The role of FIDEICOMISO of non-metallic minerals

FIDEICOMISO of non-metallic minerals is a trust development fund aimed at providing credit and technical assistance for the exploitation, beneficiation and downstream processing of non-metallics. FIDEICOMISO'S funding comes from, in order of importance, the World Bank, operational revenues and federal funds. It is a second tier financial institution operating through the commercial banking system, the latter providing the retail role. In 1987 and 1988 the FIDEICOMISO approved credits for $23 million and $46 million respectively.     

Evaluating the impact of fractures on the performance of the In Salah CO2 storage site

The In Salah Gas Joint Venture CO₂ storage project has been in operation in Algeria since 2004 and is currently the world's largest onshore CO₂ storage project. CO₂ is injected into the saline aquifer of a gas reservoir several kilometres away from the gas producers. Current focus in the project is on implementing a comprehensive monitoring strategy and modelling the injection behaviour in order to ensure and verify safe long-term storage. A key part of this effort is the understanding of the processes involved in CO₂ migration within relatively low-permeability sandstones and shales influenced by fractures and faults. We summarise our current understanding of the fault and fracture pattern at this site and show preliminary forecasts of the system performance using discrete fracture models and fluid flow simulations. Despite evidence of fractures at the reservoir/aquifer level, the thick mudstone caprock sequence is expected to provide an effective flow and mechanical seal for the storage system; however, quantification of the effects of fracture flow is essential to the site verification.     

The impact of heterogeneity on the distribution of CO2: Numerical simulation of CO2 storage at Ketzin

Numerical modelling of multiphase flow is an essential tool to ensure the viability of long-term and safe CO₂ storage in geological formations. Uncertainties arising from the heterogeneity of the formation and lack of knowledge of formation properties need to be assessed in order to create a model that can reproduce the data available from monitoring. In this study, we investigated the impact of unknown spatial variability in the petrophysical properties within a sandy channel facies of a fluviatile storage formation using stochastic methods in a Monte Carlo approach. The stochastic method has been applied to the Ketzin test site (CO₂SINK), and demonstrates that the deterministic homogeneous model satisfactorily predicts the first CO₂ arrival time at the Ketzin site. The equivalent permeability was adjusted to the injection pressure and is in good agreement with the hydraulic test. It has been shown that with increasing small-scale heterogeneity, the sharpness of the CO₂ front decreases and a greater volume of the reservoir is affected, which is also seen in an increased amount of dissolved CO₂. Increased anisotropy creates fingering effects, which result in higher probabilities for earlier arrival times. Generally, injectivity decreases with increasing heterogeneity.     

Petrochemicals from oil,natural gas,coal and biomass: Production costs in 2030–2050

Methane, coal and biomass are being considered as alternatives to crude oil for the production of basic petrochemicals, such as light olefins. This paper is a study on the production costs of 24 process routes utilizing these primary energy sources. A wide range of projected energy prices in 2030–2050 found in the open literature is used. The basis for comparison is the production cost per t of high value chemicals (HVCs or light olefin-value equivalent). A Monte Carlo method was used to estimate the ranking of production costs of all 24 routes with 10,000 trials of varying energy prices and CO₂ emissions costs (assumed to be within $0–100/t CO₂; the total CO₂ emissions, or cradle-to-grave CO₂ emissions, were considered). High energy prices in the first three quarter of 2008 were tested separately. The main findings are:

• •Production costs: while the production costs of crude oil- and natural gas-based routes are within $500–900/t HVCs, those of coal- and biomass-based routes are mostly within $400–800/t HVCs. Production costs of coal- and biomass-based routes are in general quite similar while in some cases the difference is significant. Among the top seven most expensive routes, six are oil- and gas-based routes. Among the top seven least expensive routes, six are coal and biomass routes.
• •CO₂ emissions costs: the effect of CO₂ emissions costs was found to be strong on the coal-based routes and also quite significant on the biomass-based routes. However, the effect on oil- and gas-based routes is found to be small or relatively moderate.
• •Energy prices in 2008: most of the coal-based routes and biomass-based routes (particularly sugar cane) still have much lower production costs than the oil- and gas-based routes (even if international freight costs are included).

