High-throughput microfluidic production of carbon capture microcapsules:fundamentals,applications,and perspectives

In the last three decades,carbon dioxide(CO_(2)) emissions have shown a significant increase from various sources.To address this pressing issue,the importance of reducing CO_(2) emissions has grown,leading to increased attention toward carbon capture,utilization,and storage strategies.Among these strategies,monodisperse microcapsules,produced by using droplet microfluidics,have emerged as promising tools for carbon capture,offering a potential solution to mitigate CO_(2) emissions.However,the limited yield of microcapsules due to the inherent low flow rate in droplet microfluidics remains a challenge.In this comprehensive review,the high-throughput production of carbon capture microcapsules using droplet microfluidics is focused on.Specifically,the detailed insights into microfluidic chip fabrication technologies,the microfluidic generation of emulsion droplets,along with the associated hydrodynamic considerations,and the generation of carbon capture microcapsules through droplet microfluidics are provided.This review highlights the substantial potential of droplet microfluidics as a promising technique for large-scale carbon capture microcapsule production,which could play a significant role in achieving carbon neutralization and emission reduction goals.

Carbon Capture Technologies in OAPEC Member Countries and the Circular Carbon Economy: A Roadmap to Zero Emissions by 2050

Several Organization of Arab Petroleum Exporting Countries (OAPEC) member states (OMSs) have updated their nationally determined contributions (NDCs) with the aim of achieving zero carbon emissions by 2050. Carbon neutrality requires shifting from a linear carbon economy (LCE) to a circular carbon economy (CCE). Carbon capture and storage (CCS) technologies, including reduction, recycle, reuse, removal, and storage technologies, represent an important strategy for achieving such a shift. Herein, we investigate the effects of CCS technology adoption in six OMSs—namely the Kingdom of Saudi Arabia (KSA), Qatar, the United Arab Emirates (UAE), Kuwait, Algeria, and Iraq—by examining their Circular Carbon Economy Index (CCEI) scores, which reflect compliance with CCE-transition policies. Total CCEI, current performance CCEI dimension, and future enabler CCEI dimensions scores were compared among the aforementioned six OMSs and relative to Norway, which was used as a global-high CCEI reference standard. Specifically, CCEI general scope and CCEI oil scope dimension scores were compared. The KSA, Qatar, the UAE, and Kuwait had higher CCEI scores than Algeria and Iraq, reflecting their greater adoption of CCE-transition policies and greater emission-reducing modernization investments. The current performance CCEI scores of Algeria and Iraq appear to be buttressed to some extent by their greater natural carbon sink resources. Based on the findings, we recommend specific actions for OMSs to enhance their CCE transitions and mitigate the negative impacts associated with the associated investments, including: taking rapid practical steps to eliminate carbon oil industry emissions;detailed CCS planning by national oil companies;international cooperation and coordination;and increased investment in domestic CCS utilization infrastructure.

The Joule–Thomson effect of (CO_(2)+H_(2)) binary system relevant to gas switching reforming with carbon capture and storage(CCS)

The Joule-Thomson effect is one of the important thermodynamic properties in the system relevant to gas switching reforming with carbon capture and storage(CCS). In this work, a set of apparatus was set up to determine the Joule-Thomson effect of binary mixtures(CO_(2)+ H_(2)). The accuracy of the apparatus was verified by comparing with the experimental data of carbon dioxide. The Joule-Thomson coefficients(μ_(JT)) for(CO_(2)+ H_(2)) binary mixtures with mole fractions of carbon dioxide(x_(CO_(2))= 0.1, 0.26, 0.5,0.86, 0.94) along six isotherms at various pressures were measured. Five equations of state EOSs(PR,SRK, PR, BWR and GERG-2008 equation) were used to calculate the μ_(JT)for both pure systems and binary systems, among which the GERG-2008 predicted best with a wide range of pressure and temperature.Moreover, the Joule-Thomson inversion curves(JTIC) were calculated with five equations of state. A comparison was made between experimental data and predicted data for the inversion curve of CO_(2). The investigated EOSs show a similar prediction of the low-temperature branch of the JTIC for both pure and binary systems, except for the BWRS equation of state. Among all the equations, SRK has the most similar result to GERG-2008 for predicting JTIC.

