Analysis of possible geological storage of CO2 and nuclear waste in Lithuania

Lithuania is currently dealing with two major problems in energy sector: final closure of Ignalina Nuclear Power plant (Ignalina NPP) in the end of 2009 and nuclear waste disposal and climate change mitigation issues having in mind replacement of nuclear capacities with fossil one and anticipated increase in GHG emissions. Lithuania has two options: to construct new nuclear power plant also taking into account nuclear waste disposal issue or to burn fossil fuel and to apply carbon capture and storage (CCS) for GHG emission reduction. These two options need to be investigated in Lithuania based on various studies conducted in Lithuania and abroad dealing with geological carbon storage and nuclear waste disposal potentials. There are no long-lived nuclear waste geological storage capacities in Lithuania and there is no pilot project on CCS developed in Lithuania. The aim of the article is to analyse and compare geological carbon and nuclear waste storage opportunities in Lithuania and to assess nuclear and carbon capture and storage technologies in terms of costs.     

Comparative assessment of future power generation technologies based on carbon price development

The long-term assessment of new electricity generation was performed for various long-run policy scenarios taking into account two main criteria: private costs and external GHG emission costs. Such policy oriented power generation technologies assessment based on carbon price and private costs of technologies can provide information on the most attractive future electricity generation technologies taking into account climate change mitigation targets and GHG emission reduction commitments for world regions.Analysis of life cycle GHG emissions and private costs of the main future electricity generation technologies performed in this paper indicated that biomass technologies except large scale straw combustion technologies followed by nuclear have the lowest life cycle GHG emission. Biomass IGCC with CO₂ capture has even negative life cycle GHG emissions. The cheapest future electricity generation technologies in terms of private costs in long-term perspective are: nuclear and hard coal technologies followed by large scale biomass combustion and biomass CHPs. The most expensive technologies in terms of private costs are: oil and natural gas technologies. As the electricity generation technologies having the lowest life cycle GHG emissions are not the cheapest one in terms of private costs the ranking of technologies in terms of competitiveness highly depend on the carbon price implied by various policy scenarios integrating specific GHG emission reduction commitments taken by countries and climate change mitigation targets.     

Bottom–up assessment of potentials and costs of CO2 emission mitigation in the buildings sector: insights into the missing elements

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) has calculated and shown that, currently, the buildings sector has the largest potential for low-cost carbon dioxide (CO₂) mitigation in the short to medium term from application of technological options among the sectors examined, based on bottom–up studies. The potential estimates, however, were derived with no regard to indirect costs of CO₂ mitigation, associated benefits, and non-technological options; these factors might change the magnitude of the potential and the costs associated with its implementation. The question emerges how accurate the indicators of the economic potential are according to the current IPCC method and how much they might change if all factors mentioned were taken into account. While research results are presently not sufficient to fully answer this question and quantitative analyses of non-technological options, transaction costs associated with barriers, and non-energy benefits are scarce and fragmented, this paper makes a first attempt to assess the presently available literature in the field. The paper concludes that the ballpark is right for the figures reporting the cost-effective potentials in the buildings sector; however, these assessments indeed need to be corrected by incurred transaction costs and co-benefits relevant for the particular assessment, as well as the potential of non-technological options. The paper also outlines a research agenda in the area so that a possible next Assessment Report of the IPCC can derive a more accurate estimate of the bottom–up potential of CO₂ mitigation.     

Life cycle sustainability assessment of electricity options for the UK

The UK electricity mix will change significantly in the future. This provides an opportunity to consider the full life cycle sustainability of the options currently considered as most suitable for the UK: gas, nuclear, offshore wind and photovoltaics (PV). In an attempt to identify the most sustainable options and inform policy, this paper applies a sustainability assessment framework developed previously by the authors to compare these electricity options. To put discussion in context, coal is also considered as a significant contributor to the current electricity supply. Each option is assessed and compared in terms of its economic, environmental and social implications, using a range of sustainability indicators. The results show that no one technology is superior and that certain trade‐offs must be made. For example, nuclear and offshore wind power have the lowest life cycle environmental impacts, except for freshwater ecotoxicity for which gas is the best option; coal and gas are the cheapest options (£74 and 66/MWh, respectively, at 10% discount), but both have high global warming potential (1072 and 379 g CO₂ eq./kWh); PV has relatively low global warming potential (88 g CO₂ eq./kWh) but high cost (£302/MWh), as well as high ozone layer and resource depletion. Nuclear, wind and PV increase some aspects of energy security: in the case of nuclear, this is due to inherent fuel storage capabilities (energy density 290 million times that of natural gas), whereas wind and PV decrease fossil fuel import requirements by up to 0.2 toe/MWh. However, all three options require additional installed capacity for grid management. Nuclear also poses complex risk and intergenerational questions such as the creation of 10.16 m³/TWh of nuclear waste for long‐term geological storage. Copyright © 2012 John Wiley & Sons, Ltd.     

