Carbon Capture, Utilization, And Storage Research Articles

Numerical Modeling and Economic Analysis of Ultrasonic-Assisted CO2 Absorption Process for Offshore Application

In the quest for net zero carbon emissions by 2050, Carbon Capture Utilization and Storage (CCUS) is indispensable. The development of more efficient CO2 capture processes is essential. High-frequency ultrasonic irradiation is an emerging, intensified technique that can enhance the CO2 absorption process. To advance this technology toward commercialization, it is crucial to conduct a thorough economic analysis to allow the identification of the key cost component. While equipment sizing is essential in this economic assessment, there is a lack of numerical models for estimating the size and power consumption of ultrasonic absorbers. This study introduces a numerical model for these predictions. The model was then used to determine the economic feasibility of this emerging technique against the packed bed columns based on capital expenditure (CAPEX), operational expenditure (OPEX), and unit technical cost (UTC) for 20 years of plant operation. According to the economic analysis, ultrasonic intensification requires 34% less CAPEX due to its compact design. Although its OPEX is 11% higher due to the additional electricity needed for the ultrasonic transducers, the UTC is still 3% lower than the conventional packed bed column, demonstrating a potential cost savings in implementing the ultrasonic irradiation-assisted technique during the CO2 absorption process offshore.

The role of core in twenty-first century reservoir characterization: an introduction

Abstract The first two decades of the twenty-first century have seen significant advances across a wide range of reservoir characterization techniques, from microscale digital rock physics to macroscale 3D and 4D seismic. At the same time, industry downturns and the requirements of the energy transition have demanded improved understanding of the value and impact of subsurface data to justify their acquisition and commercial relevance. Despite changing technologies and demands, the acquisition, description and analysis of core remains a fundamental tool in managing subsurface uncertainty and associated risk. Value continues to be created in relation to the reservoir property, sedimentological, diagenetic and structural characterization of subsurface reservoirs, and these are the focus of the Core Values volume. The enduring business impact of core reflects advances in acquisition methods and laboratory-based core analysis (Theme 1 of the volume); the recent development of multi-sensor core scanning and associated artificial intelligence (AI) tools that allow unprecedented high-resolution data collection and visualization (Theme 2); the integration of core-derived data with new complementary technologies, leading to improved characterization of both cored and uncored intervals (Theme 3); the changing nature and role of legacy core collections due to digitization and improved data access (Theme 4). These are complemented by the need to better understand both existing hydrocarbon resources and other subsurface energy-related systems, particularly CCUS (carbon capture, utilization and storage), geothermal energy and the long-term storage of nuclear waste (Theme 5). Through the energy transition core will remain the ground truth foundation to any subsurface understanding and evaluation. At the same time, the technologies available to maximize the applied value of core will continue to develop and evolve, with the integration of diverse and complex core-derived and core-related datasets becoming the norm. Even in the face of AI's impact and value in handling such datasets, those earth scientists who can effectively analyse, interpret and integrate core will still be best placed to meet the subsurface challenges of the future.

