High Storage Potential Research Articles

Improving emulsification performance of waxy maize starch by esterification combined with pulsed electric field

The development of high-performance edible particles for stabilizing gel-like Pickering emulsions has attracted increasing attention due to their high storage stability and potential in prolonging the release of intestinal drugs. In this study, a pulsed electric field (PEF)-assisted octenyl succinic anhydride (OSA)-modified waxy maize starch (WMS) was established, which could be used as an excellent Pickering emulsion stabilizer. The PEF treatment improved the esterification efficiency of WMS by disrupting its granule surface and crystalline structure to offer more sites for esterification. The degree of substitution (DS) of starch dually modified at 2.5–5.5 kV/cm was 3.0–46.9% higher than that of starch modified by the conventional method. The X-ray photoelectron spectroscopy results revealed that the OSA groups were distributed on the surface of starch granules, increasing the hydrophobicity of the surface. Among all the starch samples, the contact angle of the OSA-modified starch treated with PEF at an intensity of 4.5 kV/cm was close to 90°. The dual-modified starch enhanced the amphipathic property and surface activity, indicating its potential to stabilize the formation of gel-like Pickering emulsions and increase their apparent viscosity (η) and storage modulus (G′). Finally, increasing the starch particle concentration could facilitate the formation of gel-like emulsions by enhancing the entanglement and interaction between them.

Phase Change Material Evolution in Thermal Energy Storage Systems for the Building Sector, with a Focus on Ground-Coupled Heat Pumps.

The building sector is responsible for a third of the global energy consumption and a quarter of greenhouse gas emissions. Phase change materials (PCMs) have shown high potential for latent thermal energy storage (LTES) through their integration in building materials, with the aim of enhancing the efficient use of energy. Although research on PCMs began decades ago, this technology is still far from being widespread. This work analyses the main contributions to the employment of PCMs in the building sector, to better understand the motivations behind the restricted employment of PCM-based LTES technologies. The main research and review studies are critically discussed, focusing on: strategies used to regulate indoor thermal conditions, the variation of mechanical properties in PCMs-based mortars and cements, and applications with ground-coupled heat pumps. The employment of materials obtained from wastes and natural sources was also taken in account as a possible key to developing composite materials with good performance and sustainability at the same time. As a result, the integration of PCMs in LTES is still in its early stages, but reveals high potential for employment in the building sector, thanks to the continuous design improvement and optimization driven by high-performance materials and a new way of coupling with tailored envelopes.

Benthic Biofilm Potential for Organic Carbon Accumulation in Salt Marsh Sediments

Coastal salt marshes are productive environments with high potential for carbon accumulation and storage. Even though organic carbon in salt marsh sediment is typically attributed to plant biomass, it can also be produced by benthic photosynthetic biofilms. These biofilms, generally composed of diatoms and their secretions, are known for their high primary productivity and contribution to the basal food web. The growth of biofilms and the preservation of carbon produced by biofilms depends on the amount of sedimentation; low sedimentation rates will favor decomposition, while high sedimentation rates could decrease biofilm productivity. In this study, we conducted laboratory experiments to test (1) if biofilms can potentially accumulate carbon in marsh soil and (2) how different sedimentation rates affect the amount of carbon accumulation. Containers filled with a settled mud bed were inoculated with natural biofilms collected from a marsh surface and allowed to grow with favorable light exposure, nutrient supply, and absence of grazing. Mud was added weekly in different amounts, resulting in an equivalent sedimentation rate from 12 to 189 mm/yr. After 11 weeks, the sediment columns were sampled and analyzed for chl a, organic matter via loss on ignition (LOI), and total organic carbon (TOC). Chl a accumulation rates ranged from 123 to 534 mg/cm2/yr, organic matter accumulation ranged from 86 to 456 g/m2/yr, and TOC accumulation rates ranged from 31 to 211 g/m2/yr. These values are on the same order of magnitude of marsh carbon accumulation rates measured in the field. All three metrics (chl a, organic matter, and TOC) increased with increased sedimentation rate. These results show that biofilms can potentially contribute to carbon accumulation in salt marsh soils. Furthermore, areas with high sedimentation rates have the potential for higher amounts of organic matter from biofilms in the sediment.

