Reduction In Overall Emissions Research Articles

The impacts of the COVID-19 on the aircraft emissions from international routes from and to China

The COVID-19 pandemic has significantly impacted the civil aviation exchange between China and foreign countries. But few studies have focused on the effects of COVID-19 on aviation emissions. This paper seeks to calculate the emissions of six pollution (CO2, CO, HC, NOx, SO2, and PM2.5) from the international routes from and to China during 2019–2021 and discusses the impacts of COVID-19 on the emission change. The Modified BFFM2-FOA-FPM method is proposed to unify the CO2 and non-CO2 calculations. The error rate between the calculated results and the official data from Civil Aviation Administration of China is about 2.74%. The results show that the COVID-19 has resulted in a reduction in overall emissions of the international routes from and to China, but the intensity of the unit passenger turnover has increased, and the overall emissions of some airlines have increased. Moreover, compared with 2020, there is no apparent recovery of international routes from and to China in 2021.

A pathway to 25% reduction in greenhouse gas emission by 2030 using GIS-Based multi-criteria decision making for renewables, date palm (phoenix dactylifera), and carbon credits: a case for Qatar

Qatar is making concerted efforts at the national level to decrease anthropogenic greenhouse gas emissions. The country has set its National Determined Contribution (NDC) in line with the Paris Agreement to reduce its overall emissions by 25% by the year 2030. This study identifies several pathways, which Qatar can explore to achieve its set goals. It explores Qatar’s potential for renewable energy generation (solar and wind), carbon offset through planting trees, and the purchase of carbon offset credits. The study starts by investigating the available wind and solar energy potential in the country, by considering physical and legal restrictions, which limit the available land to be utilized for RE generation. Multi-criteria Decision is carried out utilizing the Analytic Hierarchy Process (AHP) for variable percentage estimation in ArcMap Geographic Information Systems software. Next, a review based on Qatar’s climate is performed to identify suitable tree species that would promote atmospheric CO2 sequestration in the country. Finally, the cost implication of offsetting emissions using verified carbon credits is considered and compared with other options. Results indicated that while a considerable area is available for both wind (37%) and solar (53%) energy generation, only 6.2% and 13.8% of Qatar are highly suitable for wind and solar energy installations, respectively. Also, while Qatar has the potential to meet 20% of its energy demand by 2030 from renewable sources by using solar PV and wind, this will only account for a 14.28% reduction in overall emissions. Additionally, planting date palm trees (Phoenix dactylifera) would significantly benefit the nation in the area of carbon sequestration and revenue generation as compared to purchasing carbon offset credits.

Reducing carbon emissions in cement production through solarization of the calcination process and thermochemical energy storage

The conceptual design of a novel cement production process has been developed during the SolCement research project. Fossil fuels used for limestone calcination are replaced by concentrated solar energy. Also, a Thermochemical energy Storage Reactor - TSR is used for transferring energy between daytime and nighttime operation. Additionally, the process enables energy recovery from waste gases and integration with carbon capture systems by isolating the rich carbon dioxide stream produced by the decomposition of limestone. A computational study simulates and compares a conventional with two different versions of the SolCement process (with and without the TSR). Simulations show that the use of a solar calciner operated at 1000 °C increases energy savings, while shifting the production capacity towards daytime improves the overall performance. The proposed scheme can lead to a 33 % reduction in fossil fuel consumption, but only a 9 % reduction in overall emissions, corresponding to 493 kg CO2/tonne clinker, since most of the carbon dioxide is produced due to limestone calcination. However, with storage and further utilization of the CO2 rich gaseous outlet stream, the predicted reduction of emissions may reach 82 %. The TSR provides 22 % of the energy required for preheating during the night operation, while simple Rankine cycles can recover from the otherwise rejected hot gas streams, 49 % and 40 % of the electrical energy required for compressing the produced carbon dioxide during daytime and nighttime operation, respectively. This results in 33 kg CO2-eq per tonne of clinker less, or an additional 0.6 % emissions reduction.

Can the Federal Reserve save the environment?