Carbon Capture from Flue Gas Based on the Combination of Non-Contact Hydrophobic Porous Ceramic Membrane and Bubbling Absorption

A hybrid system combined with a non-contact membrane and bubbling absorption is proposed to capture CO_(2) from flue gas.The non-contact way of membrane and liquid absorbent effectively avoids the reduction of gas diffusion flux through the membrane.High-porosity ceramic membranes in hybrid systems are used for gas-solid separation in fuel gas treatment.Due to the high content of H_(2)O and cement dust in the flue gas of the cement plant,the membrane is hydrophobically modified by polytetrafluoroethylene(PTFE)to improve its anti-water,anti-fouling,and self-cleaning performances.The results show that the diffusion flux of CO_(2) through the membrane is still higher than 7.0×10^(−3) mol/m^(2)s(20%CO_(2) concentration)even under the influence of water and cement dust.In addition,slaked lime selected as the absorbent is cheap and the product after bubbling absorption is nano-scale light calcium carbonate.To sum up,the hybrid system combining non-contact membrane and bubbling absorption is expected to be used to capture carbon dioxide from the flue gas of the cement plant.

Conversion Carbon Capture and Storage Factors in Temperate Human Controlled Wetland

This paper provides guidance for the quantification and reporting of blue carbon removals in the temperate coastal ecosystems,“Italian valli da pesca”or H.C.W.(Human Controlled Wetland,Lat.45°Lon.12°),where some pools as seagrasses,and salt marshes,are highly efficient at capturing and storing carbon dioxide(CO_(2))from the atmosphere.Halophyte salt marsh plants were found to have a%C on Dry Weight(D.W.)of 32.26±3.91(mean±standard deviation),macrophytes 33.65±7.99,seagrasses 29.23±2.23,tamarisk 48.42±2.80,while the first 5 centimetres of wetland mud,on average,had a%C of 8.56±0.94.Like the ISO(International Organization for Standardization)14064 guideline to quantify the GHG(Greenhouse Gas)emission,we have studied the different conversion factors to be used as a practical tool for measurement the CO_(2)sink activity.These factors are essential to calculate the overall carbon reduction in a project located in temperate wetland using a method as the ISO 14064.2,UNI-BNeutral,VCS VERRA or other that will come.

Technical Perspective of Carbon Capture,Utilization,and Storage

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.

Secondary Silicates as a Barrier to Carbon Capture and Storage in Deccan Basalt

Investigating the immobilization of CO2,previous basalt-water-CO2 interaction studies revealed the formation of carbonates over a short period,but with the extensive formation of secondary silicates(SS).The mechanisms involved in these processes remain unresolved,so the present study was undertaken to understand secondary mineral formation mechanisms.XRPD and Rietveld refinement data for neo-formed minerals show a drastic decrease in the Ca-O bond length,with the calcite structure degenerating after 80 h(hours).However,SEM images and EDS data revealed that a longer interaction time resulted in the formation of chlorite and smectite,adjacent to basalt grains which prevent basaltwater-CO2 interaction to form carbonates,thus restricting carbonate formation.As a result of this,the CO2 mineralization rate is initially high(till 80 h),but it later reduces drastically.It is evident that,for such temperature-controlled transformations,low temperature is conducive to minimizing SS surface coating at the time of mineral carbonation.

Investigation of the role of Ca(OH)2 in the catalytic Alkaline Thermal Treatment of cellulose to produce H2 with integrated carbon capture

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.

Carbon capture and storage,geomechanics and induced seismic activity

Injection of large volumes of carbon dioxide(CO) for the purposes of greenhouse-gas emissions reduction has the potential to induce earthquakes.Operators of proposed projects must therefore take steps to reduce the risks posed by this induced seismicity.In this paper,we examine the causes of injection-induced seismicity(IIS),and how it should be monitored and modelled,and thereby mitigated.Many US case studies are found where fluids are injected into layers that are in close proximity to crystalline basement rocks.We investigate this issue further by comparing injection and seismicity in two areas where oilfield wastewater is injected in significant volumes:Oklahoma,where fluids are injected into a basal layer,and Saskatchewan,where fluids are injected into a much shallower layer.We suggest that the different induced seismicity responses in these two areas are at least in part due to these different injection depths.We go on to outline two different approaches for modelling IIS:a statistics based approach and a physical,numerical modelling based approach.Both modelling types have advantages and disadvantages,but share a need to be calibrated with good quality seismic monitoring data if they are to be used with any degree of reliability.We therefore encourage the use of seismic monitoring networks at all future carbon capture and storage(CCS) sites.

Review on research and development of oxy-coal burner for carbon capture

In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.

