Excess Carbon Research Articles

On the role of Manganese Partitioning in Metastable Austenite by Quenching and Partitioning Treatment

With the aim to study the role of “frozen” concentration gradient of manganese (Mn) element in stability of retained austenite (RA) with multiple‐stage martensite transformation, a series of intercritical annealing (IA) temperatures is conducted before quenching and partitioning (Q&P) treatment. Morphology and distribution of RA are observed by field emission gun scanning electron microscope and electron back‐scatter diffraction. The volume fraction (7%–16%) and stability of metastable RA is found to be affected profoundly by IA temperature. Thermodynamic and kinetic analysis are conducted to elucidate the evolution of RA in process of IAQP treatment. The predicted levels of RA are in good accordance with measurements. It is found that the inhomogeneous partitioning of Mn in period of IA, combining with the incomplete partitioning of carbon during Q&P, radically regulated the Q&P microstructure. The incomplete partitioning of carbon in RA, with excess carbon segregation at dislocations and boundaries, lead to partition‐less bainite transformation owing to the average carbon content in RA lower than the “To” threshold.

Badanie ścieżki handlu uprawnieniami do emisji dwutlenku węgla w Chinach w kontekście tzw. podwójnego węgla

With the continuous development of the global economy, the rapid deterioration of the global ecological environment has caused a huge impact on the future development of the world. In order to solve the problem of global warming and enhance the self-development capacity of all countries, based on the concept of sustainable development, China has set the ambitious goal of dual carbon. To this end, China is actively promoting the establishment of a national carbon emissions trading system.In response to low price competitiveness, such as nonstandard trading system, the influence of the development of the carbon emissions trading system in the future, should not only attach importance to enrich and strengthen the basic function of the carbon market, also continue to carbon pricing system and in-depth reform of the fiscal and taxation system, clear up the thoughts to the carbon market trading rules, is on its relevant rights and obligations, firmly adhere to steadily promote carbon market links between countries. Currently, China’s carbon emission trading is still in its infancy, and its effect is still limited in specific practice. Meanwhile, carbon emission trading markets in developed countries such as the United States and the United Kingdom have begun to implement carbon tariffs and other means to maintain their carbon borders. Therefore, the construction of carbon emission trading is necessary for development, but also for the sustainable development of the country.The lag of China’s carbon emission market leads to the worsening of the problem of carbon excess emissions of industries in the regions not covered, and the increased economic burden caused by the carbon barriers of other countries in foreign trade. Of course, this requires China take the path of sustainable development to continue to strengthen the system construction of carbon emission rights and promote the further optimization of their functions.

Efficient CO2 absorption through wet and falling film membrane contactors: insights from modeling and simulation

The release of excessive carbon dioxide (CO2) into the atmosphere poses potential threats to the well-being of various species on Earth as it contributes to global working. Therefore, it is necessary to implement appropriate actions to moderate CO2 emissions. A hollow fiber membrane contactor is an emerging technology that combines the advantages of separation processes and chemical absorptions. This study investigates the efficacy of wet and falling film membrane contactors (FFMC) in enhancing CO2 absorption in a monoethanolamine (MEA) aqueous solution. By analyzing factors such as membrane surface area, gas flow rate, liquid inlet flow rates, gas–liquid contact time, and solvent loading, we examine the CO2 absorption process in both contactors. Our results reveal a clear advantage of FFMC, achieving an impressive 85% CO2 removal efficiency compared to 60% with wet membranes. We employ COMSOL Multiphysics 6.1 simulation software and finite element analysis to validate our findings, demonstrating a close agreement between predicted and experimental values, with an average relative error of approximately 4.3%. These findings highlight the significant promise of FFMC for applications in CO2 capture.

A simple speed bump energy harvester

As the nation progresses, energy demand increases. The generation of electricity in Malaysia is currently from natural gas, crude oil and petroleum, coal and coke, hydro and other renewable energy sources. Depletion of non-renewable energy sources and excessive carbon emissions are significant concerns. Any effort to mitigate, however small, is worth considering. In this study, energy harvesting from speed bumps is proposed and a roller speed bump energy harvester (SBEH) was conceived. From theoretical analysis, the roller SBEH can produce a theoretical power output of 1632.92 W when a car of 850 kg crosses the speed bump with a speed of 10 km/h. The primary driving force for roller SBEH was velocity and the secondary contributor was the weight of the vehicle. Greater speed and mass results in greater energy harvest. Future work will look further into its feasibility, examine the challenges of installation, perform size optimization and a proof-of-concept prototype.

