Amount Of Greenhouse Gas Emissions Research Articles

Life cycle assessment of pasture-based agrivoltaic systems: Emissions and energy use of integrated rabbit production

Agrivoltaic systems, which deliberately maximize the utility of a single parcel of land for both solar photovoltaic (PV) electricity production and agriculture, have been demonstrated as a viable technology that can ameliorate competing land uses and meet growing energy and food demands efficiently. The goal of this study is to assess the environmental impacts of a novel pasture-based agrivoltaic concept: co-farming rabbits and solar PV. A life cycle assessment (LCA) quantified the impacts of 1) the integrated agrivoltaic concept in comparison to conventional practices including 2) separate rabbit farming and PV production and 3) separate rabbit farming and conventional electricity production. The impact assessment methods employed to determine the environmental impacts were IPCC 2013 global warming potential 100a V1.03 and fossil energy demand V1.11. The results indicate that the pasture-based agrivoltaic system produces the least amount of greenhouse gas emissions (3.8 million kg CO₂ equivalent) and demands the least amount of fossil energy (46 million MJ) per functional unit of cumulative MWh output of electricity and cumulative kg of meat over 30 years in comparison to the two other scenarios under study. The pasture-based agrivoltaic system features a dual synergy that consequently produces 69.3 ​% less emissions and demands 82.9 ​% less fossil energy compared to non-integrated production. The potential for agrivoltaic systems to significantly reduce environmental impacts revealed by this LCA demonstrates that integrated solar and pasture-based agricultural systems are superior to conventional practices in terms of their comparatively lower emission and energy intensity. These findings provide empirical support for increased agrivoltaic system development more broadly.

Assessment of the applicability of methodological guidelines and guidelines for the quantitative determination of greenhouse gas emissions

The article deals with the problem of climate change. The aim of the study is to analyze and improve methodological recommendations for calculating greenhouse gas emissions. The urgency of reducing the volume of greenhouse gas emissions has been substantiated. Statistical data of emissions volumes are analyzed, the reason for the growth of emissions and the main contributors are determined. The main gases that give the greenhouse effect are identified, and their brief characteristics are given. The need to improve the monitoring and reporting system of greenhouse gas emissions at the global level has been substantiated. The goal of a perfect system for accounting and reporting of greenhouse gas emissions is to timely obtain relevant data for the systematic reduction of greenhouse gas emissions. The methodological tools for quantifying greenhouse gas emissions, approved by the Ministry of Natural Resources and Environment of Russia, are analyzed from the point of view of their applicability by organizations. Measures for their improvement are proposed, based on the international experience of building guidelines for the IPCC greenhouse gas inventory. The results obtained may be of interest to energy companies when developing corporate guidelines for quantifying greenhouse gas emissions.

Impact of seawater desalination and wastewater treatment on water stress levels and greenhouse gas emissions: The case of Chile

Many regions around the world are suffering from water stress, and desalinated water and recycled water are seen as alternatives for meeting the water demand. However, high energy consumption and associated greenhouse gas emissions are some of the main environmental impacts. This is notable for many arid and semi-arid countries where desalination and water recycling are considered options for ensuring water resources availability. This research presents the incorporation of the quantification of greenhouse gas emissions generated during the operation of desalination and wastewater treatment plants in the assessment of water stress levels using the water stress indicator adopted by the 2030 Agenda for Sustainable Development. Chile was chosen as a case study, as it is a country where there is a considerable difference between the availability of conventional water sources and the water demand, and the electrical grid is fed mainly by fossil fuels. The methodology proposed allows calculating the indirect greenhouse gas emissions due to electrical consumption for the operation of desalination and wastewater treatment plants, and the direct greenhouse gas emissions coming from biological processes used in wastewater treatment plants. The results showed that Chilean arid climate zones will not experience water stress in the future at the regional level, mainly because of the installation of several desalination plants by 2030. Meanwhile, recycled water from the urban sector will slightly contribute to the reduction in the level of water stress in almost all Chilean regions by 2030. Moreover, desalination and wastewater treatment plant will contribute only between 0.34% and 0.75% of total greenhouse gas emitted in Chile by 2030. Therefore, the operation of these industrial systems for facing water scarcity problems in northern and central zones of Chile is a suitable alternative because it does not generate large environmental problems.