To ensure the reduction of CO₂ emissions in the long-term, we suggest that policies for the petrochemicals industry focus on stimulating the use of biomass as well as carbon capture and storage features for coal-based routes.     

Public perceptions on the acceptance of geological storage of carbon dioxide and information influencing the acceptance

Public acceptance will be important for the implementation of the geological storage of carbon dioxide (CO₂). The purpose of this study is to evaluate how the general public perceives this storage and the factors crucial for its acceptance. Further, this study attempts to analyze and evaluate what kind of information would influence the public acceptance and how. In order to evaluate them, questionnaire surveys concerning the acceptance of CO₂ geological storage were conducted among Japanese university students. The questionnaire was designed under the assumption that there were five important factors with regard to the acceptance: risk perception, benefit perception, trust, and two perceptions relating to human interference with the environment (one each for CO₂ geological storage and global warming). The questionnaire also investigated the effects of two kinds of information supplied: on natural analogues and on field demonstrations of CO₂ storage. The responses were analyzed through confirmatory factor analysis, and the dynamic changes in the perceptions resulting from the supplied information were analyzed. The analysis results include the following: the five factors explained the acceptance very well (>83%), the benefit perception was primarily important for determining public acceptance, and information on the natural analogues decreased the risk perception greatly.     

Capture-ready coal plants—Options,technologies and economics

This paper summarizes the spectrum of options that can be employed during the initial design and construction of pulverized coal (PC), and integrated gasification and combined cycle (IGCC) plants to reduce the capital costs and energy losses associated with retrofitting for CO₂ capture at some later time in the future. It also estimates lifetime (40 year) net present value (NPV) costs of plants with differing levels of pre-investment for CO₂ capture under a wide range of CO₂ price scenarios. Three scenarios are evaluated—a baseline supercritical PC plant, a baseline IGCC plant and an IGCC plant with pre-investment for capture. This analysis evaluates each technology option under a range of CO₂ price scenarios and determines the optimum year of retrofit, if any. The results of the analysis show that a baseline PC plant is the most economical choice under low CO₂ prices, and IGCC plants are preferable at higher CO₂ prices (e.g., an initial price of about $22/t CO₂ starting in 2015 and growing at 2%/year). Little difference is seen in the lifetime NPV costs between the IGCC plants with and without pre-investment for CO₂ capture. This paper also examines the impact of technology choice on lifetime CO₂ emissions. The difference in lifetime emissions become significant only under mid-estimate CO₂ price scenarios (roughly between $20 and 40/t CO₂) where IGCC plants will retrofit sooner than a PC plant.     

Numerical simulations on the influence of matrix diffusion to carbon sequestration in double porosity fissured aquifers

The double porosity model for fissured rocks, such as limestones and dolomites, has some features that may be relevant for carbon sequestration. Numerical simulations were conducted to study the influence of matrix diffusion on the trapping mechanisms relevant for the long-term fate of CO₂ injected in fissured rocks. The simulations show that, due to molecular diffusion of CO₂ into the rock matrix, dissolution trapping and hydrodynamic trapping are more effective in double porosity aquifers than in an equivalent porous media. Mineral trapping, although assessed indirectly, is also probably more relevant in double porosity aquifers due to the larger contact surface and longer contact time between dissolved CO₂ and rock minerals. However, stratigraphic/structural trapping is less efficient in double porosity media, because at short times CO₂ is stored only in the fissures, requiring large aquifer volumes and increasing the risk associated to the occurrence of imperfections in the cap-rock through which leakage can occur. This increased risk is also a reality when considering storage in aquifers with a regional flow gradient, since the CO₂ free-phase will move faster due to the higher flow velocities in fissured media and discharge zones may be reached sooner.     