Total Carbon Stock and Potential Carbon Sequestration Economic Value of Mukogodo Forest-Landscape Ecosystem in Drylands of Northern Kenya

Carbon sequestration is one of the important ecosystem services provided by forested landscapes. Dry forests have high potential for carbon storage. However, their potential to store and sequester carbon is poorly understood in Kenya. Moreover, past attempts to estimate carbon stock have ignored drylands ecosystem heterogeneity. This study assessed the potential of Mukogodo dryland forest-landscape in offsetting carbon dioxide through carbon sequestration and storage. Four carbon pools (above and below ground biomass, soil, dead wood and litter) were analyzed. A total of 51 (400 m2) sample plots were established using stratified-random sampling technique to estimate biomass across six vegetation classes in three landscape types (forest reserve, ranches and conservancies) using nested-plot design. Above ground biomass was determined using generalized multispecies model with diameter at breast height, height and wood density as variables. Below ground, soil, litter and dead wood biomass; carbon stocks and carbon dioxide equivalents (CO2eq) were estimated using secondary information. The CO2eq was multiplied by current prices of carbon trade to compute carbon sequestration value. Mean ± SE of biomass and carbon was determined across vegetation and landscape types and mean differences tested by one-way Analysis of Variance. Mean biomass and carbon was about 79.15 ± 40.22 TB ha-1 and 37.25 ± 18.89 TC ha-1 respectively. Cumulative carbon stock was estimated at 682.08 TC ha-1; forest reserve (251.57 TC ha-1) had significantly high levels of carbon stocks compared to ranches (209.78 TC ha-1) and conservancies (220.73 TC ha-1, P = 0.000). Further, closed forest significantly contributed to the overall biomass and carbon stock (58%). The carbon sequestration potential was about 19.9MTCO2eq with most conservative worth of KES 39.9B (US$40M) per annum. The high carbon stock in the landscape shows the potential of dryland ecosystems as carbon sink for climate change mitigation. However, for communities to benefit from bio-carbon funds in future, sustainable landscape management and restorative measures should be practiced to enhance carbon storage and provision of other ecosystem services.

Thermal management of a high temperature sodium sulphur battery stack

The sodium sulfur battery is an advanced secondary battery with high potential for grid-level storage due to their high energy density, low cost of the reactants, and high open-circuit voltage. However, as the operating temperature of the battery is high (about 300 °C), effective thermal management is required to prevent thermal runaway under high current density operation. To develop efficient thermal management strategies, a detailed, thermo-electrochemical, non-isothermal, distributed dynamic model of a sodium-sulfur battery stack is developed. Models of three thermal management strategies are developed and analyzed in this work: active cooling, passive cooling, and hybrid cooling. The active cooling strategy uses air as the cooling medium whereas, the passive cooling strategy uses a phase change material. In the hybrid cooling strategy, both active and passive cooling strategies are used. Due to the high operating temperature of the sodium sulfur batteries, the rejected heat can be utilized effectively and consequently a high variability in the heat rejection rate may not be acceptable. Performance of these strategies is analyzed under high current density operation by evaluating the variability in the cell temperature during charge/discharge cycles, temperature difference between the cells based on their locations, and variability in the heat rejection rate. The phase change-based hybrid thermal management strategy with an embedded controller maintained the temperature variation within ±/- 2.8 °C. Considering the tradeoff between the capital cost for PCM, fan power requirement, and variability in the heat rejection rate, the optimal quantity of the PCM and the maximum air velocity for the maximum current density of 260 mA/cm2 (0.55 C-rate) were found be 0.74 g/Wh and 3 m/s, respectively.

