Reduction Of GHGs Research Articles

Integrating properties and conditions to predict spray performance of alternative aviation fuel by ANN model

Alternative aviation fuel has been confirmed benefits for GHGs reduction and energy saving. Alternative fuel use should meet drop-in fuel requirement, and one of the important factors to ensure combustion completeness is to achieve spray requirement in the whole envelop of flight. Alternative fuels are characterized different fuel properties at low temperature comparison with traditional jet fuel. For understanding fuel properties and spray-related processes under different conditions, alternative aviation fuel, including Fischer Tropsch (FT), cellulose hydrotreating jet fuel (CHJ) and traditional jet fuel (RP-3), were investigated spray performance. According to empirical equation deduced from experiment data (283 K-343 K), deviations to RP-3 enhanced significantly on surface tension and viscosity at low temperature aera (243 K-273 K). As the complex and discontinuous interaction between nozzle structure and fuel properties with temperature, and thus it is difficult to obtain appropriate empirical equation or simulation results at low temperature. Moreover, non-drop-in fuel like pure FT fuel cannot comply with the same spray mechanism as drop-in fuel. The artificial neural network (ANN) approaches have been involved to solve the complex relationship of properties with spray performance. ANN-spray model coupling with ANN-mass flow can predict not only cone angle and liquid length but also SMD and velocity in liquid zone and droplet zone with above 0.99 total correlation coefficient. Coupling simulation results of mass flow and spray performance, FT and CHJ as well as blend fuels present more obvious difference to RP-3 in droplet size distribution and velocity distribution at low temperature.

The potential GHGs reduction of co-processing aviation biofuel in life cycle

The challenge of drop-in jet biofuel should couple the reduction of GHGs emission in whole life cycle with economic competitiveness and achieving performance without reducing performance of engine and aircraft. Co-processing was recognized a promising solution due to availability of existing refining infrastructure and facilities. Based on the LCA approach, the quantitative LCA assessment model (AF-3E) has been established for discovering potential GHGs reduction by co-processing. Typical representatives of oily feedstock, including used cooking oil, soybean, rapeseed, peanut, corn oil, Xanthoceras sorbifolia, jatropha and algae, were compared co-processing with HEFA-SPK blend on GHGs and energy consumption in the whole life. Computational framework is integrated into 3 sub-models and 4 modules, which include feedstocks model, fuel model, flight model and electricity module, hydrogen module, methanol module, hexane module. In flight model, the emissions were investigated at LTO condition and cruise condition and transfer to six types of typical aircraft widely used by similarity criterion. Co-processing achieve less energy consumption and GHGs emission than HEFA-SPK blend, which is attributed to less energy consumption in fuel stage. Used cooking oil conducts 8.17% GHGs reduction in 5% bio-feedstock co-processing and 6.39% in 5% HEFA-SPK jet biofuel blend compared with petroleum-based jet fuel. By sensitivity analysis, the vital factors on GHGs have been extracted in whole life cycle. The purpose of this paper is to discover the advantages and vital factors of co-processing. The results would enhance the interests in both LCA and co-processing for sustainable aviation biofuel.Graphical

Telemedicine and the environment: life cycle environmental emissions from in-person and virtual clinic visits

Concern over climate change is growing in the healthcare space, and telemedicine has been rapidly expanding since the start of the COVID19 pandemic. Understanding the various sources of environmental emissions from clinic visits—both virtual and in-person—will help create a more sustainable healthcare system. This study uses a Life Cycle Assessment with retrospective clinical data from Stanford Health Care (SHC) in 2019–2021 to determine the environmental emissions associated with in-person and virtual clinic visits. SHC saw 13% increase in clinic visits, but due to the rise in telemedicine services, the Greenhouse Gas emissions (GHGs) from these visits decreased 36% between 2019 and 2021. Telemedicine (phone and video appointments) helped SHC avoid approximately 17,000 metric tons of GHGs in 2021. Some departments, such as psychiatry and cancer achieved greater GHG reductions, as they were able to perform more virtual visits. Telemedicine is an important component for the reduction of GHGs in healthcare systems; however, telemedicine cannot replace every clinic visit and proper triaging and tracking systems should be in place to avoid duplicative care.

