Source-sink Model Research Articles

CCUS source-sink matching model based on sink well placement optimization

Realizing the dual-carbon target is a major strategic plan made by the Party Central Committee and a solemn commitment to address climate change of global significance. Source-sink matching technology in carbon capture, utilization, and storage (CCUS) technology is crucial to achieving the dual-carbon target. However, most previous studies constructed source-sink matching models based on sink-fixed sequestration potential, making it difficult to accurately assess the potential of sequestration sites and thus affect the source-sink matching scheme. Therefore, a dynamic storage potential assessment model has been established which can quickly assess the injection capacity of sinks under different well deployment schemes and then a source-sink matching model based on the overall optimization of sink deployment schemes has been constructed by combining the dynamic storage potential assessment model. The model considers the source matching problem as a mixed-integer linear programming (MILP) problem and obtains the computational results of the dynamic storage potential assessment model to realize the correct matching and simultaneous optimization of the source-sink pipeline network layout and the sink-well deployment scheme. With the proposed model, source-sink matching cases for national-level and project-level have been analyzed. It has been shown that the dynamic storage potential assessment model and the combined method improve the accuracy of the source-sink matching model in the form of MILP while minimizing the total cost and additional computations.

The carbon-energy-water nexus of the carbon capture, utilization, and storage technology deployment schemes: A case study in China's cement industry

Carbon capture, utilization, and storage (CCUS) technology plays a crucial role in the transition towards low-carbon emissions in the cement industry. However, it also results in numerous energy and water consumption. To formulate proper CCUS deployment strategies, it is essential to optimize spatial CCUS layouts and examine the carbon-energy-water nexus of the technology. This study combines China's cement emission inventory, representing carbon sources, with carbon storage sites data, and develops a source-sink matching model to determine optimal CCUS deployment schemes under different mitigation target scenarios. In addition, the spatial distribution of energy and water consumption impacts, as well as the carbon-energy-water nexus, are evaluated. Results indicate that the deployment of CCUS in 229, 445, and 627 cement plants is necessary to mitigate 20%, 40%, and 60% of carbon emissions in China's cement industry, respectively. The estimated economic costs of these schemes are 79.4, 167.9, and 269.5 billion CNY, posing a significant financial challenge for the industry. Carbon capture technologies greatly influence the carbon-energy-water nexus of the CCUS deployment schemes, with net energy and water consumption ranging from 271.5 to 2410.9 PJ and − 28.5 to 872.4 million m3. Totally, 13–15 provinces achieve synergic carbon mitigation and water extraction effects by using the technologies with low water intensity. Nevertheless, trade-offs between carbon and energy exist regardless the technology. In conclusion, this study provides valuable insights for planning CCUS deployment schemes by revealing the multi-dimensional impacts on economic costs, energy consumption, and water consumption, which supports the decarbonization of China's cement industry.

Carrying Capacity of Low Earth Orbit Computed Using Source-Sink Models

The low-Earth-orbit (LEO) environment will likely experience an exponential growth of the anthropogenic space object population, also due to the many proposed large constellations, which could negatively affect the sustainability of the space environment if no proper regulatory actions are introduced. This paper introduces a methodology to analyze high-capacity sustainable solutions of the LEO region from 200 to 900 km altitude. Sustainability is assessed through the stable equilibrium points of a source-sink model called MIT Orbital Capacity Assessment Tool 3 (MOCAT-3). Capacity is estimated using an optimization procedure that aims to compute the optimal launch rate that maximizes the number of satellites in LEO, subject to a risk-rate constraint. Results show that the sustainable number of satellites increases with the risk rate constraint. Moreover, the resilience of the proposed solutions is tested against a more accurate time-varying atmospheric density model and perturbations of the initial equilibrium population. The compatibility of the proposed solutions with future traffic launches and a strategy to accommodate future traffic needs are presented. Limitations of the current work are discussed, chiefly the importance of validation of model coefficients and behavior before resulting capacity estimates are used to guide actual decision-making.