Enhanced carbon capture with motif-rich amino acid loaded defective robust metal-organic frameworks

The use of metal-organic frameworks(MOFs)as solid adsorption materials for carbon capture is promising,but achieving efficient and reversible adsorption with a balance of capacity and selectivity for carbon dioxide(CO_(2))over N_(2) remains a challenge.To take full advantage of the strong channel traffic and robustness of MOFs with relatively small pores,it is highly necessary to employ a defect-engineering strategy to construct a broader channel structure that can facilitate the loading of functional motif-rich amino acids(AAs).This strategy can greatly enhance the CO_(2) adsorption performance of MOF.In this study,motif-rich amino acids are loaded into the defective and robust porous frameworks via combined defect-engineering and post-synthetic methods.The defective Zr/Hf-MOF-808s modified with AAs,especially for the 18 mol%4-nitroisophthalic acid,generated defective products allowing for the loading of L-serine(L-Ser).This modification resulted in a significant improvement in both the adsorption capacity(248%improvement at 298 K,100 kPa)and the selectivity of CO_(2)/N_(2) using the ideal adsorbed solution theory(IAST),with the selectivity increasing to 120.55 and 38.27 at 15 and 100 kPa,respectively,while maintaining good cycling performance.Density functional theory(DFT)simulation,CO_(2) temperature-programmed desorption(CO_(2)-TPD),and in situ Fourier transform infrared spectroscopy(FTIR)were further employed to have a better understanding of the enhanced CO_(2) adsorption capacity.Interestingly,unlike the AAs loaded pristine MOF-808s that showed the best CO_(2) adsorption capacity with the loading of short and small glycine(Gly),the broadened channel size in our work enables the loading of functional motif-rich L-serine,which brings more active binding sites,improving CO_(2) adsorption.

Recent advances,challenges,and perspectives on carbon capture

Carbon capture,utilization and storage(CCUS)technologies play an essential role in achieving Net Zero Emissions targets.Considering the lack of timely reviews on the recent advancements in promising CCUS technologies,it is crucial to provide a prompt review of the CCUS advances to understand the current research gaps pertained to its industrial application.To that end,this review first summarized the developmental history of CCUS technologies and the current large-scale demonstrations.Then,based on a visually bibliometric analysis,the carbon capture remains a hotspot in the CCUS development.Noting that the materials applied in the carbon capture process determines its performance.As a result,the state-of-the-art carbon capture materials and emerging capture technologies were comprehensively summarized and discussed.Gaps between state-of-art carbon capture process and its ideal counterpart are analyzed,and insights into the research needs such as material design,process optimization,environmental impact,and technical and economic assessments are provided.

Hcable for Time-Lapse Seismic Monitoring of Marine Carbon Capture and Storage

To ensure project safety and secure public support, an integrated and comprehensive monitoring program is needed within a carbon capture and storage(CCS) project. Monitoring can be done using many well-established techniques from various fields, and the seismic method proves to be the crucial one. This method is widely used to determine the CO_(2) distribution, image the plume development, and quantitatively estimate the concentration. Because both the CO_(2) distribution and the potential migration pathway can be spatially small scale, high resolution for seismic imaging is demanded. However, obtaining a high-resolution image of a subsurface structure in marine settings is difficult. Herein, we introduce the novel Hcable(Harrow-like cable system) technique, which may be applied to offshore CCS monitoring. This technique uses a highfrequency source(the dominant frequency>100 Hz) to generate seismic waves and a combination of a long cable and several short streamers to receive seismic waves. Ultrahigh-frequency seismic images are achieved through the processing of Hcable seismic data. Hcable is then applied in a case study to demonstrate its detailed characterization for small-scale structures. This work reveals that Hcable is a promising tool for timelapse seismic monitoring of oceanic CCS.

Technological advancement and industrialization path of Sinopec in carbon capture,utilization and storage,China

Carbon capture,utilization and storage(CCUS)technology is an important means to effectively reduce carbon emissions from fossil energy combustion and industrial processes.With the crisis of climate change,CCUS has attracted increasing attention in the world.CCUS technology as developed rapidly in China is technically feasible for large-scale application in various industries.The R&D and demonstration of CCUS in China Petroleum&Chemical Corporation(Sinopec)are summarized,including carbon capture,carbon transport,CO_(2)enhanced energy recovery(including oil,gas,and water,etc.),and comprehensive utilization of CO_(2).Based on the source-sink matching characteristics in China,two CCUS industrialization scenarios are proposed,namely,CO_(2)-EOR,CO_(2)-driven enhanced oil recovery using centralized carbon sinks in East China and CO_(2)-EWR,CO_(2)-driven enhanced water recovery(EWR)using centralized carbon sources from the coal chemical industry in West China.Finally,a CCUS industrialization path from Sinopec's perspective is suggested,using CO_(2)-EOR as the major means and CO_(2)-EWR,CO_(2)-driven enhanced gas recovery(CO_(2)-EGR)and other utilization methods as important supplementary means.