A criteria-driven approach to the CO2 storage site selection of East Mey for the acorn project in the North Sea

Carbon Capture and Storage (CCS) is an essential tool in the fight against climate change. Any prospective storage site must meet various criteria that ensure the effectiveness, safety and economic viability of the storage operations. Finding the most suitable site for the storage of the captured CO2 is an essential part of the CCS chain of activity. This work addresses the site selection of a second site for the Acorn CCS project, a project designed to develop a scalable, full-chain CCS project in the North Sea (offshore northeast Scotland). This secondary site has been designed to serve as a backup and upscaling option for the Acorn Site, and has to satisfy pivotal project requirements such as low cost and high storage potential. The methodology followed included the filtering of 113 input sites from the UK CO2Stored database, according to general and project-specific criteria in a multi-staged approach. This criteria-driven workflow allowed for an early filtering out of the less suitable sites, followed by a more comprehensive comparison and ranking of the 15 most suitable sites. A due diligence assessment was conducted of the top six shortlisted sites to produce detailed assessment of their storage properties and suitability, including new geological interpretation and capacity calculations for each site. With the new knowledge generated during this process, a critical comparison of the sites led to selection of East Mey as the most suitable site, due to its outstanding storage characteristics and long-lasting hydrocarbon-production history, that ensure excellent data availability to risk-assess storage structures. A workshop session was held to present methods and results to independent stakeholders; feedback informed the final selection criteria. This paper provides an example of a criteria-driven approach to site selection that can be applied elsewhere.

Geochemical characterization of selected organic-rich shales from the Devonian Pimenteiras Formation, Parnaíba Basin, Brazil – Implications for methane adsorption capacity

The Parnaíba Basin in northern Brazil is one of the largest Paleozoic basins of South America and is believed to have a high potential for unconventional hydrocarbon generation and storage (shale gas). It comprises an extensive volcano-sedimentary sequence from which the Pimenteiras Formation strata (Devonian) is considered to have the highest potential as a petroleum/gas source rock. The present paper evaluates the methane adsorption capacity of the organic-rich shales of this formation using 12 samples collected from the vertical profiles of three wells. The samples were analyzed by geochemical and petrographic techniques as well as by methane adsorption capacity experiments. The total organic carbon (TOC) content varies from 1.57 to 16.6 wt% in organic richness and positively correlates with gas adsorption capacity. The gas adsorption capacity of the samples increases with a pressure between 10 and 15 MPa, with a slight decrease of the adsorbed gas up to the higher and final experimental pressures around 20 MPa. Results of Rock-Eval pyrolysis analysis indicate kerogen types II and III resulting from a mixture of marine and terrestrially derived organic matter. The type of organic matter (mainly kerogen type III) contributes to aromaticity and provides higher gas adsorption capacity. The thermal maturity of the shales varies from immature to mature according to vitrinite reflectance (0.41–0.63% Rrandom) and Tmax (373–442 °C) data. However, in many samples no notable correlation was found between adsorption capacity and thermal parameters in this study. The clay minerals can contribute to high gas adsorption capacity in Devonian shales while the high ash contents had a negative influence on the gas adsorption capacity. Even though some anomalously low values were recorded in some samples, the Pimenteiras Formation shales analyzed in this study suggest a good gas adsorption capacity.

1-Aminopyrene-modified functionalized carbon nanotubes wrapped with silicon as a high-performance lithium-ion battery anode