Prospects for hydrogen fuel cell vehicles to decarbonize road transport

This paper explores the role of hydrogen fuel cell vehicles (HFCVs) in helping to meet global climate goals of limiting long-term greenhouse gas (GHG) emissions to 1.5 °C. Employing the GREET Model and data from the International Energy Agency (IEA), the study comprehensively compares the full fuel-cycle emission profiles of HFCVs and battery electric vehicles (BEVs). The paper conducts an in-depth examination of the interplay between the carbon intensity of the electric grid and the resulting GHG emissions within the context of refueling HFCV vehicles via electrolyzers, and the analysis draws a comparison to BEVs charged using the same electric grid. The study finds that while emissions for BEVs increase, emissions for HFCVs are significantly larger when HFCVs are refueled from retail outlets producing hydrogen via electrolysis from grid electricity—a finding that was not previously reached in the current literature. The research underscores that countries operating electric grids characterized by high GHG emissions or lacking robust pathways to emission reduction would face suboptimal outcomes by adopting HFCVs powered by hydrogen sourced from distributed grid electricity generation. The gCO2e/mi for BEVs and HFCVs are also calculated when the electricity is produced from renewable energy resources. When electricity is derived from renewable energy sources, it becomes evident that the gCO2e/mi for both HFCVs and BEVs converge towards ‘zero’. The emission metric of gCO2e/mile for a HFCV refueled with the hydrogen produced from natural gas via steam methane reforming (SMR) without carbon capture utilization and storage (CCUS), stands at 105 gCO2e/mile, whereas in the absence of CCUS, it escalates notably to 247 gCO2e/mile, an approximate 150% increase in stark contrast to CCUS inclusion. This quantitative portrayal serves to underscore the substantial potential for curtailing carbon footprints achievable through the integration of CCUS, thereby amplifying its significance within the realm of hydrogen-based transportation and the broader purview of climate change mitigation endeavors. In order to provide a comprehensive perspective, the study delves into the examination of hydrogen production pathways and associated costs for the years 2021, 2030, and 2050. The forecasted supply costs are elucidated, particularly in relation to the potential hydrogen supply originating from variable renewable energy (solar PV and wind) sources and from CCUS-equipped hydrogen production facilities (considering the project pipeline of projects upto 2030). These factors are of substantial importance in shaping the hydrogen supply landscape and subsequently influencing the adoption of HFCVs in the market. The study also examines the cost implications of hydrogen delivery for varying transportation distances (for 2030), acknowledging their important role in the broader context. The challenges posed by the integration of variable renewable energy sources are also addressed, along with the imperative for effective energy storage solutions. This discourse unfolds within the overarching framework of the energy transition, prominently characterized by the ascendancy of solar PV and wind energy. The intricate interplay of these aspects assumes a critical role in shaping the trajectory of future hydrogen supply dynamics over the medium and long term.

Assessment of the CO2 Geological Storage Potential of Yanchang Shale Gas Formation (Chang7 Member) Considering the Capillary Sealing Capability of Caprock

Reducing net carbon emissions is of great significance for sustainability. Carbon capture, utilization, and storage (CCUS) technology is regarded as one of the most effective approaches to reducing net carbon emissions. A prerequisite for the implementation of the CO2 geological storage project is the assessment of the storage potential of the storage site. In this study, a calculation method of storage potential was proposed to estimate the CO2 storage potential of the Yanchang shale gas reservoir in the Ordos Basin, China. In this method, the CO2 sealing capability of the caprock is taken into account, which determines the maximum CO2 storage pressure of the reservoir. The overall CO2 storage potential consists of four types of storage states (free-state, adsorption, dissolution, and mineralization). The maximum CO2 storage pressure of the Yanchang shale gas reservoir is 13.4 MPa via breakthrough pressure experiments, and the corresponding theoretical storage potential is 7.59 × 1011 t. The potential for free-state, adsorption, dissolution, and mineralization sequestration are 8.42 × 1010 t, 6.88 × 1010 t, 2.45 × 109 t, and 6.05 × 1011 t, respectively. Due to the difficulty in completing mineralization within the engineering time scale, the mineralization potential should not be taken into account when estimating the available CO2 storage potential. The available CO2 potential (including free-state, adsorption, and dissolution) of the Yanchang shale gas reservoir is 1.54 × 1011 t, which is a considerable amount. The Yanchang shale gas formation will be able to accommodate 41.49% of global annual CO2 emissions (according to the data in 2021) if the available CO2 storage potential of the Yanchang shale gas reservoir is fully exploited.

Modeling Ecological Constraints on a CO2 Pipeline Network.

Carbon capture, utilization, and storage (CCUS) are a critical set of strategies to decarbonize the industrial and power sectors and to mitigate global climate change. Pipeline infrastructure connecting CO2 sources and sinks, if not planned strategically, can cause environmental and social impacts by disturbing local landscapes. We investigated the impacts of these considerations on optimal CO2 pipeline routing and sink locations by modifying and leveraging an open-source CCUS infrastructure model, SimCCS. We expanded SimCCS from a cost-minimizing to a multiobjective framework, explicitly incorporating environmental protection objectives. We estimated trade-offs between private costs and environmental and social impacts. Using a version of the model focused on the southeastern United States, we modeled seven scenarios with varying weights given to environmental impacts to evaluate how the pipeline network responds to the multiobjective optimization. We found that the optimal path is sensitive to environmental and social impact considerations in that a small increase in pipeline length (and cost) significantly avoids large environmental and social impacts. We hope such a tool can be used to improve the pipeline permitting and siting processes and contribute to the achievement of decarbonization goals with minimal environmental impacts.

