Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here ...Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).展开更多
CO_(2)-responsive gels,which swell upon contact with CO_(2),are widely used for profile control to plug high-permeability gas flow channels in carbon capture,utilization,and storage(CCUS)applications in oil reser-voir...CO_(2)-responsive gels,which swell upon contact with CO_(2),are widely used for profile control to plug high-permeability gas flow channels in carbon capture,utilization,and storage(CCUS)applications in oil reser-voirs.However,the use of these gels in high-temperature CCUS applications is limited due to their rever-sible swelling behavior at elevated temperatures.In this study,a novel dispersed particle gel(DPG)suspension is developed for high-temperature profile control in CCUS applications.First,we synthesize a double-network hydrogel consisting of a crosslinked polyacrylamide(PAAm)network and a crosslinked sodium alginate(SA)network.The hydrogel is then sheared in water to form a pre-prepared DPG suspen-sion.To enhance its performance,the gel particles are modified by introducing potassium methylsilan-etriolate(PMS)upon CO_(2) exposure.Comparing the particle size distributions of the modified and pre-prepared DPG suspension reveals a significant swelling of gel particles,over twice their original size.Moreover,subjecting the new DPG suspension to a 100℃ environment for 24 h demonstrates that its gel particle sizes do not decrease,confirming irreversible swelling,which is a significant advantage over the traditional CO_(2)-responsive gels.Thermogravimetric analysis further indicates improved thermal sta-bility compared to the pre-prepared DPG particles.Core flooding experiments show that the new DPG suspension achieves a high plugging efficiency of 95.3%in plugging an ultra-high permeability sandpack,whereas the pre-prepared DPG suspension achieves only 82.8%.With its high swelling ratio,irreversible swelling at high temperatures,enhanced thermal stability,and superior plugging performance,the newly developed DPG suspension in this work presents a highly promising solution for profile control in high-temperature CCUS applications.展开更多
The discovery,advances,and industrial-scale up of a unique electrochemical decarbonization chemistry,which sequesters carbon dioxide to mitigate the existential threat of planetary climate change,are presented.C2CNT■...The discovery,advances,and industrial-scale up of a unique electrochemical decarbonization chemistry,which sequesters carbon dioxide to mitigate the existential threat of planetary climate change,are presented.C2CNT■(CO_(2) to Carbon NanoTechnology)is the transition metal nucleated electrolytic splitting of CO_(2) by its trans-formation into a wide range of Graphene NanoCarbon allotropes,C_(GNC),CO_(2)→C_(GNC)+O_(2),such as carbon nanotubes and carbon nano-onions.The original 2015 C2CNT 0.0005 m2 electrode process has been scaled to larger than meter-square area electrodes and used in a series of 100 tonne annual CO_(2) removal industrial Genesis Device modules.The pathway to a further scale-up to a series of 1000 tonne decarbonization placed in series and forming a megaton annual C2CNT decarbonization plant is illustrated.展开更多
A coupled PHREEQC-MATLAB simulation approach is proposed to investigate the dynamic changes in rock porosity,gas storage capacity,formation water salinity,and reservoir temperature driven by biogeochemical interaction...A coupled PHREEQC-MATLAB simulation approach is proposed to investigate the dynamic changes in rock porosity,gas storage capacity,formation water salinity,and reservoir temperature driven by biogeochemical interactions during cyclic underground bio-methanation(UBM)of CO_(2)and H_(2),and to quantitatively examine how the evolution of these parameters influences CH_(4)production efficiency.The results indicate that during the cyclic UBM of CO_(2)-H_(2),the formation water undergoes a dynamic acid-base alternation,leading to periodic mineral dissolution and precipitation with limited impact on rock porosity.Across different mineral systems,the maximum CH_(4)production rate remains consistently around 3.6×10^(−3)mol/(L·d)in each cycle.With an increasing number of cycles,under high initial salinity conditions,the metabolic water produced by methanogens can significantly reduce the formation water salinity,gradually enhancing the CH_(4)production rate to levels comparable with those under low initial salinity.Additionally,the increased volume of produced water reduces the gas storage capacity of the reservoir.This reduction becomes more pronounced at higher initial CO_(2)-H_(2)pressures,accompanied by a more significant increase in CH_(4)production rate increment.Furthermore,the heat generated by methanogen metabolism leads to an increase in reservoir temperature,with the extent of temperature rise significantly influenced by heat loss.If the heat loss is neglected,the reservoir temperature can increase by up to 17.1℃after five cycles(10 years).When the reservoir has a higher initial temperature,the elevated thermal conditions may reduce CH_(4)production efficiency.展开更多
