Emission Reduction Process Research Articles

Numerical investigation of NOx emission characteristics in air-staged combustion system fueled by premixed ammonia/methane

For the purpose of achieving global CO2 reduction, decarbonization at the source of fuels is a practical approach. The transition phase of blending fossil fuels with carbon-free fuels for combustion is a hot topic in the current carbon emission reduction process. In order to achieve efficient and low-pollution combustion of NH3/CH4, the combustion and emission characteristics of NH3/CH4 under single-stage and air-staged combustion methods were numerically investigated in this work. The emissions were compared for different equivalence ratios and different ammonia content conditions. rate of production (ROP) and sensitivity analysis were performed for NOx, and the reaction path of NH3/CH4 was analyzed. The results indicate that the C-N interaction of the NH3/CH4 mixed combustion process is not significant and turns weaker in the lean flames. HNO intermediate is an important specie for NO generation, and HCN together with HNO intermediate, are essential species for NO generation. NH2 and NH almost dominate the promotion and inhibition of NO generation. Given that the contrasting NOx and CO emission behavior of NH3/CH4 in rich and lean flames, the single-stage combustion approach is not suitable. Air-staged combustion achieves both ensuring complete burning of NH3 and CH4 while reducing NOx and CO emissions. Moreover, the results suggest that Φpri=1.2/Φtotal=0.6 is the optimal NH3/CH4 combustion staging method for controlling NOx emissions.

The degree of population aging and carbon emissions: Analysis of mediation effect and multi-scenario simulation

The continuous deepening of aging has posed new challenges for global sustainable development. Measuring the impact of population aging on carbon emissions is crucial for the next stage of climate governance. However, the structural changes in social production and consumption make it difficult to evaluate the impact effects. Therefore, this study constructed a bidirectional fixed Space Durbin Model to explore the mediating pathway of aging's impact on carbon emissions. Furthermore, we have established high-precision prediction models to simulate the evolution trajectory of carbon emissions under multi-factor driving scenarios. The main findings are as follows: (1) The process of carbon emission reduction due to population aging has significant energy hindrance effect and industrial structure effect, while the process of carbon growth is constrained by the consumption enhancement effect, technology progress effect and labor participation effect. (2) The moderating effects of energy consumption and technological innovation on carbon emissions under the aging process are 10.74% and 10.24%, respectively, while the moderating effects of industrial structure and labor force participation are relatively weak. (3) The goodness of fit of the MNGM-ARIMA and MNGM-BPNN models is over 97%. Carbon emissions in the high aging regions show a decreasing trend in all scenarios except the energy consumption-driven scenario, while in the medium and low aging regions decrease slowly only in the R&D- and labor supply-driven scenarios. This study advocates developing heterogeneous emission reduction measures based on the degree of aging, accelerating supply side upgrading, and increasing the proportion of green consumption.

Evaluation of optimal waste lithium-ion battery recycling technology driven by multiple factors

As energy and environmental issues become increasingly prominent, the process of global carbon emission reduction is now underway. In the transportation sector, the application of electric vehicles is an effective way to achieve energy saving and emission reduction. Lithium-ion battery, an important component of electric vehicles, has received widespread attention for its advantages including small size, high energy density and smooth discharge voltage. However, their potential safety and pollution issues are becoming prominent and must be properly handled. Moreover, the technical route and future direction of LIB recycling are still unclear at this stage. Herein, this paper evaluates different waste lithium-ion battery recycling technologies in a multi-criteria decision framework to determine the best technology. A criteria system driven by multiple factors is established, including environmental impact (C1), technical risk (C2), comprehensive resource utilization (C3), resource consumption (C4) and economic performance (C5). Subsequently, since the optimal technology is novel and difficult to select, the hesitant fuzzy linguistic term sets are used to express the degree of hesitation in expert decision making. Finally, from the aspects of the choice of sorting method, the Tomada de decisao interativa multicriterio method based on the expectation effect is used to evaluate the optimal waste lithium-ion battery recycling technology, and the validity of the framework is illustrated by data analysis.