The incompatibility between industrial restructuring and low-carbon economy: a comprehensive analysis.

Numerous studies have demonstrated that the development of low-carbon economy and industrial restructuring cannot occur in a coordinated manner. However, academic literature does not provide further explanations for this phenomenon. In this paper, we introduce a novel decomposition method to reassess the relationship between industrial restructuring and low-carbon economy, which yields similar findings. Next, we construct a straightforward theoretical model to investigate two fundamental reasons that interrelate with this issue: excessively high proportion of secondary sector and excessive carbon intensity of tertiary sector. Finally, we implement a rigorous causal identification using three-dimensional panel data at the provincial, industrial, and yearly levels by undergoing multiple robustness tests and mitigating endogeneity issues. Our heterogeneity tests suggest that the impact of industrial restructuring is greater in high-polluting industries, the Eastern region, and non-digital pilot regions. Overall, our theoretical and empirical analysis serves as a vital reference for other developing and developed countries to attain harmonious development between low-carbon economy and industrial restructuring.

Effect of dislocation density on competitive segregation of solute atoms to dislocations

We report on both experimental and modeling of carbon and nitrogen segregation to dislocations in C–Mn ferritic steels. A model based on McLean theory is established to describe the competitive segregation of carbon and nitrogen in the Cottrell atmospheres around dislocations, considering the effect of dislocation density. It is expected from the model that a high dislocation density strongly depletes interstitial atoms from the matrix, resulting in a low excess quantity of atoms on dislocations. Atom probe tomography analyses performed on two different C–Mn weld steels are in accordance with the model: carbon excess is tenfold higher in comparison to nitrogen excess in the deposited metal. However, after tensile test up to failure, this trend is no longer valid and nitrogen segregates preferentially than carbon. This suggests that plastic strain can modify the material properties by changing the nature and quantity of segregated atoms around dislocations.

The role of family businesses and active family members in environmental performance

There is a growing concern about environmental issues, particularly carbon emissions, in many countries. Indonesia, with its huge population, also suffers from excessive carbon emissions. This study aims to investigate the effect of family businesses on environmental performance, specifically carbon emission disclosure. This study also explores the role of the family supervisory board and management on the quality of carbon emission disclosure. The study employed 62 non-financial family-listed firms in 2017–2019 (186 observations). The analysis found a positive and significant relationship between family enterprises and the disclosure of carbon emissions, implying that family firms expose more information about their carbon emissions. It also revealed a significant positive association between the family supervisory board and carbon emission performance, suggesting that having family members on the supervisory board aligns with policies for reducing and maintaining accountability for carbon emissions. In summary, the findings suggest that family enterprises prefer to exercise their indirect control by holding a position on the supervisory board and owning a substantial percentage of the company’s stock corresponding to their socio-emotional wealth agenda. Additionally, there is a non-linear association between family firms and the disclosure of carbon emissions. Carbon emission performance decreases as family share ownership rises to 53.1% but increases when family equity exceeds this cut-off point. Finally, family shareholders in non-polluted firms report higher quality of carbon emission disclosure.

Influence of C/N ratio on microalgae-bacteria joint culture: Treatment performance and phytoplankton dynamics in mixed wastewaters

Microalgae biotechnology may represent a potential solution for minimizing the impacts of food industry activities, acting in bioremediation of wastewaters, and producing value-added biomass. Therefore, this work aimed to evaluate the biomass production and treatment performance of 5 culture media obtained by mixing brewery and meat processing wastewaters and to test the effects of their different C/N ratios. Cultivation media under optimal conditions (C/N = 6), deficit (C/N < 6), and excess (C/N > 6) of carbon were evaluated. Microalgae biomass and total biomass have adapted to all conditions, revealing resilience and symbiosis balance. Although, treatment performance was statistically distinct (p > 0.1). Total carbon, nitrogen, and phosphorus removals were influenced by nutrient availability. Biomass growth removed total carbon, total nitrogen, and total phosphorus from the culture medium at a rate of 62 % (C/N ≥ 7.4), 59 % (C/N = 4.1), and 58 % (C/N = 4.1), respectively.

