respectively),forest areas had a longer lag(18.81 d)and recovery time(92 d).The findings revealed discrepancies in the main factors regulating vegetation carbon fluxes during droughts between arid and humid regions and between forest and nonforest ecosystems.These insights provide a new perspective on understanding and simulating carbon-climate feedback.Enhancing ecosystem diversity is a feasible measure to increase drought resistance.
基金financially supported by the China Scholarship Council(CSC)。
文摘Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and introducing CO_(2)nanobubble technology to improve the performance of cement-fly ash-based backfill materials(CFB).The properties including fluidity,setting time,uniaxial compressive strength,elastic modulus,porosity,microstructure and CO_(2)storage performance were systematically studied through methods such as fluidity evaluation,time test,uniaxial compression test,mercury intrusion porosimetry(MIP),scanning electron microscopy-energy dispersive spectroscopy analysis(SEM-EDS),and thermogravimetric-differential thermogravimetric analysis(TG-DTG).The experimental results show that the density and strength of the material are significantly improved under the synergistic effect of fractal dimension and CO_(2)nanobubbles.When the fractal dimension reaches 2.65,the mass ratio of coarse and fine aggregates reaches the optimal balance,and the structural density is greatly improved at the same time.At this time,the uniaxial compressive strength and elastic modulus reach their peak values,with increases of up to 13.46%and 27.47%,respectively.CO_(2)nanobubbles enhance the material properties by promoting hydration reaction and carbonization.At the microscopic level,CO_(2)nanobubble water promotes the formation of C-S-H(hydrated calcium silicate),C-A-S-H(hydrated calcium aluminium silicate)gel and CaCO_(3),which is the main way to enhance the performance.Thermogravimetric studies have shown that when the fractal dimension is 2.65,the dehydration of hydration products and the decarbonization process of CaCO_(3)are most obvious,and CO_(2)nanobubble water promotes the carbonization reaction,making it surpass the natural state.The CO_(2)sequestration quality of cement-fly ash-based materials treated with CO_(2)nanobubble water at different fractal dimensions increased by 12.4wt%to 99.8wt%.The results not only provide scientific insights for the design and implementation of low-carbon filling materials,but also provide a solid theoretical basis for strengthening green mining practices and promoting sustainable resource utilization.
基金supports from the National Natural Science Foundation of China(Grant Nos.52179095,52378323,and 42407216)are gratefully acknowledged.
文摘The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.
文摘On July 2^(nd),2025,32 scientists representing 15 countries gathered at Tartu,Estonia to make on-site endorsements for the Global ONCE(Ocean Negative Carbon Emissions)Program at the 12th INTECOL Wetlands Conference.This marks a significant milestone for ONCE in establishing a systematic framework for coastal wetland carbon sequestration research and global collaboration(Figs.1,2).Coastal wetlands are critical transition zones linking terrestrial and marine ecosystems,yet they face severe degradation from anthropogenic land-based activities and sea level rise that propagate impacts to the ocean.As a UN Ocean Decade Program,the Global ONCE Program champions interdisciplinary and cross-regional collaboration to enhance carbon sequestration in the ocean and coastal wetlands through science and innovation.Aligned with the Tartu Declaration on Wetlands that includes resolutions to promote the rights of global wetlands(especially peatlands)and advance the discipline of wetland science based on facts,this initiative addresses key knowledge gaps in land-ocean interactions.The goal is to harness the full potential of coastal wetlands and ocean systems for climate mitigation,thereby laying a scientific foundation for international policy formulation and implementation.
