Actual Emission Reductions Research Articles

Study on the establishment of air pollutant and carbon emission inventory and collaborative emission reduction potential of China's coking industry from 2012 to 2022

Coking industry is usually regarded as a high pollution and high energy consumption industry. China is accelerating its efforts to reduce pollution and carbon emissions in the industrial sector, which has received little attention as the world's largest producer of coke. Therefore, in this study, the trend of air pollution and carbon emissions in China's coking industry and the path of coordinated emission reduction were studied. The results indicate that the average annual emissions of PM, SO2, NOx, VOCs, and CO2 in China's coking industry from 2012 to 2022 amount to 205.98, 69.47, 193.45, 599.80 Gg and 191.10 Tg, respectively. The main sources of PM, SO2, NOx, VOCs and CO2 in coking industry were coal preparation (51.5 %), charge and pushing (39.5 %), coke oven gas (99.8 %), byproduct recovery (47.0 %) and fuel combustion (87.5 %). The emissions from coking plants in central and southern Shanxi, eastern and southern Hebei, and central Shandong are the most concentrated. Ultra-low emission transformation and deep treatment of VOCs have greatly reduced pollutant emissions in key areas of air pollutant control, but the actual emission reduction effect of these measures has been weakened by the additional emissions caused by the increase of coke production in other non-key areas. The research on synergetic emission reduction path shows that there is a great synergistic benefit between air pollutants and CO2 emission reduction in coking industry. It is estimated that the APeq (air pollutants and carbon equivalent) of China's coking industry in 2025, 2028 and 2030 will decrease by 38.2 %, 63.5 % and 70.8 % respectively compared with 2022. With the continuous promotion of pollution reduction and carbon reduction measures, the emission reduction potential of China's coking industry will gradually shift from key areas to non-key areas.

Net-Zero Heroes? Climate Change Mitigation Efforts and Strategies across Australian Group-of-Eight Universities

Businesses are increasingly declaring their operations to be “carbon neutral” or “net-zero”. But how real are these claims? We investigated the climate mitigation efforts of the eight leading universities in Australia and discovered that the actual emission reductions lag behind the net-zero rhetoric. In the last ten years, most universities increased energy consumption, while reported emissions plateaued. The energy consumption and greenhouse gas emissions of Group-of-Eight (Go8) universities were influenced by size and population growth, climate of the campus location, and energy efficiencies. The Go8 universities experienced, on average, a 25% increase in student numbers in the last decade, and most increased their energy consumption. However, Scope 1 (direct emissions) and Scope 2 (emissions from electricity consumption) remained stable for most universities from 2011 to 2019 and decreased on a per-capita basis, indicating some level of improved efficiencies. Almost all Go8 universities have net-zero commitments and aim to achieve this by similar measures: power purchase agreements (PPAs) for electricity consumption, and carbon offsets for remaining emissions. Most universities lack a strategy for direct or measurable targets regarding energy or emissions reductions along their value chain. Unlike the UK or other countries, Australia has no standardised emission reporting requirements for Scope 3 emissions (other indirect emissions). This has led to rudimentary and haphazard reporting, limiting comparability between universities. Only one university had a more complete Scope 3 inventory, and these Scope 3 emissions were five times greater than their combined Scope 1 and 2 emissions, indicating a potential for substantial under-reporting of emissions. This highlights the need for more rigorous, consistent, and sector-specific emissions accounting, especially on indirect emissions, and for an overhaul of net-zero accreditation.