Research on Spatiotemporal Changes in Carbon Footprint and Vegetation Carbon Carrying Capacity in Shanxi Province

The climate and ecological problems caused by excessive carbon dioxide emissions are attracting more and more attention, and the need for carbon reduction has reached a consensus. Carbon peak and carbon neutrality is a solemn commitment made by China to the world and a strategic arrangement to achieve economic and social transformation. This study focused on Shanxi Province, a base of power source and heavy chemical industry in China. Based on energy consumption data, carbon emission data set at the county level, land use data and socioeconomic data, we built a carbon ecological pressure index in order to analyze the spatiotemporal evolution characteristics of the carbon footprint, carbon carrying capacity and carbon ecological security status of each county in Shanxi Province from 2000 to 2020. The results showed that: (1) the total carbon footprint of Shanxi Province increased, and the number of high carbon emission counties showed an increasing trend. The largest part of carbon footprint was coal. (2) The vegetation carbon-carrying capacity showed an increasing trend in general, and forest land was the main contributor to the carbon-carrying capacity. (3) The carbon deficit of Shanxi Province was greater than 0 and behaved as a carbon source. The carbon ecological security decreased from a relatively safe level to a general safe level. (4) The carbon ecological pressure index gradually increased. It was predicted that the carbon ecological security level of each county will remain basically unchanged by 2025 and some will still be at a carbon ecological insecurity level. In general, the carbon ecological pressure index of some counties was still large. It is necessary to strengthen the use of clean energy, optimize the industrial structure and increase the carbon sink of forest land in order to reduce carbon emissions and increase the carbon sink, so as to ensure carbon ecological security and realize the goal of a low-carbon economy.

How does a scarcer allowance remake the carbon market? An evolutionary game analysis from the perspective of stakeholders

The carbon market has been playing an increasingly important role in mitigating carbon emissions. However, with the tightening of the carbon allowance, where the carbon market will evolve is still unclear. Abstracting three agents—Government, Carbon-supplier(‘CS’), Carbon-buyer(‘CB’), this paper intends to investigate the operation mechanism of carbon market from the perspective of the stakeholders. Based on the simulation analysis, it is suggested that: 1) the carbon market in China may become a major “seller's market” when carbon quota experienced dramatic reduction; 2) when the carbon price is constant, CS with excessive carbon productivity will crowd out and exploit CB in the carbon market competition; 3) strict administrative penalties and information disclosure would help promote proactive participation of CS and CB in the carbon market; and 4) the interaction between CS and CB in different strategic scenarios is influenced by the carbon price and the coefficient of demand variation for carbon quota. In contrast with previous studies, this paper has uncovered a dynamic strategic evolution mechanisms of stakeholders in the carbon market at the micro-level, contributing to carbon market governance and providing stakeholders with tailor-made climate policy tools and strategic choices.

Carbon-Embedded Tungsten Carbide Electrocatalysts Derived from Self-Deposited Tungsten Oxide for the pH-Universal Hydrogen Evolution Reaction

Tungsten carbide (WC) has been explored as a cost-effective and Earth-abundant alternative electrocatalyst for the hydrogen evolution reaction (HER) in both acid and alkaline conditions, due to its electronic structure comparable to that of platinum. Herein, we report on a simple and convenient approach for depositing the carbon-embedded WC electrocatalyst on nickel foam from the thermal reduction of a sucrose-impregnated self-deposited tungsten trioxide (WO3) precursor. Different sucrose concentrations (between 20 and 80% aqueous solution) and reduction temperatures (between 600 and 1000 °C) are tested to achieve an optimized material exhibiting the best electrocatalytic efficiency for HER. The optimized material is obtained from the precursor impregnated with 50% sucrose and thermally reduced at 800 °C. It can operate HER with overpotential values measured at 10 and 100 mA cm–2 of 0.124 and 0.232 V, respectively, at pH 14, and 0.208 and 0.333 V at pH 0.3, respectively. Furthermore, these electrodes are found to be stable in both media during controlled-current density electrolysis tests over a period of 40 h. The presence of excess amorphous carbon embedding WC is beneficial to improve the conductivity and dispersibility of the electrocatalyst and consequently its HER activity. These findings demonstrate that robust and efficient WC-based binder-free HER electrocatalysts can be produced easily from spontaneously deposited WO3 film and sucrose as the carbon source.