Techno-Economic Study of CO2 Capture from an Existing Cement Plant Using MEA Scrubbing

Carbon dioxide is the major greenhouse gas responsible for global warming. Man-made CO₂ emissions contribute approximately 63% of greenhouse gases and the cement industry is responsible for approximately 5% of CO₂ emissions emitting nearly 900 kg of CO₂ per 1000 kg of cement. CO₂ from a cement plant was captured and purified to 98% using the monoethanolamine (MEA) based absorption process. The capture cost was $51 per tonne of CO₂ captured, representing approximately 90% of total cost. Steam was the main operating cost representing 39% of the total capture cost. Switching from coal to natural gas reduces CO₂ emissions by about 18%. At normal load, about 36 MW of waste heat is available for recovery to satisfy the parasitic heat requirements of MEA process; however, it is very difficult to recover.     

Geochemical and solute transport modelling for CO2 storage, what to expect from it?

Geochemistry plays an important role when assessing the impact of CO₂ storage. Due to the potential corrosive character of CO₂, it might affect the chemical and physical properties of the wells, the reservoir and its surroundings and increase the environmental and financial risk of CO₂ storage projects in deep geological structures. An overview of geochemical and solute transport modelling for CO₂ storage purposes is given, its data requirements and gaps are highlighted, and its progress over the last 10 years is discussed. Four different application domains are identified: long-term integrity modelling, injectivity modelling, well integrity modelling and experimental modelling and their current state of the art is discussed. One of the major gaps remaining is the lack of basic thermodynamical and kinetic data at relevant temperature and pressure conditions for each of these four application domains. Real challenges are the coupled solute transport and geomechanical modelling, the modelling of impurities in the CO₂ stream and pore-scale modelling applications.     

“The Schweinrich structure”, a potential site for industrial scale CO2 storage and a test case for safety assessment in Germany

The identification of risks associated with the geological storage of CO₂ requires methods that can analyse and assess potential safety hazards. This paper evaluates how performance assessment can be used as a method for assessing the impact of CO₂ storage on health, safety and the environment (HSE) with particular respect to potential future aquifer storage in the anticlinal structure Schweinrich in Germany. The performance assessment was conducted under the CO2STORE European Fifth Framework project as one of the four cases on the aquifer storage of CO₂. It is known as the Schwarze Pumpe case study.Being a case study, it is restrictive from a feasibility study point of view—i.e., the extended identification of the key safety factors where an actual CO₂ storage project would be considered for the Schweinrich structure. The study is based on data currently available, gathered in prior surveys, and on the use of simplified models, with CO₂ leakage levels from natural analogues being the evaluation criteria. While the results should be interpreted as provisional, they point out clearly which additional data should be gathered in relation to the long-term storage performance in the event that the site warrants further investigation.     

Assessing Public Preferences for Forest Biomass Based Energy in the Southern United States

This article investigated public preferences for forest biomass based liquid biofuels, particularly ethanol blends of 10% (E10) and 85% (E85). We conducted a choice experiment study in three southern states in the United States: Arkansas, Florida, and Virginia. Reducing atmospheric CO₂, decreasing risk of wildfires and pest outbreaks, and enhancing biodiversity were presented to respondents as attributes of using biofuels. Results indicated that individuals had a positive extra willingness to pay (WTP) for both ethanol blends. The extra WTP was greater for higher blends that offered larger environment benefits. The WTPs for E10 were $0.56 gallon^?1, $0.58 gallon^?1, and $0.48 gallon^?1, and for E85 they were $0.82 gallon^?1, $1.17 gallon^?1, and $1.06 gallon^?1 in Arkansas, Florida, and Virginia, respectively. Although differences in WTP for E10 were statistically insignificant among the three states, significant differences were found in the WTP for E85 between AR and FL and between AR and VA. Preferences for the environmental attributes appeared to be heterogeneous, as respondents’ were willing to pay a premium for E10 in all three states to facilitate the reduction of CO₂ and the improvement of biodiversity but were not willing to pay more for E85 in order to enhance biodiversity.     