基金Under the auspices of the National Natural Science Foundation of China(No.42476247,42461015)the Open Research Fund of Key Laboratory of Coastal Science and Integrated Management,Ministry of Natural Resources(No.2024COSIM01)Guangxi Science and Technology Base and Talent Special Project(No.GuikeAD23026194)。
文摘Understanding the dynamics of vegetation carbon sequestration(VCS)is essential for regional carbon neutrality strategies.This study revealed the spatiotemporal patterns of VCS and its relationship with anthropogenic carbon emissions(ACEs)in Shandong Province,China during 2000-2020,and identified the sensitivity factors affecting VCS.The results show that:1)VCS increased consistently from 193.45 million t to 256.41 million t,with high values areas concentrated in the central,northeastern,and southeastern mountainous and hilly regions,while low values were found in water bodies and urban built-up areas.At the city level,Linyi,Yantai,Binzhou,and Jinan experienced the most significant rises-reaching up to 243000 t/yr.At the county level,Pingdu,Qixia,and Yiyuan also showed substantial growth,each exceeding 30400 t/yr.2)Digital Elevation Molde(DEM)was identified as the dominant natural factor influencing VCS distribution,while land use optimization measures,especially afforestation and farmland conversion in sloped terrain,were the primary human drivers of VCS increase.3)Urbanization and carbon neutrality were not mutually exclusive.While urban expansion locally reduced VCS,rural emigration enhanced carbon sinks in surrounding areas,partially offsetting urban losses.This compensatory mechanism supported VCS increases in nearly all cities and 90% of counties.Nevertheless,with ACEs continuing to rise and the offset ratio by VCS declining,achieving carbon neutrality requires regional strategies that integrate with accelerated energy conservation,emission reduction technologies,and energy transition.These findings provide a scientific basis for decomposing carbon neutrality targets across cities and counties in Shandong and a reference for developing localized land use policies in similar regions.
基金funded by the National Natural Science Foundation of China(Grant No.42377331)supported by the U.S.National Science Foundation Division of Environmental Biology award#2331162U.S.National Science Foundation Dynamics of Integrated Socio-Environmental Systems award#2408954.
文摘Large-scale afforestation and forest conservation policies have been widely implemented in Southwest China over past decades.These efforts have significantly protected the remaining long-established forests in the region and greatly expanded forested areas.Utilizing nearly 30 years of satellite time-series data,we reveal that the region’s enhanced carbon sequestration(3×10^(12) g·C annually)is primarily driven by crucial changes in forest structure and age,occurring alongside a nearly 120%increase in forested land area.We observe that dense forests maintain a rapid growth rate of approximately 2.5%annually for carbon sequestration in the initial years after establishment.However,this growth rate decelerates with increasing apparent forest age.Meanwhile,the densification(modeled as an increasing forest probability)rate of forests reaches its peak growth during the 10-20 year period,sustaining a high annual growth rate of about 1.8%.We also find that improvements in forest structure,particularly the increasing of forest canopy density and apparent forest age coupled with a notable reduction in forest fragmentation,are also the main driving factors for the enhanced carbon sequestration capacity.Based on these findings,we conclude that forest restoration policies in Southwest China have been successful not only in facilitating large-scale forest growth in Southwest China but,more critically,in promoting the structural maturation(e.g.,densification and reduced fragmentation)that is essential for enhancing the region’s carbon sink capacity and its resilience.
基金supported by the National Key R&D Program of China(No.2023YFC3709500).
文摘Global warming caused by the emission of CO_(2) in industrial flue gas has attractedmore and more attention.Therefore,to fix CO_(2) with high efficiency and environmentally friendly had become the hot research field.Compared with the traditional coal-fired power plant flue gas emission reduction technology,carbon fixation and emission reduction by microalgae is considered as a promising technology due to the advantages of simple process equipment,convenient operation and environmental protection.When the flue gas is treated by microalgae carbon fixation and emission reduction technology,microalgae cells can fix CO_(2) in the flue gas through photosynthesis,and simultaneously absorb NO_(x) and SO_(x) as nitrogen and sulfur sources required for growth.Meanwhile,they can also absorb mercury,selenium,arsenic,cadmium,lead and other heavy metal ions in the flue gas to obtain microalgae biomass.The obtained microalgae biomass can be further transformed into high valueadded products,which has broad development prospects.This paper reviews the mechanisms and pathways of CO_(2) sequestration,the mechanism and impacts of microalgal emission reduction of flue gas pollutants,and the applications of carbon sequestration in industrial flue gas by microalgae.Finally,this paper provides some guidelines and prospects for the research and application of green emission reduction technology for industrial flue gas.