CO2 capture performance of CaO-based sorbent modified with torrefaction condensate during calcium looping cycles

In this work, the organic acid-rich torrefaction condensate (TC) from biomass torrefaction process was attempted to replace commercial acetic acid (AC) for acidification treatment of CaO sorbent to improve its CO2 capture performance during calcium looping cycles. The results showed that TC-modified sorbents exhibited a much slower carbonation reactivity decay than the AC-modified one over the cycles. According to the results of characterizations (thermal decomposition, morphology, phase composition, and N2 adsorption), the enhanced cyclic stability was probably due to the presence of carbon deposition from the decomposition of heavy tar in TC, which might act as a spacer and protective overlay to slow down the sintering of CaO particles. In addition, more carbon deposition could be dispersed in-situ into the TC-modified sorbents by increasing torrefaction temperature and TC addition amount, resulting in more thorough carbon deposition overlay and better sintering resistance. However, excessive carbon deposition (>50 wt%) leaded to slightly lower carbonation conversions and rates in the first two or three cycles. But this deficiency would disappear in subsequent cycles, as some carbon deposition was consumed by the carbon dioxide released during calcination. And the carbonation conversion of TC-modified sorbent with a carbon deposition content of 69.1 wt% was still as high as 81.5% after 10 cycles.

Microstructure, mechanical properties and high-speed dry-cutting performance of AlCrSiCN composite coatings

AlCrSiCN specimens with different carbon contents were fabricated by cathodic vacuum arc technique, and the microstructures, mechanical property, tribological and high-speed dry-cutting performance were investigated. The results show that the structural transformation from dense and fine nanocomposite to coarse columnar structures was found for the AlCrSiCN coatings when increasing the C content. The excess carbon was presented in the form of nanocrystalline graphite and/or amorphous carbon. Addition of C also reduces the surface roughness and the micro-hardness. The adhesive strengths of AlCrSiCN coatings (such as C10 and C20 coatings) with a low C content were enhanced, whereas it decreased to a value of Lc2 of 17.7 N when the C content increased to 5.58 at. % for C30 coating. Tribological experiments showed that C atoms reduced the coefficient of friction due to the lubricating effect of nanocrystalline graphite and/or amorphous carbon. The high-speed dry-cutting results also showed that AlCrSiCN-coated tools performed better than those with an AlCrSiN coating, and the coatings (C10) with a lower C content possessed the greatest wear resistance.

A data driven robust optimization model for scheduling near-zero carbon emission power plant considering the wind power output uncertainties and electricity-carbon market

Under the carbon peak and neutrality targets, the power generation industry in China is facing an urgent demand for a low carbon transition and participation in the electricity-carbon market. This paper novelty proposes a near-zero carbon emission power plant (NZCEP) integrating gas turbines, wind turbines, power-to-gas and the carbon capture, utilization and storage system. And a two-stage Data-driven Set based robust optimization (DSRO) model, including a day-ahead dispatching phase and a real-time adjustment phase, is conducted to ensure the consumption of renewable energy resources and to develop the optimal operating strategy for NZCEP participation under the electricity-carbon market. The results demonstrated the following outcomes: (1) NZCEP shows better environmental benefits by reducing carbon emissions and consuming renewable energy resources. (2) the DSRO model can resist the interference of wind power output uncertainties and address the issue of traditional robust models being overly conservative. (3) under the electricity-carbon market, NZCEP shows better economic benefits, which can generate additional revenue from selling surplus carbon emission allowances (CEA). Moreover, when the annual average CEA price reaches 355 CNY/t, the NZCEP will achieve full capital cost recovery.

The Optimal Emission Reduction and Recycling Strategies in Construction Material Supply Chain under Carbon Cap–Trade Mechanism

As urbanization continues to expand in China, carbon emissions (CE) from the construction industry and the amount of construction and demolition waste (C&amp;DW) are rapidly increasing. In order to reduce CEs and environmental hazards, this paper constructs a Stackelberg game model to explore the evolution of carbon emissions reduction (CER) and recycling strategies in the construction material supply chain (CMSC) under the carbon cap–trade (C&amp;T) mechanism. The monotonicity analysis on important variables and model comparison simulation are then conducted. The results show the following: (1) A contractor’s green preference positively correlates with the CER level and recycling rate, while the CER cost exerts the opposite effect. (2) The C&amp;T mechanism incentivizes low-emission manufacturers to actively participate in CER. However, excessive carbon trading prices may put high-emitters in a dilemma, making the whole supply chain profitless. (3) The recycler’s decision to recycle C&amp;DW tends to follow the manufacturer’s CER decision. These findings not only help policy makers understand stakeholders’ behavior in CMSC under C&amp;T mechanism, but also provide a basis for the government to formulate CER policies and introduce low-carbon management.

