Microalgae: a promising tool for carbon sequestration

Increasing trends in global warming already evident, the likelihood of further rise continuing, and their impacts give urgency to addressing carbon sequestration technologies more coherently and effectively. Carbon dioxide (CO₂) is responsible for over half the warming potential of all greenhouse gases (GHG), due to the dependence of world economies on fossil fuels. The processes involving CO₂ capture and storage (CCS) are gaining attention as an alternative for reducing CO₂ concentration in the ambient air. However, these technologies are considered as short-term solutions, as there are still concerns about the environmental sustainability of these processes. A promising technology could be the biological capture of CO₂ using microalgae due to its unmatched advantages over higher plants and ocean fertilization. Microalgae are phototrophic microorganisms with simple nutritional requirements, and comprising the major primary producers on this planet. Specific pathways include autotrophic production via both open pond or closed photobioreactor (PBR) systems. Photosynthetic efficiency of microalgae ranged from 10?C20 % in comparison with 1?C2 % of most terrestrial plants. Some algal species, during their exponential growth, can double their biomass in periods as short as 3.5 hours. Moreover, advantage of being tolerant of high concentration of CO₂ (flue gas), low light intensity requirements, environmentally sustainable, and co-producing added value products put these as the favoured organisms. Advantages of microalgae in comparison with other sequestration methodologies are discussed, which includes the cultivation systems, the key process parameters, wastewater treatment, harvesting and the novel bio-products produced by microalgal biomass.     

Fighting sustainability challenges on two fronts: Material efficiency and the emerging carbon capture and storage technologies

Technological and regulatory responses to large-scale environmental threats, such as depletion of the natural resources and climate change, tend to focus on one issue at time. Emerging carbon capture and storage (CCS) technologies that are in different stages of development offer a case that demonstrates this dilemma. This article approximates the implications of two emerging CCS applications on existing steel mill’s CO₂ emissions and its use of material resources. The evaluated applications are based on the mineralization method and the comparative case represents two versions of a geological CCS method. The results of the evaluation indicate that if technical bottleneck issues related to CO₂ sequestration with mineralization can be solved, it can be possible to achieve a similar CO₂ reduction performance with mineralization-based CCS applications as with more conventional CCS applications. If the CO₂ capturing potential of mineralization-based applications could be taken into use, it could also enable the significant improvement of material efficiency of industrial operations. Urgent problem hampering the development of mineralization-based CCS applications is that the policy regimes related to CCS especially in the European Union (EU) do not recognize mineralization as a CCS method. Article suggests that the focus in the future evaluations and in policy should not be directed only on CO₂ sequestration capacity of CCS applications. Similarly important is to consider their implications on material efficiency. Article also outlines modifications to the EU’s CCS policy in terms of the formal terminology.     

基于生命周期评价的钢铁厂碱渣固碳技术比较研究

本研究以3种钢铁厂碱渣直接法固碳技术为研究对象,该技术将钢渣进行碳酸化处理,可快速永久地将CO2固化储存在钢渣中,气固相反应可分别在高压釜、泥浆反应器和超重力旋转床的水溶液中一步完成,并将其分别定义为T1、T2、T3.通过Umberto软件建立生命周期模型,对3种技术的资源环境影响进行评估.结果表明,T1的环境影响最高,其次为T3,T2的环境影响最小.技术评价显示,T3在技术效率、资源消耗、环境影响方面具有较好的综合效益.敏感性分析表明,加热效率的敏感性系数分别为0.97、0.97和0.46.转换率与温室气体排放的关系分别呈上升、倒U型和下降的变化趋势.提高加热效率、合理利用热源及选择合适的技术效率,将有利于技术优化,减少技术的环境影响,提高固碳效率.     

Integrated assessment of CCS in the German power plant sector with special emphasis on the competition with renewable energy technologies