Ambitious climate targets and emission reductions in cities: a configurational analysis

ABSTRACT Cities have become increasingly vocal in addressing climate change, crafting climate mitigation strategies, and committing to ambitious emission reductions. Previous studies found no evidence that ambitious targets, analyzed as a single factor, translate into actual emission reductions in cities. Yet, is this still the case if ambitious targets are analyzed in combination with other institutional and socioeconomic factors? We carry out a fuzzy-set Qualitative Comparative Analysis of all cities reporting their emissions to the Carbon Disclosure Project (CDP) where data are available for at least four years between 2000 and 2020. The analysis tests whether ambitious emission reduction targets, in conjunction with size, affluence, and favourable domestic enabling conditions are systematically associated with substantial emission reductions. Results show different configurations leading to emission reductions. In some configurations, ambitious targets are redundant or counterproductive. In other configurations, ambitious targets are necessary to achieve emission reductions. These results call for greater attention to cities’ heterogeneity when studying urban climate governance.

Analysis of the Actual Usage and Emission Reduction Potential of Electric Heavy-Duty Trucks: A Case Study of a Steel Plant

In order to understand the driving characteristics of electric heavy-duty trucks in practical application scenarios and promote their usage to replace diesel trucks, this study analyzed the actual usage of electric and diesel heavy-duty trucks in a steel factory based on vehicle-monitoring data and remote online monitoring data and estimated the emission reduction potential of the application of electric trucks by using a mileage-based method and the greenhouse gas emission model. The results showed that the electric heavy-duty trucks in the steel factory mostly operated for over 14 h, with a vehicle kilometers traveled (VKT) of 50–300 km each day, which could meet most of the demands of the transportation of the steel industry. The average daily energy consumption for most trucks falls within the range of 210–230 kWh/100 km, with higher consumption in winter than in summer, which can save approximately 18–26% in operating costs compared with diesel trucks. It is estimated that the usage of these electric heavy-duty trucks can achieve an annual reduction of 115.8 tons of NOx emissions, 0.7 tons of PM emissions, and 18,000 tons of CO2 emissions. To further promote the application of electric heavy-duty trucks in China, several policy suggestions, such as introducing priority road-right policies, promoting vehicle and battery leasing markets, and exempting zero-emission vehicles during heavy pollution days, were proposed.

Technoeconomic evaluation of combined rich and lean vapour compression configuration for CO2 capture from a cement plant

A combined rich and lean vapour compression configuration was investigated for CO2 capture from a cement plant. This was to assess its performance in energy consumption, actual CO2 emission reduction, and cost reduction potentials compared with the conventional process and the simple rich vapour compression and lean vapour compression configurations. Two electricity supply scenarios were considered: from natural gas combined cycle power plant and a renewable source like hydropower. The three vapour compression configurations outperformed the standard CO2 absorption configuration in energy requirement, actual CO2 emissions reduction and in CO2 avoided cost reduction. The best performance was achieved by the combined rich and lean vapour compression configuration. The reboiler heat, equivalent heat and CO2 avoided cost reduction performance was 24 – 30 %, 16 -18 % and 13 – 16 % respectively. However, the performances in energy, CO2 emissions reduction and CO2 avoided cost are only marginally better than the lean vapour compression configuration. The use of renewable electricity, like hydropower electricity will help CO2 capture processes to achieve higher CO2 emission reduction and lower CO2 avoided cost compared to fossil fuel based electricity.

Analysis of Carbon Emissions and Emission Reduction from Coal-Fired Power Plants Based on Dual Carbon Targets

The emission of greenhouse gases poses enormous pressure on current carbon emissions and carbon reduction. Accurate quantification of carbon emissions from coal-fired power plants is of great significance for achieving the dual carbon goal. To enable enterprises to better understand their carbon emissions, this study constructs a carbon emission model and carbon emission data accounting model for coal-fired power plants. Case data calculations and a carbon emission reduction analysis were conducted. The experiment showcases that the carbon sensitivity of the inner side of the boiler under control conditions is higher than that of the operating parameters controlled on the inner side of the steam turbine, with a maximum total value of 16.67 g/MJ; the annual average low calorific value of coal remains between 16,000 kJ/kg; the activity level of coal remains between 30,000 TJ; and the oxidation probability of coal char during combustion fluctuates, with a maximum of 99.8%. In the calculation of coal-fired carbon emissions, the fitting difference between the emissions of generator unit 1 and generator unit 2 is maintained within 2%. Overall, the CO2 emissions of power plants involved in the study are generally high. The model built through this study has well analyzed the carbon emissions of power plants. It is of great significance for the actual carbon emission reduction of coal-fired power plants.