CO2 abatement feasibility for blast furnace CCUS retrofits in BF-BOF steel plants in China

As one of the energy and carbon intensive industries, the steel industry's low-carbon transition will contribute to the achievement of China's carbon neutrality goal. In this study, a comprehensive source-sink matching-trinomial tree real option evaluation model for China's steel industry was established by combining the database of carbon emissions from blast furnaces of BF-BOF process steel plants, and onshore and offshore CO2 storage potential and injection capacity rate database. By using this model, we investigate the CO2 abatement potential and investment decisions for blast furnace CCUS full-chain projects in China's BF-BOF process steel plants. The results show that a total of 420.07Mt/a of CO2 reductions can be achieved, attributed to 111 steel plants screened for source-sink matching. If no extra incentive policy was included, the current carbon market only supported immediate investment in 14 steel plant CCUS retrofit full-chain projects, which could achieve 36.47Mt/a of CO2 reductions, with a critical carbon price ranging from 6.96 to 202.98USD/t, averaged at 86.97 USD/t. Technological advances, rising carbon prices and government incentives would all contribute to the development of CCUS full-chain projects in the steel industry. The findings provide a strategy for the deployment of blast furnace CCUS retrofit in China's steel industry.

Non-negligible contribution from coastal erosion to sedimentation around the archipelago: A case study of Miaodao Archipelago

The Miaodao Archipelago, located in the southern Bohai Strait, serves as a major route for the exchange of energy and materials between the Yellow and Bohai seas and is distinguished by a complicated hydrodynamic environment and provenance. Based on the grain size and elemental data of 107 surface sediment samples from the archipelago waters, and 58 coastal erosional sediment and bedrock samples, this study investigated the factors influencing the geochemical elemental distribution, discusses the provenance of the surface sediments and relative contributions, as well as proposes a sediment source–sink model for the region. The distribution of major and trace elements in the surface sediments, typically characterized by “high in the north, low in the south” patterning (except for SiO2, Ba, and Sr), with their contents primarily controlled by the input of terrestrial materials. The surface sediments in the study area are separated into the geochemical subdivisions of north and south. The main provenances of the study area include the Yellow River, the nearshore Miaodao Archipelago, and the north side of nearshore Penglai, whose sediments were transported under the combined action of the Shandong Peninsula's tidal current, waves, and longshore current. Deposition occurred under the capturing action of the archipelago. The relative contributions of the three provenance areas were 74.7%, 15.5%, and 9.8%, respectively; the relative contribution of coastal erosion reaches 1/3 of the river. Studies have demonstrated that the contribution of coastal erosion provenances to sea surface sediments is non-negligible, and in fact, it may even be quite important; thus, in the context of decreasing riverine inputs to the sea and enhanced coastal erosion processes, the contribution of coastal erosion requires special attention.

Effects of Orbit Raising and Deorbiting in Source-Sink Evolutionary Models

The sustainability of the low-Earth-orbit (LEO) environment is threatened by the growing number of anthropogenic space objects planned to be launched in the coming years. This paper investigates the evolution of objects residing in LEO through the MIT Orbital Capacity Assessment Tool (MOCAT), an evolutionary multishell, multispecies source-sink model. The proposed novelty considers the flow of objects crossing multiple shells during orbit raising and deorbiting maneuvers, modeled through the secular variation of the semimajor axis under a low-thrust continuous applied control. To this aim, a higher-fidelity MOCAT version, including active satellites, derelicts, debris, and rocket bodies, has been developed and used. The results demonstrate that incorporating orbit transfer fluxes into the model results in a higher number of collisions, which leads to a greater quantity of debris and poses a greater threat to the safety of LEO.