The study presents the results of an integrated assessment of carbon capture and storage (CCS) in the power plant sector in Germany, with special emphasis on the competition with renewable energy technologies. Assessment dimensions comprise technical, economic and environmental aspects, long-term scenario analysis, the role of stakeholders and public acceptance and regulatory issues. The results lead to the overall conclusion that there might not necessarily be a need to focus additionally on CCS in the power plant sector. Even in case of ambitious climate protection targets, current energy policy priorities (expansion of renewable energies and combined heat and power plants as well as enhanced energy productivity) result in a limited demand for CCS. In case that the large energy saving potential aimed for can only partly be implemented, the rising gap in CO₂ reduction could only be closed by setting up a CCS-maximum strategy. In this case, up to 22% (41 GW) of the totally installed load in 2050 could be based on CCS. Assuming a more realistic scenario variant applying CCS to only 20 GW or lower would not be sufficient to reach the envisaged climate targets in the electricity sector. Furthermore, the growing public opposition against CO₂ storage projects appears as a key barrier, supplemented by major uncertainties concerning the estimation of storage potentials, the long-term cost development as well as the environmental burdens which abound when applying a life-cycle approach. However, recently, alternative applications are being increasingly considered?Cthat is the capture of CO₂ at industrial point sources and biomass based energy production (electricity, heat and fuels) where assessment studies for exploring the potentials, limits and requirements for commercial use are missing so far. Globally, CCS at power plants might be an important climate protection technology: coal-consuming countries such as China and India are increasingly moving centre stage into the debate. Here, similar investigations on the development and the integration of both, CCS and renewable energies, into the individual energy system structures of such countries would be reasonable.     

Making carbon sequestration a paying proposition

Atmospheric carbon dioxide (CO₂) has increased from a preindustrial concentration of about 280 ppm to about 367 ppm at present. The increase has closely followed the increase in CO₂ emissions from the use of fossil fuels. Global warming caused by increasing amounts of greenhouse gases in the atmosphere is the major environmental challenge for the 21st century. Reducing worldwide emissions of CO₂ requires multiple mitigation pathways, including reductions in energy consumption, more efficient use of available energy, the application of renewable energy sources, and sequestration. Sequestration is a major tool for managing carbon emissions. In a majority of cases CO₂ is viewed as waste to be disposed; however, with advanced technology, carbon sequestration can become a value-added proposition. There are a number of potential opportunities that render sequestration economically viable. In this study, we review these most economically promising opportunities and pathways of carbon sequestration, including reforestation, best agricultural production, housing and furniture, enhanced oil recovery, coalbed methane (CBM), and CO₂ hydrates. Many of these terrestrial and geological sequestration opportunities are expected to provide a direct economic benefit over that obtained by merely reducing the atmospheric CO₂ loading. Sequestration opportunities in 11 states of the Southeast and South Central United States are discussed. Among the most promising methods for the region include reforestation and CBM. The annual forest carbon sink in this region is estimated to be 76 Tg C/year, which would amount to an expenditure of $11.1–13.9 billion/year. Best management practices could enhance carbon sequestration by 53.9 Tg C/year, accounting for 9.3% of current total annual regional greenhouse gas emission in the next 20 years. Annual carbon storage in housing, furniture, and other wood products in 1998 was estimated to be 13.9 Tg C in the region. Other sequestration options, including the direct injection of CO₂ in deep saline aquifers, mineralization, and biomineralization, are not expected to lead to direct economic gain. More detailed studies are needed for assessing the ultimate changes to the environment and the associated indirect cost savings for carbon sequestration.     

Science-based permitting of geological sequestration of CO2 in brine reservoirs in the U.S.

We present a science-based approach to the regulation and permitting of CO₂ sequestration activities. Any such regulatory scheme should address both operational (or short-term) issues and the long-term goals of geological sequestration of CO₂. In the United States many of the key operational issues, such as permitting injection wells and CO₂ pipelines, are reasonably well addressed in current Federal- and State-based rules and legislation. The long-term, overarching goal of sequestration projects of decreasing the rate of increase in atmospheric concentrations of CO₂ is not addressed by current regulations. We propose a hierarchical approach, in which the State/Federal government is responsible for developing regional assessments that result in broad regions of brine reservoirs being rated as “sequestration ready” (and designated in this paper as general permits). The burden faced by an applicant in permitting an injection site should be considerably less if the general area of the chosen site has been ranked favorably. Such a phased, hierarchical permitting process would be helpful in addressing public and stakeholder concerns related to the impact and safety of geological sequestration operations. It will also build in coordination between neighboring injection sites, where interferences are likely because of the large amount of CO₂ to be injected.     