Integrated supply chain network design and superstructure optimization problem: A case study of microalgae biofuel supply chain

In recent years, several strategies have been developed and adopted in a bid to manage the biofuel supply chain. In this paper, a two-stage optimization model is proposed for integrated microalgae biofuel supply chain network design and superstructure optimization problems. In the first stage, the design of the carbon capture, utilization, and storage (CCUS) network is taken into account. A robust mixed integer linear programming (RMILP) model is proposed to optimize the strategic CCUS decisions, including the simultaneous selection of emission sources, capture facilitates, Carbon Dioxide (CO2) pipelines, intermediate transportation sites and storage sites, or microalgae cultivation sites. The second stage is dedicated to biorefinery superstructure optimization in order to determine the optimal/promising biorefinery configurations. The presented model is able to handle the inherent uncertainty of critical input parameters. Moreover, the results show that biodiesel production cost cannot compete with current diesel price, but it can be reduced significantly by improving biomass productivity.

Public perceptions of CCUS in Central and Eastern Europe – implications for community engagement

Carbon capture, utilization, and storage (CCUS) is emerging as a subject of major interest for EU climate policy due to their potential role in avoiding hard-to-abate CO2 emissions, as well as to lead to “negative emissions” through direct air capture or bioenergy with carbon capture and storage. Despite CCUS technologies being deployed since the 1970s, their widespread implementation is still challenged by a range of factors, including policy inertia, high costs, and relative novelty in the public discourse. In particular, as CCUS emerges slowly into the realm of public and political debate, opinions on these technologies and associated projects are easily changeable and affected by a range of factors, which make concerted public and community engagement extremely important for deploying them where they matter most.The Central and Eastern Europe (CEE) region is characterized by a higher-than-average economic dependence on heavy industry, old assets and infrastructure, and a high occurrence of regions where the transition to climate neutrality will have a significant impact on local economies, employment, and social welfare [1]. CCUS could play an important role in decarbonizing the heavy industry sectors of the region, particularly given the potentially significant storage capabilities of countries such as Romania and Poland, as well as emerging storage potential in the Black Sea and Eastern Mediterranean Sea. However, climate policy in these jurisdictions is sluggish, and there is a general failure to approach CCUS in a systematic way, with targeted application to sectors where it can have the highest impact, such as cement and oil refining. As a result, the public debate around CCUS is practically non-existent, and where public opinions do emerge, they may be significantly influenced by the context of a particular project and generate significant resistance based on the relationship with project developers, the amplification of perceived risks, and the lack of appropriate explanations of costs, benefits and risks. This in turn can lead to a reticence of political stakeholders to commit to deploying CCUS, causing the public debate to further stagnate and creating a vicious circle whereby opportunities to familiarize the public with these technologies (well in advance of their deployment) are missed.In order to deploy CCUS at pace and scale, as part of the catching-up climate policies of CEE countries, public perception of CCUS must be thoroughly researched and developed into appropriate guidelines for community engagement by project developers. There is experience in the region – the feasibility study for Romania’s planned Getica CCS demonstrator (subsequently abandoned) included comprehensive research into the perceptions of local communities, and a toolkit for communications around CCUS by project developers. Similarly, learnings from Poland’s failed Belchatow CCS project can serve to re-assess the state of public opinion on CCS, and how the local and national-level contexts for CCUS perceptions interact. The CEE region has significant potential for deploying CCUS, and public perception must be an integral part of planning as the region moves into the key decade of 2030-2040 for implementing large-scale projects.

Exploring CO2 storage potential in Lithuanian deep saline aquifers using digital rock volumes: a machine learning guided approach