Carbon capture,utilization,and storage(CCUS)represents a critical technological pathway for global car-bon emission reduction.CCUS-enhanced oil recovery(EOR)technology is the most feasible CCUS technol-ogy demonstrati...Carbon capture,utilization,and storage(CCUS)represents a critical technological pathway for global car-bon emission reduction.CCUS-enhanced oil recovery(EOR)technology is the most feasible CCUS technol-ogy demonstrating dual benefits of enhanced energy production and carbon reduction.This study comprehensively described the key influencing factors governing CO_(2)-EOR and geological storage and systematically analyzed reservoir properties,fluid characteristics,and operational parameters.The mech-anisms of these parameters on EOR versus CO_(2) storage performance were investigated throughout CCUS-EOR processes.This paper proposes a coupled two-stage CCUS-EOR process:CO_(2)-EOR storage stage and long-term CO_(2) storage stage after the CO_(2) injection phase is completed.In each stage,the main control factors impacting the CO_(2)-EOR and storage stages are screened and coupled with rigorous technical anal-ysis.The key factors here are reservoir properties,fluid characteristics,and operational parameter.A novel CCUS-EOR synergistic method was proposed to optimize the lifecycle performance of dual objective of EOR and storage.Furthermore,based on multi-objective optimization,considering the lifecycle,a multi-scale techno-economic evaluation method was proposed to fully assess the CCUS-EOR project per-formance.Finally,a set of recommendations for advancing CCUS-EOR technologies by deploying multi-factor/multi-field coupling methodologies,novel green intelligent injection materials,and artificial intel-ligence/machine learning technologies were visited.展开更多
With global carbon emissions continuing to rise,carbon dioxide(CO_(2))capture and resource utilization have become central challenges in achieving the“dual carbon”goals(carbon peak and carbon neutrality).Traditional...With global carbon emissions continuing to rise,carbon dioxide(CO_(2))capture and resource utilization have become central challenges in achieving the“dual carbon”goals(carbon peak and carbon neutrality).Traditional carbon capture and storage(CCS)technology can only temporarily sequester CO_(2),whereas emerging green catalytic technologies(photo/electro/thermal catalysis)enable the conversion of CO_(2) into high-value chemicals(e.g.,fuels,pharmaceutical intermediates),advancing the closure of the artificial carbon cycle[1,2].展开更多
Carbon dioxide(CO_(2))is the primary greenhouse gas contributing to anthropogenic climate change which is associated with human activities.The majority of CO_(2) emissions are results of the burning of fossil fuels fo...Carbon dioxide(CO_(2))is the primary greenhouse gas contributing to anthropogenic climate change which is associated with human activities.The majority of CO_(2) emissions are results of the burning of fossil fuels for energy,as well as industrial processes such as steel and cement production.Carbon capture,utilization,and storage(CCUS)is a sustainable technology promising in terms of reducing CO_(2) emissions that would otherwise contribute to climate change.From this perspective,the discussion on carbon capture focuses on chemical absorption technology,primarily due to its commercialization potential.The CO_(2) absorptive capacity and absorption rate of various chemical solvents have been summarized.The carbon utilization focuses on electrochemical conversion routes converting CO_(2) into potentially valuable chemicals which have received particular attention in recent years.The Faradaic conversion efficiencies for various CO_(2) reduction products are used to describe efficiency improvements.For carbon storage,successful deployment relies on a better understanding of fluid mechanics,geomechanics,and reactive transport,which are discussed in details.展开更多
A series of metal-organic frameworks MOF-808-X(6-connected)were synthesized by regulating the ZrOCl2·8H2O/1,3,5-benzenetricarboxylic acid(BTC)molar ratio(X)and tested for the direct synthesis of dimethyl carbonat...A series of metal-organic frameworks MOF-808-X(6-connected)were synthesized by regulating the ZrOCl2·8H2O/1,3,5-benzenetricarboxylic acid(BTC)molar ratio(X)and tested for the direct synthesis of dimethyl carbonate(DMC)from CO2 and CH3OH with 1,1,1-trimethoxymethane(TMM)as a dehydrating agent.The effect of the ZrOCl2·8H2O/BTC molar ratio on the physicochemical properties and catalytic performance of MOF-808-X was investigated.Results showed that a proper ZrOCl2·8H2O/BTC molar ratio during MOF-808-X synthesis was fairly important to reduce the redundant BTC or zirconium clusters trapped in the micropores of MOF-808-X.MOF-808-4,with almost no redundant BTC or zirconium clusters trapped in the micropores,exhibited the largest surface area,micropore size,and the number of acidic-basic sites,and consequently showed the best activity among all MOF-808-X,with the highest DMC yield of 21.5% under the optimal reaction conditions.Moreover,benefiting from the larger micropore size,MOF-808-4 outperformed our previously reported UiO-66-24(12-connected),which had even more acidic-basic sites and larger surface area than MOF-808-4,mainly because the larger micropore size of MOF-808-4 provided higher accessibility for the reactant to the active sites located in the micropores.Furthermore,a possible reaction mechanism over MOF-808-4 was proposed based on the in situ FT-IR results.The effects of different reaction parameters on DMC formation and the reusability of MOF-808-X were also studied.展开更多
The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel indu...The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.展开更多
The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon s...The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea. The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases, modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts.展开更多
The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plant...The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plants. The net photosynthetic COa assimilation （PN）, the photosynthetic assimilation of CO2 and bicarbonate （PN＇）, the proportion of increased leaf area （lEA） and the stable carbon isotope composition （δ13C） of Orychophragmus violaceus （Ov） and Brassica juncea （B j） under three bicarbonate levels （5, 10 and 15 mm NaHCO3） were examined to determine the relationship among PN, PN＇ and fLA. PN＇, not PN, changed synchronously with fLA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate （including exogenous bicarbonate and dissolved CO2-generated bicarbonate） utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31% at 15 mm bicarbonate, respectively. Meanwhile, the propor- tions of exogenous bicarbonate and total bicarbonate uti- lised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11% and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.展开更多