Certification framework based on effective trapping for geologic carbon sequestration

We have developed a certification framework (CF) for certifying the safety and effectiveness of geologic carbon sequestration (GCS) sites. Safety and effectiveness are achieved if CO₂ and displaced brine have no significant impact on humans, other living things, resources, or the environment. In the CF, we relate effective trapping to CO₂ leakage risk which takes into account both the impact and probability of leakage. We achieve simplicity in the CF by using (1) wells and faults as the potential leakage pathways, (2) compartments to represent environmental resources that may be impacted by leakage, (3) CO₂ fluxes and concentrations in the compartments as proxies for impact to vulnerable entities, (4) broad ranges of storage formation properties to generate a catalog of simulated plume movements, and (5) probabilities of intersection of the CO₂ plume with the conduits and compartments. We demonstrate the approach on a hypothetical GCS site in a Texas Gulf Coast saline formation. Through its generality and flexibility, the CF can contribute to the assessment of risk of CO₂ and brine leakage as part of the certification process for licensing and permitting of GCS sites around the world regardless of the specific regulations in place in any given country.     

Natural analogue of the rise and dissolution of liquid CO2 in the ocean

The behavior of natural carbon dioxide (CO₂) droplets (8–10 mm in diameter) were observed in a seafloor hydrothermal system at the Okinawa Trough. The natural CO₂ droplet contain 95–98% of CO₂, 2–3% of H₂S, and other gas species. The ascending CO₂ droplets were tracked by a remotely operated vehicle (ROV), and depth, temperature, salinity, pH and partial pressure of CO₂ (pCO₂) in seawater near the CO₂ droplets were measured during droplet ascent by a conductivity-temperature-depth sensor (CTD) and in situ pH/pCO₂ sensor. The visual images of the rising CO₂ droplets were recorded with a high definition television camera on the ROV. A mapping survey (400 m × 400 m; 4 horizontal layers) revealed a dominant distribution of low pH area over the natural CO₂ venting site. The size and rise rate of CO₂ droplets decreased during their ascent in the water column from depths of 1424 to 679 m (a tracking interval of 745 m). The CO₂ droplets dissolved gradually to become small flakes of CO₂ hydrate while rising, and these ascending flakes were found to disappear at 679 m depth. Although a pH as low as 5 was detected just above the liquid CO₂ venting site on the seafloor, no detectable pH depression in the water column ambient to the rising CO₂ droplets was observed. The results of the pH mapping survey showed only localized pH depression over the CO₂ venting site.     

Role and impact of CO2–rock interactions during CO2 storage in sedimentary rocks

Before implementing CO₂ storage on a large scale its viability regarding injectivity, containment and long-term safety for both humans and environment is crucial. Assessing CO₂–rock interactions is an important part of that as these potentially affect physical properties through highly coupled processes. Increased understanding of the physical impact of injected CO₂ during recent years including buoyancy driven two-phase flow and convective mixing elucidated potential CO₂ pathways and indicated where and when CO₂–rock interactions are potentially occurring. Several areas of interactions can be defined: (1) interactions during the injection phase and in the near well environment, (2) long-term reservoir and cap rock interactions, (3) CO₂–rock interactions along leakage pathways (well, cap rock and fault), (4) CO₂–rock interactions causing potable aquifer contamination as a consequence of leakage, (5) water–rock interactions caused by aquifer contamination through the CO₂ induced displacement of brines and finally engineered CO₂–rock interactions (6). The driving processes of CO₂–rock interactions are discussed as well as their potential impact in terms of changing physical parameters. This includes dissolution of CO₂ in brines, acid induced reactions, reactions due to brine concentration, clay desiccation, pure CO₂–rock interactions and reactions induced by other gases than CO₂. Based on each interaction environment the main aspects that are possibly affecting the safety and/or feasibility of the CO₂ storage scheme are reviewed and identified. Then the methodologies for assessing CO₂–rock interactions are discussed. High priority research topics include the impact of other gaseous compounds in the CO₂ stream on rock and cement materials, the reactivity of dry CO₂ in the absence of water, how CO₂ induced precipitation reactions affect the pore space evolution and thus the physical properties and the need for the development of coupled flow, geochemical and geomechanical models.     

