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Thermo-hydro-geomechanical (THM)-coupled physical problems widely occur in geologic carbon dioxide (CO2) sequestration (GCS), which has gained increasing attention in recent years. There are many in-house and commercial software programs developed for THM-coupled numerical simulation. However, only a few programs permit large-scale, complex analysis and prediction of GCS problems. Therefore, the authors developed an in-house code named AEEA Coupler to link two industrial standard simulation software programs, Abaqus (mechanical engineering) and Eclipse (petroleum engineering), which enable THM simulation of large-scale complex geological models (including multiple fractures and faults) possible. In this paper, the authors introduce interpolation and adaptive search algorithms and data exchange techniques between different grids using reservoir analysis and finite-element mesh methods in the mechanical analysis of a reservoir. After that, the applicability and accuracy of the AEEA Coupler are tested by comparing the results with certain benchmarks. Finally, a complicated problem is identified to demonstrate the power of the AEEA Coupler in solving coupled processes in geoscience projects.

Ottawa sand and Angular sand consist of particles with distinct shapes. The x-ray computed tomography (XCT) image stacks of their in-situ confined compressive testings are provided in this paper. For each image stack, a contact network, a thermal network and a network feature - edge betweenness centrality - of each edge in the networks are also provided. The readers can use the image data to construct digital sands with applications of (1) extracting microstructural parameters such as particle size, particle shape, coordination number and more network features; (2) analysing mechanical behaviour and transport processes such as fluid flow, heat transfer and electrical conduction using either traditional simulation tools such as finite element method and discrete element method or newly network models which could be built based on the network files available here.

Two-phase computational fluid dynamics (CFD) models for a hybrid pulsed sieve-plate solvent extraction column, as well as a standard pulsed sieve-plate column, have been developed with commercial software ANSYS FLUENT. Hydrodynamic performance including two-phase distribution and velocity fields are generated with the models and comparisons are made between two columns. Important parameters including holdup and axial-dispersion coefficients are studied systematically, and CFD successfully predicts the higher holdup and lower axial-dispersion coefficients for the hybrid pulsed sieve-plate column as measured in the experiments. CFD also gives reasonable predictions for the effect of pulsation intensity, dispersed-phase velocity, and continuous-phase velocity on holdup, except for the effect of pulsation intensity in low pulsation region, and the cause has been discussed from the perspective of droplet breakage and coalescence. Comparison with literature data shows that CFD underestimates the holdup of hybrid pulsed sieve-plate column and standard pulsed sieve-plate column by 23.3% and 31.4%, respectively, and the cause has been discussed from the perspective of drag law. CFD gives good prediction of axial-dispersion coefficients for the hybrid pulsed sieve-plate column and the standard pulsed sieve-plate column with ARD of 12.0% and 14.3%, respectively. This study shows CFD to be a useful tool to predict performance for the novel hybrid pulsed sieve-plate column as well as the standard pulsed sieve-plate column.

Global warming and climate change due to anthropogenic carbon dioxide (CO2) have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields. Therefore, CO2 capture, use, and storage have become particularly important. In this review, general background and methods for CO2 capture and separation, in particular, on ionic liquids (ILs)-based solvents and materials, are discussed. Comprehensive surveys of ILs for CO2 absorption are presented, which focused mainly on experimental researches, and then the concept is extended to functionalized absorbents and recent developments for CO2 capture. Major advantages and disadvantages of amines-based and ILs-based absorbents are discussed in this review. Solutions of traditional amines (MEA, MDEA, DEA, AMP, PZ, etc.) and ILs (conventional ILs, functionalized ILs, etc.) are summarized. Moreover, research progresses on CO2 separation are also introduced focusing mainly on amines and ILs-based membranes (e.g. supported amines membranes, SILMs). Futhermore, the fixation of CO2 into cyclic carbonates catalyzed by ILs (pure ILs, complex catalyst system with ILs, supported ILs, etc.) is summarized, clearly explaining the mechanism of CO2 fixation with ILs. Finally, exploration of some recent studies about CO2 capture and conversion by ILs and challenges for further progress are presented and related suggestions are put forward.

Terminal velocity of liquid drops is one of the key parameters in liquid–liquid extraction column design. It is important in determining residence time, droplet lifetime, and mass transfer rate. In present paper, the rising behavior of a single drops were investigated in a low interfacial tension system by high speed camera. An n-butanol/water system was used as test system. Correlations for terminal velocity were evaluated and compared, both explicitly and implicitly. Moreover, the influence of salt addition in aqueous phase was also studied, including salt concentrations and types. A Weber–Reynolds correlation was derived on the basis of experimental data. Drag coefficient was then calculated and showed a good agreement compared to the correlations in literatures.

