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
Carbon capture,utilization,and storage(CCUS)is estimated to contribute substantial CO_(2)emission reduction to carbon neutrality in China.There is yet a large gap between such enormous demand and the current capacity,...Carbon capture,utilization,and storage(CCUS)is estimated to contribute substantial CO_(2)emission reduction to carbon neutrality in China.There is yet a large gap between such enormous demand and the current capacity,and thus a sound enabling environment with sufficient policy support is imperative for CCUS development.This study reviewed 59 CCUS-related policy documents issued by the Chinese government as of July 2022,and found that a supporting policy framework for CCUS is taking embryonic form in China.More than ten departments of the central government have involved CCUS in their policies,of which the State Council,the National Development and Reform Commission(NDRC),the Ministry of Science and Technology(MOST),and the Ministry of Ecological Environment(MEE)have given the greatest attention with different focuses.Specific policy terms are further analyzed following the method of content analysis and categorized into supply-,environment-and demand-type policies.The results indicate that supply-type policies are unbalanced in policy objectives,as policy terms on technology research and demonstration greatly outnumber those on other objectives,and the attention to weak links and industrial sectors is far from sufficient.Environment-type policies,especially legislations,standards,and incentives,are inadequate in pertinence and operability.Demand-type policies are absent in the current policy system but is essential to drive the demand for the CCUS technology in domestic and foreign markets.To meet the reduction demand of China's carbon neutral goal,policies need to be tailored according to needs of each specific technology and implemented in an orderly manner with well-balanced use on multiple objectives.展开更多
Thecoal-to-liquidcoupledwithcarbon capture,utilization,and storage technology has the potential to reduce CO_(2)emissions,but its carbon footprint and cost assessment are still insufficient.In this paper,coal mining t...Thecoal-to-liquidcoupledwithcarbon capture,utilization,and storage technology has the potential to reduce CO_(2)emissions,but its carbon footprint and cost assessment are still insufficient.In this paper,coal mining to oil production is taken as a life cycle to evaluate the carbon footprint and levelized costs of direct-coal-toliquid and indirect-coal-to-liquid coupled with the carbon capture utilization and storage technology under three scenarios:non capture,process capture,process and public capture throughout the life cycle.The results show that,first,the coupling carbon capture utilization and storage technology can reduce CO_(2)footprint by 28%-57%from 5.91 t CO_(2)/t:oil of direct-coal-to-liquid and 24%-49%from 7.10 t CO_(2)/t:oil of indirect-coal-to-liquid.Next,the levelized cost of direct-coal-to-liquid is 648-1027$/t of oil,whereas that of indirect-coal-to-liquid is 653-1065$/t of oil.When coupled with the carbon capture utilization and storage technology,the levelized cost of direct-coalto-liquid is 285-1364$/t of oil,compared to 1101-9793/t of oil for indirect-coal-to-liquid.Finally,sensitivity analysis shows that CO_(2)transportation distance has the greatest impact on carbon footprint,while coal price and initial investment cost significantly affect the levelized cost ofcoal-to-liquid.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
Life cycle assessments(LCAs)of early-stage technologies can provide valuable insights about key drivers of emissions and aid in prioritizing research into further emissions-reduction opportunities.Despite this potenti...Life cycle assessments(LCAs)of early-stage technologies can provide valuable insights about key drivers of emissions and aid in prioritizing research into further emissions-reduction opportunities.Despite this potential value,further development of LCA methods is required to handle the increased uncertainty,data gaps,and confidentially of early-stage data.This study presents a discussion of the life cycle carbon footprinting of technologies competing in the final round of the NRG COSIA Carbon XPRIZE competition-a US$20 million competition for teams to demonstrate the conversion of CO_(2) into valuable products at the scale of a small industrial pilot using consistent deployment conditions,boundaries,and methodological assumptions.This competition allowed the exploration of how LCA can be used and further improved when assessing disparate and early-stage technologies.Carbon intensity estimates are presented for two conversion pathways:(i)CO_(2) mineralization and(ii)catalytic conversion(including thermochemical,electrochemical,photocatalytic and hybrid process)of CO_(2),aggregated across teams to highlight the range of emissions intensities demonstrated at the pilot for individual life cycle stages.A future scenario is also presented,demonstrating the incremental technology and deployment conditions that would enable a team to become carbon-avoiding relative to an incumbent process(i.e.reducing emissions relative to a reference pathway producing a comparable product).By considering the assessment process across a diverse set of teams,conversion pathways and products,the study presents generalized insights about opportunities and challenges facing carbon capture and-utilization technologies in their next phases of deployment from a life cycle perspective.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