Silicon (Si) is regarded as a great promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and low lithium storage potential. However, the practical application of pure silicon is greatly limited by its low electrical conductivity and large volume expansion. It is well known that the modification ofsilicon negative materials with carbon tubes is a good strategy to overcome the low conductivity and poor cycling stability of silicon anode. In this work, the APOCs@Si composite is successfully synthesized by 1-aminopyrene (AP) modified oxidized carbon nanotubes (OCs) compounded silicon nanoparticles under ultrasonication-stirring condition. The APOCs@Si electrode presents a considerable reversible capacity of 913.7 mAh·g−1 with a stable structure after 610 cycles at a current density of 0.5A g−1, and the first reversible capacity is 3543.0 mAh g−1 at 0.1A g−1. The physico-chemical properties indicate that the incorporation of AP and OCs builds the interwoven CNTs networks, which serve as a matrix to buffer the volume expansion of silicon and boost the electronic conductivity of the electrode, to achieve remarkable capacity and cycle performance of APOCs@Si electrode. These remarkable results have further showed AP modified OCs as a buffer matrix significantly improve the cycle performance of silicon anode materials.

Machine Learning-Aided Materials Design Platform for Predicting the Mechanical Properties of Na-Ion Solid-State Electrolytes

Na-ion solid-state electrolytes (Na-SSEs) exhibit high potential for electrical energy storage owing to their high energy densities and low manufacturing cost. However, their mechanical properties that are critical to maintaining structural stability at the interface are still insufficiently understood. In this study, a machine learning-based regression model was developed for predicting the mechanical properties of Na-SSEs. As a training set, 12,361 materials were obtained from a well-known materials database (Materials Project) and were represented with their respective chemical and structural descriptors. The developed surrogate model exhibited remarkable accuracies (R2 score) of 0.72 and 0.87, with mean absolute errors of 11.8 and 15.3 GPa for the shear and bulk modulus, respectively. This model was then applied to predict the mechanical properties of 2432 Na-SSEs, which have been validated with first-principles calculations. Finally, the optimization process was performed to develop an ideal materials screening platform by adding the minimized data set, wherein the prediction uncertainty is reduced. We believe that the platform proposed in this study can accelerate the search for Na-SSEs with ideal mechanical properties at minimum cost.

Inorganic-organic composite solid electrolyte based on cement and Polyacrylamide prepared by a synchronous reaction method

Inorganic-organic composite solid electrolyte (CSE) has a high potential for future energy storage. Compared with ceramic-based CSE, cement-based CSE can be prepared at room temperature, which is conducive to incorporation of polymer into CSE. However, the content of polymer in CSE is limited to the small level, which hinders the performance of the electrolyte. In this work, a novel synchronous reaction method (SRM) is proposed to prepare CES, which can exceed the content limit of polymer remarkably. Through SRM, cement hydration and polymer polymerization are simultaneously carried out to solve the problem of cement slurry fluidity caused by the addition of polymer. Infrared and 1H-NMR spectra confirm that the CSE has been successfully prepared, and Polyacrylamide (PAM) can be detected in CSE. GPC results show that the molecular mass of PAM in the CSE increases with the monomer content. SEM results reveal that PAM and hardened cement are well combined and evenly distributed at the micro level. The microstructure, ionic conductivity and compressive strength of CSE change considerably with the polymer content. In general, with the increase of polymer content, the internal structure is gradually improved, also the ionic conductivity and compressive strength are improved remarkably. The multi-functionality results indicate that the CSE prepared by synchronous reaction method with 20 wt.% PAM shows the best combination of the ionic conductivity (10.52 mS/cm) and the compressive strength (53.78 MPa). An all-solid supercapacitor (ASS) was assembled by the solid electrolyte and rGO/Ni foam composite electrodes, which shows good electrochemical energy storage performance. Therefore, the solid electrolyte synthetized with SRM provides a promising way for the application of all-solid electrochemical energy storage.