This study examines the environmental effect of monetary policy, particularly within the framework of global value chains (GVCs). Given the escalating climate concerns and the urgent need for sustainable solutions, it is crucial to investigate the environmental consequences of monetary policy decisions which directly influence domestic production and international input-sourcing activities. As the monetary policy is likely to be associated with a variety of economic factors influencing environmental outcomes, it is critical to introduce an exogenous shock that reflects variations in monetary policies to derive unbiased causal estimates. We thus adopt a proxy-vector autoregression (VAR) approach with U.S. monetary policy surprise as an exogenous instrument. We uncover compelling evidence that one standard deviation of contractionary monetary policy surprise leads to a reduction in overall emissions by approximately 0.5 percent. However, the more significant and concerning result is the observed rise in emission intensities by 0.2 percent. We highlight the key mechanism underlying this outcome: higher domestic credit costs discourage firms from effectively outsourcing production tasks abroad, thereby increasing the generation of air pollutants per unit of output arising from reduced production efficiency. The identification of a previously unrecognized environmental externality calls for a reevaluation of policy approaches and underscores the importance of integrating environmental considerations into monetary policy frameworks.

“No fences make bad neighbors” but markets make better ones: cap-and-trade reduces cross-border SO2 in a natural experiment

The clean air interstate rule (CAIR) was a regional cap-and-trade program announced in 2005 which covered 27 eastern US states and sought to reduce sulfur dioxide emissions from coal-fired power plants. The rule was later vacated after a court found that the non-targeted design of the program did not comply with the Clean Air Act provision to regulate interstate air pollution. Using a custom air pollution dispersion model, I calculate the interstate SO2 pollution from 493 coal-fired power plants across the United States between 1997 and 2020. In a difference-in-differences setup with plants not covered by CAIR in the control group, I estimate the treatment effect of the program on overall- and cross-border SO2 emissions and find a 24% reduction in overall emissions and reduces the risk that a plant violates air quality standards across state borders by 2–4%. I report evidence of heterogeneous treatment effects where the reduction in overall emissions attributed to CAIR is lower among plants transporting SO2 in excess of 1% of the National Air Quality Standards to another state.

Comparative study of hydrogen and kerosene commercial aircraft with advanced airframe and propulsion technologies for more sustainable aviation

Present work performs a comparative study of two medium-range commercial jets with future airframe and propulsion technologies powered by hydrogen and kerosene fuel to achieve a substantial reduction in overall aviation emissions. The study aims to investigate the cumulative effect of different energy networks combined with airframe efficiency gains achieved by aircraft-related technologies to suggest a better option for the potential next-generation commercial aircraft similar to the Airbus A320. Advanced airframe and engine technologies include laminar flow control, active load alleviation, new materials and structures, and ultra-high bypass ratio turbofan engines. Two aircraft with hydrogen and kerosene propulsion systems were sized to compare their performance characteristics, equivalent CO2 emission, and direct operating costs. The design was performed using a multi-fidelity approach and included the effects of future airframe technologies and the hydrogen propulsion system. The design comparison showed a significant contribution of airframe and propulsion technologies in achieving more environmentally friendly aircraft. The green hydrogen option showed a 41–63% reduction in overall emissions compared to the kerosene aircraft depending on flight conditions while the blue hydrogen variant achieved a 21–26% reduction level. A rather optimistic price scenario shall be met to enable an operational benefit of green hydrogen while the blue hydrogen variant has more potential of being economically acceptable by the market. In circumstances when operating costs drive the decision-making more than emissions, kerosene may be a more favorable option as a compromise between emission and costs, given the positive effect of airframe and propulsion technologies.