Assessing the economic feasibility of regional deep saline aquifer CO2 injection and storage: A geomechanics-based workflow applied to the Rose Run sandstone in Eastern Ohio, USA

Typical top-down regional assessments of CO₂ storage feasibility are sufficient for determining the maximum volumetric capacity of deep saline aquifers. However, they do not reflect the regional economic feasibility of storage. This is controlled, in part, by the number and type of injection wells that are necessary to achieve regional CO₂ storage goals. In contrast, the geomechanics-based assessment workflow that we present in this paper follows a bottom-up approach for evaluating regional deep saline aquifer CO₂ storage feasibility. The CO₂ storage capacity of an aquifer is a function of its porous volume as well as its CO₂ injectivity. For a saline aquifer to be considered feasible in this assessment it must be able to store a specified amount of CO₂ at a reasonable cost per ton of CO₂. The proposed assessment workflow has seven steps that include (1) defining the storage project and goals, (2) characterizing the geology and developing a geomechanical model of the aquifer, (3) constructing 3D aquifer models, (4) simulating CO₂ injection, (5,6) evaluating CO₂ injection and storage feasibility (with and without injection well stimulation), and (7) determining whether it is economically feasible to proceed with the storage project. The workflow was applied to a case study of the Rose Run sandstone aquifer in the Eastern Ohio River Valley, USA. We found that it is feasible in this region to inject 113 Mt CO₂/year for 30 years at an associated well cost of less than US $1.31/t CO₂, but only if injectivity enhancement techniques such as hydraulic fracturing and injection induced micro-seismicity are implemented.     

Effective EU and Member State policies for stimulating CCS

Although CO₂ capture and storage (CCS) is widely recognised as an option to mitigate climate change, consistent and effective EU policies to advance CCS are still absent. This paper discusses policy instruments for advancing large-scale deployment of CCS in the European Union, and evaluates them in a multi-criteria analysis. The EU Emissions Trading Scheme (EU-ETS) is a cost-effective instrument for limiting greenhouse gas emissions, but it is questionable whether its currently limited time horizon and short-trading periods will lead to substantial CCS diffusion. Complementary policies at the EU and the Member State level may repair this and provide sufficient incentives for CCS. Potential policies include financial instruments such as investment subsidies, a feed-in scheme, or a CO₂ price guarantee, as well as a CCS mandate or a low-carbon portfolio. These policy options differ with respect to their environmental effectiveness, possible interaction with the EU-ETS, costs and financial risk involved, and their competition with other mitigation options. Interactions between Member State policies and the EU-ETS are smaller in scope than those of EU-wide policies, but they are more likely to lead to displacement of financial resources from other low-carbon technologies. In addition, national policies may pose a significant part of the financial risk of CCS operations with Member States, reducing the operator's incentive to innovate. Overall, structural policies at the EU level, such as a mandate or a low-carbon portfolio standard would be more conducive for realising large-scale deployment of CCS across the EU as well as more acceptable to environmental organisations.     