An introduction of future fuels on working ship for GHGs reduction: Trailing suction hopper dredger case study

This paper examines technical feasibility of implementation of future fuels on Trailing Suction Hopper Dredger (TSHD) working ship, with goal to reduce GHGs. In order to determine suitable future fuel for that purpose, the analysis of fuel efficiency, emissions and environmental impact, viability, availability, safety regulations preparedness and current market engine solutions is done first, and methanol, ammonia and hydrogen are chosen as possible choices. Among them, methanol and ammonia are chosen for further detailed examination of their possible implementation with retrofit of a TSHD prototype fuelled by marine diesel oil (MDO), thus enabling comparison of design versions. After evaluation of design versions for operational, safety and risk, and ecological properties, the marine methanol fuel (MMF) proves its technical feasibility for implementation on TSHD ship, while ammonia failed to satisfy risk reduction requirements from the authorities. Although methanol fuel does not reduce GHGs completely, it enables “green transition” towards fulfilling of IMO future goals of zero carbon emission. The hydrogen is not assessed here because of the technological readiness level not as close in sight as for ammonia and methanol.

Material circularity indicator for accelerating low‐carbon circular economy in Thailand's building and construction sector

AbstractThailand's steady growth of urban areas and industrial estates, the construction sector needs to adopt a low‐carbon circular economy (CE) model that emphasizes material circularity and resource efficiency. This research aims to measure the low‐carbon CE of the construction industry through significant representative products, life cycle assessment and material circularity indicator (MCI) were measured on significant representative products materials were evaluated. In the results of the study, it was found that the MCI and GHGs revealed the following results: 1 ton of construction steel products = 0.73 and 2.32 kgCO2/ton, 1 bag (50 kg) of mortar and cement products = 0.17 and 16.92 kgCO2/bag, 1 m3 of ready‐mixed concrete at compressive strength 240 kilograms per square centimeter = 0.11 and 253.63 kgCO2/m3, 1 m3 of wood and composite wood products = 0.17 and 745.84 kgCO2/bag, also 1 m2K/W (meters squared Kelvin per Watt) of glass wool insulation = 0.50 and 1.63 kgCO2/m2K/W, respectively. These values are indicated as national baselines for monitoring CE performance that contribute to the industry's long‐term viability and turn to sustainability in Thailand through the key strategic issues in Thailand's CE and low‐carbon society. The GHGs reduction of 11 million tons is expected, which can also increase the 10% of material circularity, also the estimation of the economic value, by considering the value added from material reduction and the price of carbon credit from construction and demolition waste reduction affect the Thai construction industry by approximately 67 million dollars.

GHGs Reduction Capacity of Agroforestry Systems in Tropical Africa: A Review

The main crucial agroforestry systems (AFS) of tropics Africa are homestead, woody species planting, multistory dwelling and spread the woody plants. Traditional AFS interaction is important for shading Coffee tree, improving soil fertility, climate regulation, alternative income source, and reducing the pressure on natural forests. These systems are important for ecological balance and human wellbeing. This review was aimed to explore the capacity of AFS for reduction of GHGs from atmosphere and mitigate climate change in tropical Africa. AFS has sequestered significant amount of CO2 and reduced GHGs sink from the atmosphere. Several research reports were recognized as AFS has been substantially carbon-capturing from the atmosphere compared to the mono-crops, dry woodlands, andor pasture land. In tropical Africa region AFS has been estimated to 2.11 × 1091 Mg C yr-1 of aboveground biomass carbon sequester. Multi-strata AFS was reported highest (16-36 Mgt ha-1 yr-1) amount of carbon sequestration. Soil organic carbon (SOC) stock of fruit-coffee, coffee-enset and enset system agroforestry systems were estimated 186.41 Mg ha-1, 178.8 Mg ha-1 and 177.8 Mg ha-1 respectively at 0-60 cm soil depth. According to Intergovernmental Panel on Climate Change (IPCC) and several research results, nowadays AFS development was one of well rcognized to climate change mitigation strategy. Multipurpose tree management on farm land and grazing land is strongly recommended for increased GHG emission reduction capacity of AFS in tropics.