Source-Sink Matching Model Focusing on the Feasibility of CO2 Pipeline Transport

Source-Sink Matching Model Focusing on the Feasibility of CO2 Pipeline Transport

A landscape source–sink model to understanding the seasonal dynamics of antibiotics in soils at watershed scale

Human and veterinary antibiotics occur widely in soil ecosystems and pose a serious threat to soil health. Landscape structure can be linked to Earth surface processes and anthropogenic footprints and may influence the variability of antibiotics in soil. In this study, an improved landscape source–sink model was used to characterize source–sink structures using the location-weighted landscape index (LWLI), which can be linked to antibiotic seasonality. The topographic wetness index was employed to identify source and sink landscapes, which represent antibiotic transport pathways via topography-driven hydrological processes. The results indicate that LWLI values and antibiotic seasonality are typically higher in farmland soils than in forest and orchard soils. LWLI values exhibit significant positive correlations with antibiotic seasonality in soils (R2: 0.33–0.58). Furthermore, landscape source–sink structures have a significant influence on antibiotic seasonality between winter and other seasons in farmland soils; however, these structures affect antibiotic seasonality between summer and other seasons in forest and orchard soils. The results of this study indicate that water movement regulated by landscape structure may play a crucial role in influencing antibiotic seasonality in soils at the watershed scale, and the landscape source–sink model can be used to quantitatively evaluate antibiotic seasonality in soil environment.

Investment decisions on carbon capture utilization and storage retrofit of Chinese coal-fired power plants based on real option and source-sink matching models

Carbon Capture Utilization and Storage (CCUS) is the only technological option for decarbonizing existing coal-fired power plants (CFPPs) deeply, yet its current scale is far from the level required to meet global climate goals. How carbon price can facilitate CCUS decarbonization of CFPPs in China is a great concern. This study couples a CCUS source-sink matching optimization model covering onshore and offshore geological storages with a trinomial-tree real options model, by which the Chinese critical carbon prices for CCUS investment at different emission reduction potentials are quantified. The results show that when the carbon price reaches 100, 200, and 400 CNY/t, then 24, 28, and 314 GW of CFPPs will enable to invest in CCUS immediately, achieving cumulative 1.8, 2.1, and 24.3 GtCO2 emission reductions over their remaining lifetime. To meet the global warming 2 °C target constraint on China's power sector, the carbon price need to reach 370 CNY/t.

Numerical approach toward ternary hybrid nanofluid flow with nonlinear heat source-sink and fourier heat flux model passing through a disk

Numerical approach toward ternary hybrid nanofluid flow with nonlinear heat source-sink and fourier heat flux model passing through a disk

Population dynamics of shoreface to upper offshore occupation of the lower Ordovician brachiopod Tarfaya purmamarcaensis (Benedetto)

Occupation of shallow environments by rhynchonelliform brachiopods is rare during the early late Tremadocian (Tr2). However, in the NW Argentina basin the plectorthoidean Tarfaya purmamarcaensis occupied high-energy environments during this time interval. This species forms up to 15 cm thick monospecific concentrations in shoreface and offshore transition settings, and polytypic pavements in relatively deeper water offshore environments. Generation of such concentrations could be linked to the population dynamics of T. purmamarcaensis. A geometric morphometrics analysis allowed us to recognize four growth stages in the ontogeny of the species. The juvenile phases are absent in high-energy proximal environments and are scarce in the shoreface; in contrast, no representatives of the fourth phase (hypermature adults) have been found in the open platform deposits, and adults are almost absent. Although shell concentrations are usually linked to physical processes (i.e., storm events), the low taphonomic alteration of the shells suggests that transport was not a highly influential factor. Morphological differences (i.e., development of cardinal canals, ribs incurved posterolaterally) in specimens from different environments suggest that the population dynamics could have been the main cause in generating different concentrations. According to the source-sink model, high productivity of brachiopods in the shoreface environment and a passive transport of larvae to the offshore might explain not only the thicker shallow-water concentrations but also the differences in shell growth of populations inhabiting these environments.

Application of source-sink theory and MCR model to assess hydrochemical change risk in Lhasa River basin, Tibet, China