Emissions from a net-zero building in India: life cycle assessment

This study quantifies the gap between net-zero energy and net-zero carbon through a life cycle assessment (LCA) of a net-zero energy building (NZEB) in Ahmedabad, Gujarat, India. The annual net-zero energy evaluations of a building do not account for the greenhouse gas (GHG) emissions released before the building operation phases. Nor does it account for the GHG emissions during the end-of-life processes. As a consequence, an NZEB may not be a net-zero emission building over its lifespan. Comprehensive carbon-based evaluations are necessary to ensure an overall reduction in emissions is in line with the goals of the United Nations Paris Agreement. The LCA frameworks of ISO 14040 and EN 15978 form the basis of analysis and a method is presented based on data collection, consistency checks, uncertainty evaluation, impact assessment and interpretation of the results. It also acknowledges the lack of a nationalised inventory for LCA in India. The results show that despite an annual net-zero operation status of a building, the building has a negative impact with 866 tCO₂e across a calculated lifespan of 60 years. The case study reveals the sensitivities of the analysis towards the system boundary, data quality requirements and acceptable limits of uncertainty. <em><strong>Practice relevance</strong></em> For an NZEB in Ahmedabad, the life cycle GHG emissions were calculated to be 866 tCO₂e. Although the building has a net-zero energy status for its operational phase, it does not have a net-zero carbon status across its lifespan when embodied and end-of-life processes are considered. This comprehensive approach enables the possibility to compensate for these emissions. For example, the NZEB can target a net-zero carbon status within a planned time frame through the provision of additional electricity generation using solar photovoltaic panels. The quantification of carbon requires a context-specific, regional and temporal life cycle inventory. The inventory developed for this case study can be used for many buildings in Gujarat built between 2012 and 2018. Expanding the research can lead to possibilities of benchmarking and standardisation. The methodology can also be adapted for existing buildings across India.

Multi-objective optimisation of a grid-connected hybrid PV-battery system considering battery degradation

ABSTRACT Variable nature of solar energy leads to inconsistent performance of photovoltaic systems. Integration of photovoltaic systems with storage and grid mitigates variability issues and helps maximise self-consumption. This work presents a design methodology for a grid-connected photovoltaic system integrated with storage to meet an annual hourly average demand of 135 kWh of an establishment situated in northern India which receives a daily average solar insolation of 5.16 kWh/m2. System design has been carried out to meet the energy demand at minimised annualised cost. The annualised cost of the optimised system has been found to be US$115184.20/year. Analysis shows that the proposed model results in reduction in annualised cost by 32.27% and a net reduction in emissions by 610 MT as compared with the traditional grid power. Furthermore, multi-objective optimisation carried out to explore system design trade-offs between annualised cost, peak to average ratio of grid energy, and emissions, indicates that overall reduction in emissions by 15% could be obtained at 6.5% increased cost. It is also observed that reduction in grid-outages by 25% leads to reduction in AC by as high as 42.4%.

Carbon and energy footprint of nonmetallic composite pipes in onshore oil and gas flowlines

A Life Cycle Assessment (LCA) analysis was conducted to compare the carbon and energy footprint of several non-metallic composite pipes and carbon steel (CS) pipes used in onshore sour oil and gas (O&G) production flowlines, based on a specific deployment case (cradle-to-gate scenario). This work provides a systematic approach to assessing the carbon and energy footprint of fiber reinforced thermoplastic/thermoset pipes used in the O&G industry, while also accounting for the end-of-life recycling at the material phase, through the use of the recycled-content allocation method. The impact of corrosion allowance (CA), commonly used at design phase of CS pipes, is explicitly included and discussed. From the raw material extraction to the installation phase, all non-metallic pipe technologies assessed in this study were found to have a lower carbon and energy footprint than CS pipes. The reduction in CO2 emissions can reach up to 60% while the energy footprint can be reduced by up to 50%. The material phase, particularly the composite layer for non-metallic pipes, was found to be the main contributor to the product footprint for all pipe technologies and any optimization in this phase could translate into a significant reduction in the overall CO2 footprint of the pipe. The manufacturing phase is the second largest contributor to the emissions and was found to be (on average) five times bigger for CS pipes than any of the non-metallic pipe technologies assessed in this study. The use of stronger and lighter fiber reinforcements (e.g., carbon fibers) to substitute conventional glass fibers in RTP pipes enabled a noticeable reduction in the product weight. However, the potential in reduction of overall emissions was outweighed by the exceedingly high carbon intensity of carbon fibers. The results of this study are supporting an ongoing strategy for mass deployment of nonmetallic pipes (a traditional driver in reducing operating costs) and provide a path for cleaner production and distribution of hydrocarbon resources. The conclusions of this work could be further developed by accounting for the operational phase of the pipes in question.