In the context of carbon capture,utilization,and storage,the high-value utilization of carbon storage presents a significant challenge.To address this challenge,this study employed the bipolar membrane electrodialysis...In the context of carbon capture,utilization,and storage,the high-value utilization of carbon storage presents a significant challenge.To address this challenge,this study employed the bipolar membrane electrodialysis integrated with carbon utilization technology to prepare Na_(2)CO_(3)products using simulated seawater concentrate,achieving simultaneous saline wastewater utilization,carbon storage and high-value production of Na_(2)CO_(3).The effects of various factors,including concentration of simulated seawater concentrate,current density,CO_(2)aeration rate,and circulating flow rate of alkali chamber,on the quality of Na_(2)CO_(3)product,carbon sequestration rate,and energy consumption were investigated.Under the optimal condition,the CO_(3)^(2-)concentration in the alkaline chamber reached a maximum of 0.817 mol/L with 98 mol%purity.The resulting carbon fixation rate was 70.50%,with energy consumption for carbon sequestration and product production of 5.7 k Whr/m^(3)CO_(2)and1237.8 k Whr/ton Na_(2)CO_(3),respectively.This coupling design provides a triple-win outcome promoting waste reduction and efficient utilization of resources.展开更多
This work systematically reviews the complex mechanisms of CO_(2)-water-rock interactions,microscopic simulations of reactive transport(dissolution,precipitation and precipitate migration)in porous media,and microscop...This work systematically reviews the complex mechanisms of CO_(2)-water-rock interactions,microscopic simulations of reactive transport(dissolution,precipitation and precipitate migration)in porous media,and microscopic simulations of CO_(2)-water-rock system.The work points out the key issues in current research and provides suggestions for future research.After injection of CO_(2) into underground reservoirs,not only conventional pressure-driven flow and mass transfer processes occur,but also special physicochemical phenomena like dissolution,precipitation,and precipitate migration.The coupling of these processes causes complex changes in permeability and porosity parameters of the porous media.Pore-scale microscopic flow simulations can provide detailed information within the three-dimensional pore and throat space and explicitly observe changes in the fluid-solid interfaces of porous media during reactions.At present,the research has limitations in the decoupling of complex mechanisms,characterization of differential multi-mineral reactions,precipitation generation mechanisms and characterization(crystal nucleation and mineral detachment),simulation methods for precipitation-fluid interaction,and coupling mechanisms of multiple physicochemical processes.In future studies,it is essential to innovate experimental methods to decouple“dissolution-precipitation-precipitate migration”processes,improve the accuracy of experimental testing of minerals geochemical reaction-related parameters,build reliable characterization of various precipitation types,establish precipitation-fluid interaction simulation methods,coordinate the boundary conditions of different physicochemical processes,and,finally,achieve coupled flow simulation of“dissolution-precipitation-precipitate migration”within CO_(2)-water-rock systems.展开更多
CO_(2)emission mitigation is one of the most critical research frontiers.As a promising option of carbon capture,utilization and storage(CCUS),CO_(2)storage with enhanced gas recovery(CSEGR)can reduce CO_(2)emission b...CO_(2)emission mitigation is one of the most critical research frontiers.As a promising option of carbon capture,utilization and storage(CCUS),CO_(2)storage with enhanced gas recovery(CSEGR)can reduce CO_(2)emission by sequestrating it into gas reservoirs and simultaneously enhance natural gas production.Over the past decades,the displacement behaviour of CO_(2)—natural gas has been extensively studied and demonstrated to play a key role on both CO_(2)geologic storage and gas recovery performance.This work thoroughly and critically reviews the experimental and numerical simulation studies of CO_(2)displacing natural gas,along with both CSEGR research and demonstration projects at various scales.The physical property difference between CO_(2)and natural gas,especially density and viscosity,lays the foundation of CSEGR.Previous experiments on displacement behaviour and dispersion characteristics of CO_(2)/natural gas revealed the fundamental mixing characteristics in porous media,which is one key factor of gas recovery efficiency and warrants further study.Preliminary numerical simulations demonstrated that it is technically and economically feasible to apply CSEGR in depleted gas reservoirs.However,CO_(2)preferential flow pathways are easy to form(due to reservoir heterogeneity)and thus adversely compromise CSEGR performance.This preferential flow can be slowed down by connate or injected water.Additionally,the optimization of CO_(2)injection strategies is essential for improving gas recovery and CO_(2)storage,which needs further study.The successful K12—B pilot project provides insightful field-scale knowledge and experience,which paves a good foundation for commercial application.More experiments,simulations,research and demonstration projects are needed to facilitate the maturation of the CSEGR technology.展开更多
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the Cooperative Project of the Chinese Academy of Engineering(Grant No.202001SDZD01).