To investigate the microbial utilization of organic carbon in peatland ecosystem, water samples were collected from the Dajiuhu Peatland and nearby lakes, central China across the year of 2014. The acridine orange （A...To investigate the microbial utilization of organic carbon in peatland ecosystem, water samples were collected from the Dajiuhu Peatland and nearby lakes, central China across the year of 2014. The acridine orange （AO） staining and Biolog Eco microplates were used to numerate microbial counts and determine the carbon utilization of microbial communities. Meanwhile, physicochemical characteristics were measured for subsequent analysis of the correlation between microbial carbon utilization and environmental factors. Results indicated that total microbial counts were between 106107 cells/L. Microbial diversities and carbon utilization rates showed a similar pattern, highest in September and lowest in November. Microbial communities in the peat pore waters preferred to utilize N-bearing carbon sources such as amines and amino acids compared with microbial communities in lakes. The network analysis of microbial utilization of 31 carbon substrates clearly distinguished microbial communities from peat pore waters and those from lakes. Redundancy analysis （RDA） showed the total organic nitrogen content （P=-0.03, F=2.5） and daily average temperature （P=0.034, F=2.4） significantly controlled microbial carbon utilization throughout the sampling period. Our report is the first one to address the temporal and spatial variations of carbon uti- lization of microbial communities which are closely related to the decomposition of organic matter in the Dajiuhu Peatland in context of climate warming.展开更多
Carbon neutrality(or climate neutrality)has been a global consensus,and international experience exchange is essential.Given the differences in the degree of social development,resource endowment and technological lev...Carbon neutrality(or climate neutrality)has been a global consensus,and international experience exchange is essential.Given the differences in the degree of social development,resource endowment and technological level,each country should build a carbon-neutral plan based on its national conditions.Compared with other major developed countries(e.g.,Germany,the United States and Japan),China's carbon neutrality has much bigger challenges,including a heavy and time-pressured carbon reduction task and the current energy structure that is over-dependent on fossil fuels.Here we provide a comprehensive review of the status and prospects of the key technologies for low-carbon,near-zero carbon,and negative carbon emissions.Technological innovations associated with coal,oil-gas and hydrogen industries and their future potential in reducing carbon emissions are particularly explained and assessed.Based on integrated analysis of international experience from the world's major developed countries,in-depth knowledge of the current and future technologies,and China's energy and ecological resources potential,five lessons for the implementation of China's carbon neutrality are proposed:(1)transformation of energy production pattern from a coal-dominated pattern to a diversified renewable energy pattern;(2)renewable power-to-X and large-scale underground energy storage;(3)integration of green hydrogen production,storage,transport and utilization;(4)construction of clean energy systems based on smart sector coupling(ENSYSCO);(5)improvement of ecosystem carbon sinks both in nationwide forest land and potential desert in Northwest China.This paper provides an international perspective for a better understanding of the challenges and opportunities of carbon neutrality in China,and can serve as a theoretical foundation for medium-long term carbon neutral policy formulation.展开更多
A bidirectional labeling method was established to distinguish the proportions of HCO3- and CO2 utiliza- tion pathways of microalgae in Lake Hongfeng. The method was based on microalgae cultured in a medium by adding ...A bidirectional labeling method was established to distinguish the proportions of HCO3- and CO2 utiliza- tion pathways of microalgae in Lake Hongfeng. The method was based on microalgae cultured in a medium by adding equal concentrations of NaH13CO3 with different 613C values simultaneously. The inorganic carbon sources were quantified according to the stable carbon isotope composition in the treated microalgae. The effects of extracellular carbonic anhydrase （CAex） on the HCO3 and CO2 utilization pathways were distinguished using acetazolamide, a potent membrane-impermeable carbonic anhydrase inhibitor. The results show utilization of the added HCO3- was only 8% of the total carbon sources in karst lake. The proportion of the HCO3- utilization path- way was 52% of total inorganic carbon assimilation. Therefore, in the natural water of the karst area, the microalgae used less bicarbonate that preexisted in the aqueous medium than CO2 derived from the atmosphere. CAex increased the utilization of inorganic carbon from the atmosphere. The microalgae with CAex had greater carbon sequestration capacity in this karst area.展开更多
Photosynthesis is crucial to the reduction of carbon dioxide in the atmosphere.The key enzyme of photosynthesis,Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco),has two mutably competing substrates,CO2 and O2....Photosynthesis is crucial to the reduction of carbon dioxide in the atmosphere.The key enzyme of photosynthesis,Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco),has two mutably competing substrates,CO2 and O2.It has features of carboxylase and oxygenase.Rubisco performs the function of carboxylase to reduce inorganic carbon to form organic substances,which precondition is that more carbon dioxide accumulates around it.Carbon dioxide concentrating mechanisms(CCMs)are vital to cope with the limit of carbon dioxide.Various bicarbonate use pathway has a differential contribution to inorganic carbon assimilation.Bicarbonate transport,extracellular bicarbonate dehydration,or H+-ATPase-driven bicarbonate uptake,which induced CCMs,can support a considerable share of photosynthesis in photosynthetic organisms.However,CCMs in thylakoid membranes may be the most important.The CCMs occurred in the plasma membrane were secondary,evolutionary,and inducible,while CCMs coupled with photosynthetic oxygen evolution in thylakoid membranes,were primitive,major,and indispensable.A hypothetical schematic model of CCMs occurred in the plasma membrane and thylakoid membranes being proposed.展开更多