CO2泄漏对稻田水基础水质指标的影响研究

碳捕集与封存（CCS）技术是当前抑制大气中CO₂过快增长的有效方法,但在CCS项目实施过程中仍存在CO₂泄漏而影响地表环境及生态的风险.本研究以龙粳31号和龙稻18号为实验对象,模拟研究地质封存CO₂以不同速率泄漏对稻田水环境基础水质指标D_CO2、pH、DO和ORP的影响,探讨稻田水对地质封存CO₂泄漏的响应规律.结果表明：CO₂泄漏对稻田水的D_CO2、pH、DO和ORP长期影响显著,不同CO₂泄漏速率对稻田水质指标的影响差异显著.在各指标平衡后,稻田水各水质指标均呈现明显的日变化规律,其中D_CO2呈早晚高、午间低的先减后增规律,而pH、DO和ORP均呈早晚低、午间高的先增后减规律.根据各指标差异性分析,建议将稻田水D_CO2作为稻田系统CO₂泄漏监测的主要指标,将pH、DO、ORP作为CO₂泄漏监测的辅助指标.     

Embedding CCS infrastructure into the European electricity system: a policy coordination problem

Carbon dioxide capture and storage (CCS) has recently been receiving increasing recognition in policy debates. Various aspects of possible regulatory frameworks for its implementation are beginning to be discussed in Europe. One of the issues associated with the wide use of CCS is that it requires the establishment of a carbon dioxide (CO₂) transport network, which could result in the spatial restructuring of power generation and transmission systems. This poses a significant coordination problem necessitating public planning and regulation. This paper provides a survey over multiple research strands on CCS, particularly energy system modeling and spatial optimization, pertaining to the efficient installment of CCS-related infrastructure throughout Europe. It integrates existing findings and highlights the factors that determine policy coordination needs for a potential wide implementation of CCS in the next decades.     

CO2 Capture in Pulp and Paper Mills: CO2 Balances and Preliminary Cost Assessment

This paper investigates overall CO₂ balances of combined heat and power (CHP) plants with CO₂ capture and storage (CCS) in Kraft pulp and paper mills. The CHP plants use biomass-based fuels and feature advanced gasification and combined cycle technology. Results from simple process simulations of the considered CHP plants are presented. Based on those results and taking into account the major direct and indirect changes in CO₂ emissions, the study shows that implementing CCS leads to steep emission reductions. Furthermore, a preliminary cost assessment is carried out to analyse the CO₂ mitigation cost and its dependence on the distance that the CO₂ must be transported to injection sites.     

Equal Opportunity for Biomass in Greenhouse Gas Accounting of CO2 Capture and Storage: A Step Towards More Cost-Effective Climate Change Mitigation Regimes

Carbon dioxide capture and permanent storage (CCS) is one of the most frequently discussed technologies with the potential to mitigate climate change. The natural target for CCS has been the carbon dioxide (CO₂) emissions from fossil energy sources. However, CCS has also been suggested in combination with biomass during recent years. Given that the impact on the earth's radiative balance is the same whether CO₂ emissions of a fossil or a biomass origin are captured and stored away from the atmosphere, we argue that an equal reward should be given for the CCS, independent of the origin of the CO₂. The guidelines that provide assistance for the national greenhouse gas (GHG) accounting under the Kyoto Protocol have not considered CCS from biomass (biotic CCS) and it appears that it is not possible to receive emission credits for biotic CCS under the first commitment period of the Kyoto Protocol, i.e., 2008–2012. We argue that it would be unwise to exclude this GHG mitigation alternative from the competition with other GHG mitigation options. We also propose a feasible approach as to how emission credits for biotic CCS could be included within a future accounting framework.     

Reducing the energy penalty of CO2 capture and compression using pinch analysis

Integration of CO₂ capture and storage (CCS) into coal-fired power stations is seen as a way of significantly reducing the carbon emissions from stationary sources. A large proportion of the estimated cost of CCS is because of the additional energy expended to capture the CO₂ and compress it for transport and storage, reducing the energy efficiency of the power plant. This study uses pinch analysis and heat integration to reduce the overall energy penalty and, therefore, the cost of implementing CCS for power plants where the additional heat and power for the CCS plant will be provided by the existing power plant. A combined pinch analysis and linear programming optimisation are applied to determine targets for the energy penalty of existing power plants. Two existing pulverised brown coal power plants with new CCS plants using solvent absorption are used as the basis for the study that show the energy penalty can be reduced by up to 50% by including effective heat integration. The energy penalty can be further reduced by pre-drying the coal.     