Thermodynamic assessment of the novel concept of the energy storage system using compressed carbon dioxide, methanation and hydrogen generator

The main aim of this paper is to characterize the concept of a novel energy storage system, based on compressed CO2 storage installation, that uses an infrastructure of depleted coal mines to provide required volume of tanks, and, additionally, hydrogen generators, and a methanation installation to generate synthetic natural gas that can be used within the system or taken out of it, e.g., to a gas grid. A detailed mathematical model of the proposed solution was built using own codes and Aspen Plus software. Thermodynamic evaluation, aiming at determining parameters, composition and streams in all the most important nodes of the system for the nominal point and when changing a defined decision variable δ (in the range from 0.1 to 0.9) was made. The evaluation was made based on the storage efficiency, volume of the tanks and flows of energy within the system. The storage efficiency in the nominal point reached 45.08%, but was changing in the range from 35.06% (for δ = 0.1) to 63.93% (for δ = 0.9). For the nominal value of δ, equal to 0.5, volume of the low-pressure tank (LPT) was equal to 132,869 m3, while of the high pressure tank (HPT) to 1219 m3. When changing δ these volumes were changing from 101,900 m3 to 190,878 m3 (for LPT), and from 935 to 1751 m3 (for HPT), respectively. Detailed results are presented in the paper and indicate high storage potential of the proposed solution in regions with underground mine infrastructure.

Hydrogen adsorption on c-ZrO2(111), t-ZrO2(101), and m-ZrO2(111) surfaces and their oxygen-vacancy defect for hydrogen sensing and storage: A first-principles investigation

Hydrogen adsorption on the c-ZrO2(111), t-ZrO2(101), and m-ZrO2(111) surfaces has been assessed using DFT-D2 method. Stabilities of ZrO2 surfaces are in orders: c-ZrO2(111) > t-ZrO2(101) > m-ZrO2(111) for pristine ZrO2 surfaces, and [c-ZrO2(111) + VO] > [t-ZrO2(101) + VO] > [m-ZrO2(111) + VO] for O-vacancy ZrO2 surfaces. H2 adsorption abilities of ZrO2 surfaces are in order: [m-ZrO2(111) + VO] > [t-ZrO2(101) + VO] > c-ZrO2(111) > m-ZrO2(111) > [c-ZrO2(111) + VO] > t-ZrO2(101). The c-ZrO2(111), m-ZrO2(111), and [t-ZrO2(101) + VO] surfaces have a high potential for hydrogen storage. The t-ZrO2(101), [t-ZrO2(101) + VO], and [m-ZrO2(111) + VO] used as H2 sensing materials was suggested.

Comparative analysis of thermally activated building systems in wooden and concrete structures regarding functionality and energy storage on a simulation-based approach

Thermally activated building systems (TABS) represent a practicable and energy efficient possibility for heating of buildings. Whereas TABS in concrete structures are well-established, wood-based materials are barely considered. State-of-the-art simulations were conducted for various ceiling structures based on different wood-based materials and concrete regarding the thermal performance. Steady-state simulations demonstrate that TABS in wooden structures are fundamentally functional and able to achieve an appropriate heat flux of 26 W/m² while meeting the comfort requirement of maximum 4 K temperature difference between room air temperature and surface temperature, although considerably higher fluid temperatures are necessary compared to TABS in concrete. The results of transient simulations show that heat storage capacities of up to 1065 Wh/m² can be achieved within the wooden variants compared to 696 Wh/m² for concrete on condition of an equivalent heat flux underneath the ceiling. Furthermore, a combination of different wooden layers within the structure can contribute to both, a comparatively high energy storage potential and a high heat flux density simultaneously, compromising the fact that a higher heat flux density is often accompanied by a lower thermal storage capacity in the simulated models and vice versa. These findings could be used to develop an element of timber as energy storage system.

Biomass Carbon and Nitrogen Content of Wild Fruit Species in Southwest Serbia

To select woody fruit species for biomass cropping, a study of the carbon and nitrogen content of the bark and wood of five wild fruit species in Southwest Serbia was conducted. Compared with common hazel, wild cherry, walnut, and european pear, the european crab apple has a high potential for carbon and nitrogen storage, representing a promising fruit species for biomass production.