基金supported by the National Key Research and Development Program of China(2021YFE0101300 and 2021YFD1901102)the project supported by the Natural Science Basic Research Plan in Shaanxi Province,China(2023-JC-YB-185)the Ningxia Key Research and Development Program,China(2023BCF01018)。
文摘Long-term mulching has improved crop yields and farmland productivity in semiarid areas,but it has also increased greenhouse gas(GHG)emissions and depleted soil fertility.Biochar application has emerged as a promising solution for addressing these issues.In this study,we investigated the effects of four biochar application rates(no biochar(N)=0 t ha^(-1),low(L)=3 t ha^(-1),medium(M)=6 t ha^(-1),and high(H)=9 t ha^(-1))under film mulching and no mulching conditions over three growing seasons.We assessed the impacts on GHG emissions,soil organic carbon sequestration(SOCS),and maize yield to evaluate the productivity and sustainability of farmland ecosystems.Our results demonstrated that mulching increased maize yield(18.68-41.80%),total fixed C in straw(23.64%),grain(28.87%),and root(46.31%)biomass,and GHG emissions(CO_(2),10.78%;N_(2)O,3.41%),while reducing SOCS(6.57%)and GHG intensity(GHGI;13.61%).Under mulching,biochar application significantly increased maize yield(10.20%),total fixed C in straw(17.97%),grain(17.69%)and root(16.75%)biomass,and SOCS(4.78%).Moreover,it reduced the GHG emissions(CO_(2),3.09%;N_(2)O,6.36%)and GHGI(12.28%).These effects correlated with the biochar addition rate,with the optimal rate being 9.0 t ha^(-1).In conclusion,biochar application reduces CO_(2) and N_(2)O emissions,enhances CH_(4) absorption,and improves maize yield under film mulching.It also improves the soil carbon fixation capacity while mitigating the warming potential,making it a promising sustainable management method for mulched farmland in semiarid areas.
基金funded by the National Natural Science Foundation of China(Grant No.42277146)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_0273)the Transportation Science and Technology Project of Jiangsu Province of China(Grant No.HTSQ(B)2021-249).
文摘Cement treatment,such as cement-mixing columns,is commonly used for deep soft soil improvement to increase the bearing capacity and reduce settlement.However,cement production entails high energy consumption and carbon and pollutant emissions.CO_(2)capture and mineralization represent promising solutions to these issues.This study proposes a sustainable alternative:a novel CO_(2)-carbonated MgO-mixing column that integrates CO_(2)mineralization with soil reinforcement.This approach involves in situ mixing of MgO with deep soil to form columns,which are then carbonated and solidified by injecting captured CO_(2)through gas-permeable pipe piles,achieving both carbon reduction and soil improvement.In this study,CO_(2)-carbonated MgO-mixing columns were comprehensively evaluated to investigate variations in strength,deformation,pH,and CO_(2)sequestration with depth.Two rapid and cost-effective methods to assess its mechanical properties,uniformity,and CO_(2)sequestration capacity are proposed.The results show that the carbonated MgO-treated soil has good strength along the depth direction,with an average unconfined compressive strength(UCS)of 1.02 MPa and a lower pH than that of cement-mixing columns.It also achieves notable CO_(2)sequestration,ranging from 4.88%to 13.10%(average 8.31%),and exhibits good uniformity,as shown by electrical resistivity tests.Needle penetration and electrical resistivity tests could be used to effectively predict the UCS,deformation modulus,and CO_(2)sequestration.XRD,FTIR,SEM,and TG-DTG analyses reveal distinct microstructural differences at various depths,with unhydrated MgO,magnesite,and dypingite/hydromagnesite present in shallow columns,and brucite,nesquehonite,and dypingite/hydromagnesite present in deep columns.These products bind soil particles and fill pores,enhancing the strength of the MgO-mixing column.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(Grant No.52121003)the National Natural Science Foundation of China(Grant No.52104046).
文摘Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that significantly impacts permeability,mechanical strength,injection efficiency,and sequestration safety.For this,we tried to explore the key factors driving the swelling of shale upon CO_(2)injection and its subsequent impact on reservoir properties.Utilizing a self-developed high-temperature-pressure gas adsorption apparatus,we measured strain in Jurassic shale at 308 K under constant hydrostatic pressure with helium(He)at 1300 psi(1 psi=6.895 kPa)and CO_(2)at 850 psi.Next,we investigated the influence of CO_(2)concentration on swelling protentional while maintaining constant pressure,uncovering the anisotropic deformation in relation to pressure.It shows that CO_(2)adsorption induces significant swelling in shale,following a Langmuir-type pressure relationship.Deformation is more pronounced perpendicular than that parallel to the bedding plane.At low pressure,vertical swelling is 2.28 times greater than the horizontal;while at high pressure,the vertical compression is 31.26 times greater than the horizontal.It seems that the anisotropic swelling enhances permeability predictions during CO_(2)injection.Mixed gases under constant compression can prompt gas desorption,stress redistribution,and alterations in pore structure,amplifying He compression effect.The strain induced after replacing CO_(2)with He exceeds that from pure He injection.The asynchronous response of CO_(2)-induced swelling and mechanical compression can precipitate crack propagation and fracturing.Overall,anisotropic swelling from CO_(2)adsorption changes pore structure and permeability,affecting fluid flow and storage.Considering CO_(2)concentration and anisotropic characteristics in reservoir modeling is essential for optimizing injection strategies and enhancing reservoir efficiency.