China's policy framework for carbon capture,utilization and storage:Review,analysis,and outlook

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.

Novel in-capsule synthesis of metal-organic framework for innovative carbon dioxide capture system

Metal-Organic Frameworks(MOFs)have been developed as solid sorbents for CO_(2) capture applications and their properties can be controlled by tuning the chemical blocks of their crystalline units.A number of MOFs(e.g.,HKUST-1)have been developed but the question remains how to deploy them for gas-solid contact.Unfortunately,the direct use of MOFs as nanocrystals would lead to serious problems and risks.Here,for the first time,we report a novel MOF-based hybrid sorbent that is produced via an innovative in-situ microencapsulated synthesis.Using a custom-made double capillary microfluidic assembly,double emulsions of the MOF precursor solutions and UV-curable silicone shell fluid are produced.Subsequently,HKUST-1 MOF is successfully synthesized within the droplets enclosed in the gas permeable microcapsules.The developed MOF-bearing microcapsules uniquely allow the deployment of functional nanocrystals without the challenge of handling ultrafine particles,and further,can selectively reject undesired compounds to protect encapsulated MOFs.

Multi-scale analysis of carbon mineralization in lime-treated soils considering soil mineralogy

Mineral carbonation is emerging as a reliable CO_(2) capture technology that can mitigate climate change.In lime-treated clayey soils,mineral carbonation occurs through the carbonation of free lime and cementitious products derived from pozzolanic reactions.The kinetics of the reactions in lime-treated clayey soils are variable and depend primarily on soil mineralogy.The present study demonstrates the role of soil mineralogy in CO_(2) capture and the subsequent changes caused by carbon mineralization in terms of the unconfined compressive strength(UCS)of lime-treated soils during their service life.Three clayey soils(kaolin,bentonite,and silty clay)with different mineralogical characteristics were treated with 4%lime content,and the samples were cured in a controlled environment for 7 d,90 d,180 d,and 365 d.After the specified curing periods,the samples were exposed to CO_(2) in a carbonation cell for 7 d.The non-carbonated samples purged with N2 gas were used as a benchmark to compare the mechanical,chemical-mineralogical,and microstructure changes caused by carbonation reactions.Experimental investigations indicated that exposure to CO_(2) resulted in an average increase of 10%in the UCS of limetreated bentonite,whereas the strength of lime-treated kaolin and silty clay was reduced by an average of 35%.The chemical and microstructural analyses revealed that the precipitated carbonates effectively filled the macropores of the treated bentonite,compared to the inadequate cementation caused by pozzolanic reactions,resulting in strength enhancement.In contrast,strength loss in lime-treated kaolin and silty clay was attributed to the carbonation of cementitious phases and partly to the tensile stress induced by carbonate precipitation.In terms of carbon mineralization prospects,lime-treated kaolin exhibited maximum carbonation due to the higher availability of unreacted lime.The results suggest that,in addition to the increase in compressive strength,adequate calcium-bearing phases and macropores determine the efficiency of carbon mineralization in lime-treated clayey soils.

Lifecycle carbon footprint and cost assessment for coal-to-liquid coupled with carbon capture,storage,and utilization technology in China

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.

Screening,preparation,and prototyping of metal–organic frameworks for adsorptive carbon capture under humid conditions

Adsorption-based carbon capture has been recognized as an attractive method for mitigating global warming.Metal–organic frameworks(MOFs)are promising candidate adsorbents for this purpose due to their high adsorption uptake and selectivity for carbon dioxide.However,in real-world applications,such as direct air capture,the presence of moisture in the feed gas may pose a grand challenge for CO_(2)adsorption in MOFs.This paper aims to address the issue of water–CO_(2)co-adsorption in MOFs and present screening criteria for selecting MOFs that preferentially adsorb CO_(2)under humid conditions.First,we uncover a comprehensive overview of CO_(2)–water co-adsorption characteristics of various MOFs.Then,the high-throughput screening methods are summarized.Both computational and experimental efforts have been dedicated to identify the promising MOFs for humid CO_(2)capture.According to the screening results and adsorption mechanism,the optimal preparation strategies are proposed tomodulate the effect of water on CO_(2)uptake in MOFs.Finally,current MOF-based CO_(2)capture prototypes are presented to evaluate their practical feasibility and performance.This work could offer valuable guidance for the development and application of MOFs for CO_(2)capture in the presence of water and inspire further research in this field.

Prospects for green steelmaking technology with low carbon emissions in China

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.