The increasing significance of carbon capture, utilization and storage (CCUS) as a climate mitigation strategy has underscored the importance of accurately evaluating subsurface reservoirs for CO2 sequestration [1]. In this context, digital rock volumes, obtained through advanced imaging techniques such as micro-Xray computed tomography (MXCT), offer intricate insights into the porous and permeable structures of geological formations [2]. This study presents a comprehensive methodology for assessing CO2 storage viability within Lithuanian deep saline aquifers, namely Syderiai and Vaskai, by utilizing petrophysical properties estimated from digital rock volumes [3, 4]. These petrophysical properties were derived from core samples collected from these formations. Utilizing machine learning algorithms, porosity was estimated while the Lattice Boltzmann method (LBM) was applied to determine permeability [5]. The methodology employed for estimating these petrophysical parameters was initially validated using samples from formations analogous to Lithuanian formations. Subsequently, it was applied to rock samples specifically obtained from Lithuanian formations. The estimated petrophysical properties were compared with peer-reviewed data from published literature. When fluids such as CO2 or H2 are injected into sub-surface reservoirs, they can alter pore and grain characteristics. Therefore, it is crucial to extract representative element volumes (REVs) from segmented volumes to study the impact of fluids on porosity and their distribution [6]. These mini models, representing small portions of the larger formation, assist in predicting fluid flow within the formation, which is vital for assessing the efficiency and safety of carbon capture and storage (CCS) operations. Subsequently, numerical modelling was conducted using the petrophysical parameters as inputs to assess the storage capacity of the Lithuanian formations using tNavigator software [7]. This research contributes to an enhanced understanding of pore space distribution and its role in various aspects of long-term CO2 storage. It also demonstrates the potential of integrating advanced imaging techniques, machine learning, and numerical modeling for accurate assessment and effective management of subsurface CO2 storage. This study shall aid in enhanced understanding of pore space distribution and their contribution towards various aspects of long-term storage. The results can be extended to study the geochemical reactions and geo-mechanical behaviour of the rocks. Such studies shall further facilitate identification of reservoir(s) wherein sequestration potential can be reliably explored.

Carbon capture, circular utilization, and sequestration (CCCUS): A multifunctional technology coupling underground biomethanation with geothermal energy production

The urgent need to address climate change, driven by the increasing concentrations of greenhouse gases, has made it imperative for the world to focus on enhancing carbon emission mitigation and carbon utilization. Consequently, carbon-negative technologies have garnered significant attention, such as Carbon Capture, Utilization, and Storage (CCUS). In order to achieve the circular utilization of carbon and improve the economic viability of conventional carbon-negative technologies, this paper proposes the innovative concept of Carbon Capture, Circular Utilization, and Sequestration (CCCUS). This multifunctional carbon-negative technology couples underground biomethanation of carbon dioxide and hydrogen-rich industrial by-product gases with geothermal energy production. CCCUS also offers several additional functions, such as renewable natural gas storage, natural gas displacement, and carbon dioxide geological sequestration. Furthermore, a preliminary assessment of the techno-economic feasibility of CCCUS is undertaken. A numerical case study, conducted using the XGS gas storage in the Sichuan Basin, China, unveiled that over a 425-day period, the conversion ratio of carbon dioxide to methane in the working gas can achieve 98.9%. Moreover, the net present value (NPV) of CCCUS over a 30-year period is estimated to be approximately 4.67 × 108 CNY under the base scenario. These findings, along with field monitoring and laboratory experiments, preliminarily present evidence supporting the potential techno-economic feasibility of CCCUS. This paper offers a fresh perspective on the development of the circular carbon economy.

Cryogenic CO2 capture from oxy-combustion flue gas by a hybrid distillation + physical absorption process

Hybrid flowsheets are defined, in the context of process intensification, as alternatives suitable for replacing energy-intensive separation methods through the combination of more than one unit operation. Given the undoubted importance of carbon capture, utilization, and storage (CCUS) in the next decades in the path to net-zero emissions and even negative emissions scenarios, this work focuses on CO2 capture from an oxy-combustion flue gas by means of a distillation-based hybrid process that avoids CO2 freeze-out, which is capable of delivering a liquid CO2-rich stream that can in principle be pumped to transport pressures with lower energy consumption in comparison to conventional post-combustion CO2 capture processes based on chemical absorption. A distillation-based process and a hybrid distillation + physical absorption process have been studied based on simulations in Aspen Hysys® V11 using the Peng-Robinson Equation of State and the “Acid Gas – Physical Solvents” thermodynamic property package. Firstly, a CO2 capture process based on cryogenic distillation has been proposed and a sensitivity analysis on the operating pressure and specified CO2 recovery has been performed in order to determine the most convenient configuration, balancing capital and operating costs. Then, a hybrid capture process has been proposed and analyzed, where cryogenic distillation is the bulk removal step and physical absorption into a mixture of homologues of the dimethylether of polyethylene glycol (DEPG) is the finishing step. Energy and economic analyses have shown that the hybrid process, delivering a CO2 product respecting the stringent purity requirement on the oxygen content for application for Enhanced Oil Recovery (EOR) and in the food industry is less energy intensive than the standalone cryogenic distillation, though it is characterized by higher capital costs.