文摘Carbon capture,utilization,and storage(CCUS)is estimated to contribute substantial CO_(2)emission reduction to carbon neutrality in China.There is yet a large gap between such enormous demand and the current capacity,and thus a sound enabling environment with sufficient policy support is imperative for CCUS development.This study reviewed 59 CCUS-related policy documents issued by the Chinese government as of July 2022,and found that a supporting policy framework for CCUS is taking embryonic form in China.More than ten departments of the central government have involved CCUS in their policies,of which the State Council,the National Development and Reform Commission(NDRC),the Ministry of Science and Technology(MOST),and the Ministry of Ecological Environment(MEE)have given the greatest attention with different focuses.Specific policy terms are further analyzed following the method of content analysis and categorized into supply-,environment-and demand-type policies.The results indicate that supply-type policies are unbalanced in policy objectives,as policy terms on technology research and demonstration greatly outnumber those on other objectives,and the attention to weak links and industrial sectors is far from sufficient.Environment-type policies,especially legislations,standards,and incentives,are inadequate in pertinence and operability.Demand-type policies are absent in the current policy system but is essential to drive the demand for the CCUS technology in domestic and foreign markets.To meet the reduction demand of China's carbon neutral goal,policies need to be tailored according to needs of each specific technology and implemented in an orderly manner with well-balanced use on multiple objectives.
基金the National Natural Science Foundation of China(Grant Nos.72174196 and 71874193)Open Fund of State Key Laboratory of Coal Resources and Safe Mining(China University of Mining and Technology)(Grant Nos.SKLCRSM21KFA05 and SKLCRSM22KFA09)the Fundamental Research Funds for the Central Universities(Grant No.2022JCCXNY02).
文摘Thecoal-to-liquidcoupledwithcarbon capture,utilization,and storage technology has the potential to reduce CO_(2)emissions,but its carbon footprint and cost assessment are still insufficient.In this paper,coal mining to oil production is taken as a life cycle to evaluate the carbon footprint and levelized costs of direct-coal-toliquid and indirect-coal-to-liquid coupled with the carbon capture utilization and storage technology under three scenarios:non capture,process capture,process and public capture throughout the life cycle.The results show that,first,the coupling carbon capture utilization and storage technology can reduce CO_(2)footprint by 28%-57%from 5.91 t CO_(2)/t:oil of direct-coal-to-liquid and 24%-49%from 7.10 t CO_(2)/t:oil of indirect-coal-to-liquid.Next,the levelized cost of direct-coal-to-liquid is 648-1027$/t of oil,whereas that of indirect-coal-to-liquid is 653-1065$/t of oil.When coupled with the carbon capture utilization and storage technology,the levelized cost of direct-coalto-liquid is 285-1364$/t of oil,compared to 1101-9793/t of oil for indirect-coal-to-liquid.Finally,sensitivity analysis shows that CO_(2)transportation distance has the greatest impact on carbon footprint,while coal price and initial investment cost significantly affect the levelized cost ofcoal-to-liquid.
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Funding for the study was provided by the XPRIZE Foundation.
文摘Life cycle assessments(LCAs)of early-stage technologies can provide valuable insights about key drivers of emissions and aid in prioritizing research into further emissions-reduction opportunities.Despite this potential value,further development of LCA methods is required to handle the increased uncertainty,data gaps,and confidentially of early-stage data.This study presents a discussion of the life cycle carbon footprinting of technologies competing in the final round of the NRG COSIA Carbon XPRIZE competition-a US$20 million competition for teams to demonstrate the conversion of CO_(2) into valuable products at the scale of a small industrial pilot using consistent deployment conditions,boundaries,and methodological assumptions.This competition allowed the exploration of how LCA can be used and further improved when assessing disparate and early-stage technologies.Carbon intensity estimates are presented for two conversion pathways:(i)CO_(2) mineralization and(ii)catalytic conversion(including thermochemical,electrochemical,photocatalytic and hybrid process)of CO_(2),aggregated across teams to highlight the range of emissions intensities demonstrated at the pilot for individual life cycle stages.A future scenario is also presented,demonstrating the incremental technology and deployment conditions that would enable a team to become carbon-avoiding relative to an incumbent process(i.e.reducing emissions relative to a reference pathway producing a comparable product).By considering the assessment process across a diverse set of teams,conversion pathways and products,the study presents generalized insights about opportunities and challenges facing carbon capture and-utilization technologies in their next phases of deployment from a life cycle perspective.