The Lhasa River, one of the tributaries of the Yarlung Zangbo River on the Tibetan Plateau, provides water for the vast majority of residents in Tibet. The main purpose of this study is to identify regional environmental risk factors that may be affecting the Lhasa River basin. The minimum cumulative resistance (MCR) model was used to determine the “source-sink” risk pattern of the Lhasa River by identifying the sources of metal ions and trace elements in the basin. The results show that loss of soil ions, climate conditions and environmental factors contribute to the hydrochemical characteristics of the Lhasa River basin. The distribution of soil type greatly overlaps with the likelihood of soil ions loss. The low-risk and high-risk zones mainly consist of calcic soils and litho soils, respectively. In terms of the climate and environmental risk factors, rainfall erosivity poses the greatest risk during the low-flow season, vegetation coverage during the high-flow season, and freeze-thaw erosivity during the normal-flow season. High-risk sources and low-risk sources were identified by the MCR model. The high-risk sources were the vegetated and unused lands, which are vulnerable to weathering of Ca and Mg rich sedimentary and mixed rocks, while low-risk sources were the urban, construction, industrial and mining areas and forest land. This study can contribute to the development of policies for the sustainable management of water resources and the protection of the water environment in the Lhasa River Basin.

Novel Source–Sink Model for Space Environment Evolution with Orbit Capacity Assessment

The increasing number of anthropogenic space objects (ASOs) in low Earth orbit (LEO) poses a threat to the safety and sustainability of the space environment. Multiple companies are planning to launch large constellations of hundreds to thousands of satellites in the near future, increasing the probability of collisions and debris generation. This paper analyzes the long-term evolution of the LEO ASO population with the goal of estimating LEO orbital capacity. This is carried out by introducing a new probabilistic source–sink model. The developed source–sink model is a multishell multispecies model, which includes different object species, such as active and derelict satellites, and debris. Furthermore, debris are divided into the following two subgroups: trackable and nontrackable debris, the last ones representing a significant hazard for active satellites. In addition, the proposed model accounts for collision events and atmospheric drag effects, which include the influence of solar activity. Indeed, the Jacchia–Bowman 2008 thermospheric density model is exploited. The results prove that considering untracked debris within the model produces more collisions, and therefore a smaller population of active satellites affecting the safety of LEO and its orbital capacity.

Distribution of Biodegradable Dissolved Organic Matter and Its Affecting Factors in a Typical Peri-urban Watershed in Yangtze River Delta

Dissolved organic matter (DOM) plays key roles in the carbon biogeochemical cycle, and biodegradable dissolved organic matter (BDOM) is one of the key fractions of DOM. Rapid urbanization and intensive human activities substantially influence the distribution of DOM at the watershed scale. Identifying the spatial and temporal variability in BDOM has become an important and urgent issue of water quality control in rapid urbanization areas. However, limited studies have been conducted to explore the role of human activities on the occurrence and distribution of BDOM in peri-urban watersheds. In this study, the spatial and temporal distribution of BDOM and related affecting factors were investigated in a typical peri-urban watershed (Zhangxi watershed) located at Ningbo City in Yangtze River Delta. Water samples were collected in wet and dry seasons in 2019 based on topographic features, land use, and intensity of human activities. The BDOM were characterized by fluorescence excitation-emission matrix and parallel factor analysis (EEM-PARAFAC), and land use patterns were analyzed using the Source-Sink Landscape Model. The results of this study showed that the BDOM concentrations ranged from 0.57 to 6.80 mg·L-1. Obvious spatial and temporal heterogeneities of BDOM were found at the watershed scale, and significantly higher concentrations of BDOM were observed in the wet season than those in the dry season. Furthermore, relatively high concentrations of BDOM were found in areas with relatively higher intensive human activities. Two fluorescent components (a terrestrial humic-like substance and protein-like substance) were observed using the PARAFAC model. The results of spatial analysis showed that terrestrial humic-like fluorescent components were closely positively correlated with anthropogenic parameters (percentages of agricultural and urban land and ratio of source and sink landscapes). The results showed that the occurrence and distribution of BDOM were strongly influenced by human activities, which could provide scientific guidance for water quality control and related land management in peri-urban aquatic ecosystems.