Policy evaluation of vehicle exhaust standards in Japan from 1995 to 2005 based on two human health risk indices for air pollution and global warming

Measures for vehicle exhaust emissions aimed at reducing either air pollution or global warming could have counterproductive effects on one another. Increasing diesel passenger vehicles, which generally have lower CO₂ emissions than gasoline counterparts, leads to increasing particulate matter (PM) emissions, while gasoline has lower PM emissions than diesel. It is said that stringent limits on PM emission factors discourages improved CO₂ emission factors. Without including both effects in a risk evaluation, one cannot evaluate whether the total risk is reduced or not. Hence, we evaluated representative exhaust emission measures based on risk evaluation for both air pollution and global warming. Considering consumer choice between diesel and gasoline passenger vehicles and emissions standards adopted in Japan from 1995 to 2005, we built five cases for vehicle policy evaluation. For each case, we estimated disability-adjusted life years (DALY) as an index of human health risk caused by lung cancer linked to inhalation exposure of elemental carbon in PM as well as due to global warming linked to CO₂. The results of our risk evaluation reveal that the case adopting the 2005 new long-term Japanese emission standard reduces the human health risk caused by lung cancer due to air pollution by 0.6 × 10³ DALY, but would increase the risk due to global warming by 31.9 × 10³ DALY compared with the case of adopting EURO 4, for the same conditions of passenger vehicle choice from 1995. These results suggest that the characteristics of Japanese emissions standards are mainly designed to reduce air pollution.     

A model for the CO2 capture potential

Global warming is a result of increasing anthropogenic CO₂ emissions, and the consequences will be dramatic climate changes if no action is taken. One of the main global challenges in the years to come is therefore to reduce the CO₂ emissions.Increasing energy efficiency and a transition to renewable energy as the major energy source can reduce CO₂ emissions, but such measures can only lead to significant emission reductions in the long-term. Carbon capture and storage (CCS) is a promising technological option for reducing CO₂ emissions on a shorter time scale.A model to calculate the CO₂ capture potential has been developed, and it is estimated that 25 billion tonnes CO₂ can be captured and stored within the EU by 2050. Globally, 236 billion tonnes CO₂ can be captured and stored by 2050. The calculations indicate that wide implementation of CCS can reduce CO₂ emissions by 54% in the EU and 33% globally in 2050 compared to emission levels today.Such a reduction in emissions is not sufficient to stabilize the climate. Therefore, the strategy to achieve the necessary CO₂ emissions reductions must be a combination of (1) increasing energy efficiency, (2) switching from fossil fuel to renewable energy sources, and (3) wide implementation of CCS.     

Petrophysical analysis to investigate the effects of carbon dioxide storage in a subsurface saline aquifer at Ketzin, Germany (CO2SINK)

To test the injection behaviour of CO₂ into brine-saturated rock and to evaluate the dependence of geophysical properties on CO₂ injection, flow and exposure experiments with brine and CO₂ were performed on sandstone samples of the Stuttgart Formation representing potential reservoir rocks for CO₂ storage. The sandstone samples studied are generally fine-grained with porosities between 17 and 32% and permeabilities between 1 and 100 mD.Additional batch experiments were performed to predict the long-term behaviour of geological CO₂ storage. Reservoir rock samples were exposed over a period of several months to CO₂-saturated reservoir fluid in high-pressure vessels under in situ temperature and pressure conditions. Petrophysical parameters, porosity and the pore radius distribution were investigated before and after the experiments by NMR (Nuclear Magnetic Resonance) relaxation and mercury injection. Most of the NMR measurements of the tested samples showed a slight increase of porosity and a higher proportion of large pores.     

Site selection in CO2 ocean sequestration: Dependence of CO2 injection rate on eddy activity distribution

Site selection in CO₂ ocean sequestration is examined based on the idea that a site where injected CO₂ is efficiently diluted is favourable in reducing/avoiding biological impacts. Simulations of CO₂ injection into several sites by an eddy-resolving oceanic general circulation model (OGCM) show that the maximum CO₂ concentration differs by a factor of 10 among sites. The distribution of eddy activity is the most important causative factor producing the geographical differences in CO₂ dilution. Based on the relationship between the maximum CO₂ concentration and eddy activity, we estimated the distribution of the maximum CO₂ injection rate by a proposed method, which does not cause chronic impacts on biota. Around Japan, extensive ocean volume has the potential to dilute 20 million tonnes per year without chronic impacts, and some areas can be injected with 80 million tonnes per year.