Stochastic differential game of joint emission reduction in the supply chain based on CSR and carbon cap-and-trade mechanism

This paper considers both carbon emission reduction and corporate social responsibility (CSR) goodwill as endogenous variables in the joint emission reduction process of the supply chain system. The joint emission reduction strategy of the three-tier supply chain system is examined from a long-term perspective utilizing stochastic differential game models. Three models, namely the cooperative game, the Nash non-cooperative game, and the Stackelberg master–slave game, are developed to analyse and compare the equilibrium strategies under each model. The results indicate that the manufacturer-led Stackelberg master–slave game can achieve the Pareto improvement in the profits of the supplier, manufacturer, retailer, and the entire supply chain system.

Emission Reduction Decisions in Blockchain-Enabled Low-Carbon Supply Chains under Different Power Structures

With the global climate problem becoming increasingly severe, governments have adopted policies to encourage enterprises to invest in low-carbon technologies. However, the opacity of the carbon emission reduction process leads to incomplete consumer trust in low-carbon products as well as higher supply chain transaction costs. Based on this, this paper constructs Stackelberg game models with and without blockchain under different power structures and compares the impact of these models on low-carbon emission reduction decisions. The results show that: (1) blockchain does not necessarily improve enterprise profits and can only help enterprises maintain optimal profits within a certain range when the carbon emission cost is low; (2) when consumers’ environmental awareness is high, the blockchain can incentivize manufacturers to enhance carbon emission reduction, and it has an obvious promotional effect on retailers’ profits; and (3) the profit gap between enterprises in the supply chain is larger under different power structures, and the implementation of blockchain can coordinate profit distribution and narrow the gap between enterprises. Compared with the manufacturer-dominated model, the emission reduction in products is maximized under the retailer-dominated model. Our study provides theoretical support for the government to regulate greenhouse gas emissions as well as for the optimization of enterprises’ decision-making supported by blockchain.

Life cycle assessment of atmospheric environmental impact on the large-scale promotion of electric vehicles in China

Decarbonizing the transportation sector emerges as a pivotal step in addressing climate change. In recent years, rapid growth in China’s new energy automotive industry has significantly contributed to transportation decarbonization. However, environmental challenges in producing and recycling electric vehicles (EVs) may limit emission reduction benefits. In this study, we establish a comprehensive life cycle assessment model for vehicles to analyze the gap in air pollutant and greenhouse gas emissions between electric vehicles and internal combustion engine vehicles (ICEVs). Based on this model, the environmental benefits of further promoting electric vehicles in China are evaluated. Results reveal that, compared to ICEVs, EVs reduce life cycle emissions of CO2 by 12%, NOx by 69%, and VOCs by 9%. Primary constraints on EVs in emission reduction are traced to raw material and component production, notably lithium batteries. By 2025, under the low carbon EVs policy scenario, widespread EV production and sales could cut lifecycle emissions by 3.55 million tons of CO2, 3,6289 tons of NOx, and 4315 tons of VOCs. During the driving stage, these indicators contribute 495%, 124%, and 253%, respectively, to total emission reduction throughout the lifecycle. This study conducts a comprehensive lifecycle analysis of greenhouse gases and various air pollutants for Chinese EVs. It integrates the latest market trends, application progress, and policy guidelines into scenario design, identifying key sources and indicators of atmospheric pollution in the EV production chain. The findings offer valuable policy insights into China’s role in the global emission reduction process.

How does the coal-to-gas policy mitigate carbon emissions? The role of fintech development

As energy transition becomes an important way to achieve carbon dioxide (CO2) emission reduction globally, this paper takes China as an example and uses the difference-in-difference (DID) model suitable for policy research to explore the impact of coal-to-gas (CTG) policy, which aims at promoting energy transition and reducing pollutant emissions, on CO2 emissions, and explores the mechanism of action and the spatial spillover effects of the policy. The results of the study show that, first, the implementation of the CTG policy can reduce CO2 emissions in China, and the results still hold under a series of robustness tests. Second, the CTG policy can achieve CO2 emission reduction through regional industrial restructuring, and the rapid development of financial technology promotes the process of CO2 emission reduction in China. Finally, the implementation of the CTG policy may cause the problem of CO2 leakage due to regional differences in the policy. This study not only provides a reference for setting global energy transition policies, but also provides new ideas for China's CO2 emission reduction and CO2 leakage, and provides data support for policy formulation.