Exergy efficiency and exergy destruction assessment of heat transfer and fluid flow through spiral passages using source-sink model

Exergy efficiency and exergy destruction of forced turbulent convective fluid flow through spiral passages using sourcesink model are assessed. Constant and temperature dependent thermophysical properties of process fluid in sink regions have been considered, while in the source regions phase change material is kept at constant temperature. Moreover, the effect of a secondary flow phenomenon due to spiral motion of the fluid flow through narrowing spiral passages has been evaluated in the sink passage domain. It was found that this phenomenon plays an important role in decreasing the exergy destruction as a result of energy exchange between source and sink in this compact type of energy carrier or storage equipment. It was found that the De (Dean Number) whose magnitude is a measure of the secondary flow, has positive impact on exergy efficiency while decreasing along the spiral passage. The fluid properties that are temperature dependent have a significant influence on the enhancement of heat transfer process, exergy efficiency and exergy destruction. It is concluded that the source-sink model could be considered from engineering point of view as a good simple model for evaluating the thermodynamic performance of this type of thermal energy process device.

A digital twin application for vineyards sustainable management

Environmental protection and production sustainability are the key actions required to the farming activities, especially to those with higher add value as wine production. Vineyard are one of the most demanding activities in terms of water consumption and environmental impacts, which can be mitigated only with a systematic approach based on smart agriculture to support and optimize vineyard management. This paper proposes a vineyard digital twin (VDT) based on a mathematical model able to predict the vegetative and productive growth of a vineyard (leaf area, shoot length, crop and yield mass), qualitative product parameters (sugar and acid) and the water footprint associated with production. The model implements a soil-atmosphere source-sink model, where water balance across vine is coupled with potential carbon demand functions to estimate water and temperature stresses and, through a mechanistic model for sugar accumulation and acid concentration, will evaluate the expected grape quality. The distinctive trait of this model is the integration and feedback among prediction of grapevine quality and vegetative growth, using a common boundary data set and integrating the agronomical operations on vineyard seasonal development. The VDT prototype will help producers to systematize, formalize, and accumulate knowledge to improve and optimize management processes to achieve sustainable production, increasing products healthy and reducing environmental footprint.

Analysis of Vegetable Waste Pollution Risk and Resource Potential Based on Geographical Information System and Remote Sensing

Land resources are an important foundation for human survival and development. In recent years, land resources have experienced rapid industrialization and urbanization. With the expansion of urban construction land and the sharp decline of natural and agricultural landscapes, ecological and social problems have gradually surfaced. Based on the intuitive interpretation of LandsatTM/ETM +/OLI image data from 2016 to 2020, this work created an annual land use reference database. The use of resources and the recovery of nutrients from vegetable waste are necessary measures to achieve sustainable and environmentally friendly agriculture. Collecting and analyzing data from the literature are to determine the risk of vegetable waste pollution and the possibility of resource utilization. The amount of vegetable waste produced and the total amount of nitrogen, total phosphorus, and total potassium pollution in the study area are estimated, and ArcGIS is used to characterize TN (total nitrogen) and TP (total phosphorus). The spatial distribution of TK (total potassium) pollution intensity and pollution risk comprehensive index determines the key areas of vegetable waste nonpoint source pollution control in the region and compares the resource utilization potential of vegetable waste based on the demand for fertilizer. This paper combines the research of the subject; takes cultivated land as the research object; clarifies the main pollutants, contaminated area, content, and distribution of cultivated land; uses factor analysis method to conduct a preliminary study on the causes of heavy metal contaminated soil in the study area; and adopts a source-sink balance model, analyze the cumulative characteristics of soil pollution. Based on geographical information system (GIS) and remote sensing technology, this paper investigates the risk assessment of vegetable waste pollution and discusses the analysis of resource potential.

Benthic Biofilms in Glacier-Fed Streams from Scandinavia to the Himalayas Host Distinct Bacterial Communities Compared with the Streamwater.