Public perceived risks and benefits of carbon capture, utilization, and storage (CCUS): Scale development and validation

As a critical technology to mitigate climate change, the large-scale implementation of carbon capture, utilization, and storage (CCUS) depends on both technological advancement and public acceptance, which is significantly influenced by the perceived risks and benefits. Existing studies, however, have yet to reach a consensus regarding the measurement of CCUS in these two aspects. To fill this gap, this paper develops and validates new scales based on four studies. Specifically, Study 1 generates the initial item pool based on a literature review and semi-structured interviews, and then invites experts to examine the content validity of these items; Study 2 identifies the dimensions and assesses the reliability and validity of the measures through an exploratory and confirmatory factor analysis; Study 3 conducts a one-way ANOVA to test known-group validity; and Study 4 employed structural equation modeling to evaluate the nomological validity. The results demonstrate the internal consistency, reliability, and construct validity of the new scales developed to measure CCUS. This study provides a valuable tool for investigating public perceptions of CCUS and can help policymakers develop future publicity strategies.

Analyzing the current state and future development of carbon capture, utilization and storage (CCUS) strategies and technologies in China

Carbon capture, utilization, and storage (hereafter as CCUS) encompass the procedures of capturing carbon dioxide before it is emitted into the atmosphere, transporting it via pipelines or vehicles and finally utilizing it or storing it in a secure manner. CCUS is vital in transitioning the world into more sustainable and low carbon energy production since it serves as a temporary “band-aid” in reducing the impacts of humanity’s high dependence on fossil fuels. The Chinese government has recently committed itself to reach carbon neutrality by 2060 and CCUS technologies will be a critical cornerstone in reaching this substantial goal. Up to 60% of China’s energy supply in 2019 derived from coal, thus an effective CCUS strategy integrated with the 1,110 operational Chinese coal power plants could be decisive in reaching their carbon neutrality goal. This research paper will analyze the most effective best available technologies (BATs) in terms of cost efficiency and practicality, providing a comprehensive report on the optimal steps for China to take in order to reach its carbon neutral goals through CCUS.

CO[formula omitted] storage or utilization? A real options analysis under market and technological uncertainty

Carbon Capture and Storage (CCS) and Carbon Capture and Utilization (CCU) are considered essential solutions to reduce greenhouse gas (GHG) emissions worldwide. A crucial difference between the two is that CCS is already a mature technology, while CCU is still in the R&D phase. Hence, firms are confronted with a dilemma, where they have to choose between either the mature CCS, the emerging CCU, or the installation of both in a Carbon Capture Utilization and Storage (CCUS) system. In this study, we analyze different strategies that the firm can pursue and determine the optimal investment timing. In doing so, we take into account both technological uncertainty, i.e. the unknown time-to-market of CCU, and market uncertainty, i.e. the CO2 price. Three different CCUS value chains in the cement industry are analyzed. We find that the anticipated arrival of profitable CCU technologies in the future does not delay investments in CCS in the current period. Investments in CCS and CCU can be accelerated by reducing the volatility of the CO2 price, or by increasing the growth rate of the CO2 price. Finally, we find that a higher fraction of CO2 emissions that can be used in CCU, results in sooner adoption of CCS today.

Guidelines for the selection of corrosion resistant alloys for CCS and CCUS injection wells

Carbon capture and sequestration (CCS) and carbon capture utilization and storage (CCUS) projects continue to develop as an effective method to reduce anthropogenic CO2 emissions. Injection wells for these projects are often required to retain integrity over long operational lives, sometimes 50 years or longer. When it is determined from process conditions that free water may or will be present, either condensing from the CO2 injectate itself or due to injection into a water-bearing formation, the need for a corrosion resistant alloy (CRA) is required to ensure sufficiently long service life. For well designers and operators, there is a growing need for comprehensive guidelines for the selection of suitable corrosion resistant alloys (CRAs). This paper summarizes important parameters developed through the Plains CO2 Reduction (PCOR) Partnership that need to be considered for general materials selection for use within CO2 injection wells based on available data.