Air quality and greenhouse gas implications of autonomous vehicles in Vancouver, Canada

This study explores vehicle fleet emissions changes due to connected and autonomous vehicle (CAV) diffusion, over the years 2030 and 2040 in Metro Vancouver, using the US Environmental Protection Agency’s MOtor Vehicle Emission Simulator (MOVES). Impacts were assessed across scenarios with varying future vehicle kilometers traveled (VKT), transit use, fuel-type, and diffusion rate. In all models, greenhouse gas emissions (GHGs) were reduced due to increasing electric vehicles, though reductions varied. At best, CAVs decreased GHGs by 20% compared to no-CAV conditions in 2040. At worst, we model a 6% decrease in GHGs if autonomy provokes increased use of personal vehicles (Motor City scenario), even with 85% electric vehicles. An overall reduction in emissions is seen for other pollutants, with the exception of PM, ranging from emissions reductions of up to 20% (PM exhaust) to an increase in emissions by 30% (PM2.5 brakewear) in 2040. Increased VKT per CAV had the most significant impact.

From Futile to Utile: Addressing the Key Role of Florida’s Electric Utility Companies in Mitigating Sea-Level Rise.

Florida’s unique tax structure, revenue sources, and diverse environment provide an opportunity to address sea-level rise through the lens of the highest carbon emitters: electric utility companies. The proposed solutions include: [1] a gradual increase in taxes and fees on some aspects of Florida electric utility companies, [2] offering tax credits and subsidies for transitioning to more environmentally-friendly power-generation, and [3] reforming electric utility regulations as an incentive to adopt a more climate-conscious, public welfare approach — all while maintaining a profit-making structure that can both maintain revenue and reduce the impact of sea level rise in Florida. An analysis of three potential solutions indicates that the case for carbon dioxide mitigation initiatives is strong and able to yield significant revenue over time, while simultaneously contributing to the overall reduction in emissions to help reduce the impact of sea level rise in Florida and beyond.

Projected Direct Carbon Dioxide Emission Reductions as a Result of the Adoption of Electric Vehicles in Gauteng Province of South Africa

There are genuine worldwide concerns regarding the contribution of internal combustion engine (ICE) vehicles to greenhouse gas (GHG) emissions. Passenger electric vehicles (EVs) are considered as a viable solution to the rapidly increasing global GHG emissions from ICE vehicles. This study investigated the future impact of perceived adoption of electric vehicles in Gauteng Province of South Africa on carbon emissions. Estimations of carbon dioxide (CO2) emissions were made with data from 2000 to 2018 to provide a reference period for the analysis. Projections of CO2 emissions from 2020 to 2030 were undertaken using three future cases, namely: mitigation, business as usual, and high economic growth based on the projected 20% population of electric vehicles, and four scenarios representing varying proportions of different types of EVs. The results showed an increasingly significant trend in CO2 emissions during the reference period. CO2 emissions estimated using the mitigation case showed an overall reduction in emissions of between 30% and 35%, depending on the scenario. The business as usual case showed an increase in emissions of 1–5% by 2030. The high economic growth case showed a high increase in CO2 emissions of 35–41% by 2030. The study indicates a need to accelerate the adoption of EVs with a 20% projection of the vehicle population still not enough to make a meaningful contribution towards decreasing CO2 emissions from passenger vehicles.