Geothermal energy is a kind of renewable,sustainable and clean energy resource.Geothermal energy is abundant in carbonate reservoirs.However,low matrix permeability limits its exploitation.The super-critical carbon di...Geothermal energy is a kind of renewable,sustainable and clean energy resource.Geothermal energy is abundant in carbonate reservoirs.However,low matrix permeability limits its exploitation.The super-critical carbon dioxide(SC-CO_(2))jet fracturing is expected to efficiently stimulate the carbonate geothermal reservoirs and achieve the storage of CO_(2) simultaneously.In this paper,we established a transient seepage and fluid-thermo-mechanical coupled model to analyze the impact performance of sc-CO_(2) jet fracturing.The mesh-based parallel code coupling interface was employed to couple the fluid and solid domains by exchanging the data through the mesh interface.The physical properties change of sC-CO_(2) with temperature were considered in the numerical model.Results showed that SC-CO_(2) jet frac-turing is superior to water-jet fracturing with respect to jetting velocity,particle trajectory and pene-trability.Besides,stress distribution on the carbonate rock showed that the tensile and shear failure would more easily occur by SC-CO_(2) jet than that by water jet.Moreover,pressure and temperature control the jet field and seepage field of sC-CO_(2) simultaneously.Increasing the jet temperature can effectively enhance the impingement effect and seepage process by decreasing the viscosity and density of SC-CO_(2).The key findings are expected to provide a theoretical basis and design reference for applying SC-CO_(2) jet fracturing in carbonate geothermal reservoirs.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.展开更多
The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a ca...The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a carbon-neutral process that has the potential to be carbon-negative.This study has shown that the conversion of cellulose tosuppressedcan be achieved through the reforming of gaseous intermediates in a fixed bed of 10%Ni/ZrO2.Reforming occurs at low temperatures≤773 K,which could allow for improved sustainability.展开更多
Early childhood caries （ECC） is a considerable pediatric and public health problem worldwide. Preceding studies have focused primarily on bacterial diversity at the taxonomic level. Although these studies have provi...Early childhood caries （ECC） is a considerable pediatric and public health problem worldwide. Preceding studies have focused primarily on bacterial diversity at the taxonomic level. Although these studies have provided significant information regarding the connection between dental caries and oral micmbiomes, further comprehension of this microbial community＇s ecological relevance is limited. This study identified the carbon source metabolic differences in dental plaque between children with and without ECC. We compared the microbial community functional diversity in 18 caries-free subjects with 18 severe ECC patients based on sole carbon source usage using a Biolog assay. The anaerobic microbial community in the ECC patients displayed greater metabolic activity than that of the control group. Specific carbon source metabolism differed significantly between the two groups. Subjects from the two groups were well distinguished by cluster and principal component analyses based on discriminative carbon sources. Our results implied that the microbial functional diversity between the ECC patients and healthy subjects differed significantly. In addition, the Biolog assay furthered our understanding of oral microbiomes as a composite of functional abilities, thus enabling us to identify the ecologically relevant functional differences among oral microbial communities.展开更多
It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a C...It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a CO_(2)concentration system,often based on amine binding or lime reaction,which is energy intensive and carries a high carbon footprint.Alternatively,C2CNT electrolytic molten carbonate decarbonization does not require CO_(2)pre-concentration and also provides a useful product(graphene nanocarbons)from the captured CO_(2).Here,a method of effective CO_(2)diffusion is demonstrated that simultaneously thermally insulates the decarbonization source gas from the high-temperature C2CNT system.Open pore,low-density,thermal insulations are implemented as membranes that facilitate effective CO_(2)diffusion for high-temperature decarbonization.Selected,high-temperature,strongly thermal insulating,silica composites are measured with porosities,,exceeding 0.9(>90%porosity),and which display,as measured by SEM,large open channels facilitating CO_(2)diffusion.A derived and experimentally verified estimate for the CO_(2)diffusion constant through these membranes is DM-porous=ε^(3/2)DCO_(2),where DCO_(2)is the diffusion constant in air.DM-porous is applicable to a wide-range of CO_(2)concentrations both in the air and N2.The CO_(2)diffusion constant is translated to the equivalent decarbonization system mole influx of CO_(2)and shown capable of sustaining high rates of CO_(2)removal.Combined with the strong electrolyte affinity for CO_(2)compared to N_(2),O_(2),or H_(2)O,the system comprises a framework for decarbonization without pre-concentration of CO_(2).展开更多
文摘Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).