The experimental and numerical investigations of single drop in liquid/liquid extraction system have been reviewed with particular focus on experimental techniques and computational fluid dynamic simulation approaches. Comprehensive surveys of available experimental techniques and numerical approaches for single drop rising and falling were given. Subsequently, single drop mass transfer was also reviewed both experimentally and numerically. Additionally, single drop breakage and coalescence process and the influencing factors were summarized and compared, so as to establish sub-models for population balance model. Future directions on single drop mass transfer, drop breakage and coalescence were suggested. It is believed that the single drop is a powerful tool to assist extraction process design from lab-scale to pilot-scale.

Two types of novel anticorrosive ceramic internals, the hybrid ceramic internal and ceramic plate, are designed and tested under pilot conditions for future industrial application in lithium extraction from salt lake brine. A standard liquid–liquid system with medium interfacial tension, 30% TBP in Shellsol 2046–water with acetic acid as solute, is used to test axial dispersion and mass-transfer parameters, which are important to determine height of extraction columns, over a range of operating conditions. Results show that the hybrid ceramic internal has 50% lower axial dispersion coefficient and 50% higher mass-transfer coefficient, both contributing to better mass-transfer performance. Under proper operating conditions, the height of the transfer unit of the hybrid ceramic internal can reach as low as approximately 0.2 m, which shows very good efficiency and makes it promising for application in the near future.

An improved understanding of investment decisions on low-carbon technology will greatly facilitate assessing the effectiveness of carbon emissions mitigation policies. We use the example of implementing CCS (carbon capture and storage) within ICL (indirect coal liquefaction), a controversial technology in China, by constructing a RO (real options) model for the investment decision-making process to assess how different climate policies affect low-carbon technology investors under highly uncertain circumstances. We find that a carbon tax provides the strongest signal for investment and that a market-based measure provides firms with flexibility. Moreover, different types of carbon markets generate substantially different effects on firm behavior, and the CO2 price level exerts a more powerful influence on investors than market volatility or the policy's implementation date. Considering the regional disparities among the coal-abundant but less-developed provinces and the affluent coastal regions in China, we suggest that a sub-national CDM (clean development mechanism) would complete the current domestic policy framework to balance the development requirement and CO2 abatement, whereas extraordinary administrative efforts are necessary to raise the current price of CO2 credits to an effective level, to broaden the carbon market coverage and consolidate the carbon market foundation.

An improved understanding of investment decisions on low-carbon technology will greatly facilitate assessing the effectiveness of carbon emissions mitigation policies. We use the example of implementing CCS (carbon capture and storage) within ICL (indirect coal liquefaction), a controversial technology in China, by constructing a RO (real options) model for the investment decision-making process to assess how different climate policies affect low-carbon technology investors under highly uncertain circumstances. We find that a carbon tax provides the strongest signal for investment and that a market-based measure provides firms with flexibility. Moreover, different types of carbon markets generate substantially different effects on firm behavior, and the CO2 price level exerts a more powerful influence on investors than market volatility or the policy's implementation date. Considering the regional disparities among the coal-abundant but less-developed provinces and the affluent coastal regions in China, we suggest that a sub-national CDM (clean development mechanism) would complete the current domestic policy framework to balance the development requirement and CO2 abatement, whereas extraordinary administrative efforts are necessary to raise the current price of CO2 credits to an effective level, to broaden the carbon market coverage and consolidate the carbon market foundation.

Urbanization has transformed daily lives and industrial production in China. We investigate the effects of this process on Chinese energy consumption patterns. Three energy-consuming sectors intricately associated with urbanization are identified and analyzed: residential households, transportation, and the building materials industry. Urbanization has profoundly affected each; moreover, the latter two are high energy consumption and potentially high carbon producing. We estimate energy consumption attributable to each sector to quantitatively evaluate their impacts on societal transition. Transportation and the production of building materials are identified as the most significant linkages from urbanization to energy consumption. Strikingly, despite the large increase in the proportion of the population that is urban, the share of urban energy consumption, as estimated here, in total energy consumption has remained stable. This suggests that economic growth, in the form of the production of goods for export and domestic consumption, is the most important driver of energy demand in China.

Urbanization has transformed daily lives and industrial production in China. We investigate the effects of this process on Chinese energy consumption patterns. Three energy-consuming sectors intricately associated with urbanization are identified and analyzed: residential households, transportation, and the building materials industry. Urbanization has profoundly affected each; moreover, the latter two are high energy consumption and potentially high carbon producing. We estimate energy consumption attributable to each sector to quantitatively evaluate their impacts on societal transition. Transportation and the production of building materials are identified as the most significant linkages from urbanization to energy consumption. Strikingly, despite the large increase in the proportion of the population that is urban, the share of urban energy consumption, as estimated here, in total energy consumption has remained stable. This suggests that economic growth, in the form of the production of goods for export and domestic consumption, is the most important driver of energy demand in China.