Analysis of emission evolution and synergistic reduction effect of air pollutants and CO2 from Chinese coal-fired power plants

The coal-fired power industry is the largest coal-consuming sector in China, and it serves as a significant source of air pollutants and carbon emissions. In this study, we investigated the evolution of air pollutants and CO2 emissions originating from coal-fired power plants (CFPPs) from 2013 to 2020 based on a unit-based bottom-up inventory, and then we quantitatively assessed their combined reduction effects from 2013 to 2060. Our findings indicated that air pollutant emissions experienced a rapid decrease from 2013 to 2020, with nearly 46.0%–64.2% of the reduction occurring within the years 2013–2017. However, CO2 emissions displayed a slight increase during the same period. The top five provinces with the most robust synergistic reduction effects for both air pollutants and CO2 were Jiangsu, Hebei, Henan, Shanxi, and Shandong. The primary measures to the reduction in CO2 emissions were energy structure adjustment and energy conservation and consumption reduction. By 2060, emissions of PM2.5, SO2, NOx, Hg, and CO2 had decreased by 57.9–92.1%, 26.0–80.6%, 18.1–69.4%, 26.6–86.3%, and 35.8–76.1% compared to the levels in 2020, respectively. As the emission reduction process advanced, the reduction effect on CO2 became more pronounced within the synergistic process. We believe that our highly detailed emission inventory comprehensively captures the historical evolution of PM2.5, SO2, NOx, Hg, and CO2 emissions from CFPPs. Furthermore, the scenario analysis results we have obtained will be instrumental in supporting policy development aimed at achieving the synergistic reduction of air pollutants and carbon emissions.

Research on the impact of green finance on China's carbon neutralization capacity.

At present, the life and production of our society are still accompanied by high pollution emissions. The proposal of the "double carbon" goal puts forward clearer requirements for China's energy conservation and emission reduction process. To cope with stricter green development requirements, green finance came into being, contributing a new path to the realization of the "double carbon" goal. This paper is based on the panel data of 30 provinces and cities in China (except Tibet, Hong Kong, Macao, and Taiwan) from 2011 to 2020, using the fixed effect model, threshold model, mediator model, and SDM model to study the impact of green finance on carbon neutralization capacity and its impact path based on reasonable measurement of regional green finance development level and carbon neutralization capacity. The study found that due to the existence of the "green paradox" and "forced emission reduction", China's green finance has a significant positive U-shaped impact path on carbon neutralization capacity; at the same time, informal regulation has a significant single-threshold effect in this path. When informal regulation crosses 0.47, the impact of green finance on carbon neutralization capacity will change from negative to positive, overcoming the impact of the "green paradox"; there is a nonlinear mediating effect of marketization level and technological innovation in the path of green finance affecting carbon neutralization capacity. In addition, green finance not only affects local carbon neutralization capacity but also has a positive spillover effect on neighboring regions.

Does energy-consuming right trading have double dividend effect on firm's economic performance and carbon emission?

Whether the market-based environmental regulation policy can achieve a win-win situation of economic growth and carbon emission reduction has always been an academic controversial topic. Taking the pilot policy of energy-consuming right trading (ECRT) of China in 2016 as a quasi-natural experiment, this paper uses the difference-in-differences (DID) method to investigate the policy impact of ECRT on the economic performance and carbon emissions of firms. An economy-environment composite index has been conducted for testing double dividend effect of ECRT. The empirical results show that ECRT can improve the economic performance and reduce carbon emissions of firms significantly. The double dividend effect is more significant in high-carbon emission firms, non-state-owned firms and prior to COVID-19 pandemic. ECRT policy has Porter innovation mechanism, in which innovation input is the main contribution of economic dividend effect and green technology innovation is the main contribution of environmental dividend effect. The conclusions of this paper provide empirical evidence and policy implications for realizing the common development of economy and environment, accelerating the process of emission reduction and building a national energy trading market.