基金Lin Du acknowledges the financial support provided by China Scholarship Council(CSC)via a Ph.D.Scholarship(202008510128)supported by Core Technology Project of China National Petroleum Corporation(CNPC)"Research on Thermal Miscible Flooding Technology"(2023ZG18)。
文摘CO_(2)-responsive gels,which swell upon contact with CO_(2),are widely used for profile control to plug high-permeability gas flow channels in carbon capture,utilization,and storage(CCUS)applications in oil reser-voirs.However,the use of these gels in high-temperature CCUS applications is limited due to their rever-sible swelling behavior at elevated temperatures.In this study,a novel dispersed particle gel(DPG)suspension is developed for high-temperature profile control in CCUS applications.First,we synthesize a double-network hydrogel consisting of a crosslinked polyacrylamide(PAAm)network and a crosslinked sodium alginate(SA)network.The hydrogel is then sheared in water to form a pre-prepared DPG suspen-sion.To enhance its performance,the gel particles are modified by introducing potassium methylsilan-etriolate(PMS)upon CO_(2) exposure.Comparing the particle size distributions of the modified and pre-prepared DPG suspension reveals a significant swelling of gel particles,over twice their original size.Moreover,subjecting the new DPG suspension to a 100℃ environment for 24 h demonstrates that its gel particle sizes do not decrease,confirming irreversible swelling,which is a significant advantage over the traditional CO_(2)-responsive gels.Thermogravimetric analysis further indicates improved thermal sta-bility compared to the pre-prepared DPG particles.Core flooding experiments show that the new DPG suspension achieves a high plugging efficiency of 95.3%in plugging an ultra-high permeability sandpack,whereas the pre-prepared DPG suspension achieves only 82.8%.With its high swelling ratio,irreversible swelling at high temperatures,enhanced thermal stability,and superior plugging performance,the newly developed DPG suspension in this work presents a highly promising solution for profile control in high-temperature CCUS applications.
文摘The discovery,advances,and industrial-scale up of a unique electrochemical decarbonization chemistry,which sequesters carbon dioxide to mitigate the existential threat of planetary climate change,are presented.C2CNT■(CO_(2) to Carbon NanoTechnology)is the transition metal nucleated electrolytic splitting of CO_(2) by its trans-formation into a wide range of Graphene NanoCarbon allotropes,C_(GNC),CO_(2)→C_(GNC)+O_(2),such as carbon nanotubes and carbon nano-onions.The original 2015 C2CNT 0.0005 m2 electrode process has been scaled to larger than meter-square area electrodes and used in a series of 100 tonne annual CO_(2) removal industrial Genesis Device modules.The pathway to a further scale-up to a series of 1000 tonne decarbonization placed in series and forming a megaton annual C2CNT decarbonization plant is illustrated.
基金Supported by the Horizon Europe Program(101129729)Sichuan Haiju Plan Project(2024JDHJ0012)China Scholarship Council Project(202208080058).
文摘A coupled PHREEQC-MATLAB simulation approach is proposed to investigate the dynamic changes in rock porosity,gas storage capacity,formation water salinity,and reservoir temperature driven by biogeochemical interactions during cyclic underground bio-methanation(UBM)of CO_(2)and H_(2),and to quantitatively examine how the evolution of these parameters influences CH_(4)production efficiency.The results indicate that during the cyclic UBM of CO_(2)-H_(2),the formation water undergoes a dynamic acid-base alternation,leading to periodic mineral dissolution and precipitation with limited impact on rock porosity.Across different mineral systems,the maximum CH_(4)production rate remains consistently around 3.6×10^(−3)mol/(L·d)in each cycle.With an increasing number of cycles,under high initial salinity conditions,the metabolic water produced by methanogens can significantly reduce the formation water salinity,gradually enhancing the CH_(4)production rate to levels comparable with those under low initial salinity.Additionally,the increased volume of produced water reduces the gas storage capacity of the reservoir.This reduction becomes more pronounced at higher initial CO_(2)-H_(2)pressures,accompanied by a more significant increase in CH_(4)production rate increment.Furthermore,the heat generated by methanogen metabolism leads to an increase in reservoir temperature,with the extent of temperature rise significantly influenced by heat loss.If the heat loss is neglected,the reservoir temperature can increase by up to 17.1℃after five cycles(10 years).When the reservoir has a higher initial temperature,the elevated thermal conditions may reduce CH_(4)production efficiency.
基金the financial support from the National Key Research and Development Program of China(2022YFE0206700)the Science Foundation of China University of Petroleum,Beijing(2462021YJRC012).