Assessment of CO2 storage potential and carbon capture,utilization and storage prospect in China

Carbon capture, utilization and storage (CCUS) is regarded as a very promising technology to reduce CO₂ emission in China, which could improve the contradiction between economic development and environment protection. In order to study the CO₂ storage potential for deploying CCUS projects in China, considering China's special geological features and current national conditions, a new evaluation method of CO₂ storage capacity was proposed using the mass balance approach combined with various CO₂ storage mechanisms in different formations, and the CO₂ storage capacity was calculated in saline aquifer for CO₂-EWR, oil reservoir for CO₂-EOR and coal bed for CO₂-ECBM respectively. The result shows that China has great CO₂ storage potential, which is estimated to be over 1841 Gt. The different features and application prospect of CO₂-EWR, CO₂-EOR and CO₂-ECBM in China were analyzed, which give guidance on critical technologies breakthrough and costs reduction along the CCUS chain. With the joint effort and support by policy and finance, CCUS will make great contribution to the development of low carbon economy for China and the world.     

Techno-economic evaluation of coal-to-liquids (CTL) plants with carbon capture and sequestration

Coal-to-liquids (CTL) processes that generate synthetic liquid fuels from coal are of increasing interest in light of the substantial rise in world oil prices in recent years. A major concern, however, is the large emissions of CO₂ from the process, which would add to the burden of atmospheric greenhouse gases. To assess the options, impacts and costs of controlling CO₂ emissions from a CTL plant, a comprehensive techno-economic assessment model of CTL plants has been developed, capable of incorporating technology options for carbon capture and storage (CCS). The model was used to study the performance and cost of a liquids-only plant as well as a co-production plant, which produces both liquids and electricity. The effect of uncertainty and variability of key parameters on the cost of liquids production was quantified, as were the effects of alternative carbon constraints such as choice of CCS technology and the effective price (or tax) on CO₂ emissions imposed by a climate regulatory policy. The efficiency and CO₂ emissions from a co-production plant also were compared to the separate production of liquid fuels and electricity. The results for a 50,000 barrels/day case study plant are presented.     

Evaluation of geologic storage options of CO2: Applicability,cost, storage capacity and safety

CO₂ emissions in the atmosphere are increasing continually, which are mainly originated from burning of fossil fuels. The fossil fuels are expected to remain a major component of the world’s energy supply in the near future, because of their inherent advantages. Therefore, various measures have to be considered to reduce anthropogenic CO₂ emissions. Increasing the efficiency of energy usage and/or developing lower carbon or non-carbon energies to replace high carbon fuels may bring the result of the reduction of the accumulation of CO₂ in the atmosphere. The other alternative to reduce CO₂ concentrations in atmosphere include gaseous storage in various deep geological formations, liquid storage in the ocean, and solid storage by reaction of CO₂ with metal oxides to produce stable carbonates. In this article, the geological storage options of CO₂ are examined. They are discussed in terms of applicability, cost, storage capacity and safety.     

External costs of electricity generation options in Lithuania

This article deals with external cost of electricity generation in Lithuania. The external costs of electricity generation are the most important environmental criteria shaping decisions within the electricity system. External costs of electricity generation were calculated based on ExternE methodology for Lithuania during EU (European Union) Framework 6 project Cost Assessment for Sustainable Energy Systems (CASES). The article presents the methodology and results of external costs of electricity generation in Lithuania. The assessment of external costs provided that future energy policy should be oriented towards the renewable energy generation technologies having the lowest external costs. External costs for electricity generation technologies were analysed in terms of external costs categories, electricity generation technologies life cycle stages and time frame 2010–2030.     