基金supported by the National Natural Science Foundation of China(Nos.52204206 and U24A2090)the Fundamental Research Funds for the Central Universities of China(No.2023CDJXY-006).
文摘Geological sequestration of CO_(2)is critical for deep decarbonization,but the geomechanical stability of coal reservoirs remains a major challenge.This study integrates nanoindentation,XRD/SEM-EDS chemo physical characterization and 4D CT visualization to investigate the time-evolving mechanical degradation of bituminous coals with ScCO_(2)injection.The main results show that 4 d of ScCO_(2)treatment caused 50.47%–80.99%increase in load–displacement deformation and 26.92%–76.17%increase in creep depth at peak load,accompanied by 55.01%–63.38%loss in elastic modulus and 52.83%–74.81%reduction in hardness.The degradation exhibited biphasic kinetics,characterized by rapid surface-driven weakening(0–2 d),followed by stabilized matrix-scale pore homogenization(2–4 d).ScCO_(2)preferentially dissolved carbonate minerals(dolomite),driving pore network expansion and interfacial debonding,while silicate minerals resisted dissolution but promoted structural homogenization.These coupled geochemical-mechanical processes reduced the mechanical heterogeneity of the coal and altered its failure modes.The results establish a predictive framework for reservoir stability assessment and provide actionable insights for optimizing CO_(2)enhanced coalbed methane recovery.
基金supported by the National Natural Science Foundation of China(Nos.52374064,52274056)China Scholarship Council(No.202406450086).
文摘Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,unreasonable CO_(2)-EOR strategies,encompassing well placement and well control parameters,will lead to premature gas channeling in production wells,resulting in large amounts of CO_(2) escape without any beneficial effect.Due to the lack of prediction and optimization tools that integrate complex geological and engineering information for the widely used CO_(2)-EOR technology in promising industries,it is imperative to conduct thorough process simulations and optimization evaluations of CO_(2)-EOR technology.In this paper,a novel optimization workflow that couples the AST-GraphTrans-based proxy model(Attention-based Spatio-temporal Graph Transformer)and multi-objective optimization algorithm MOPSO(Multi-objective Particle Swarm Optimization)is established to optimize CO_(2)-EOR strategies.The workflow consists of two outstanding components.The AST-GraphTrans-based proxy model is utilized to forecast the dynamics of CO_(2) flooding and sequestration,which includes cumulative oil production,CO_(2) sequestration volume,and CO_(2) plume front.And the MOPSO algorithm is employed for achieving maximum oil production and maximum sequestration volume by coordinating well placement and well control parameters with the containment of gas channeling.By the collaborative coordination of the two aforementioned components,the AST-GraphTrans proxy-assisted optimization workflow overcomes the limitations of rapid optimization in CO_(2)-EOR technology,which cannot consider high-dimensional spatio-temporal information.The effectiveness of the proposed workflow is validated on a 2D synthetic model and a 3D field-scale reservoir model.The proposed workflow yields optimizations that lead to a significant increase in cumulative oil production by 87%and 49%,and CO_(2) sequestration volume enhancement by 78%and 50%across various reservoirs.These findings underscore the superior stability and generalization capabilities of the AST-GraphTrans proxy-assisted framework.The contribution of this study is to provide a more efficient prediction and optimization tool that maximizes CO_(2) sequestration and oil recovery while mitigating CO_(2) gas channeling,thereby ensuring cleaner oil production.
基金supported by China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202202)Major Industry Innovation Plan of Anhui Province(AHZDCYCX-LSDT2023-01).