Spatiotemporal Evolution of Global Greenhouse Gas Emissions Transferring via Trade: Influencing Factors and Policy Implications.

Global climate change caused by greenhouse gas emissions (GHGs) from anthropogenic activities have already become the focus of the world. A more systematic and comprehensive analysis on the factors influencing the changes of global GHGs transferring via trade have not been fully discussed. To this end, employing spatial econometric regression models and multi-regional input-output models, this paper reveals factors influencing the GHGs transferring via trade changes in 39 major economies, so as to develop the relevant GHGs reduction policies. The results indicate that regions with the highest net outflow of GHGs transferring via trade are primarily Russia and Canada, and the adverse effects of promoting GHGs reduction on the national economy could be avoided by these regions owing to trade relations. Additionally, factors influencing the changes in GHGs transferring via trade have significant spatial autocorrelation, and population size and energy structure exert significant spatial spillover effects on the changes in the GHGs transferring via trade. On this basis, this paper suggests that one more effective way to prevent trade from the rigorous demands of environmental governance measures while preserving the economic benefits of international trade may be to facilitate cooperation between countries on GHGs mitigation. Further, we articulate more balanced environment governance policies, including conducting the sharing of advanced energy technologies and developing clearer production technologies.

Mitigating CH4 and N2O Emissions from the Rice Crop System in IGP Region in India

Rice cropping system as an agriculture practices is considered as one of the major emission source of methane (CH4) and nitrous Oxide (N2O). In agriculture, man-made activities contribute CH4 (77%) and N2O (60%).This article reports on emission measurements from the Indo Gangetic plains (IGP) of India from four different treatment methods. Implementation of biogas spent slurry (BSS) method was most effective in reducing GHGs emissions. The findings should help in regulating and implementing management strategies regarding the reduction of GHGs from the agricultural fields and avoid environmental losses and claims.

The IMO Initial Strategy for the Reduction of GHGs from International Shipping: A Commentary

Abstract In 2018 the IMO adopted the initial Strategy for the international shipping industry’s reduction of global greenhouse gas emissions towards achieving the goal set in the 2015 Paris Agreement. At this time the Strategy is no more than a preliminary structure to frame the measures that will need to be adopted for the short, medium and long terms. In the short term (2018–2023) a first suite of measures will be adopted, and the initial Strategy will be revised and adopted as changed in 2023 with proposed measures for the medium term (2023–2030) and long term (2030–2050 and beyond). New international standards, tools and best practices will be needed to supplement the existing energy efficiency management rules in the International Convention on the Prevention of Pollution from Ships, 1973/78. This article discusses the Strategy and the role of the IMO in leading the shipping industry on the road to decarbonization.

파리협정과 BAU 감축목표 이행에 대한 고찰

파리협정과 BAU 감축목표 이행에 대한 고찰

Optimization to water supply system design and operation scheme in high rise buildings

Greenhouse Gas emission from high-rise buildings has been increasing mainly due to excessive energy consumption of the HVAC system, structural system and electrical system. Electricity consumption for pump system accounts for 15% of total electricity usage in building. Therefore the reduction of electricity in operation is crucial to the overall reduction of GHGs in urban areas. In this study, a lab-scale experiment was conducted to test the electricity consumption in applying different design approaches; the energy efficiency of the system was calculated. Finally, this study proposes the advanced water supply design scheme to reduce electricity consumption of the pump system.
 Article history: Received 12 March 2018, Revised 03 April 2018, Accepted 27 April 2018

Refining drop-in jet fuel coupling GHGs reduction in LCA with airworthiness in aero-engine and aircraft