Application of Pulse Neutron Oxygen Activation Logging in Carbon Dioxide Injection Wells

Carbon dioxide injection to improve oil recovery is an important link in carbon capture, utilization, and storage (CCUS) and an important means of tertiary oil recovery. Conducting gas injection profile logging in injection wells can reflect the inter-and intra-layer suction differences in gas injection wells, reveal the contradictions between injection and production, and provide a basis for gas plugging and profile control; The integrity of the wellbore is an important part of the storage stage of CCUS, which directly determines the burial and storage effect, and wellbore leakage directly affects the gas injection and oil displacement effect; The inspiratory index test can evaluate the formation's gas absorption capacity and provide a reasonable injection pressure of the formation at this stage. Since carbon dioxide gas usually exists in a supercritical fluid state in the wellbore, traditional logging techniques have certain limitations. This paper focuses on the adaptability research of pulse neutron oxygen activation logging principle and construction technology, and combined with the application example of gas injection wells in CCUS block of Huang3 District in Changqing Oilfield, it is clarified that the pulse neutron oxygen activation logging can be used to carry out suction profiling, suction index testing and wellbore integrity evaluation in carbon dioxide injection wells, and it has good application effects.

Asphaltene Flow Assurance Risk Evaluation Case Study to Establish Guidelines for CCUS in Arabian Gulf Carbonate Oil Field

Summary In this paper, we present a case study for a comprehensive series of asphaltene flow assurance risk evaluations in the Arabian Gulf Carbonate Oil Field, where CO2 enhanced oil recovery (EOR) is recognized as one of the highest potential technologies for full-field implementation. At first, the sampling location was carefully selected considering the target reservoir’s features because the reliability of asphaltene studies highly depends on sample representativeness. After the quality assurance and quality control of collected samples, asphaltene onset pressures (AOPs) were measured at multiple temperatures under CO2 mixing conditions. The experimental design was optimized in terms of not only improving evaluation accuracy but also minimizing the experimental/sampling cost. The AOP measurements showed clear potential risks associated with CO2 injection. Subsequently, the numerical model analysis was conducted with the cubic-plus-association equation of state model to identify the risk area during CO2 injection. The analysis suggested that risk area is applicable to not only near-wellbore region at the sampling location but also tubing section/surface facility. Furthermore, risk level can be higher at the deeper location of the target reservoir. Finally, CO2-induced asphaltene formation damage risk was investigated from the viewpoints of precipitated asphaltene particle size and pore throat size in the porous media. As a result, the clogging risks from CO2-induced asphaltene were estimated to be high in the target reservoir. By virtue of the comprehensive risk evaluation, the asphaltene flow assurance risk associated with CO2 injection was identified field-wide. The findings from the evaluation encouraged us to move on to future actions, such as more detailed formation damage risk evaluation and mitigation plan development. The extended asphaltene risk evaluation covering the precipitation to deposition phenomena and the reverse engineering for sampling operations based on the experimental design made a worthy demonstration to reduce unnecessary cost and time while obtaining the key information to drive the project. The procedure in this work can contribute to establishing a subsurface part of a guideline for carbon capture, utilization, and storage (CCUS) from the viewpoint of asphaltene flow assurance risk evaluation.

Mechanistic insights to drive catalytic hydrogenation of formamide intermediates to methanol via deaminative hydrogenation

Amine-promoted hydrogenation of CO2 to methanol typically proceeds via a formamide intermediate when amines are used as additives or if the hydrogenation is performed in carbon capture solvents. The catalysts used for the hydrogenation of the formamide intermediate dictate the selectivity of the products formed: 1) Deoxygenative hydrogenation (C–O bond cleavage) resulting in N-methylation of amine and deactivation of the solvent, 2) Deaminative hydrogenation (C–N bond cleavage) resulting in formation of methanol and regeneration of the solvent. To date, catalytic reductions of CO2 with amine promoters suffer from poor selectively for methanol which we attribute to the limiting formamide intermediate, though to date, the conditions that favor C–N cleavage have yet to be fully understood. To better understand the reactivity of the formamide intermediates, a range of heterogenous catalysts were used to study the hydrogenation of formamide. Well-known gas phase CO2 hydrogenation catalysts catalyze the hydrogenation of formamide to N-methyl product via C–O bond cleavage. However, the selectivity can be readily shifted to selective C–N bond cleavage by addition of an additive with sufficient basicity for both homogenous and heterogeneous catalytic systems. The base additive shifts the selectivity by deprotonating a hemiaminal intermediate formed in situ during the formamide hydrogenation. This prevents dehydration process leading to N-methylated product, which is a key capture solvent deactivation pathway that hinders amine use in carbon capture, utilization, and storage (CCUS). The findings from this study provide a roadmap on how to improve the selectivity of known heterogenous catalysts, enabling catalytic reduction of captured CO2 to methanol.