文摘CO_(2)sequestration through steel slag is one of the effective approaches to simultaneously realize the resource utilization of industrial solid waste,reduce carbon emissions,and enhance the stability of steel slag as a construction base,with considerable application prospects.Nevertheless,the components responsible for CO_(2)sequestration in steel slag predominantly exist as silicates,whose chemical inertness leads to suboptimal CO_(2)sequestration efficiency in the slag.Based on the strategy of activating the silicate components in steel slag with the alkali metal potassium(K)to improve the CO_(2)sequestration performance of steel slag,both experiments and theoretical calculations were performed to give a deep insight into the effect and mechanism of K modification on enhancing the CO_(2)sequestration capability of steel slag.In experiments,CO_(2)sequestration capacity of steel slag modified with 3 wt.%K reached 100.15 g/kg at 1000 K.Theoretical analysis has revealed that although K exhibits low reactivity,it enhances the electronic transition and amplifies charge localization at specific sites within Ca_(2)SiO_(4),consequently improving its CO_(2)sequestration capacity.However,an excessive doping of K led to the partial inactivation of some active sites within Ca_(2)SiO_(4).Furthermore,CO_(2)chemisorption on Ca_(2)SiO_(4)surface predominantly occurs through the chelate configuration of CO_(3)^(2−),suggesting the formation of a CaCO_(3)precursor.Thus,both the experimental results and theoretical calculations reveal the role of K on enhancing CO_(2)sequestration capability of steel slag.In summary,K modification offers promising prospects for improving CO_(2)sequestration properties of steel slag and provides support for the industrial implementation of carbon sequestration by steel slag.
基金supported by the Science and Technology Research Partnership for Sustainable Development(SATREPS)。
文摘The iron and steel industries generate large amounts of unavoidable CO_(2)emissions as well as considerable quantities of slags.More than one-half of the emitted CO_(2)is produced in blast furnaces during ironmaking,and thus it is meaningful to use blast furnace slags to capture CO_(2)while addressing the byproducts and flue gas of ironmaking.Mineral carbonation of slags is a promising route to achieve carbon neutrality and effective slag utilization.To exploit slag more effectively and capture CO_(2)in flue gas,an in-depth investigation into the carbonation of blast furnace slags generated with different cooling methods was conducted.The effects of the solid–liquid ratio and introduced CO_(2)concentration on carbonation were determined.The CO_(2)uptake capacity of air-cooled slag(0.04 g/g)was greater than that of water-quenched slag.The CO_(2)uptake capacities of the two slags were comparable with those of slags in previous works,indicating the potential of the two slags for CO_(2)sequestration and utilization even with low-energy input and this fact suggests that this process is feasible.
基金supported by the National Key Research and Development Program of China,China(Grant No.:2022YFE0206700)the National Natural Science Foundation of China,China(Grant No.:52474035)。
文摘Enhanced CO_(2)sequestration(ECS)within low-permeable reservoirs during CO_(2)-enhanced oil recovery(CO_(2)-EOR)processes has gained significant interest,primarily driven by the need to mitigate the greenhouse effect caused by excessive CO_(2)emissions.In this work,the in-situ nuclear magnetic resonance(NMR)is applied to investigate the oil production and CO_(2)sequestration within the micropores of low-permeable reservoirs.Additionally,the impact of CO_(2)-water-oil-rock reactions on CO_(2)-EOR and CO_(2)sequestration is studied by analysis of the changes in minerals,pore structures,and wettability of cores by scanning electron microscopy(SEM),X-ray diffraction(XRD),and contact angle measurements with the experiments of CO_(2)-water-oil-rock interaction in the high-temperature and high-pressure(HT-HP)reactor.The results reveal that the residual water saturation(Swr),CO_(2)injection pressure,and the interaction among CO_(2),water,oil,and rock all exerted a considerable impact on oil recovery and CO_(2)sequestratio n.Compared with the oil recovery and CO_(2)sequestration of the two oil-satu rated cores(Core No.2 and Core No.3)after CO_(2)injection,the accumulated oil recoveries of the two cores with S_(wr)=0.5are enhanced by 1.8%and 4.2%,and the CO_(2)sequestration ratios are increased by 3%and 10%,respectively.Compared with the CO_(2)-water-rock that occurred in oil-saturated cores,the CO_(2)-water-rock reaction for cores(S_(wr)=0.5)is more intense,which leads to the formation of more hydrophilic rock on pore surfaces after the reaction,thereby reducing the adhesion work of CO_(2)stripping oil.The oil and water mixtures in pores also inhibit CO_(2)premature breakthrough from cores,therefore expanding the swept volume of CO_(2)in cores.Otherwise,oil recovery and CO_(2)sequestration in small pores of cores are significantly improved with the rise in CO_(2)injection pressure due to the enhanced driving pressure degree and also the improved mutual solubility and mass transfer between CO_(2)and oil.