文摘Carbon capture,utilization,and storage(CCUS)represents a critical technological pathway for global car-bon emission reduction.CCUS-enhanced oil recovery(EOR)technology is the most feasible CCUS technol-ogy demonstrating dual benefits of enhanced energy production and carbon reduction.This study comprehensively described the key influencing factors governing CO_(2)-EOR and geological storage and systematically analyzed reservoir properties,fluid characteristics,and operational parameters.The mech-anisms of these parameters on EOR versus CO_(2) storage performance were investigated throughout CCUS-EOR processes.This paper proposes a coupled two-stage CCUS-EOR process:CO_(2)-EOR storage stage and long-term CO_(2) storage stage after the CO_(2) injection phase is completed.In each stage,the main control factors impacting the CO_(2)-EOR and storage stages are screened and coupled with rigorous technical anal-ysis.The key factors here are reservoir properties,fluid characteristics,and operational parameter.A novel CCUS-EOR synergistic method was proposed to optimize the lifecycle performance of dual objective of EOR and storage.Furthermore,based on multi-objective optimization,considering the lifecycle,a multi-scale techno-economic evaluation method was proposed to fully assess the CCUS-EOR project per-formance.Finally,a set of recommendations for advancing CCUS-EOR technologies by deploying multi-factor/multi-field coupling methodologies,novel green intelligent injection materials,and artificial intel-ligence/machine learning technologies were visited.
基金supported by the National Natural Science Foundation of China(22472069,22102064,and 22302080)China Postdoctoral Science Foundation(2024M760028).
文摘With global carbon emissions continuing to rise,carbon dioxide(CO_(2))capture and resource utilization have become central challenges in achieving the“dual carbon”goals(carbon peak and carbon neutrality).Traditional carbon capture and storage(CCS)technology can only temporarily sequester CO_(2),whereas emerging green catalytic technologies(photo/electro/thermal catalysis)enable the conversion of CO_(2) into high-value chemicals(e.g.,fuels,pharmaceutical intermediates),advancing the closure of the artificial carbon cycle[1,2].
基金the National Natural Science Foun-dation of China(51836006).
文摘Carbon dioxide(CO_(2))is the primary greenhouse gas contributing to anthropogenic climate change which is associated with human activities.The majority of CO_(2) emissions are results of the burning of fossil fuels for energy,as well as industrial processes such as steel and cement production.Carbon capture,utilization,and storage(CCUS)is a sustainable technology promising in terms of reducing CO_(2) emissions that would otherwise contribute to climate change.From this perspective,the discussion on carbon capture focuses on chemical absorption technology,primarily due to its commercialization potential.The CO_(2) absorptive capacity and absorption rate of various chemical solvents have been summarized.The carbon utilization focuses on electrochemical conversion routes converting CO_(2) into potentially valuable chemicals which have received particular attention in recent years.The Faradaic conversion efficiencies for various CO_(2) reduction products are used to describe efficiency improvements.For carbon storage,successful deployment relies on a better understanding of fluid mechanics,geomechanics,and reactive transport,which are discussed in details.
基金financially supported by the Natural Science Foundation of Shanxi Province,China(201601D102006)the Science Foundation for Young Scientists of Shanxi Province,China(201701D221052)+2 种基金the National Natural Science Foundation of China(21776294)the Key Science and Technology Program of Shanxi Province,China(MD2014-09,MD2014-10)the Independent Research Project of the State Key Laboratory of Coal Conversion(2018BWZ002)~~
文摘A series of metal-organic frameworks MOF-808-X(6-connected)were synthesized by regulating the ZrOCl2·8H2O/1,3,5-benzenetricarboxylic acid(BTC)molar ratio(X)and tested for the direct synthesis of dimethyl carbonate(DMC)from CO2 and CH3OH with 1,1,1-trimethoxymethane(TMM)as a dehydrating agent.The effect of the ZrOCl2·8H2O/BTC molar ratio on the physicochemical properties and catalytic performance of MOF-808-X was investigated.Results showed that a proper ZrOCl2·8H2O/BTC molar ratio during MOF-808-X synthesis was fairly important to reduce the redundant BTC or zirconium clusters trapped in the micropores of MOF-808-X.MOF-808-4,with almost no redundant BTC or zirconium clusters trapped in the micropores,exhibited the largest surface area,micropore size,and the number of acidic-basic sites,and consequently showed the best activity among all MOF-808-X,with the highest DMC yield of 21.5% under the optimal reaction conditions.Moreover,benefiting from the larger micropore size,MOF-808-4 outperformed our previously reported UiO-66-24(12-connected),which had even more acidic-basic sites and larger surface area than MOF-808-4,mainly because the larger micropore size of MOF-808-4 provided higher accessibility for the reactant to the active sites located in the micropores.Furthermore,a possible reaction mechanism over MOF-808-4 was proposed based on the in situ FT-IR results.The effects of different reaction parameters on DMC formation and the reusability of MOF-808-X were also studied.
文摘The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.
文摘The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea. The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases, modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts.
基金supported by the National Key Basic Research Program of China(2013CB956701)the National Natural Science Foundation of China (No.31070365)+1 种基金the project on social development of Guizhou Province (SY[2010]3043)the State Key Laboratory of Environmental Geochemistry (SKLEG2014909)
文摘The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plants. The net photosynthetic COa assimilation （PN）, the photosynthetic assimilation of CO2 and bicarbonate （PN＇）, the proportion of increased leaf area （lEA） and the stable carbon isotope composition （δ13C） of Orychophragmus violaceus （Ov） and Brassica juncea （B j） under three bicarbonate levels （5, 10 and 15 mm NaHCO3） were examined to determine the relationship among PN, PN＇ and fLA. PN＇, not PN, changed synchronously with fLA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate （including exogenous bicarbonate and dissolved CO2-generated bicarbonate） utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31% at 15 mm bicarbonate, respectively. Meanwhile, the propor- tions of exogenous bicarbonate and total bicarbonate uti- lised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11% and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.