Mediterranean shrublands carbon sequestration: environmental and economic benefits

To date, only a few attempts have been done to estimate the contribution of Mediterranean ecosystems to the global carbon cycle. Within this context, shrub species, composition and structure of the Mediterranean shrublands developing along the Latium coast (Italy) were analyzed in order to evaluate their contribution to carbon (C) sequestration, also taking into consideration the economic benefits at a national level. The considered shrublands had a shrub density of 1,200?±?500 shrubs ha^?1. Shrubs were classified into small (S), medium (M) and large (L), according to their volume (V) and leaf area index (LAI). The total yearly carbon dioxide (CO₂) sequestration per species (SC_y) was calculated multiplying the total photosynthetic leaf surface area (spt) of each species by the mean yearly photosynthetic rate and the total yearly photosynthetic activity time (in hours). Q. ilex and A. unedo had the highest SC_y (46.2?±?15.8 kg CO₂ year^?1, mean value), followed by P. latifolia (17.5?±?6.2 kg CO₂ year^?1), E. arborea, E. multiflora, C. incanus, P. lentiscus, R. officinalis, and S. aspera (6.8?±?4.2 kg CO₂ year^?1, mean value). The total yearly CO₂ sequestration per shrub (SC_shy) was 149?±?5 kg CO₂ year^?1 in L, decreasing 30 % in M and 80 % in S shrubs. Taking into account the frequency of S, M and L and their SC_shy, the total CO₂ sequestration of the Mediterranean maquis was quantified in 80 Mg CO₂ ha^?1?year^?1, corresponding to 22 Mg C ha^?1?year^?1. From a monetary viewpoint, this quantity could be valued to more than 500 US$ ha^?1?year^?1. Extending this benefit to the Mediterranean shrublands throughout the whole country, we obtained a nationwide estimated annual benefit in the order of $500 million.     

Biomass-based carbon capture and utilization in kraft pulp mills

Corporate image, European Emission Trading System and Environmental Regulations, encourage pulp industry to reduce carbon dioxide (CO₂) emissions. Kraft pulp mills produce CO₂ mainly in combustion processes. The largest sources are the recovery boiler, the biomass boiler, and the lime kiln. Due to utilizing mostly biomass-based fuels, the CO₂ is largely biogenic. Capture and storage of CO₂ (CCS) could offer pulp and paper industry the possibility to act as site for negative CO₂ emissions. In addition, captured biogenic CO₂ can be used as a raw material for bioproducts. Possibilities for CO₂ utilization include tall oil manufacturing, lignin extraction, and production of precipitated calcium carbonate (PCC), depending on local conditions and mill-specific details. In this study, total biomass-based CO₂ capture and storage potential (BECCS) and potential to implement capture and utilization of biomass-based CO₂ (BECCU) in kraft pulp mills were estimated by analyzing the impacts of the processes on the operation of two modern reference mills, a Nordic softwood kraft pulp mill with integrated paper production and a Southern eucalyptus kraft pulp mill. CO₂ capture is energy-intensive, and thus the effects on the energy balances of the mills were estimated. When papermaking is integrated in the mill operations, energy adequacy can be a limiting factor for carbon capture implementation. Global carbon capture potential was estimated based on pulp production data. Kraft pulp mills have notable CO₂ capture potential, while the on-site utilization potential using currently available technologies is lower. The future of these processes depends on technology development, desire to reuse CO₂, and prospective changes in legislation.

     

Persuasiveness,importance and novelty of arguments about Carbon Capture and Storage

Carbon Capture and Storage (CCS) is a promising technology for reducing carbon emissions, but the public is often reluctant to support it. To understand why public support is lacking, it is crucial to establish what citizens think about the arguments that are used by proponents and opponents of CCS. We determined the persuasiveness, importance and novelty of 32 arguments for and against CCS using a discrete choice experiment in which respondents made consecutive choices between pairs of pro or con arguments. We used latent class models to identify population segments with different preferences. The results show that citizens find arguments about climate protection, which is the primary goal of CCS, less persuasive than other arguments, such as normative arguments (for example ‘a waste product such as CO₂ should be disposed of properly’) or arguments about benefits of CCS for energy production and economic growth. This discrepancy complicates communication that aims to convince citizens of the benefits of CCS for climate protection.     