Lithium storage properties of Sn/C composite anode materials

In this paper, tin-carbon composites were prepared by the hot carbon reduction method and used as anode materials for lithium-ion batteries. The results show that the hot carbon reduction method can effectively reduce SnO2 to spherical metallic tin, and the excess of carbon affects the size and shape of tin spherical particles. The higher the tin content is, the higher the lithium intercalation potential of the anode material is. The improvement of cyclic stability of tin-carbon composites is at the expense of reversible capacity. The core-shell structure of pitch pyrolysis carbon can effectively inhibit the reversible capacity decay caused by tin volume expansion.

The Problem with the Anthropocene: Kainos, Not Anthropos

The Problem with the Anthropocene: <i>Kainos</i>, Not <i>Anthropos</i>

Analysis of hydropower development in China

With the environmental destruction becoming more and more serious, all the countries on earth pool their minds to solve the environmental problems. The use of carbon is one of the most serious problems causing environmental pollution. The country's rapid development leads to excessive carbon emissions. To solve this problem, the country is researching and developing new energy sources. For China, water resources are part of the solution. If reasonable development and good use of water resources, can properly relieve the pressure brought by environmental pollution. This paper summarizes China's previous hydropower generation, and puts forward some suggestions in order to improve China's hydropower technology and reduce the damage to the environment.

Collaborative energy–water–carbon management based on energy substitution and multiple compound responses

Symbiotic consistency among several limited resources has become increasingly prominent. Dependence on fossil fuels, combined with energy consumption–induced water scarcity and excess carbon emissions, jeopardizes sustainable development. This study developed a provincial-scale energy substitution and response (ESR) model to (a) aggregate homogeneous regions and emphasize consistency of results; (b) formulate energy-substitution strategies based on ecological utility maximization; (c) explore responses from the threefold perspective of environmental improvement, economic utility, and system robustness; and (d) reveal the effects of the main factors and their interactions to support policymaking. An approach that combines the k-means algorithm, multiregional input–output analysis, ecological network analysis, and factorial analysis was applied to China to verify the models. It was found that the uneven transfer of interregional ecological flows across regions is not conducive to the health of metabolic mechanisms. Energy substitution can bring the multiple benefits of resource conservation, environmental improvement, profit growth, and sustainability enhancement. Regions I, IV, and V can take the lead in implementing substitutions while Regions II and III can adopt a joint substitution strategy to obtain compound effects. Natural gas and liquefied petroleum gas facilities should be built in more developed regions while clean energy subsidies should be supplemented in underdeveloped areas. This study's findings offer a new perspective for coordinating environmental, economic, and social development while avoiding high unemployment and regional population loss caused by energy system restructuring.

Frequent high-temperature volcanic combustion events delayed biotic recovery after the end-Permian mass extinction

The Early Triassic after the end-Permian mass extinction was a time of repeated environmental degradation, which delayed biotic recovery. Although repeated volcanic activity during the Early Triassic has been cited as the cause, the evidence for this hypothesis needs to be confirmed with convincing proxies. This study presents sedimentary molecular evidence for the continuity of volcanic combustion events into the Early Triassic. Geochemical analysis of combustion-derived organic molecules from the uppermost Permian to the Lower Triassic exposed in the Chaohu and Qingyan sections, South China, reveals multiple spikes of a polyaromatic hydrocarbon, coronene, formed by high-temperature organic matter combustion (>1200 K), in the transitions of the Permian–Triassic, Dienerian, Smithian–Spathian, and Olenekian–Anisian boundaries. The frequent high-temperature volcanic combustions ceased 2.7 Myr after the end-Permian mass extinction, and substantial biotic recovery began. The Earth's surface system has mechanisms to buffer high CO2 levels and global warming in the long term, as evidenced in the Cretaceous greenhouse period. Nevertheless, if volcanic activity is overly frequent, the Earth's surface buffering mechanisms cannot keep pace. A simple box model based on excess carbon input revealed by frequent combustion events reproduces the observed carbon isotopic record of carbonate. This model implies that combustion events impacted carbon cycle disturbances and the global climate (e.g., global warming and related environmental destruction). Frequent high-temperature volcanic combustion was a crucial mechanism of delayed biotic recovery during the Early Triassic.