Ambient Air Quality in the Czech Republic: Past and Present

Based on an analysis of related core papers and reports, this review presents a historical perspective on ambient air pollution and ambient air quality development in the modern-day Czech Republic (CR) over the past seven decades, i.e., from the 1950s to the present. It offers insights into major air pollution problems, reveals the main hot spots and problematic regions and indicates the principal air pollutants in the CR. Air pollution is not presented as a stand-alone problem, but in the wider context of air pollution impacts both on human health and the environment in the CR. The review is arranged into three main parts: (1) the time period until the Velvet Revolution of 1989, (2) the transition period of the 1990s and (3) the modern period after 2000. Obviously, a major improvement in ambient air quality has been achieved since the 1970s and 1980s, when air pollution in the former Czechoslovakia culminated. Nevertheless, new challenges including fine aerosol, benzo[a]pyrene and ground-level ozone, of which the limit values are still vastly exceeded, have emerged. Furthermore, in spite of a significant reduction in overall emissions, the atmospheric deposition of nitrogen, in particular, remains high in some regions.

Curbing Carbon: An Experiment on Uncertainty and Information About CO &lt;sub&gt;2&lt;/sub&gt; Emissions

We investigate how consumers respond to uncertainty about CO2 emission size. In an incentivized online experiment, participants can acquire a valuable good that emits an unknown amount of CO2. We find that beliefs about emission size are strongly predictive of purchases, even exceeding the effect of substantial changes in the price of the good. Moreover, information that makes beliefs more precise causes a 26% reduction in overall emissions, even though average beliefs are unchanged. The reduction occurs as the marginal willingness to pay for emission reduction declines with emission size, so people who are too optimistic about emissions are more responsive to information. We also test for the formation of self-serving beliefs. Contrary to theories of motivated reasoning, increasing the surplus from buying the product does not change patterns of attention or belief formation about emissions. Overall, the results suggest that information about CO2 impact can be an important policy lever, and that willingness-to-pay for emission reductions should take into account the size of emissions.

Impacts of plug-in electric vehicles in the portuguese electrical grid

Powertrain electrification is currently the best alternative to ensure sustainable energy efficient personal mobility, increasing the integration of intermittent Renewable Energy Sources (RES), improving air quality in urban centres, and reducing greenhouse gas emissions from the transport sector and their dependence on fossil energy sources. With the increasing number of Electric Vehicles (EVs) available from automotive manufacturers, one key question that arises is the capability of the electrical grid to feed the increasing energy demand of the EV fleet without major investments. This paper shows that a progressive penetration of EVs, even at a rapid rate, is perfectly possible for vehicles that offer autonomy, energy consumption and charging characteristics that are currently available in the market. This analysis is based on data acquired during a year, using a Plug-in Hybrid Electric Vehicle (PEV) as the only vehicle for a typical, Southern European Portuguese family. The energy consumption of a gasoline and electric vehicle is presented, as well as its impact on the household load pattern. An analysis of the impact on the grid is also presented, considering several penetration rates (100 thousand, 500 thousand and 1 million vehicles). As well as the avoided use of fossil fuel per vehicle and consequent reduction in overall emissions when compared with a conventional vehicle.

Greenhouse gas emissions from dung, urine and dairy pond sludge applied to pasture. 1. Nitrous oxide emissions

Nitrous oxide (N2O) from excreta deposited by grazing ruminants is a major source of greenhouse gas emissions in Australia. Experiments to measure N2O emissions from dairy cow dung, urine and pond sludge applied to pasture, and the effectiveness of the nitrification inhibitor nitrapyrin in reducing these emissions, were conducted in south-western Victoria, Australia. In Experiment 1, emissions from urine, with and without nitrapyrin, and from dung were measured. Treatments applied in September 2013 resulted in cumulative emissions (245 days) of 0.60, 5.35, 4.15 and 1.02 kg N2O-nitrogen (N)/ha for the nil, urine (1000 kg N/ha), urine (1000 kg N/ha) + nitrapyrin (1 kg active ingredients/ha), and dung (448 kg N/ha) treatments, respectively, giving emission factors of 0.47% and 0.09% for urine and dung respectively. Nitrapyrin reduced N2O emissions from urine for 35 days, with an overall reduction in emissions of 25%. In Experiment 2, sludge, with and without nitrapyrin, was applied in May 2014, and dung was applied in May, August, November 2014 and January 2015. Cumulative emissions (350 days) were 0.19, 0.49, 0.31 and 0.39 kg N2O-N/ha for the nil, sludge (308 kg N/ha), sludge (308 kg N/ha) + nitrapyrin (1 kg active ingredients/ha), and dung (total 604 kg N/ha) treatments, respectively, giving emission factors of 0.10% and 0.03% for sludge and dung. Nitrapyrin reduced N2O emissions from sludge for 60 days, with an overall reduction in emissions of 59%. A third experiment on two soil types compared emissions from urine and dung, with and without nitrapyrin, applied in different seasons of the year. Emissions were highly seasonal and strongly related to soil water status. Emission factors (90 days) ranged from 0.02% to 0.19% for urine and 0.01% to 0.12% for dung. Nitrapyrin reduced emissions from urine by 0–35% and had little effect on emissions from dung. Overall, the experiments found that nitrapyrin was an effective tool in reducing emissions from urine, dung and sludge applied to pasture, but the magnitude varied across the year, with nitrapyrin being most effective when soils had &gt;70% water-filled pore space when major emissions occurred.