Needs, resources and climate change: Clean and efficient conversion technologies

Energy “powers” our life, and energy consumption correlates strongly with our standards of living. The developed world has become accustomed to cheap and plentiful supplies. Recently, more of the developing world populations are striving for the same, and taking steps towards securing their future energy needs. Competition over limited supplies of conventional fossil fuel resources is intensifying, and more challenging environmental problems are springing up, especially related to carbon dioxide (CO₂) emissions. There is strong evidence that atmospheric CO₂ concentration is well correlated with the average global temperature. Moreover, model predictions indicate that the century-old observed trend of rising temperatures could accelerate as carbon dioxide concentration continues to rise. Given the potential danger of such a scenario, it is suggested that steps be taken to curb energy-related CO₂ emissions through a number of technological solutions, which are to be implemented in a timely fashion. These solutions include a substantial improvement in energy conversion and utilization efficiencies, carbon capture and sequestration, and expanding the use of nuclear energy and renewable sources. Some of these technologies already exist, but are not deployed at sufficiently large scale. Others are under development, and some are at or near the conceptual state.     

Non-nuclear,low-carbon,or both? The case of Taiwan

The Fukushima nuclear accident in Japan has renewed debates on the safety of nuclear power, possibly hurting the role of nuclear power in efforts to limit CO₂ emissions. I develop a dynamic economy-wide model of Taiwan with a detailed set of technology options in the power sector to examine the implications of adopting different carbon and nuclear power policies on CO₂ emissions and the economy. Without a carbon mitigation policy, limiting nuclear power has a small economic cost for Taiwan, but CO₂ emissions may increase by around 4.5% by 2050 when nuclear is replaced by fossil-based generation. With a low-carbon target of a 50% reduction from year 2000 levels by 2050, the costs of cutting CO₂ emissions are greatly reduced if both carbon sequestration and nuclear expansion were viable. This study finds that converting Taiwan's industrial structure into a less energy-intensive one is crucial to carry out the non-nuclear and low-carbon environment.     

Materials challenges in CO2 capture and storage

Abstract

To achieve deep reductions in CO₂ emission from power generation, technologies for CO₂ capture and storage are required to complement other approaches such as improved fuel use efficiency, the switch to low carbon fuels, and the use of renewable and nuclear energy. Three main options currently exist for CO₂ capture: removal of CO₂ from the flue gas; removal of carbon from the fuel before combustion; and oxyfuel combustion systems that have CO₂ and water, which can be separated by condensation, as principal combustion products. On the transport and storage side, the materials issues arise from corrosion and may be solved by drying and purification of the CO₂ stream. On the capture side, there are few specific issues regarding the materials used in technologies such as chemical absorption of CO₂ in an appropriate solvent (usually amines). The high temperature membranes used to separate oxygen from nitrogen in oxyfuel combustion systems raise materials issues in relation to ionic conduction, thermal and mechanical stability and lifetime when integrated in boilers, fluidised beds and gas turbine systems. The performance of systems integrating ceramic oxygen separating membranes is largely dependant on operating temperature, so the behaviour of these materials at ever higher temperatures is a real technical challenge. Membranes can also be used instead of chemical absorption for the separation of CO₂ and hydrogen in fuel de-carbonisation.     

The environmental impact and risk assessment of CO2 capture, transport and storage - An evaluation of the knowledge base

In this study, we identify and characterize known and new environmental consequences associated with CO₂ capture from power plants, transport by pipeline and storage in geological formations. We have reviewed (analogous) environmental impact assessment procedures and scientific literature on carbon capture and storage (CCS) options. Analogues include the construction of new power plants, transport of natural gas by pipelines, underground natural gas storage (UGS), natural gas production and enhanced oil recovery (EOR) projects. It is investigated whether crucial knowledge on environmental impacts is lacking that may postpone the implementation of CCS projects. This review shows that the capture of CO₂ from power plants results in a change in the environmental profile of the power plant. This change encompasses both increase and reduction of key atmospheric emissions, being: NO_x, SO₂, NH₃, particulate matter, Hg, HF and HCl. The largest trade-offs are found for the emission of NO_x and NH₃ when equipping power plants with post-combustion capture. Synergy is expected for SO₂ emissions, which are low for all power plants with CO₂ capture. An increase in water consumption ranging between 32% and 93% and an increase in waste and by-product creation with tens of kilotonnes annually is expected for a large-scale power plant (1 GW_e), but exact flows and composition are uncertain. The cross-media effects of CO₂ capture are found to be uncertain and to a large extent not quantified. For the assessment of the safety of CO₂ transport by pipeline at high pressure an important knowledge gap is the absence of validated release and dispersion models for CO₂ releases. We also highlight factors that result in some (not major) uncertainties when estimating the failure rates for CO₂ pipelines. Furthermore, uniform CO₂ exposure thresholds, detailed dose-response models and specific CO₂ pipeline regulation are absent. Most gaps in environmental information regarding the CCS chain are identified and characterized for the risk assessment of the underground, non-engineered, part of the storage activity. This uncertainty is considered to be larger for aquifers than for hydrocarbon reservoirs. Failure rates are found to be heavily based on expert opinions and the dose-response models for ecosystems or target species are not yet developed. Integration and validation of various sub-models describing fate and transport of CO₂ in various compartments of the geosphere is at an infant stage. In conclusion, it is not possible to execute a quantitative risk assessment for the non-engineered part of the storage activity with high confidence.     