High Degree of Electrification in Heavy-Duty Vehicles

Because of the rising demand for CO2 emission limits and the high cost of fuel, the electrification of heavy-duty vehicles has become a hot topic. Manufacturers have tried a variety of designs to entice customers, but the outcomes vary depending on the application and availability of recharging. Without affecting vehicle range, plug-in hybrids provide a potential for the automobile industry to reach its CO2 reduction objectives. However, the actual CO2 emission reductions will largely rely on the energy source, user behavior, and vehicle design. This research compares a series plug-in hybrid medium-duty truck against two baselines: nonhybrid and pure electric commercial trucks. As well as evaluating and contrasting the different tools to quantify CO2 emissions, this manuscript offers fresh information on how to simulate various powertrain components used in electrified vehicles. According to the findings, plug-in hybrids with batteries larger than 50 kWh can reduce emissions by 30%, while still meeting the 2030 well-to-wheel CO2 regulations. The recommended battery size for plug-in hybrid is 100 kWh, and for electric vehicles it is 320 kWh. The range of a plug-in hybrid is 18% longer than that of nonhybrid, 6% longer than that of a full hybrid, and 76% longer than that of a pure electric powertrain with a fully charged battery.

Does emission trading system reduce mining cities’ pollution emissions? A quasi-natural experiment based on Chinese prefecture-level cities

The emissions trading system is the most crucial measure taken by the Chinese government to control environmental pollution, but its actual effects on mining cities remain unknown. Therefore, the data of Chinese prefecture-level cities from 2003 to 2018 were used to evaluate the actual emission reduction effects of the emissions trading system in mining cities through the difference-in-difference method. The empirical results provide convincing evidence: (1) The emissions trading system of Chinese government has reduced pollution emissions in mining cities by 22%, and achieved the policy effects of emission reduction. (2) Compared with the mining cities in western and eastern regions, the mining cities in the central region have shown better policy effects of emission reduction. At the same time, the emissions trading system can promote the pollutant emissions reduction in mining cities in old industrial bases, growing mining cities and regenerative mining cities. (3) Further analysis revealed that the emissions trading system mainly achieved pollutant emissions reduction in mining cities through marketization and technological innovation (especially the innovation of green technology). Carbon market policies that adapt to local conditions should be implemented by the Chinese government to enhance the level of marketization and technological innovation, and maximize the policy effect of the emissions trading system.

Carbon emission reduction effect of China's low-carbon energy transition policy: An empirical analysis based on policy quantification

To better address climate change and environmental pollution, it is of great practical significance to comprehensively evaluate the impact of low-carbon energy transition policies on carbon emission reduction. This paper conducts a policy quantitative evaluation of low-carbon energy transition policies from three dimensions: policy intensity, policy objective, and policy instrument. On this basis, the ridge regression model is used to analyze the carbon emission reduction effect of policies. The results show that (1) changes in policy quantities mainly cause the evolution of total policy effectiveness. The government's emphasis on low-carbon energy transition has fluctuated. (2) The two policy objectives of optimizing the use of fossil energy and developing a low-carbon concept are less synergistic with other policy objectives and neither has a significant impact on carbon reduction. (3) The government prefers to adopt command control policy instruments, but their actual carbon emission reduction effects are inferior to that of economic incentive policy instruments. These findings can provide a decision-making basis for the government to further formulate and optimize policies.