文摘Significant variations in global temperatures and weather patterns over time are known as climate change.Although it occurs naturally,human activities—particularly the burning of fossil fuels,deforestation,and industrial processes—are accelerating these changes,which have various detrimental effects on the environment.This review aims to highlight the edapho-climatic requirements of this cactus and the advantages and challenges of its cultivation to mitigate climate change.The prickly pear cactus is a plant with numerous financial and environmental advantages.It needs well-draining,sandy or gravelly soil to avoid root rot and do best in full sun.With a strong tolerance for dryness,they thrive in arid or semi-arid regions with scorching summers and prefer sparing watering.Despite being suited to tropical climates,some species can tolerate freezing temperatures and sporadic frost.Once established,these hardy plants require little care and thrive in nutrient-poor soils,which makes them perfect for xeriscaping or challenging growing environments.Because of its high water use efficiency ratio and low water requirements,prickly pear can be grown in marginally dry and semi-arid areas.The cactus does contribute to the ecological and socioeconomic fight against climate change.For instance,it supports sustainable agriculture,biodiversity preservation,soil restoration,carbon sequestration,and effective water usage.Demarcating dry and semi-arid zones and fostering employment in these areas is beneficial from a socioeconomic standpoint.The prickly pear’s traditional cultural heritage supports its current economic function as a crop that can withstand drought.While ecological threats necessitate balanced management,this adaptability promotes sustainable growth.Innovations in bioenergy and value-added goods build on its historical applications,increasing its socioeconomic advantages and,eventually,its worldwide significance.
基金funded by the Gansu Provincial Department of Education's University Teacher Innovation Fund Project(2025A-001)the Gansu Provincial Philosophy and Social Science Planning Project(2024YB088).
文摘Optimizing the spatial pattern of carbon sequestration service is essential for advancing regional low-carbon development,accelerating the achievement of the"dual carbon"goals,and promoting the high-quality development of ecological environment.The carbon sequestration capacity within the mountain-desert-oasis system(MDOS),a unique landscape pattern,exhibits significant gradient characteristics,and its carbon sink potential can be substantially improved through multi-scale spatial optimization.This study employed the Integrated Valuation of Ecosystem Services and Tradeoff(InVEST)model to estimate carbon storage and sequestration(CSS)in the Gansu section of Heihe River Basin,China,a representative MDOS,based on land use/land cover(LULC)data from 1990 to 2020.The Patch-level Land Use Simulation(PLUS)model was coupled to simulate LULC and estimate carrying CSS under natural development(ND),ecological protection(EP),water constraint(WC),and economic development(ED)scenarios for 2035.Furthermore,the study constructed and optimized the CSS pattern on the basis of economic and ecological benefits,exploring the guiding significance of different scenarios for pattern optimization.The results showed that CSS spatial distribution is closely correlated with LULC pattern,and CSS is expected to improve in the future.CSS showed an overall increase across subsystems during 1990–2020,but varied across LULC types.CSS of construction land in all subsystems exhibited an increasing trend,while CSS of unused land showed a decreasing trend,with specific changes of 1.68×103 and 3.43×105 t,respectively.Regional CSS dynamics were mainly driven by conversions among unused land,cultivated land,and grassland.The CSS pattern of MDOS was divided into carbon sink functional region(CSFR),low carbon conservation region(LCCR),low carbon economic region(LCER),and economic development region(EDR).Water resources coordination served as the basis of pattern optimization,while the four dimensions—ecological carbon sink,low-carbon maintenance,agricultural carbon reduction and sink enhancement,and urban carbon emission reduction—framed the optimization framework.ND,EP,WC,and ED scenarios provided guidance as the basic reference,optimal benefit,"dual carbon"baseline,and upper development limit,respectively.Additionally,the detailed CSS sub-partitions of MDOS covered most potential scenarios of such ecosystems,demonstrating the applicability of these sub-partitions.These findings provide valuable references for enhancing CSS and hold important significance for low-carbon territorial spatial planning in the MDOS.