Does environmental regulation in the form of resource agglomeration decrease agricultural carbon emissions? Quasi-natural experimental on high-standard farmland construction policy

Reducing agricultural carbon emissions is an essential lever for mitigating climate change and promoting high-quality agricultural development. Environmental regulation in the form of resource agglomeration, represented by the high-standard farmland construction policy, plays a vital role in the emission reduction process. Using the panel data of 31 provinces in China from 2001 to 2019 and taking the high-standard farmland construction policy as a quasi-natural experiment, this paper constructs a continuous differences-in-differences (DID) model to explore the impact and mechanism of environmental regulation in the form of resource agglomeration (RAER) on agricultural carbon emission reduction. The results show that RAER significantly reduces agricultural carbon emissions by an average of 3.9%. This conclusion still holds after robustness tests such as endogenous tests, eliminating policy interference, and sample reprocessing. This abatement utility is mainly realized through the technique effect of promoting green technology innovation and the composition effect of optimizing crop cultivation structure. Based on the resource attribute characteristics, the agricultural carbon emission reduction effects of RAER are, in descending order, capital and facility. Further study found heterogeneity in four aspects of the effect of RAER on agricultural carbon emission reduction: regional, planted crops, carbon emission sources, and carbon emission intensity. Therefore, decision-makers should deepen environmental regulation reform through resource agglomeration, implement adapting to local conditions for the high-standard farmland construction policy, and promote policy innovation and system optimization of agricultural carbon emission reduction.

Carbon reduction consciousness, determinants and value of low-carbon transition: Evidence from textual and empirical analysis of Chinese listed manufacturing enterprises

In this paper, we first construct a carbon reduction consciousness score using a textual analysis method, applied to annual reports of Chinese manufacturing enterprises from 2006 to 2021. Then, we categorize the low-carbon transition level of enterprises based on content analysis to analyze its determinants and value. We find that carbon reduction consciousness can facilitate low-carbon transition level. Meanwhile, larger and state-owned enterprises are more likely to implement low-carbon transition. Furthermore, we observe that implementing low-carbon transition creates enterprise value, and the effect is stronger for non-state-owned enterprises and sub-samples from 2016 to 2021. In mechanism analysis, we find that a higher low-carbon transition level promotes the increase of research and development (R&D) investment to generate enterprise value. Our study provides theoretical support for strengthening dynamic management of enterprise low-carbon emission reduction process to achieve carbon neutrality and emission peak goals.

An Improved Flower Pollination Algorithm based Modelling Method of Photovoltaic Modules

In recent years, with the acceleration of the global carbon emission reduction process, the sustainable development of clean energy has become the leading role, and the photovoltaic (PV) market has ushered in a hotter market. For accurately estimating the power generation of PV modules under different weather conditions, the modeling of solar cells or PV modules is very important. However, the conventional optimization algorithms cannot satisfy the accuracy of identification of the five parameters in the single diode model. In this paper, an improved FPA is proposed to estimate the five model parameters of the PV modules. In the proposed algorithm, the FPA is improved by considering different updating methods of solution for each pollen, with or without Levy flight. Experimental results validate that the proposed improved FPA can accurately identify the five model parameters and satisfy the modeling demands of PV arrays in engineering applications.