Carbon emission reduction of shore power from power energy structure in China

With the construction of China’s ecological civilization and the proposal of carbon peaking and carbon neutrality goals, shore power has been vigorously developed as an important technology for the future green development of ports. However, China’s electricity is still mostly coal-fired, which produces many carbon emissions. Coupled with regional differences, shore power is by no means certain to lower carbon emissions compared with fuel throughout China. Considering the power energy structure in different regions, this paper establishes a carbon emission correlation model between fuel and shore power during ship berthing, calculates the feasibility and actual emission reduction effect of shore power in coastal ports, and studies the restriction condition of starting time for the use of shore power for ships attached to ports according to the national policy of mandatory use of shore power. The results show that only a small part of coastal provinces and cities are suitable for using shore power, and it is limited by the berthing time of the ship. However, this condition is not related to the size of ships but related to the proportion of power generation. Therefore, the government should develop shore power according to local conditions, and vigorously increase the proportion of clean energy, so that the shore power truly achieve zero carbon emissions.

Carbon performance, financial performance and market value: The moderating effect of pay incentives

AbstractWe investigate the interrelationships among carbon performance, CEO Pay, executive compensation, financial performance and market value. Using data relating to non‐financial firms from UK FTSE 350 from 2009 to 2018, our findings are fourfold. First, our results suggest that actual carbon performance is negatively associated with financial performance and market value of firms. Second, we document that self‐reported carbon performance has no effect on financial performance. By contrast, we observe that self‐reported carbon reduction initiatives performance has positive impact on market value. Third, our results suggest that CEO Pay, and executive compensation have positive moderating effect on the association between self‐reported carbon performance and financial performance. In addition, we show that self‐reported carbon performance–market value nexus is positively moderated by CEO Pay and executive compensation. Fourth, we observe that CEO Pay, and executive compensation have no moderating impact on actual carbon performance–market value nexus. Our findings demonstrate that while firms appear to employ compensation incentives to symbolically enhance their self‐reported carbon performance, this does not result in actual carbon emission reduction. Our findings have key implications for policymakers.

Emission reduction targets and outcomes of the Clean Development Mechanism (2005–2020)

The Clean Development Mechanism (CDM) allows developing countries to earn carbon credit units by reducing greenhouse gas emissions. Here we assess the emission reduction outcomes of the CDM between 2005 and 2020. The analysis covers 3,311 CDM projects hosted by 79 countries and over 10,000 Monitoring Reports. We identify which host countries and project types departed from original forecasts more. Overall, the total amount of actual emission reductions was 16% below the targets envisaged by project proponents. Emission reduction projects consistently under-performed over the year, but performance varied between and within regions. Industrial HFCs and N2O projects exceeded their targets, whereas landfill gas and methane avoidance projects under-performed by larger margins. Economic gains were unevenly distributed. Estimated revenues relative to GDP were higher for larger emerging economies, and disproportionately smaller for the deprived members of the Global South. Four host countries (China, India, South Korea and Brazil) not only dominated the market, but also gained an advantage from the higher carbon prices before 2012. Least Developed Countries had their carbon credits issued in more recent years when prices were much lower. The results show an imbalance in economic outcomes and raise questions about the effectiveness and equity of this Kyoto mechanism. Weak targets under Paris Agreement could intensify these challenges.

Renewable energy certificates threaten the integrity of corporate science-based targets

Current greenhouse gas accounting standards allow companies to use renewable energy certificates (RECs) to report reductions in emissions from purchased electricity (scope 2) as progress towards meeting their science-based targets. However, previous analyses suggest that corporate REC purchases are unlikely to lead to additional renewable energy production. Here we show that the widespread use of RECs by companies with science-based targets has led to an inflated estimate of the effectiveness of mitigation efforts. When removing the emission reductions claimed through RECs, companies’ combined 2015–2019 scope 2 emission trajectories are no longer aligned with the 1.5 °C goal, and only barely with the well below 2 °C goal of the Paris Agreement. If this trend continues, 42% of committed scope 2 emission reductions will not result in real-world mitigation. Our findings suggest a need to revise accounting guidelines to require companies to report only real emission reductions as progress towards meeting their science-based targets. Companies commonly use renewable energy certificates to report progress towards emission reduction targets. However, this use of certificates is unlikely to result in actual emission reductions, which undermines the credibility of corporate emission reduction claims and their alignment with the Paris Agreement goal.