THE DESIGN AND SIMULATION OF THE LINEAR ENGINE GENERATOR USED FOR ELECTRIC PROPULSION SYSTEM OF THE MARINE TRANSPORTATION AND OFFSHORE GAS/OIL PLATFORMS

Maritime shipping and offshore gas/oil platforms account for a large amount of greenhouse gas emissions. It is beneficial to use the linear engine generator (LEG) fuelled by low or zero-carbon fuel as the electric propulsion system for marine transportation and offshore gas/oil platforms to achieve net-zero carbon emission. The LEG could replace the diesel engine and gas turbine for marine applications, with its advantages of simple mechanical structure and adaptability to various fuels, such as hydrogen, ammonia, methane, biofuels, and various energy sources like nuclear and solar energy. This article introduces the ammonia/hydrogen-fuelled LEG prototype for electric propulsion system for marine transportation. The LEG parametric sensitivity analyses are done for performance evaluation through simulation modelling. Furthermore, a detailed design of 1.8 kW electrical output LEG is presented.

Quantifying greenhouse gas emissions from decommissioned oil and gas steel structures: Can current policy meet NetZero goals?

To help achieve global aims to reach Net Zero greenhouse gas (GHG) emissions, a clearly structured method for calculating emissions from decommissioning oil and gas structures is required. In order to understand the GHG consequences of recycling secondary steel from decommissioned structures, this paper presents a new methodology in decommissioning, based on the UN’s International Resource Panel (IRP)’s Value Retention method that combines life cycle assessment principles, the waste hierarchy and the circular economy to holistically calculate GHG emissions produced as a consequence of manufacturing primary and secondary steel, manufacturing a product from this steel and the associated transport emissions. The Value Retention Model presented here combines the concept of material value and product value to obtain realistic GHG emission calculations based on end-of-use and end-of-life scenarios, including recycling and reuse options. The results show that reusing a steel jacket structure in situ will retain 55,040 tCO2(eq) in GHG emissions, not including removal operations or transport emissions. New regulation is urgently required to update the current outdated emissions calculation guidelines, enable the provision of both realistic baseline emissions figures and to provide a mechanism for reporting ‘after operations’ figures.

Effective Mainstreaming of Agricultural Emissions into Climate Action Agenda: The Case of Institutions and Smallholder Dairy Production Systems, Western Kenya

Small-scale farming production systems are integral drivers of global sustainability challenges and the climate crisis as well as a solution space for the transition to climate compatible development. However, mainstreaming agricultural emissions into a climate action agenda through integrative approaches, such as Climate Smart Agriculture (CSA), largely reinforces adaptation–mitigation dualism and pays inadequate attention to institutions’ linkage on the generation of externalities, such as Greenhouse Gas (GHG) emissions. This may undermine the effectiveness of local–global climate risk management initiatives. Literature data and a survey of small-scale farmers’ dairy feeding strategies were used in the simulation of GHG emissions. The effect of price risks on ecoefficiencies or the amount of GHG emissions per unit of produced milk is framed as a proxy for institutional feedbacks on GHG emissions and effect at scale. This case study on small-scale dairy farmers in western Kenya illustrates the effect of local-level and sectoral-level institutional constraints, such as market risks on decision making, on GHG emissions and the effectiveness of climate action. The findings suggest that price risks are significant in incentivising the adoption of CSA technologies. Since institutional interactions influence the choice of individual farmer management actions in adaptation planning, they significantly contribute to GHG spillover at scale. This can be visualised in terms of the nexus between low or non-existent dairy feeding strategies, low herd productivity, and net higher methane emissions per unit of produced milk in a dairy value chain. The use of the Sustainable Food Value Chain (SFVC) analytical lens could mediate the identification of binding constraints, foster organisational and policy coherence, as well as broker the effective mainstreaming of agricultural emissions into local–global climate change risk management initiatives. Market risks thus provide a systematic and holistic lens for assessing alternative carbon transitions, climate financing, adaptation–mitigation dualism, and the related risk of maladaptation, all of which are integral in the planning and implementation of effective climate action initiatives.