Abstract The current challenge of drop-in jet fuel should couple the reduction of GHGs emission in whole life cycle with economic competitiveness and achieving performance as same as traditional jet fuel without reducing safe service life in engine and aircraft. From the insight of GHGs reduction, the whole life cycle, including sustainable feedstock, refining process integration and low emission in combustion are optimized for reduction in energy input and emission output. From the insight of airworthiness in aero-engine and aircraft, a certification process is achieved by extracting safety criteria from the “history experience” of petroleum-based jet fuel as the source and to predict the aero-engine safety implications of alternative aviation fuels as the target by “similar analogy”. The critical key parameters have been extracted by fundamental process related with safety and performance on achieving the duty of engine in the whole flight envelop. Alternative jet fuel can be qualified for certifying drop-in jet fuel and accordingly confirm with identical safe service life in engine and aircraft by analogizing the boundaries of critical key parameters with petroleum-based jet fuel. The critical parameters thereof, including carbon distribution and classification as well as C/H ratio, can conduct directly for feedstock choice and refining process modification. Accordingly, a process of refining algae-based jet fuel was modified coupling the requirement of GHGs reduction in life cycle with airworthiness in aero-engine and aircraft. Based on process integration to connect upstream feedstock to downstream combustion outcomes of alternative jet biofuel and co-product, GHGs in fuel stage deduced further by co-product and nutrient recovery in spite of additional separation process.

A Bayesian belief network framework to predict SOC dynamics of alternative management scenarios

Understanding the key drivers that affect a decline of soil organic carbon (SOC) stock in agricultural areas is of major concern since leading to a decline in service provision from soils and potentially carbon release into the atmosphere. Despite an increasing attention is given to SOC depletion and degradation processes, SOC dynamics are far from being completely understood because they occur in the long term and are the result of a complex interaction between management and pedo-climatic factors. In order to improve our understanding of SOC reduction phenomena in the mineral soils of Veneto region, this study aimed to adopt an innovative probabilistic Bayesian belief network (BBN) framework to model SOC dynamics and identify management scenarios that maximise its accumulation and minimise GHG emissions.Results showed that the constructed BBN framework was able to describe SOC dynamics of the Veneto region, predicting probabilities of general accumulation (11.0%) and depletion (55.0%), similar to those already measured in field studies (15.3% and 50%, respectively). A general enhancement in the SOC content was observed where a minimum soil disturbance was adopted. This outcome suggested that management strategies of conversion from croplands to grasslands, no tillage and conservation agriculture are the most promising management strategies to reverse existing SOC reduction dynamics. Moreover, measures implying SOC stocks were also those providing major benefits in terms of GHGs reduction emissions. Finally, climate change scenarios slightly affected management practice. Advancements in our BBN framework might include more detailed classes at higher resolution as well as any socio-cultural or economic aspect that should improve the evaluation of prediction scenarios.

A Hybrid Life-Cycle Analysis and Two-Stage Stochastic Programming Model for Low-Carbon Management upon Urban Water Resources

Due to population growth and economic development, water demands for municipal, industrial, and agricultural users are increasing. It is a challenging and critical issue in water resources system to properly allocate and utilize water resources to satisfy the goals of different stakeholders and greenhouse gases mitigation. In this study, a hybrid life-cycle analysis and two-stage stochastic programming model was proposed to analyze the water-allocation strategies based on complicated urban water resource system. The hybrid model can effectively assess the low-carbon performance of an urban water resources system in the framework of life-cycle analysis. The environmental impacts and GHGs reduction of urban water resources were firstly considered as the objective and constraint for solving the water allocation problems. The results indicated that the firststage solutions of surface water conveyance of Dalian could be [3.83×10 8 , 8.25×10 8 ] in 2015, and [3.83×10 8 , 9.21×10 8 ] in 2020; Meanwhile, the first-stage solutions of surface water conveyance of Dalian could be [4.26×10 8 , 8.68×10 8 ] in 2015, and [5.35×10 8 , 10.7×10 8 ] in 2020.