Exploring CCS community acceptance and public participation from a human and social capital perspective

The delay or cancellation of energy infrastructure projects, such as wind farms and nuclear power plants and more recently carbon capture and storage (CCS) because of community resistance and poor public participation processes are well known. Yet, some communities accept these projects with relative ease. The term acceptance implies passivity and as such does not necessarily reflect community approval or support. If acceptance is passive, what are the characteristics of a community in which the acceptance of CCS is achieved with relative ease; and what best-practice public participation processes are most appropriate for it? This paper attempts to answer these questions through a case study of Australia's Otway Project. Qualitative research methods were used to conduct a human and social capital analysis of the Otway community. An assessment of the project's public participation process was made in light of that analysis. The study found that the community needed capacity-building to enable it to become well-informed about CCS; and to help it develop the negotiation skills necessary to have the proponent address its concerns about the project in a timely manner. An assessment of the Otway public participation process found that while it implemented the majority of best practice principles in public participation, it lacked an adherence to three: transparency, fairness and capacity. A mindfulness of all principles of best practice in public participation would have ensured a fairer and more transparent process.     

Deep Geological CO2 Storage: Principles Reviewed, and Prospecting for Bio-energy Disposal Sites

The principles of hydrocarbon exploration and production provide well-established and tested principles and technologies to investigate storage of fluids in the subsurface. CO₂ can be stored in the subsurface using settings of: (A) thick permeable coal seams; (B) depleted oil and gas fields; (C) saline aquifers of regional extent, with an overlying seal. The North Sea Sleipner project shows that CO₂ can be injected into the pore space of deep geological aquifers deeper than 800 m at 1 Mt/yr, using established technology. Suitable sediment sequences of saline aquifers exist in all hydrocarbon-producing areas, are volumetrically much larger than exploited oil and gas fields, and hold the potential to easily store all worldwide CO₂ emissions until 2050. Geological principles are established to assess entire continents for candidate sites of CO₂ storage. This shows that opportunity may be widespread, but needs more specific local investigations. Onshore sub-Saharan Africa is considered the most problematic region – but even here there are potentially viable sediment sequences. No demonstration projects currently exist for CO₂ capture and storage using small-scale onshore facilities. A simple estimate, assuming CO₂ value of $20 per ton, suggests that single boreholes onshore may be viable over 20 years with supply rates of 100,000 ton CO₂ per year. In principle, atmospheric CO₂ could be captured by cultivated biomass, and co-fired in existing power stations. Or energy crops could be grown, CO₂ to be used, and stored deep below ground, in a country distant from an original fossil-fuel CO₂ emission site.     

Public acceptance and risk-benefit perception of CO<Subscript>2</Subscript> geological storage for global warming mitigation in Japan

CO₂ geological storage will be one of the cost-effective options for global warming mitigation, and this technology is under development widely in the world. However, the technology may face the challenge of public acceptance before its implementation. In order to evaluate the public acceptance, questionnaire surveys were conducted among Japanese university students. A cognitive map of geological storage, together with other major global warming mitigation options, everyday life activities, etc., was constructed by means of a statistical analysis of the responses to the questionnaire. The risk-benefit cognitive map consists of the following factors: “risk perception,” “benefit perception,” and “public acceptance.” The risk perception is further disaggregated into “dread risk” and “unknown risk.” Additionally, a second survey was conducted after providing the students with additional information on global warming and CO₂ geological storage, and the effects of the information on their perceptions were evaluated. The effects of risk and benefit perceptions on public acceptance were evaluated and discussed based on the cognitive maps representing the perceptions before and after providing the information. The analyses revealed that the benefit perception was more influential than the risk perception on the public acceptance of CO₂ geological storage. The benefit perception increased greatly after providing the information; however, the unknown risk remained considerably large. Further, RD&D relating unknown risk, for example, the monitoring technology for stored CO₂ and the risk assessment of CO₂ leakage, and the supply of related information to the public would be beneficial for increasing the public acceptance.     

Negative emissions of carbon dioxide through chemical-looping combustion (CLC) and gasification (CLG) using oxygen carriers based on manganese and iron