Renewable energy certificates allow companies to overstate their emission reductions

Many companies purchase renewable energy certificates to report reduced emissions, but this may not lead to actual emission reductions. We need emission accounting that is both accurate and that incentivizes companies to make impactful contributions to decarbonizing electricity grids.

Carbon Handprint Approach for Cities and Regions: A Framework to Reveal and Assess the Potential of Cities in Climate Change Mitigation

Cities play a pivotal role in climate change mitigation; however, the methodology to quantify actual emission reduction potential of climate interventions implemented by cities and regions has been lacking. The aim of this study is to create a framework to assess positive climate impacts of cities and regions by modifying the life-cycle assessment (LCA)-based carbon handprint framework. Additionally, a step-by-step guidance to perform calculations is presented. A case study of the Finnish city of Espoo is used to further develop and test the regional handprint approach both qualitatively and quantitatively. According to our research, a city′s carbon handprint can be determined through the three main mechanism categories of ownership, operating environment and projects. In the case of Espoo, the carbon handprint of building public electric vehicle charging stations on city-owned land from the mechanism category of ownership showed to be up to 110 tCO2eq/a for 18 charging stations. However, the overall handprint of a city consists of several actions, to be calculated separately. The regional carbon handprint approach provides a useful instrument to reliable quantify and communicate the innovative climate actions implemented by a city and it can be used in cities′ climate work as well as in marketing and branding purposes. Handprint turns the focus on possibilities for increasing a city vitality. As a provider of climate solutions, a city can attract new taxpayers and by focusing efforts to a certain sector, a city can help companies to reach synergies in fields essential from the climate point of view.

CO2 fleet regulation and the future market diffusion of zero-emission trucks in Europe

Fuel economy regulation is a powerful instrument to reduce CO2 emissions of vehicles and has recently been extended to heavy-duty vehicles. In Europe, truck manufacturers are required to reduce the CO2 emissions of newly sold vehicles by 30% until 2030 compared to 2019/2020. Accordingly, several manufacturers have announced the introduction of zero emission vehicles (ZEVs) such as battery electric or fuel cell trucks. However, the sales shares of zero emission trucks to meet the targets have not been analyzed in the literature yet. Here, we derive sales share scenarios for zero emission trucks in Europe based on emissions reduction options and their associated costs. We find that manufacturers will require at least 4–22% of their newly sold heavy-duty vehicles to be zero emission in 2030, depending on their strategy to improve their diesel trucks. This implies a stock share of 2–11% for ZEV trucks in Europe in 2030. Yet, high sales shares for ZEVs and the super credits granted by the regulation allow manufacturers to meet their target with little CO2 reduction in the conventional fleet leading to low actual emission reduction.

Emission Characteristics of Hybrid Electric Bus During Peak Period Based On Remote Monitoring

Based on the OBD remote monitoring system, the real-time data of Tianjin 607 bus is collected, and two representative groups of data are selected for analysis. The results show that the vehicles start and stop frequently during peak period, the frequency of electric motor use increases from 27.72% in off-peak period to 53.72% in peak period, the average driving speed is faster than usual, and the drivers tend to drive more intensely for catching up time. Under the same working conditions, the frequency of electric motor use is positively correlated with the emission reduction benefits brought by the use of hybrid electric vehicles. Under different road conditions, especially in the peak operation, the exhaust temperature is low, which has a greater impact on the actual emission reduction benefits of the electric motor. The key to fundamentally alleviate the emission problem of bus in peak period is to improve the vehicle operation conditions and the conversion rate of SCR system.