How government green investment affects the carbon emission reduction process: empirical evidence from prefecture-level cities in China

Government green investment (GGI) is one of the effective tools for reducing carbon emissions (CEs). This is of great significance for the realization of “carbon peaking and carbon neutrality.” This study innovatively considers the multidimensional CE reduction (CER) process indexes to explore the impact mechanism of GGI on China’s CER process. At the same time, CER is particularly critical in resource-dependent regions. This study incorporates this perspective to explore the CER effect of GGI in these regions. This paper developed a multidimensional evaluation system for China’s CER process, using panel data of 269 prefecture-level cities from 2008 to 2019 to explore the impact of GGI on China’s CER process. The results indicated that 1) GGI promotes CER in China as a whole and effectively inhibits CEs,per capitaCEs, and CE intensity; 2) GGI promotes CER to some extent by enhancing the energy efficiency and total factor productivity; 3) it plays a larger role in CER in regions with a high energy endowment; and 4) the impact of GGI on CER is heterogeneous in geographical regions, city sizes, and economic development levels. This study makes policy recommendations for reducing CEs, including intensifying GGI and playing its investment-pulling role, thereby increasing the investment related to improving energy efficiency and total factor productivity and promoting government intervention in areas with high energy endowments.

Methane emission mitigation in hypoxic freshwater triggered by oxygen-carrying dual-modified sediment-based biochar

Anthropogenic deoxygenation of freshwater systems has attracted widespread global attention due to its potential to threaten ecosystem biodiversity, increase internal nutrient loading, and enhance greenhouse gas emissions. However, the exploration of effective, economical, and green solutions available to combat hypoxia and its impacts on freshwater remains a longstanding challenge. Herein, oxygen-carrying dual-modified sediment-based biochar (O-KN-SBC) was developed as a new approach to sustainably restore hypoxic freshwater and synchronously mitigate methane (CH4) emission. The O-KN-SBC was observed in column incubation experiments to elevate dissolved oxygen (DO) concentration by 6 times and reduce CH4 emission by 18 times compared to the control. Electrochemical analysis confirmed the ability of modified biochar to promote electron transfer and its role as an electron shuttle to mediate biological processes. Microbial analysis suggested that the restored oxygen-enriched ambiance could greatly promote the expression of pmoA gene with an 8-fold increase and the shift of methanotrophs from Type I dominance to Type I and II co-dominance. Last but not least, partial least squares path modeling revealed that in the presence of O-KN-SBC, CH4 fluxes had strong associations with functional genes namely pmoA and mcrA, which mainly depended on the ambient water quality (especially DO, nitrate, and organic carbon). Our study not only develops a promising approach to sustainably address hypoxia and warming related issues in freshwater systems, but also demonstrates the roles of water quality improvement and microbial community reconstruction in the greenhouse gas emission reduction process.

Development and investigation of a pollutants emission reduction process from a coal-gasification power plant integrated with fuel cell and solar energy

Abstract Even though coal resources are the most abundant among fossil fuels, coal-fired plants release large amounts of greenhouse gases into the atmosphere. In this regard, reducing environmental challenges and crises caused by coal burning can be a promising option to reduce today's crises in the energy field. The integration of coal-fired plants with renewable-driven energy systems can simultaneously improve thermodynamic performance and reduce pollutants emission rates. This article presents the thermodynamic and pollutant emission investigations of a new coal-fired plant coupled with a linear Fresnel solar collector (LFSC)-driven solar unit, a parabolic trough solar collector (PTSC)-driven solar unit, a high-temperature fuel cell stack (molten carbonate fuel cell stack [MCFCS]) and a heat recovery system (based on the steam turbine and gas turbine-based power cycles). The plant is able to produce electricity and hot water (HW). The main structure of the offered plant is based on coal, whereas, is coupled with renewables-based cycles to mitigate environmental impacts. The plant could generate ~ 207 MW of power and 3728 m3/h of HW. In such conditions, the energy efficiency of 73.1% and exergy efficiency of 44.18% could be achievable. Further, the emitted gas rates of the plant were nearly 403 tons/h. A comprehensive comparison is also presented for the plant's behavior under different types of coal (petcoke and anthracite). In addition, a two-function optimization is developed to determine the maximum value of exergy efficiency and the minimum value of total pollutants emission rate.