Carbon capture and storage (CCS) is an economically attractive strategy for avoiding carbon dioxide (CO₂) emissions from, e.g., power plants to the atmosphere. The combination of CCS and biomass combustion would result in a reduction of atmospheric CO₂, or net negative emissions, as plant growth is a form of sequestration of atmospheric carbon. Carbon capture can be achieved in a variety of ways, one of which is chemical looping. Chemical-looping combustion (CLC) and chemical looping gasification (CLG) are two promising technologies for conversion of biomass to heat and power or syngas/methane with carbon capture. There have been significant advances made with respect to CLC in the last two decades for all types of fuel, with much less research on the gasification technology. CLG offers some interesting opportunities for production of biofuels together with carbon capture and may have several advantages with respect to the bench mark indirect gasification process or dual-bed fluidized bed (DFBG) in this respect. In CLG, an oxygen carrier is used as a bed material instead of sand, which is common in indirect gasification, and this could have several advantages: (i) all generated CO₂ is present together with the syngas or methane in the fuel reactor outlet stream, thus in a concentrated stream, viable for separation and capture; (ii) the air reactor (or combustion chamber) should largely be free from trace impurities, thus preventing corrosion and fouling in this reactor; and (iii) the highly oxidizing conditions in the fuel reactor together with solid oxide surfaces should be advantageous with respect to limiting formation of tar species. In this study, two manganese ores and an iron-based waste material, LD slag, were investigated with respect to performance in these chemical-looping technologies. The materials were also impregnated with alkali (K) in order to gauge possible catalytic effects and also to establish a better understanding of the general behavior of oxygen carriers with alkali, an important component in biomass and biomass waste streams and often a precursor for high-temperature corrosion. The viability of the oxygen carriers was investigated using a synthetic biogas in a batch fluidized bed reactor. The conversion of CO, H₂, CH₄, and C₂H₄ was investigated in the temperature interval 800–950 °C. The reactivity, or oxygen transfer rate, was highest for the manganese ores, followed by the LD slag. The conversion of C₂H₄ was generally high but could largely be attributed to thermal decomposition. The K-impregnated samples showed enhanced reactivity during combustion conditions, and the Mangagran-K sample was able to achieve full conversion of benzene. The interaction of the solid material with alkali showed widely different behavior. The two manganese ores retained almost all alkali after redox testing, albeit exhibiting different migration patterns inside the particles. LD slag lost most alkali to the gas phase during testing, although some remained, possibly explaining a small difference in reactivity. In summary, the CLC and CLG processes could clearly be interesting for production of heat, power, or biofuel with negative CO₂ emissions. Manganese ores are most promising from this study, as they could absorb alkali, giving a better conversion and perhaps also inhibiting or limiting corrosion mechanisms in a combustor or gasifier.

     

加速碳酸化技术对城市垃圾焚烧飞灰重金属稳定性影响研究

对南方某城市生活垃圾焚烧厂新鲜焚烧飞灰对CO₂的吸收及其碳酸化的过程进行了研究,实验从水分添加量、CO₂的分压等因素,考察了飞灰中重金属Pb的稳定化效果,并利用X射线衍射实验(XRD)、扫描电镜实验(SEM)对反应机理进行了分析.结果表明,不添加水分时,焚烧飞灰对CO₂的吸收效果较差;当水分添加量大于10％时,焚烧飞灰对CO₂的吸收效果较好.焚烧飞灰对纯CO₂的吸收效果较好,空气中的CO₂含量较低,在反应1 d后吸收效果不是十分明显.XRD实验结果表明,CO₂的吸收会使焚烧飞灰中大量的Ca(OH)₂与CO₂反应转化为CaCO₃,从而降低焚烧飞灰的碱性;部分重金属的氧化物会被碳酸化成生相应的碳酸盐.SEM实验结果表明,经过碳酸化处理后的飞灰颗粒表面生成了片状和圆柱状的晶体物质.     

Obstacles for CCS deployment: an analysis of discrepancies of perceptions

The potential for CO₂ emission reductions through carbon capture and storage (CCS) is depending on investments that can bring the technology from the current R&D through to commercial applications. The intermediate step in this development is demonstration plants that can prove the technical, economic, social, and ecological feasibility of CCS technologies. Based on a CCS stakeholder questionnaire survey and a literature review, we critically analyse discrepancies regarding perceptions of deployment obstacles and experiences from early demonstration plants. The analysis identifies discrepancies between CCS policies versus important deployment considerations and CCS stakeholder policy demands. The discrepancy gap is emphasised by lessons from restructured, postponed, and cancelled CCS projects. To bridge this cognitive gap towards proving CCS through demonstration activities, the article highlights policy implications of establishing a broad understanding of deployment obstacles. Attention to these obstacles is important for policymakers and industry in channelling efforts to demonstrating CCS, hence validating the current focus on CCS as a key abatement potential. Under present conditions, the findings question the robustness of current CCS abatement potential estimates and deployment goals as established by policymakers and in scenarios.