Fuel consumption analysis and cap and trade system evaluation for Canadian in situ oil sands extraction

A better understanding of fuel use and greenhouse gas (GHG) emissions resulting from Canadian oil sands (bitumen) extraction can help to meet the global carbon budget and design effective climate policies. To date, no studies have published actual fuel use data, analyzed drivers for the decline of emission intensities (EIs) from in situ oil sands extraction, and evaluated the effectiveness of the cap and trade system in Alberta that aims to control GHG emissions for the world's fourth largest oil production region. This study retrieved operating fuel use data from a public database for 18 in situ oil sands extraction schemes. From 2015 to 2019, the weighted average of fuel use was 0.23 103 m3/m3 undiluted bitumen. The weighted averages of fuel use for the schemes using Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS) were 0.20 103 m3 fuel/m3 of undiluted bitumen and 0.34 103 m3 fuel/m3 of undiluted bitumen, respectively. The average EIs for SAGD ranged from 0.25 metric ton (t) CO2e/m3 to 0.98 t CO2e/m3, and the average EIs for CSS ranged from 0.61 t CO2e/m3 to 1.18 t CO2e/m3. In addition, the study pointed out that production ramping up and maturity of reservoirs contributed to the decline in EIs. The study concluded that the current Alberta cap and trade system is not effective to control GHG emissions from in situ oil sands extraction. Some operations were rewarded for emission credits because of production increases, rather than actual emission reductions. An industry-wide benchmark (cap) should be considered to encourage competition. An absolute emission cap should be imposed to prevent facilities from simply increasing production to drive down EI values.

Where did the time (series) go? Estimation of marginal emission factors with autoregressive components

This paper offers a novel contribution to the literature on marginal emission factors by proposing a robust empirical methodology for their estimation across both time and space. Our ARIMA model with time-effects not only outperforms the established models in the economics literature but it also proves more reliable than variations adopted in the field of engineering. Utilising half-hourly data on carbon emissions and generation in Great Britain, the results allow us to identify a more stable path of MEFs than obtained with existing methodologies. We also estimate marginal emission effects over subsequent time periods (intra-day), rather than focussing only on individual settlement periods (inter-day). This allows us to evaluate the annual cycle of emissions as a result of changes in the economic and social activity which drives demand. Moreover, the reliability of our approach is further confirmed upon exploring the cross-country context. Indeed, our methodology proves reliable when applied to the case of Italy, which is characterised by a different data generation process. Crucially, we provide a more robust basis for valuing actual carbon emission reductions, especially in electricity systems with high penetration of intermittent renewable technologies.

Using waste CO2 from corn ethanol biorefineries for additional ethanol production: life‐cycle analysis

AbstractCorn ethanol plants generate high‐purity carbon dioxide (CO2) while producing ethanol. If that CO2 could be converted into ethanol by carbon capture and utilization technologies it would be possible to increase ethanol production more than 37% without additional corn grain inputs. Gas fermentation processes use microbes to convert carbon‐containing gases into ethanol and so have the potential to be used with the CO2 from biorefineries for this purpose. However, as CO2 utilization technologies for converting thermodynamically stable CO2 are typically energy intensive, it is necessary to evaluate the related life‐cycle greenhouse gas (GHG) emissions (carbon intensities or CIs) to see whether there are actual emission reduction benefits. In this study, we evaluate the CIs of ethanol produced from high‐purity CO2 in corn ethanol plants by gas fermentation plus electrochemical reduction. Our analysis shows that the sources of electricity and hydrogen are key drivers of CO2‐based ethanol's GHG emissions. With wind electricity, the design cases show the potential of near‐zero CI ethanol (1.1 g CO2e/MJ), but that can increase to up to 331–531 g CO2e/MJ when today's U.S. Midwest electricity mix is used. To avoid the renewable electricity intermittency issue, we considered a power purchase agreement option using wind electricity 40% of the time and using the regional mix for the rest, which provides a 42% GHG emission reduction from the CI of gasoline. © 2020 The Authors and UChicago Argonne, LLC, Operator of Argonne National Laboratory. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.