Post-2020 Emission Projection and Potential Reduction Analysis in Agricultural Sector

In 2014, the United Nations Framework Convention on Climate Change (UNFCCC) agreed to submit the Intended Nationality Determined Contributions (INDCs) at the conference of parties held in Lima, Peru. Then, the South Korean government submitted the INDCs including GHGs reduction target and reduction potential on July, 2015. The goal of this study is to predict GHGs emission and to analyze reduction potential in agricultural sector of Korea. Activity data to estimate GHGs emission was forecast by Korea Agricultural Simulation Model (KASMO) of Korea Rural Economic Institute and estimate methodology was taken by the IPCC and guideline for MRV (Measurement, Reporting and Verification) of national greenhouse gases statistics of Korea. The predicted GHGs emission of agricultural sectors from 2021 to 2030 tended to decrease due to decline in crop production and its gap was less after 2025. Increasing livestock numbers such as sheep, horses, swine, and ducks did not show signigicant impact the total GHGs emission. On a analysis of the reduction potential, GHGs emission was expected to reduce 253 Gg CO₂SUB-eq/SUB. by 2030 with increase of mid-season water drainage area up to 95% of total rice cultivation area. The GHGs reduction potential with intermittent drainage technology applied to 10% of the tatal paddy field area, mid-drainage and no organic matter would be 92 Gg CO₂SUB-eq/SUB. by 2030.

Co-Control of GHGs and Local Pollutants Under New Climate Regime

China is under great pressure to make a legally binding commitment to reduce GHGs emissions under the upcoming agreement to be reached through UNFCCC talks in 2015. China will move toward a new era in addressing climate change. Against this background, the new regime for international climate governance is undergoing profound changes, manifested in economic development, GHGs emissions, and international cooperation. In the meantime, the domestic response to climate change will get deeper and more closely linked with environmental protection and ecological governance, covering the fog and haze control, GHGs reduction in industrial sectors, and short-lived climate pollutants control. In the view that climate change adaptation and mitigation, to some extent, facilitates environmental protection, and vice versa, adequate attention and recognition should be given to co-control of GHGs and local pollutants.

Spatio-temporal analysis of car distance, greenhouse gases and the effect of built environment: A latent class regression analysis

This work examines the temporal–spatial variations of daily automobile distance traveled and greenhouse gas emissions (GHGs) and their association with built environment attributes and household socio-demographics. A GHGs household inventory is determined using link-level average speeds for a large and representative sample of households in three origin–destination surveys (1998, 2003 and 2008) in Montreal, Canada. For the emission inventories, different sources of data are combined including link-level average speeds in the network, vehicle occupancy levels and fuel consumption characteristics of the vehicle fleet. Urban form indicators over time such as population density, land use mix and transit accessibility are generated for each household in each of the three waves. A latent class (LC) regression modeling framework is then implemented to investigate the association of built environment and socio-demographics with GHGs and automobile distance traveled. Among other results, it is found that population density, transit accessibility and land-use mix have small but statistically significant negative impact on GHGs and car usage. Despite that this is in accordance with past studies, the estimated elasticities are greater than those reported in the literature for North American cities. Moreover, different household subpopulations are identified in which the effect of built environment varies significantly. Also, a reduction of the average GHGs at the household level is observed over time. According to our estimates, households produced 15% and 10% more GHGs in 1998 and 2003 respectively, compared to 2008. This reduction can be associated to the improvement of the fuel economy of vehicle fleet and the decrease of motor-vehicle usage – e.g., a decrease of 4% is observed for fuel efficiency rates and 12% for distance according to the raw average estimates from 1998 with respect to 2008. A strong link is also observed between socio-demographics and the two travel outcomes. While number of workers is positively associated with car distance and GHGs, low and medium income households pollute less than high-income households.

Life cycle modeling of energy matrix scenarios, Belgian power and partial heat mixes as case study

The present paper introduces a life cycle modeling approach for representing actual demand of energy or energy intensive products delivered within a system (electricity, heat, etc.) for optimization of the energy mix, according to some of the available life cycle impact assessments (LCIAs). Unlike classical LCA modeling approach, the real amount of several energy products leaving the system and the interactions due to the presence of multi-output processes are considered within the present approach. As a case study, future scenarios are obtained for the Belgian electricity mix production and the heat mix potentially substituted by CHP or biomass, switching between abandoning or not power from nuclear energy. The possibility of using natural gas, biomass for cogeneration, wind power and solar photovoltaic energy are considered within the availability ranges of these resources. Finally, results are presented from successive optimizations according to the sustainability potential defined in a previous paper. A pathway to a more sustainable Belgian energy system is obtained. Finally it is concluded that under the modeling conditions and without nuclear energy it is not possible to obtain a reduction of GHGs and despite diminishing of non-renewable resource consumption, a rising of toxicity is obtained.