Beyond conventional corporate responses to climate change towards deep decarbonization: a systematic literature review

Over the past 20 years, the literature on corporate responses to climate change has offered a vast array of theoretical and practical insights into organizational efforts to reduce business-related carbon emissions. However, it remains unclear whether these efforts will result in significant reductions of carbon emissions. Presently, it becomes crucial to understand, if, why, and how companies can effectively respond to the current challenges of deep decarbonization, defined as the process of emission reduction down to, or close to, zero to limit global warming. By means of a systematic literature review with 370 identified papers, we are able to categorize the main findings of the literature according to the four most common areas of investigation, including drivers, actions, barriers, and facilitators. Additionally, we conduct a comparative analysis of the literature along these four areas of investigation according to two categories: conventional responses and deep decarbonization responses. The results show that the literature on conventional responses to climate change (n = 321) extensively covers all four areas of investigation; however, it only touches on the descriptive (i.e., ‘what’) aspects of decarbonization. The recent and emerging literature on deep decarbonization responses (n = 49) provides novel insights on the prescriptive (i.e., ‘why’ and ‘how’) aspects of deep decarbonization. However, this literature is restricted to mostly regional and industrial foci, and it does not connect drivers, barriers, and facilitators in a systematic way. Thus, we highlight key implications for future research and practice in order to effectively address corporate deep decarbonization.

Review of Policy Framework for the Development of Carbon Capture, Utilization and Storage in China

Carbon capture, utilization and storage (CCUS) has been applied in many countries and has proven to be a key carbon-reduction technology for the future. China currently emits the most carbon, and prior research findings indicate the high potential of CCUS technology to support the country's emission-reduction process. China introduced CCUS technology at the end of the 20th century and has since implemented a series of related policies. This paper compares the development status of CCUS in China and other countries, studies the legal and policy framework and the development process of CCUS in China, and analyzes the defects in relevant laws and policies. The results show that China's current legal and policy system is not conducive to the further development of CCUS; specifically, there is no special law, and the policy system is incomplete. Consequently, it is difficult to advance and give full play to the emission-reduction effect of CCUS. To promote CCUS development in China, this paper proposes corresponding countermeasures, including formulating a special law, perfecting the CCUS policy system, expanding government financial support, and improving CCUS public awareness and support.

Allocation of carbon emission permits in heterogeneous complex network systems: A DEA-based study among China’s industrial sectors

The official proposal of China’s carbon peaking and carbon neutrality goals has made it necessary to accelerate the energy conservation and emission reduction process. The industrial system, as the main source of energy consumption and pollution emissions in China, should also undertake the emission reduction task. Allocation of emission permit (AEP) among industrial sectors should consider energy input heterogeneity as well as industrial energy intensity. Therefore, this paper extends the AEP model in complex network systems considering energy heterogeneity. The characteristics of this allocation model are as follows. (1) We extend the model to parallel network systems by considering energy consumption structure heterogeneity. (2) Industrial energy density is defined as a constraint for allocation according to realistic requirements. (3) We construct a multiobjective programming model that simultaneously considers maximizing output and minimizing energy inputs. Finally, we apply the model to CO2 emission reduction quota allocation among industrial sectors in China and provide empirical findings and policy implications.

Carbon asset remolding and potential benefit measurement of machinery products in the light of lean production and low-carbon investment

For machinery manufacturing firms, a rather concerned barrier to arrive at carbon neutrality is the uncertain benefit of carbon emission reduction. To control the increasing cost triggered by carbon pricing mechanism and transition of carbon emission pattern, this paper restructures the whole production process of machinery products from the perspectives of low-carbon management and revaluation of carbon assets of process-flow to unearth the potential of carbon benefit of machinery products. Our theoretical analysis and case study keeping an eye on engineering machinery and port machinery jointly draw following key findings: First, the process management can effectively reduce carbon emissions as similar as the role of green-tech investment, and can arrive at a rather impressive emission reduction performance with less upfront investment. Second, to enhance carbon benefits sustainably, machinery manufacturing firms should control carbon emissions in the whole life-cycle and integrate carbon assets into production costs. Third, both carbon emission reduction and waste recycling can argument the return on carbon assets. Hence one can see that to create the competitive edge in the low-carbon sphere of machinery products, machinery manufacturing firms should remold the value-added process of carbon emission reduction in products' whole-life at the peak of total costs.