Greenhouse Gases: Science and Technology最新文献

As coal pore development is decisive for choosing the engineering site and predicting the CO₂ storage capacity, this paper provides a new method to define the double T₂ cutoff values by using cumulative amplitude ratio measured by nuclear magnetic resonance measurements, classifies the coal pore systems, and analyzes the influences on cumulative amplitude ratio. The following cognitions are achieved. The minimum ratio always varies narrowly and ranges from 0.9 to 1.1, which is quite stable and approximately equals to 1. Ranges of maximum and average ratios are 1.2–3.5 and 1.1–1.8, respectively. T_2c1 represents the dividing point of diffusion pore and permeation pore, and its average value is about 4.1 ms. T_2c2 represents the dividing point of permeation pore and cleat, with an average value of about 81.9 ms. The volumetric proportions of diffusion pore range from 1.5% to 76.2%, with an average value of 34.6%; the volumetric proportions of permeation pore are from 14.9% to 98.5%, with an average of 46.8%; while the volumetric proportions of cleat are between 8.4% and 57.5%, with an average of 26.6%. According to the different influencing degrees on maximum and average ratios, three types of parameters can be divided. The first type is strong correlation parameters and includes permeability, volumetric percentage of cleat, and relative volumetric percentage of cleat. The second type is medium correlation parameters, such as volumetric percentage of diffusion pore. The third type is weak correlation parameters, including T₂ cutoff values, porosity, and maximum vitrinite reflectance. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

This study aims to develop a methodology for calibrating subsurface stress changes through time-lapse vertical seismic profiling (VSP) integration. The selected study site is a region around the injector well located within Farnsworth field unit (FWU), where there is an ongoing CO₂-enhanced oil recovery (EOR) operation. In our study, a site-specific rock physics model was created from extensive geological, geophysical, and geomechanical characterization through 3D seismic data, well logs, and core assessed as part of the 1D MEM conducted on the characterization well within the study area. The Biot-Gassmann workflow was utilized to combine the rock physics and reservoir simulation outputs to determine the seismic velocity change due to fluid substitution. Modeled seismic velocities attributed to mean effective stress were determined from the geomechanical simulation outputs, and the stress-velocity relationship developed from ultrasonic seismic velocity measurements. A machine learning-assisted workflow comprised of an artificial neural network and a particle swarm optimizer (PSO) was utilized to minimize a penalty function created between the modeled seismic velocities and the observed time-lapse VSP dataset. The successful execution of this workflow has affirmed the suitability of acoustic time-lapse measurements for 4D-VSP geomechanical stress calibration pending measurable stress sensitivities within the anticipated effective stress changes and the availability of suitable and reliable datasets for petroelastic modeling. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

Geologic CO₂ sequestration in porous saline aquifers is a promising approach to reducing atmospheric concentrations of CO₂. Reactive transport simulations provide the opportunity to analyze which factors influence geochemical reactivity in the reservoir, understand those most important for promoting CO₂ trapping, and assess individual sites. Field-scale aquifer characterization is time and resource intensive such that here, reactive transport simulations are leveraged to enhance understanding of selected aquifer properties including porosity, permeability, depth of storage, and carbonate mineralogy on the overall CO₂ trapping potential to better select sites promoting geochemical reactivity for CO₂ trapping. There are different mechanisms for sequestrating CO₂. Once injected, CO₂ will dissolve into the brine to create an acidic environment, resulting in the dissolution of pre-injection formation minerals. Released ions can reprecipitate as secondary minerals. The dissolved CO₂ and mineralized CO₂ are considered as a more secure form of CO₂ trapping in this study compared to the free supercritical CO₂. Here, a framework leveraging a controlled set of field scale simulations is developed to facilitate rapid, optimized site selection. Simulations vary aquifer properties to understand the impact of each unique property on CO₂ trapping, tracking, and comparing the amount of supercritical, aqueous, and mineralized CO₂. The rate at which the CO₂ injected into the aquifer is converted to aqueous or mineralized CO₂ is newly defined here as the sequestration efficiency and used to compare simulation results. The reservoir depth and fraction of carbonate minerals in the formation are shown to be more important factors than reservoir porosity and permeability in affecting CO₂ trapping. However, the impact of aquifer properties on the evolution of injected CO₂ depends on the stage of the sequestration project. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