Lipid droplets (LDs) are important cellular organelles that govern the storage and turnover of lipids. Little is known about how the size of LDs is controlled, although LDs of diverse sizes have been observed in different tissues and under different (patho)physiological conditions. Recent studies have indicated that the size of LDs may influence adipogenesis, the rate of lipolysis and the oxidation of fatty acids. Here, a genome-wide screen identifies ten yeast mutants producing “supersized” LDs that are up to 50 times the volume of those in wild-type cells. The mutated genes include: FLD1 which encodes a homologue of mammalian seipin; five genes (CDS1, INO2, INO4, CHO2 and OPI3) that are known to regulate phospholipid metabolism; two genes (CKB1 and CKB2) encoding subunits of the casein kinase 2; and two genes (MRPS35 and RTC2) of unknown function. Biochemical and genetic analyses reveal that a common feature of these mutants is an increase in the level of cellular phosphatidic acid (PA). Results from in vivo and in vitro analyses indicate that PA may facilitate the coalescence of contacting LDs, resulting in the formation of “supersized” LDs. In summary, our results provide important insights into how the size of LDs is determined and identify novel gene products that regulate phospholipid metabolism.

ICL (Indirect coal liquefaction), an alternative fuel-supplying technology, has drawn much attention and caused considerable debate in China's energy sector. The hurdles to its development include the high risk of investment into large-scale installations, the high CO2 emissions and water resource consumption. A comprehensive assessment of ICL is urgently needed. This study provides an economic assessment and a technical analysis based on process simulations. To address the future challenge of curbing CO2 emissions, three absorption methods are compared for capturing the CO2 released from the ICL process: DM (a novel absorbent), MEA and Rectisol. The comparative results suggest that physical absorbents, represented by Rectisol and DMC, have a remarkable advantage over chemical absorption processes, represented by MEA. The Rectisol process costs the least, while the DMC process is close to the same level. As a novel absorbent, DMC has the potential to be widely used in the future. The economic analysis of CL predicted a high capital cost of over 35 billion yuan and an overall product cost of approximately 3800 yuan/ton for the baseline. In addition, via a sensitivity analysis, coal price, electricity price and capacity factor were identified as the three most influential factors affecting the overall product cost.

ICL (Indirect coal liquefaction), an alternative fuel-supplying technology, has drawn much attention and caused considerable debate in China's energy sector. The hurdles to its development include the high risk of investment into large-scale installations, the high CO2 emissions and water resource consumption. A comprehensive assessment of ICL is urgently needed. This study provides an economic assessment and a technical analysis based on process simulations. To address the future challenge of curbing CO2 emissions, three absorption methods are compared for capturing the CO2 released from the ICL process: DM (a novel absorbent), MEA and Rectisol. The comparative results suggest that physical absorbents, represented by Rectisol and DMC, have a remarkable advantage over chemical absorption processes, represented by MEA. The Rectisol process costs the least, while the DMC process is close to the same level. As a novel absorbent, DMC has the potential to be widely used in the future. The economic analysis of CL predicted a high capital cost of over 35 billion yuan and an overall product cost of approximately 3800 yuan/ton for the baseline. In addition, via a sensitivity analysis, coal price, electricity price and capacity factor were identified as the three most influential factors affecting the overall product cost.

The increasing pressure resulting from the need for CO2 mitigation is in conflict with the predominance of coal in China's energy structure. A possible solution to this tension between climate change and fossil fuel consumption fact could be the introduction of the carbon capture and storage (CCS) technology. However, high cost and other problems give rise to great uncertainty in R&D and popularization of carbon capture technology. This paper presents a real options model incorporating policy uncertainty described by carbon price scenarios (including stochasticity), allowing for possible technological change. This model is further used to determine the best strategy for investing in CCS technology in an uncertain environment in China and the effect of climate policy on the decision-making process of investment into carbon-saving technologies.

The increasing pressure resulting from the need for CO2 mitigation is in conflict with the predominance of coal in China's energy structure. A possible solution to this tension between climate change and fossil fuel consumption fact could be the introduction of the carbon capture and storage (CCS) technology. However, high cost and other problems give rise to great uncertainty in R&D and popularization of carbon capture technology. This paper presents a real options model incorporating policy uncertainty described by carbon price scenarios (including stochasticity), allowing for possible technological change. This model is further used to determine the best strategy for investing in CCS technology in an uncertain environment in China and the effect of climate policy on the decision-making process of investment into carbon-saving technologies.

The increasing pressure resulting from the need for CO2 mitigation is in conflict with the predominance of coal in China's energy structure. A possible solution to this tension between climate change and fossil fuel consumption fact could be the introduction of the carbon capture and storage (CCS) technology. However, high cost and other problems give rise to great uncertainty in R&D and popularization of carbon capture technology. This paper presents a real options model incorporating policy uncertainty described by carbon price scenarios (including stochasticity), allowing for possible technological change. This model is further used to determine the best strategy for investing in CCS technology in an uncertain environment in China and the effect of climate policy on the decision-making process of investment into carbon-saving technologies.