Microbial life in glacier-fed streams (GFSs) is dominated by benthic biofilms which fulfill critical ecosystem processes. However, it remains unclear how the bacterial communities of these biofilms assemble in stream ecosystems characterized by rapid turnover of benthic habitats and high suspended sediment loads. Using16S rRNA gene amplicon sequence data collected from 54 GFSs across the Himalayas, European Alps, and Scandinavian Mountains, we found that benthic biofilms harbor bacterial communities that are distinct from the bacterial assemblages suspended in the streamwater. Our data showed a decrease in species richness in the benthic biofilms compared to the bacterial cells putatively free-living in the water. The benthic biofilms also differed from the suspended water fractions in terms of community composition. Differential abundance analyses highlighted bacterial families that were specific to the benthic biofilms and the suspended assemblages. Notably, source-sink models suggested that the benthic biofilm communities are not simply a subset of the suspended assemblages. Rather, we found evidence that deterministic processes (e.g., species sorting) shape the benthic biofilm communities. This is unexpected given the high vertical mixing of water and contained bacterial cells in GFSs and further highlights the benthic biofilm mode of life as one that is determined through niche-related processes. Our findings therefore reveal a "native" benthic biofilm community in an ecosystem that is currently threatened by climate-induced glacier shrinkage. IMPORTANCE Benthic biofilms represent the dominant form of life in glacier-fed streams. However, it remains unclear how bacterial communities within these biofilms assemble. Our findings from glacier-fed streams from three major mountain ranges across the Himalayas, the European Alps and the Scandinavian Mountains reveal a bacterial community associated with benthic biofilms that is distinct from the assemblage in the overlying streamwater. Our analyses suggest that selection is the underlying process to this differentiation. This is unexpected given that bacterial cells that are freely living or attached to the abundant sediment particles suspended in the water continuously mix with the benthic biofilms. The latter colonize loose sediments that are subject to high turnover owing to the forces of the water flow. Our research unravels the existence of a microbiome specific to benthic biofilms in glacier-fed streams, now under major threats due to global warming.

Extended Carbon Emission Pinch Analysis for the Low-Carbon Tobacco Industry

The tobacco industry is an important contributor to realizing the carbon reduction goal. Less attention is paid to the carbon emissions of the tobacco industry. The tobacco production system is generally a carbon sink, where carbon sequestration by photosynthesis in tobacco planting and by soil are sufficient to offset the carbon emissions of the tobacco production system. This work proposed an integrated framework of life-cycle assessment (LCA) and Source-Sink Model to determine the optimal allocation of carbon sources to sinks with the objective of maximizing the profitable external benefits. From an economic perspective, internal carbon sources could be offset by the internal carbon sink of the tobacco production system. The additional internal carbon sinks can be transferred in the form of carbon trading, increasing external revenue. A case-study tobacco manufacturing plant in Sichuan, China, was chosen to demonstrate the feasibility of the proposed work. This study assesses the carbon footprint and economic benefits of a tobacco industry supply chain case (from tobacco cultivation to finished product) and analyzes the energy restructuring of different percentages of renewable energy to replace thermal power. The objective of the study is to maximise the offsetting of carbon emissions from the tobacco production system, while achieving optimal internal costs and profitable external benefits.

A Simple Model for Tropical Convective Cloud Shield Area Growth and Decay Rates Informed by Geostationary IR, GPM, and Aqua/AIRS Satellite Data

AbstractDeep convective system maximum areal extent is driven by the stratiform anvil area since convective area fractions are much less than unity when systems reach peak size. It is important to understand the processes that drive system size given the impact large systems have on rainfall and that of anvils on high cloud feedbacks. Using satellite diabatic heating and convective‐stratiform information mapped to convective systems, composite analyses suggest that system maximum sizes occur at the temporal mid‐point of system lifecycles with both maximum size and duration correlating with peak heating above the melting level. However, variations in system growth rates exist, with the overall smooth composites emerging as the average of highly variable system trajectories. Thus, this study focuses on understanding convective system growth rates on short (30‐min) timescales via development of a simple analytical source—sink model that predicts system area changes. Growth occurs when detrained convective mass (inferred from the vertical gradient of diabatic heating and temperature lapse rates) and/or generation of convective area exceeds a sink term whose magnitude is proportional to the current cloud shield size. The model works well for systems over land and ocean, and for systems characterized by varying degrees of convective organization and duration (1.5–35 hr, with correlations often >0.8 across lifetime bins). The model may serve as a useful foundation for improved understanding of processes driving changes in tropics‐wide convective system cloud shields, and further supports conceptual development and evaluation of prognostic climate model stratiform anvil area parameterizations.