CO2 chemical conversion to useful products: An engineering insight to the latest advances toward sustainability

In the fossil‐fuel‐based economies, current remedies for the CO₂ reduction from large‐scale energy consumers (e.g. power stations and cement works) mainly rely on carbon capture and storage, having three proposed generic solutions: post‐combustion capture, pre‐combustion capture, and oxy fuel combustion. All the aforementioned approaches are based on various physical and chemical phenomena including absorption, adsorption, and cryogenic capture of CO₂. The purified carbon dioxide is sent for the physical storage options afterwards, using the earth as a gigantic reservoir with unknown long‐term environmental impacts as well as possible hazards associated with that. Consequently, the ultimate solution for the CO₂ sequestration is the chemical transformation of this stable molecule to useful products such as fuels (through, for example, Fischer–Tropsch chemistry) or polymers (through successive copolymerization and chain growth). This sustainably reduces carbon emissions, taking full advantage of CO₂‐derived chemical commodities, so‐called carbon capture and conversion. Nevertheless, the surface chemistry of CO₂ reduction is a challenge due to the presence of large energy barriers, requiring noticeable catalysis. This work aims to review the most recent advances in this concept selectively (CO₂ conversion to fuels and CO₂ copolymerization) with chemical engineering approach in terms of both materials and process design. Some of the most promising studies are expanded in detail, concluding with the necessity of subsidizing more research on CO₂ conversion technologies considering the growing global concerns on carbon management. Copyright © 2013 John Wiley & Sons, Ltd.     

Pore scale CFD simulation of supercritical carbon dioxide drainage process in porous media saturated with water

During the geological carbon sequestration, the short-term behavior of CO₂ is controlled mainly by two-phase flow of supercritical carbon dioxide (ScCO₂) and water in saline aquifers. A better understanding of ScCO₂-water two-phase flow in the porous media under the geological conditions will improve predictions of the long-term CO₂ storage reliability. In this paper, the computational fluid dynamic (CFD) simulation method was used to study the flow and distribution of ScCO₂ and water in the porous media at the pore scale. It was found that as the contact angle decreases and the surface tension increases, the relative permeability of water increases and the relative permeability of carbon dioxide decreases. As the viscosity ratio increases, the relative permeability of carbon dioxide increases, but the relative permeability of water does not change significantly.     

Cost-effective CO2 emission reduction through heat,power and biofuel production from woody biomass: A spatially explicit comparison of conversion technologies

Bioenergy is regarded as cost-effective option to reduce CO₂ emissions from fossil fuel combustion. Among newly developed biomass conversion technologies are biomass integrated gas combined cycle plants (BIGCC) as well as ethanol and methanol production based on woody biomass feedstock. Furthermore, bioenergy systems with carbon capture and storage (BECS) may allow negative CO₂ emissions in the future. It is still not clear which woody biomass conversion technology reduces fossil CO₂ emissions at least costs. This article presents a spatial explicit optimization model that assesses new biomass conversion technologies for fuel, heat and power production and compares them with woody pellets for heat production in Austria. The spatial distributions of biomass supply and energy demand have significant impact on the total supply costs of alternative bioenergy systems and are therefore included in the modeling process. Many model parameters that describe new bioenergy technologies are uncertain, because some of the technologies are not commercially developed yet. Monte-Carlo simulations are used to analyze model parameter uncertainty. Model results show that heat production with pellets is to be preferred over BIGCC at low carbon prices while BECS is cost-effective to reduce CO₂ emissions at higher carbon prices. Fuel production – methanol as well as ethanol – reduces less CO₂ emissions and is therefore less cost-effective in reducing CO₂ emissions.     