Potential carbon storage of Indonesian mangroves

Even though it only covers 0.1% of the surface of the continent, mangrove forests recorded as carbon-rich forests on earth. Forest loss and degradation together, especially in the tropics contributes about 12% of the total annual anthropogenic CO2 emissions. Mangrove forests ecosystem have high carbon storage potential. The study results show that the ratio of carbon to area in mangrove ecosystems is almost 13 times greater than that of tropical rainforest ecosystems in Indonesia. This study has used published data recorded in Google Scholar and Science Direct. Indonesia’s mangroves, with a total area of 3.1 million ha, store a total carbon of 5.2 Gt. The average stand biomass or aboveground biomass is around 407.15 tons ha−1, storing carbon as much as 191.36 tons ha−1 which is equivalent to the potential for CO2 absorption (CO2e) by mangrove stands of 702.29 tons ha−1. Papua has the largest mangrove forest in Indonesia that has the potential for CO2e. Assessment of carbon storage in soil needs to be done in estimating the total carbon stored in mangrove ecosystems, given the large potential for stored carbon that plays a role in climate change mitigation.

Thermodynamic and economic assessment of compressed carbon dioxide energy storage systems using a post-mining underground infrastructure

The paper presents the results of thermodynamic and economic analysis of a compressed carbon dioxide energy storage system using low-pressure reservoir, where carbon dioxide cannot be stored at a high-pressure, like in standard concepts. Such limitations may occur in post-mining underground excavations, the availability of which will increase in the coming years due to the ongoingdecarbonisation of economies in many countries. In this paper the concepts of two systems using an isobaric high-pressure tank and a non-isobaric low-pressure reservoir which are built within a post-mine shaft are presented. The paper presents the results of technical analysis for systems with various structures. The results of the analysis show the storage potential and effectiveness of the compressed carbon dioxide energy storage system, which includes one, two or three sections of carbon dioxidecompressor together with thermal energy storage tanks and the same number of expander's sections. The analyses were carried out for various ranges of allowable pressure change in the low-pressure reservoir. The paper identifies the pros and cons of the systems, such as high values of energy storage efficiency (which may reach almost 80%) and their technical complexity. The storage capacity and the required tank volumes were also assessed. For the system with single-section compressor and single-section expander, more in-depth analyses were carried out. The analyses were carried out for the assumed geometry of the mine shaft. For this solution economic analysis were also carried out. For the decision variables considered, the Levelized Cost of Storage ranges from 314.6 to 439.4 €/MWh. The inspiration for the development of the system was the high storage potential of underground mine infrastructure available in the region of the Upper Silesia located in Poland; however, the solution is universal and may be applied in other industrial regions.

Development of an Integrated Carbon Capture, Utilization, and Storage Hub in the United States