Spatio-Temporal Analysis of Car Distance, Greenhouse Gases and the Effect of Built Environment: A Latent Class Regression Analysis

This work examines the temporal-spatial variations of daily automobile distance traveled and greenhouse gas emissions (GHGs) and their association with built environment attributes and household socio-demographics. A GHGs household inventory is determined using link-level average speeds for a large and representative sample of households in three origin-destination surveys (1998, 2003 and 2008) in Montreal, Canada. For the emission inventories, different sources of data are combined including link-level average speeds in the network, vehicle occupancy levels and fuel consumption characteristics of the vehicle fleet. Built environment indicators over time such as population density, land use mix and transit accessibility are generated for each household in each of the three waves. A latent class (LC) regression modeling framework is then implemented to investigate the association of built environment and socio-demographics with GHGs and automobile distance traveled. Among other results, it is found that population density, transit accessibility and land-use mix have small but statistically significant negative impact on GHGs and car usage. Despite that this is in accordance with past studies, the estimated elasticities are greater than those reported in the literature for North American cities. Moreover, different household subpopulations are identified in which the effect of built environment varies significantly. Also, a reduction of the average GHGs at the household level is observed over time. According to our estimates, households produced 15% and 10% more GHGs in 1998 and 2003 respectively, compared to 2008. This reduction is associated to the improvement of the fuel economy of vehicle fleet and the decrease of motor-vehicle usage. A strong link is also observed between socio-demographics and the two travel outcomes. While number of workers is positively associated with car distance and GHGs, low and medium income households pollute less than high-income households.

Emission Trading As Green Solution: Legal Perspective

The present study throws light on the usefulness of Emission Trading as Green Solution in present scenario. Emission trading principle initiated from the technocracy movement which proposed Energy Accounting System in 1930s. Now this is recognized as Emission Trading in Kyoto Protocol which came into force on February 16th, 2005. The obligations of signatory countries are: Reduction of emission of Green House Gases (hereinafter GHGs) notified in Annex-I of Kyoto Protocol and engaging in emission trading if the signatory nations maintain or increase the emission of GHGs.Emission trading brings flexibility to this strict obligation. It aims at achieving the mandate of emission limitation for reduction of GHGs in the signatory nations. It is a cap and trade system under Kyoto. ‘Cap’ is the limit (national level commitments) which is set by the government agency on the amount of emission of the notified pollutants. The pollutant emit ters are required to hold equivalent number of credits or allowances representing the right to emit a specific amount, so that the amount of credits should not exceed the cap.Kyoto has classified signatory countries into two categories, firstly, Annex-I countries (developed countries), which accept GHGs reduction obligations and have to submit Greenhouse Gas Inventory (hereinafter GGI) and non-Annex-I countries (developing countries), which have no GHG emis sion reduction obligations and may participate in Clean Development Mechanism (hereinafter CDM). Thus, emission trading is carried out by Annex- I countries. They buy credits from non-Annex-I economies (CDM) or from Annex-I countries under Joint Implementation or Annex-I countries with excess allowances.Non-compliance in first commitment period (2008-2012) will attract penal ization under which the Annex-I country will have to submit 1.3 emission allowances in the second commitment period on per ton gas emissions. It is said that the individual targets of Annex-I parties will result in a total cut of 5% in GHG emissions from 1990 levels. Emission trading as a green solution has been criticized on many grounds. Practically, most countries devolve their emission targets to individual industrial entities. Hence, the ultimate buyers of credit are often indi vidual companies which in turn will put the monetary burden of such cred its on the consumers. It is also politically popular because of its vul nerability to lobbying. It is expected that even without Kyoto Protocol obligations by year 2010, there will be a 29 % cut in GHGs.On the whole, the major reason of its criticism is that of the benchmark taken and the percentage of the reduction. Without these two, the authen ticity of emission trading cannot be proved as it has some adverse ef fects too, which might hinder the development of developing countries.