CO2 storage in geological media: Role,means, status and barriers to deployment

Carbon dioxide capture and geological storage is an enabling technology that will allow the continued use well into this century of fossil fuels, mainly coal, for power generation and combustion in industrial processes because they are relatively abundant, cheap, available and globally distributed, thus enhancing the security and stability of energy systems. Geological media suitable for CO₂ storage through various physical and chemical trapping mechanisms must have the necessary capacity and injectivity, and must confine the CO₂ and impede its lateral migration and/or vertical leakage to other strata, shallow potable groundwater, soils and/or atmosphere. Such geological media are mainly oil and gas reservoirs and deep saline aquifers that are found in sedimentary basins. Storage of gases, including CO₂, in these media has been demonstrated on a commercial scale by enhanced oil recovery operations, natural gas storage and acid gas disposal. Some of the risks associated with CO₂ capture and geological storage are similar to, and comparable with, any other industrial activity for which extensive safety and regulatory frameworks are in place. Specific risks associated with CO₂ storage relate to the operational (injection) phase and to the post-operational phase, of which the risks of most concern are those posed by the potential for acute or chronic CO₂ leakage from the storage site. Notwithstanding the global climate effect of CO₂ returning to the atmosphere, the local risks to health and safety, environment and equity need to be properly assessed and managed. Currently there are very few operations in the world where CO₂ is injected and stored in the ground, mostly if not exclusively as a by-product of an operation driven by other considerations than climate change, such as oil production or regulatory requirements regarding H₂S. These operations show that there are no major technological barriers to CO₂ geological storage, and that challenges and barriers lie elsewhere. A major challenge in the implementation of CO₂ geological storage is the high cost of CO₂ capture, particularly for dilute streams like those from power plants and industrial combustion processes. There are concerns that public opinion and public's acceptance or rejection of this technology will likely affect the large-scale implementation of CO₂ geological storage. The current paucity of policy, legislation and a proper regulatory framework in most jurisdictions is presently the most significant barrier. The resolution of these challenges will affect the economics and financial risk of CO₂ geological storage and will accelerate or delay the deployment of this technology for reducing anthropogenic CO₂ emissions into the atmosphere.     

Carbon capture and storage

Carbon capture and storage (CCS) covers a broad range of technologies that are being developed to allow carbon dioxide (CO₂) emissions from fossil fuel use at large point sources to be transported to safe geological storage, rather than being emitted to the atmosphere. Some key enabling contributions from technology development that could help to facilitate the widespread commercial deployment of CCS are expected to include cost reductions for CO₂ capture technology and improved techniques for monitoring stored CO₂. It is important, however, to realise that CCS will always require additional energy compared to projects without CCS, so will not be used unless project operators see an appropriate value for reducing CO₂ emissions from their operations or legislation is introduced that requires CCS to be used. Possible key advances for CO₂ capture technology over the next 50 years, which are expected to arise from an eventual adoption of CCS as standard practice for all large stationary fossil fuel installations, are also identified. These include continued incremental improvements (e.g. many potential solvent developments) as well as possible step-changes, such as ion transfer membranes for oxygen production for integrated gasifier combined cycle and oxyfuel plants.     

Sectoral trends in global energy use and greenhouse gas emissions

Integrated assessment models have been used to project both baseline and mitigation greenhouse gas emissions scenarios. Results of these scenarios are typically presented for a number of world regions and end-use sectors, such as industry, transport, and buildings. Analysts interested in particular technologies and policies, however, require more detailed information to understand specific mitigation options in relation to business-as-usual trends. This paper presents sectoral trend for two of the scenarios produced by the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios. Global and regional historical trends in energy use and carbon dioxide emissions over the past 30 years are examined and contrasted with projections over the next 30 years. Macro-activity indicators are analyzed as well as trends in sectoral energy and carbon demand. This paper also describes a methodology to calculate primary energy and carbon dioxide emissions at the sector level, accounting for the full energy and emissions due to sectoral activities.     

Optimizing a CO2 value chain for the Norwegian Continental Shelf

This paper presents a mathematical model for designing a carbon dioxide (CO₂) value chain. Storage of CO₂ in geological formations is recognized as an important alternative for carbon abatement. When CO₂ is deposited in oil reservoirs it can sometimes be used to achieve additional oil production, enhanced oil recovery (EOR). The model determines an optimal CO₂ value chain from a fixed set of CO₂ emission points and a set of potential injection sites. It designs a transport network and chooses the best suited oil fields with EOR potential or other geological formations for storage. A net present value criterion is used. The model is illustrated by an example of a Norwegian case with 14 oil fields, two aquifers and five CO₂ sources. A sensitivity analysis is performed on the most important parameters.