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 Central Guidance on Local Science and Technology Development Fund of Hebei Province(No.226Z3102G)the Fundamental Research Funds of Hebei University of Technology(No.JBKYTD2001)the Science Research Project of Hebei Education Department(No.QN2022089)。
文摘In the context of carbon capture,utilization,and storage,the high-value utilization of carbon storage presents a significant challenge.To address this challenge,this study employed the bipolar membrane electrodialysis integrated with carbon utilization technology to prepare Na_(2)CO_(3)products using simulated seawater concentrate,achieving simultaneous saline wastewater utilization,carbon storage and high-value production of Na_(2)CO_(3).The effects of various factors,including concentration of simulated seawater concentrate,current density,CO_(2)aeration rate,and circulating flow rate of alkali chamber,on the quality of Na_(2)CO_(3)product,carbon sequestration rate,and energy consumption were investigated.Under the optimal condition,the CO_(3)^(2-)concentration in the alkaline chamber reached a maximum of 0.817 mol/L with 98 mol%purity.The resulting carbon fixation rate was 70.50%,with energy consumption for carbon sequestration and product production of 5.7 k Whr/m^(3)CO_(2)and1237.8 k Whr/ton Na_(2)CO_(3),respectively.This coupling design provides a triple-win outcome promoting waste reduction and efficient utilization of resources.
基金Supported by the National Natural Science Foundation of China(52234003,52222402,52304044).
文摘This work systematically reviews the complex mechanisms of CO_(2)-water-rock interactions,microscopic simulations of reactive transport(dissolution,precipitation and precipitate migration)in porous media,and microscopic simulations of CO_(2)-water-rock system.The work points out the key issues in current research and provides suggestions for future research.After injection of CO_(2) into underground reservoirs,not only conventional pressure-driven flow and mass transfer processes occur,but also special physicochemical phenomena like dissolution,precipitation,and precipitate migration.The coupling of these processes causes complex changes in permeability and porosity parameters of the porous media.Pore-scale microscopic flow simulations can provide detailed information within the three-dimensional pore and throat space and explicitly observe changes in the fluid-solid interfaces of porous media during reactions.At present,the research has limitations in the decoupling of complex mechanisms,characterization of differential multi-mineral reactions,precipitation generation mechanisms and characterization(crystal nucleation and mineral detachment),simulation methods for precipitation-fluid interaction,and coupling mechanisms of multiple physicochemical processes.In future studies,it is essential to innovate experimental methods to decouple“dissolution-precipitation-precipitate migration”processes,improve the accuracy of experimental testing of minerals geochemical reaction-related parameters,build reliable characterization of various precipitation types,establish precipitation-fluid interaction simulation methods,coordinate the boundary conditions of different physicochemical processes,and,finally,achieve coupled flow simulation of“dissolution-precipitation-precipitate migration”within CO_(2)-water-rock systems.
基金financially supported by the National Natural Science Foundation of China(51906256 and 52074337)Fundamental Research Funds for the Central Universities(21CX06033A)
文摘CO_(2)emission mitigation is one of the most critical research frontiers.As a promising option of carbon capture,utilization and storage(CCUS),CO_(2)storage with enhanced gas recovery(CSEGR)can reduce CO_(2)emission by sequestrating it into gas reservoirs and simultaneously enhance natural gas production.Over the past decades,the displacement behaviour of CO_(2)—natural gas has been extensively studied and demonstrated to play a key role on both CO_(2)geologic storage and gas recovery performance.This work thoroughly and critically reviews the experimental and numerical simulation studies of CO_(2)displacing natural gas,along with both CSEGR research and demonstration projects at various scales.The physical property difference between CO_(2)and natural gas,especially density and viscosity,lays the foundation of CSEGR.Previous experiments on displacement behaviour and dispersion characteristics of CO_(2)/natural gas revealed the fundamental mixing characteristics in porous media,which is one key factor of gas recovery efficiency and warrants further study.Preliminary numerical simulations demonstrated that it is technically and economically feasible to apply CSEGR in depleted gas reservoirs.However,CO_(2)preferential flow pathways are easy to form(due to reservoir heterogeneity)and thus adversely compromise CSEGR performance.This preferential flow can be slowed down by connate or injected water.Additionally,the optimization of CO_(2)injection strategies is essential for improving gas recovery and CO_(2)storage,which needs further study.The successful K12—B pilot project provides insightful field-scale knowledge and experience,which paves a good foundation for commercial application.More experiments,simulations,research and demonstration projects are needed to facilitate the maturation of the CSEGR technology.