The Integrated Midcontinent Stacked Carbon Storage Hub (IMSCS-HUB) is a first of a kind carbon capture, utilization, and storage (CCUS) project in the midwestern United States. The project is supported under the US Department of Energy’s Carbon Storage Assurance Facility Enterprise (CarbonSAFE) program. The IMSCS-HUB will collect 15 million metric tonnes (MT) per year or more in Iowa and Nebraska and transport it to saline and CO2 enhanced oil recovery (EOR) storage sites in western Nebraska, Kansas, and Texas. Sources include multiple ethanol plants (approximately 1.8 MT/Year), coal fired electric plants (approximately 12.6 MT/Year), and natural gas fired electric plants (approximately 0.6 MT/Year). The passage of an updated tax credit for storage in February 2018 provides a strong economic driver for all of the sources in the hub to develop a hub project. The tax credit provides approximately $50/T for CO2 stored in saline storage units and $35/T for CO2 stored as part of CO2-EOR production. In addition, the inclusion of many bio-energy sources such as ethanol plants allows for early implementation of the project by taking advantage of inexpensive capture ($10/MT to $12/MT) and subsidies from California’s Low Carbon Fuel Standard program. Capture cost estimates for the electric utilities is approximately $33/MT. Transport costs range from $0.6/MT to $5.40/MT. Storage costs range from $3/MT to $4/MT. The hub partners include Battelle, Advanced Resources International, Archer Daniels Midland, Nebraska Public Power District, and others. The region of the project stretching from eastern Iowa to southwestern Nebraska acts as a source corridor, where sources add CO2 to the transport network. The transportation network will consist of a common carrier trunk line designed to connect the largest sources. Smaller sources will be connected through spur lines. The final routing will be selected using the location of existing rights away and environmental factors such as resource locations the critical species habitats. SimCCS and other tools will be used to finalize the routes. The region of the project from southwestern Nebraska to southwest Kansas in a storage corridor where CO2 may be stored in either saline projects or CO2-EOR projects. South of Kansas the CO2 will be transported to Texas for utilization in CO2-EOR. Two saline storage sites and two EOR opportunities have been identified as anchor projects for the storage corridor. The anchor sites are at the northern and southern sides of the storage corridor and will act to validate the storage potential of the entire corridor. In Nebraska saline storage is being planned in Perkins county and CO2-EOR is being studied at Sleepy Hollow Field in Red Willow county. In Kansas, saline storage and CO2- EOR are being planned for Patterson-Heinitz-Hartland (Patterson) Field in Kearney County. Multiple storage formations occur vertically at each site allowing for stacked storage minimizing the surface footprint for monitoring and maximizes the use of storage resources at each site. Data from new tests wells or seismic surveys for each of the sites has been used to create detailed geologic and reservoir models. Modeling for each of the anchor saline sites indicates at least a 50 million tonne storage capacity. The CO2-EOR projects are expected to utilize 2.2 MT and 3.9 MT of CO2 and produce 4.3 and 9.8 million barrels of oil for Sleepy Hollow and Patterson Fields, respectively. The inclusion of CO2-EOR along with saline storage adds an additional economic driver for the project with an estimated revenue of $128/MT and $154/MT of CO2 utilized. The results of the first two phases of the project demonstrate the feasibility of the midcontinent hub concept that couples a diverse set of redundant sources to multiple saline and CO2-EOR projects. The results show that the economics and geology are favorable for early implementation of commercial scale CCUS. The existence of low carbon fuel standard subsidies, storage tax credits, and revenue from produced oil act as economic drivers to support the hub in addition to the climate benefit gained by storing CO2 the hub supports local agriculture and oil production helping to create public support. This presentation will discuss the project development and project economics and how they relate to both stacked saline storage and CO2-EOR in the development of a storage hub. The development of a hub project allows the transport of CO2 from areas such as Iowa that have poor storage potential to areas such as western Nebraska, Kansas, and Texas that have high storage potential. This is critical to the implementation of CCUS in the midcontinent US. The presentation will also discuss the advantage of including redundant sources and sinks to develop a CO2 market that can sustain itself as a commercial enterprise after government funding ends.

An Experimental Study of the Decomposition and Carbonation of Magnesium Carbonate for Medium Temperature Thermochemical Energy Storage