基金supported by the National Natural Science Foundation of China(Nos. 41572325 and 41130207)
文摘To investigate the microbial utilization of organic carbon in peatland ecosystem, water samples were collected from the Dajiuhu Peatland and nearby lakes, central China across the year of 2014. The acridine orange （AO） staining and Biolog Eco microplates were used to numerate microbial counts and determine the carbon utilization of microbial communities. Meanwhile, physicochemical characteristics were measured for subsequent analysis of the correlation between microbial carbon utilization and environmental factors. Results indicated that total microbial counts were between 106107 cells/L. Microbial diversities and carbon utilization rates showed a similar pattern, highest in September and lowest in November. Microbial communities in the peat pore waters preferred to utilize N-bearing carbon sources such as amines and amino acids compared with microbial communities in lakes. The network analysis of microbial utilization of 31 carbon substrates clearly distinguished microbial communities from peat pore waters and those from lakes. Redundancy analysis （RDA） showed the total organic nitrogen content （P=-0.03, F=2.5） and daily average temperature （P=0.034, F=2.4） significantly controlled microbial carbon utilization throughout the sampling period. Our report is the first one to address the temporal and spatial variations of carbon uti- lization of microbial communities which are closely related to the decomposition of organic matter in the Dajiuhu Peatland in context of climate warming.
基金supported by the Henan Institute for Chinese Development Strategy of Engineering&Technology(Grant No.2022HENZDA02)by the Science&Technology Department of Sichuan Province Project(Grant No.2021YFH0010).
文摘Carbon neutrality(or climate neutrality)has been a global consensus,and international experience exchange is essential.Given the differences in the degree of social development,resource endowment and technological level,each country should build a carbon-neutral plan based on its national conditions.Compared with other major developed countries(e.g.,Germany,the United States and Japan),China's carbon neutrality has much bigger challenges,including a heavy and time-pressured carbon reduction task and the current energy structure that is over-dependent on fossil fuels.Here we provide a comprehensive review of the status and prospects of the key technologies for low-carbon,near-zero carbon,and negative carbon emissions.Technological innovations associated with coal,oil-gas and hydrogen industries and their future potential in reducing carbon emissions are particularly explained and assessed.Based on integrated analysis of international experience from the world's major developed countries,in-depth knowledge of the current and future technologies,and China's energy and ecological resources potential,five lessons for the implementation of China's carbon neutrality are proposed:(1)transformation of energy production pattern from a coal-dominated pattern to a diversified renewable energy pattern;(2)renewable power-to-X and large-scale underground energy storage;(3)integration of green hydrogen production,storage,transport and utilization;(4)construction of clean energy systems based on smart sector coupling(ENSYSCO);(5)improvement of ecosystem carbon sinks both in nationwide forest land and potential desert in Northwest China.This paper provides an international perspective for a better understanding of the challenges and opportunities of carbon neutrality in China,and can serve as a theoretical foundation for medium-long term carbon neutral policy formulation.
基金supported by the National Natural Sciences Foundation of China (U1612441)Foundation of Guizhou Province ([2014] 2131)Doctor Foundation of Guizhou Normal University (0514014)
文摘A bidirectional labeling method was established to distinguish the proportions of HCO3- and CO2 utiliza- tion pathways of microalgae in Lake Hongfeng. The method was based on microalgae cultured in a medium by adding equal concentrations of NaH13CO3 with different 613C values simultaneously. The inorganic carbon sources were quantified according to the stable carbon isotope composition in the treated microalgae. The effects of extracellular carbonic anhydrase （CAex） on the HCO3 and CO2 utilization pathways were distinguished using acetazolamide, a potent membrane-impermeable carbonic anhydrase inhibitor. The results show utilization of the added HCO3- was only 8% of the total carbon sources in karst lake. The proportion of the HCO3- utilization path- way was 52% of total inorganic carbon assimilation. Therefore, in the natural water of the karst area, the microalgae used less bicarbonate that preexisted in the aqueous medium than CO2 derived from the atmosphere. CAex increased the utilization of inorganic carbon from the atmosphere. The microalgae with CAex had greater carbon sequestration capacity in this karst area.