As an essential greenhouse gas, CO₂ is the leading cause of global warming and environmental problems. An efficient strategy to lower CO₂ emissions is the hydrate-based method of CO₂ geological storage. The stability and formation process of hydrate is the premise and foundation of the hydrate method of CO₂ geological storage. However, the formation rule of CO₂ hydrate has a significant impact on the formation characteristics of CO₂ hydrate. This paper thoroughly examines the formation properties of CO₂ hydrate in porous media systems. The quantitative impacts and laws of many parameters on the CO₂ hydrate production process are thoroughly examined. On this basis, the internal mechanism of particle size, pore distribution, and critical size of particles in porous media systems on the kinetics of CO₂ hydrate formation are detailed. Finally, the shortcomings of the studies on CO₂ hydrate formation kinetics in porous media systems and the main directions in the future are pointed out. The influence of pore distribution in porous media on the CO₂ hydrate formation process still needs further study. The relative results will be useful in the future for CO₂ capture and sequestration in sediments. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

As the global climate crisis intensifies, ecosystems, human society and economic activities are significantly affected. Countries around the world have successively put forward the goal of carbon neutrality or zero carbon. At the 75th session of the United Nations General Assembly, the Chinese government explicitly proposed making efforts to reach the goal of Carbon Peak (peak of carbon emissions before 2030) and Carbon Neutrality (Dual Carbon) (carbon neutrality before 2060). In October 2021, the CPC Central Committee and the State Council issued the “Opinions on Fully, Accurately and Comprehensively Implementing the New Development Concepts to Achieve Carbon Peak and Carbon Neutrality” and the Action Plan for Achieving Carbon Peak before 2030, specifying the targets and tasks related to achieving carbon peak and carbon neutrality in China. As the world's largest developing country, the world's largest manufacturer, and a country with the most complete industrial categories, China will face multiple challenges such as climate change, economic transition, and environmental protection, which requires systematic support from policy, economy, technology, and society. How to achieve the goal will be a great challenge to China's sustainable development. The academic community has conducted extensive exploration on the realization of China's carbon peak and carbon neutrality in many fields, such as energy transformation, industrial structure upgrading, transportation carbon reduction, urban planning and construction, carbon sink enhancement, low-carbon technologies, green finance, and supporting policies. Among them, policy planning and technological innovation are the most important to achieve the goal of carbon peak and carbon neutrality. Second, industrial adjustment and enterprise implementation are also important. Therefore, this review will focus on the development status and prospects of policy support, technological innovation, industrial adjustment, and enterprise implementation for achieving dual carbon goals in China. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.

A packed bed reactor (PBR)-based chemical looping combustion (CLC), also referred to as unmixed combustion (UMC), was reported as an alternative to fire in the literature. In this process, the oxygen carriers undergo oxidation and reduction reactions in alternate cycles using air and fuel as the reactive gases, respectively. The energy generated in these reactions can radially be transferred for applications like heating air which was successfully demonstrated. The results showed that 85–95% of the generated energy can radially be transferred while maintaining sustained combustion in the bed (at temperatures between 723 and 1173 K). While extending its application for heating liquids like water, it was found in the modeling and simulation study that the existing design resulted in quenching of the bed below 773 K in the oxidation cycle and achieving sustained combustion was not possible for all practical ranges of operating parameters. Hence it was decided to modify the existing system by increasing the volume ratio of the annular bed to the liquid section. Theoretical estimations revealed that increasing this ratio by four times or higher can result in maintaining sustained combustion conditions in the bed while having continuous radial heat transfer to the water flowing in the laminar range. The general guidelines for designing a UMC-based liquid heating system were then prepared and used to propose a new design for water heating. The modeling and simulation studies for this proposed design also indicated that it is a feasible design. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.