To improve the energy efficiency of an industrial process thermochemical energy storage (TCES) can be used to store excess or typically wasted thermal energy for utilisation later. Magnesium carbonate (MgCO3) has a turning temperature of 396 °C, a theoretical potential to store 1387 J/g and is low cost (~GBP 400/1000 kg). Research studies that assess MgCO3 for use as a medium temperature TCES material are lacking, and, given its theoretical potential, research to address this is required. Decomposition (charging) tests and carbonation (discharging) tests at a range of different temperatures and pressures, with selected different gases used during the decomposition tests, were conducted to gain a better understanding of the real potential of MgCO3 for medium temperature TCES. The thermal decomposition (charging) of MgCO3 has been investigated using thermal analysis techniques including simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), TGA with attached residual gas analyser (RGA) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) (up to 650 °C). TGA, DSC and RGA data have been used to quantify the thermal decomposition enthalpy from each MgCO3.xH2O thermal decomposition step and separate the enthalpy from CO2 decomposition and H2O decomposition. Thermal analysis experiments were conducted at different temperatures and pressures (up to 40 bar) in a CO2 atmosphere to investigate the carbonation (discharging) and reversibility of the decarbonation–carbonation reactions for MgCO3. Experimental results have shown that MgCO3.xH2O has a three-step thermal decomposition, with a total decomposition enthalpy of ~1050 J/g under a nitrogen atmosphere. After normalisation the decomposition enthalpy due to CO2 loss equates to 1030–1054 J/g. A CO2 atmosphere is shown to change the thermal decomposition (charging) of MgCO3.xH2O, requiring a higher final temperature of ~630 °C to complete the decarbonation. The charging input power of MgCO3.xH2O was shown to vary from 4 to 8136 W/kg with different isothermal temperatures. The carbonation (discharging) of MgO was found to be problematic at pressures up to 40 bar in a pure CO2 atmosphere. The experimental results presented show MgCO3 has some characteristics that make it a candidate for thermochemical energy storage (high energy storage potential) and other characteristics that are problematic for its use (slow discharge) under the experimental test conditions. This study provides a comprehensive foundation for future research assessing the feasibility of using MgCO3 as a medium temperature TCES material. Future research to determine conditions that improve the carbonation (discharging) process of MgO is required.

Mapping Groundwater Potential Zones Using a Knowledge-Driven Approach and GIS Analysis

Despite the Sahara being one of the most arid regions on Earth, it has experienced rainfall conditions in the past and could hold plentiful groundwater resources. Thus, groundwater is one of the most precious water resources in this region, which suffers from water shortage due to the limited rainfall caused by climatic conditions. This article will assess the knowledge-driven techniques employed to develop a model to integrate the multicriteria derived from geologic, geomorphic, structural, seismic, hydrologic, and remotely sensed data. This model was tested on the defunct Kom Ombo area of Egypt’s Nile river basin in the eastern Sahara, which covers ~28,200 km2, to reveal the promising areas of groundwater resources. To optimize the output map, we updated the model by adding the automated depression resulting from a fill-difference approach and seismic activity layers combined with other evidential maps, including slope, topography, geology, drainage density, lineament density, soil characteristics, rainfall, and morphometric characteristics, after assigning a weight for each using a Geographic Information System (GIS)-based knowledge-driven approach. The paleochannels and soil characteristics were visualized using Advanced Land Observing Satellite (ALOS)/Phased Array type L-band Synthetic Aperture Radar (PALSAR) data. Several hydromorphic characteristics, sinks/depressions, and sub-basin characteristics were extracted using Shuttle Radar Topography Mission (SRTM) data. The results revealed that the assessed groundwater potential zones (GPZs) can be arranged into five distinctive groups, depending on their probability for groundwater, namely very low (6.56%), low (22.62%), moderate (30.75%), high (29.71%), and very high (10.34%). The downstream areas and Wadi Garara have very high recharge and storage potential. Interferometry Synthetic Aperture Radar (InSAR) coherence change detection (CCD) derived from Sentinel-1 data revealed a consistency between areas with high InSAR CCD (low change) that received a plausible amount of surface water and those with very low InSAR CCD values close to 0 (high change). Landsat data validated the areas that received runoff and are of high potentiality. The twenty-nine groundwater well locations overlaid on the GPZs, to assess the predicted model, indicated that about 86.17% of the wells were matched with very good to moderate potential zones.

Territorial mapping to increase soil carbon storage

ABSTRACT The ‘4 per 1000’ initiative aims to increase soil organic carbon stocks to offset carbon dioxide emissions. For a French case study, this graphic offers evidence of the links between carbon stocks and agricultural productions at the territorial level: stocks are positively associated with animal loads, whereas soils with arable crops have much lower stocks despite a higher storage potential. Territorial mapping of both storage capacities and organic resources is needed to optimize soil carbon storage.