基金the foundations of the National Natural Science Foundation of China[No.U1612441-2]the National Key Research and Development Program of China[2016YFC0502602]Support Plan Projects of Science and Technology Department of Guizhou Province[No.(2021)YB453]。
文摘Photosynthesis is crucial to the reduction of carbon dioxide in the atmosphere.The key enzyme of photosynthesis,Ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco),has two mutably competing substrates,CO2 and O2.It has features of carboxylase and oxygenase.Rubisco performs the function of carboxylase to reduce inorganic carbon to form organic substances,which precondition is that more carbon dioxide accumulates around it.Carbon dioxide concentrating mechanisms(CCMs)are vital to cope with the limit of carbon dioxide.Various bicarbonate use pathway has a differential contribution to inorganic carbon assimilation.Bicarbonate transport,extracellular bicarbonate dehydration,or H+-ATPase-driven bicarbonate uptake,which induced CCMs,can support a considerable share of photosynthesis in photosynthetic organisms.However,CCMs in thylakoid membranes may be the most important.The CCMs occurred in the plasma membrane were secondary,evolutionary,and inducible,while CCMs coupled with photosynthetic oxygen evolution in thylakoid membranes,were primitive,major,and indispensable.A hypothetical schematic model of CCMs occurred in the plasma membrane and thylakoid membranes being proposed.
基金the National Key R&D Program of China(No.2019YFB1504102).
文摘Geothermal energy is a kind of renewable,sustainable and clean energy resource.Geothermal energy is abundant in carbonate reservoirs.However,low matrix permeability limits its exploitation.The super-critical carbon dioxide(SC-CO_(2))jet fracturing is expected to efficiently stimulate the carbonate geothermal reservoirs and achieve the storage of CO_(2) simultaneously.In this paper,we established a transient seepage and fluid-thermo-mechanical coupled model to analyze the impact performance of sc-CO_(2) jet fracturing.The mesh-based parallel code coupling interface was employed to couple the fluid and solid domains by exchanging the data through the mesh interface.The physical properties change of sC-CO_(2) with temperature were considered in the numerical model.Results showed that SC-CO_(2) jet frac-turing is superior to water-jet fracturing with respect to jetting velocity,particle trajectory and pene-trability.Besides,stress distribution on the carbonate rock showed that the tensile and shear failure would more easily occur by SC-CO_(2) jet than that by water jet.Moreover,pressure and temperature control the jet field and seepage field of sC-CO_(2) simultaneously.Increasing the jet temperature can effectively enhance the impingement effect and seepage process by decreasing the viscosity and density of SC-CO_(2).The key findings are expected to provide a theoretical basis and design reference for applying SC-CO_(2) jet fracturing in carbonate geothermal reservoirs.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.
文摘The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a carbon-neutral process that has the potential to be carbon-negative.This study has shown that the conversion of cellulose tosuppressedcan be achieved through the reforming of gaseous intermediates in a fixed bed of 10%Ni/ZrO2.Reforming occurs at low temperatures≤773 K,which could allow for improved sustainability.
基金The National Natural Science Foundation of China(81200762 and 81470769)supported this work
文摘Early childhood caries （ECC） is a considerable pediatric and public health problem worldwide. Preceding studies have focused primarily on bacterial diversity at the taxonomic level. Although these studies have provided significant information regarding the connection between dental caries and oral micmbiomes, further comprehension of this microbial community＇s ecological relevance is limited. This study identified the carbon source metabolic differences in dental plaque between children with and without ECC. We compared the microbial community functional diversity in 18 caries-free subjects with 18 severe ECC patients based on sole carbon source usage using a Biolog assay. The anaerobic microbial community in the ECC patients displayed greater metabolic activity than that of the control group. Specific carbon source metabolism differed significantly between the two groups. Subjects from the two groups were well distinguished by cluster and principal component analyses based on discriminative carbon sources. Our results implied that the microbial functional diversity between the ECC patients and healthy subjects differed significantly. In addition, the Biolog assay furthered our understanding of oral microbiomes as a composite of functional abilities, thus enabling us to identify the ecologically relevant functional differences among oral microbial communities.
文摘It is hypothesized and demonstrated that thermal insulation membranes can provide an effective barrier to heat flow and simultaneously facilitate effective CO_(2)diffusion.Decarbonization technology often requires a CO_(2)concentration system,often based on amine binding or lime reaction,which is energy intensive and carries a high carbon footprint.Alternatively,C2CNT electrolytic molten carbonate decarbonization does not require CO_(2)pre-concentration and also provides a useful product(graphene nanocarbons)from the captured CO_(2).Here,a method of effective CO_(2)diffusion is demonstrated that simultaneously thermally insulates the decarbonization source gas from the high-temperature C2CNT system.Open pore,low-density,thermal insulations are implemented as membranes that facilitate effective CO_(2)diffusion for high-temperature decarbonization.Selected,high-temperature,strongly thermal insulating,silica composites are measured with porosities,,exceeding 0.9(>90%porosity),and which display,as measured by SEM,large open channels facilitating CO_(2)diffusion.A derived and experimentally verified estimate for the CO_(2)diffusion constant through these membranes is DM-porous=ε^(3/2)DCO_(2),where DCO_(2)is the diffusion constant in air.DM-porous is applicable to a wide-range of CO_(2)concentrations both in the air and N2.The CO_(2)diffusion constant is translated to the equivalent decarbonization system mole influx of CO_(2)and shown capable of sustaining high rates of CO_(2)removal.Combined with the strong electrolyte affinity for CO_(2)compared to N_(2),O_(2),or H_(2)O,the system comprises a framework for decarbonization without pre-concentration of CO_(2).