A Comprehensive Review of Fishbone Well Applications in Conventional and Renewable Energy Systems in the Path towards Net Zero

Fishbone drilling (FbD) involves drilling multiple micro-holes branching out in various directions from the primary vertical or deviated wellbore. FbD is similar to multilateral micro-hole drilling and can be employed to boost hydrocarbon production in naturally fractured formations or during refracturing operations by connecting existing natural fractures. Key design elements in fishbones include determining the number, length, and spacing between the branches, and the angle at which the branches deviate from the main borehole. Fishbone wells have emerged as a promising technology for improving well performance and reducing environmental impact. In this paper, we present a comprehensive review of the different applications of fishbone wells in conventional and renewable energy systems. We discuss the potential of fishbone wells for enhanced oil and gas recovery, as well as their application in unconventional resources such as coal bed methane. Moreover, we examine the feasibility of fishbone wells in renewable energy systems, such as geothermal energy and carbon capture, utilization, and storage (CCUS). We highlight the various benefits of fishbone wells, including reduced carbon footprint, enhanced efficiency, and increased sustainability. Finally, we discuss the challenges and limitations associated with fishbone wells in different energy systems. This review provides a comprehensive overview of the potential and challenges of fishbone wells in reducing carbon footprint and improving well performance in a wide range of energy systems.

Enhancing shale gas recovery by carbon dioxide injection: A method of carbon capture, utilization and storage (CCUS)

CO2 injection in shale gas reservoir can not only increase the production of shale gas, but also realize carbon dioxide capture, utilization and storage. At present, most experimental studies of CO2 injection in shale are carried out by conventional core experiments. However, it is difficult to analyze the process of CO2 replacing shale gas and adsorption in shale pores on microscopic scale. In this study, nuclear magnetic resonance (NMR) technology is used to analyze the migration and conversion of CH4 in process of CO2 injection and depressurization production. Based on above experiments, microscopic mechanism of competitive adsorption of CH4 and CO2 during CO2 injection is clarified, and the stimulation mechanism of CO2 injection to improve shale gas recovery is further proposed. The results show that CH4 preferentially exists in form of adsorption state in shale. When CH4 adsorption amount reaches a certain degree, CH4 gas in form of free state gradually appears. During depressurization stage, further depressurization failed to promote the desorption of adsorbed gas when pressure reduced to 3 MPa. Therefore, adsorbed CH4 gas still exists after depressurization production. Shale has stronger adsorption capacity for CO2 than CH4. CO2 can replace CH4 adsorbed on the pore surface, and promote the desorption of adsorbed CH4 gas to free state. CO2 has the best displacement effect on adsorbed CH4 in pores with diameter of 15.04–21.62 nm, but it fails to replace CH4 in pores with diameter less than 1.08 nm. The competitive adsorption of CO2 and CH4 can effectively promote the further desorption of residual adsorbed CH4 gas after depressurization, and significantly improve the cumulative shale gas production.

CO2 pipelines release and dispersion: A review

Carbon Capture, Utilization, and Storage (CCUS) is an emerging industry in response to climate change. With this, more pipelines are being built to transport CO2 to sequestration sites. CO2, though non-toxic and non-flammable, is an asphyxiant that can cause death when exposed to high concentrations. Hence, there is a need to evaluate the release and dispersion behavior of CO2 from pipelines. Industrial-scale experiments of CO2 dispersion have been performed to acquire quantitative data. However, the sheer number of scenarios that could possibly occur is difficult to perform one-by-one experimentally. Computational tools, such as Computational Fluid Dynamics (CFD), and risk assessment methodologies, such as Quantitative Risk Assessment (QRA), have then been utilized to predict CO2 dispersion behavior and hazards, respectively. In this review, the different industrial-scale experiments, CFD models for CO2 dispersion, and risk assessment of CO2 transport pipelines were discussed. Moreover, we emphasize the possibility of using machine learning as a tool to increase the accuracy and efficiency in predicting CO2 dispersion behavior. The future direction of predicting CO2 dispersion behavior through the use of machine learning was also explored.