Nonlinear MPC for Emission Efficient Cooperative Adaptive Cruise Control

Advanced driver assistant systems (ADAS) are primarily introduced to increase safety in every day trafic situations. Adaptive cruise control (ACC) systems represent an important example for such ADAS. The worldwide increasing trafic volume and the demand for the reduction of overall emissions call for the development of ADAS which concern not only safety but also the reduction of vehicle emissions and fuel consumption. In this work a cooperative adaptive cruise control (CACC) approach is introduced which focuses on these goals. A scenario with two consecutive driving vehicles and infrastructure-to-vehicle (I2V) communication is considered. The rear vehicle's longitudinal dynamics are controlled by a nonlinear model predictive control (NMPC) scheme with the target of emission and fuel eficient driving. The prospective velocity of the preceding vehicle is estimated by a prediction model based on the measured inter-vehicle distance and the I2V communication to enable an anticipatory driving behavior for the controlled vehicle. The results of hardware-in-the-loop (HIL) experiments on a dynamic engine test bench are presented and show a significant reduction of vehicle emissions and fuel consumption.

Role of primary sedimentation on plant-wide energy recovery and carbon footprint

The goal of this paper is to show the effect of primary sedimentation on the chemical oxygen demand (COD) and solids fractionation and consequently on the carbonaceous and energy footprints of wastewater treatment processes. Using a simple rational procedure for COD and solids fraction quantification, we quantify the effects of varying fractions on CO2 and CO2-equivalent mass flows, process energy demand and energy recovery. Then we analysed two treatment plants with similar biological nutrient removal processes in two different climatic regions and quantified the net benefit of gravity separation before biological treatment. In the cases analysed, primary settling increases the solid fraction of COD that is processed in anaerobic digestion, with an associated increase in biogas production and energy recovery, and a reduction in overall emissions of CO2 and CO2-equivalent from power importation.

Reduction potential of operational carbon dioxide emission of Nakanoshima business/cultural area as a model for low-carbon districts in warm climates

This study examines a scenario for realizing large-scale reductions of operational carbon dioxide (CO2) emission in commercial districts in temperate and tropical zones. In warm climates, energy usage for heating is not dominant in a building's energy usage, and hence, every available emission reduction technology must be fully utilized to achieve a large overall reduction in emissions, as in the scenario examined in this study. The focus is on commercial buildings in Nakanoshima area, a sandbank 3 km long and 50 ha wide, a central business and cultural area in the city of Osaka, Japan. The commercial buildings in Nakanoshima with approximately 1.2 million square meters of total floor area emitted 88 thousand tons of CO2 in 2008. The method used in this paper combines: 1) energy flow analysis, 2) community-scale building performance simulation validated with actual energy consumption and supported by detailed field survey and reference survey, and 3) what-if analysis assuming technological deployment and social change based on a long-term perspective. It enables a comprehensive understanding of how much energy is consumed for what purpose as well as how much energy can be reduced by implementing which technologies and measures. The result showed that approximately 65% emissions of the present operational CO2 emission could be reduced in the coming decades.