Towards sustainable construction through the application of low carbon footprint products

The production of cement generates a large amount of greenhouse gas emissions; in addition, the scarcity of natural resources used in the development of building materials and products has propelled many governments, non-government organizations, construction and cement industries, and researchers around the globe to invest their time and energy towards reducing the dependency of the natural materials; one possible way of achieving sustainability is through the utilization of the locally available waste or industrial by-products as a partial or whole replacement for the conventional materials. University of Malaya (UM) has made a meaningful contribution in the development of sustainable building materials and demonstration projects. UM is the first university in Malaysia to build a cement-free house on its campus. Two single-storey houses, namely Low-Cost Model House (LCMH) and Geopolymer Concrete House (GPCH) have been built using environmentally friendly materials within the university campus. Locally available agricultural and industrial waste and by-products such as palm oil fuel ash (POFA), palm oil clinker (POC), manufactured sand (M-sand), and steel slag aggregate (SSA), were used in the development and construction of these houses. Apart from the materials, environmentally friendly methods of construction were also adopted. This article mainly evaluates the system of construction and the application of sustainable building materials used in the LCMH & GPCH along with its advantages in terms of environment, economy and the social aspects. Overall, it can be concluded that adopting green technology and incorporating waste by-products in concrete has numerous advantages. The revision in the concrete mixes by using alternative substitute materials from waste products would pave the way for reducing environmental problems, harmful effects of waste due to improper disposal methods, reliance on non-renewable substances and promotion of sustainable construction. The prime idea of building the LCMH and GPCH in University of Malaya campus is to raise awareness on the utilization of waste and industrial by-product materials; further, the dissemination of the information is to expand the use of these materials and construction practice not only in Malaysia, but also in other countries.

Assessment of Greenhouse Gas Emissions in Soybean Cultivation Fertilized with Biochar from Various Utility Plants

Organic matter is an indispensable element of soil. Its quantity and quality affect its properties, e.g., structure, buffering, sorption capacity, air–water relations, and thermal properties. The purpose of the research was to assess greenhouse gas (GHG) emissions in soybean cultivation, fertilized with biochar from various crops. Two experimental factors were included: the dose of biochar and the type of biochar used as per raw material used in its production. The adopted functional unit was 1 ton of soybeans. To reach the adopted goal, a strict field experiment was carried out. The total amount of GHG emitted by the cultivation was calculated according to the ISO 14040 and ISO 14044 standards. The system boundaries included: GHG emissions from fertilizers and seeds used, GHG emissions related to biochar production, emissions related to fossil fuel combustion, and emissions related to the decomposition of crop residues and soil organic matter and the decomposition of biochar. The results of the research indicate a significant potential of biochar to reduce GHG emissions in agricultural production. From the environmental and production perspective, the addition of biochar at 60 Mg ha−1 is the most advantageous. A further increase in the addition of biochar was related to a decrease in plant yield and an increase in GHG emissions per functional unit of the product. The use of biochar in soybean cultivation resulted in a 25% reduction in GHG emissions compared to the object without the biochar addition. The amount of GHG emissions for soybeans ranged from 846.9 to 1260.1 kg of CO2/Mg. The use of biochar from forest biomass resulted in a higher yield, 12% on average, compared to sunflower husk biochar. The introduction of biochar to soils can be an effective improvement in the economic and environmental efficiency of plant production, as it increases the use of nutrients by the plant and intensifies carbon sequestration in soils.

Defining Focus Areas for Digitization to Reduce Construction Industry Generated CO2 Emissions

The amount of greenhouse gas emissions generated by the construction industry is significant, therefore it should be addressed to protect our environment in the 21st century. The present research is the starting point for a more complex analysis in bioengineering science. It examines the possibilities of implementing digital technologies and the gains that their application can achieve. The research provides an overview of CO2 emissions from construction processes and identifies areas that may focus on future detailed analysis. The study consists of two main parts: a literature review and an interview with digitization experts focused on the issues identified. The present research guides future development focus areas comparing interviews by market and scientific studies. It is essential to determine how significant results can be achieved by using modern digital tools and methodologies. In this way, the extent to which they affect global emissions can be examined, and their impact can be quantified. In the research, the full spectrum of the construction industry was explored, hence we comprehensively analyzed the impact and problems of the processes belonging to each phase of the lifecycle. Although the environmental impact of raw material extraction and processing is significant, its techniques can be improved primarily through innovative solutions that require organizational or governmental intervention. By examining the building phase and post-building phases of the lifecycle, significant reductions in emissions can be achieved through more detailed design, optimized construction, and well-thought-out operation and demolition processes. As a result, immediate interventions are needed in existing methods and procedures. Sustainable construction can be supported by applying new, more accurate, innovative, and higher quality design, construction, operation, and demolition methods. These changes will facilitate the implementation of digitization processes in the construction industry at a higher level and prepare proposals for the solution of environmental problems in the construction industry.

Spatial Variability of Soil Organic Carbon and Total Nitrogen in Desert Steppes of China’s Hexi Corridor

Stock estimates are critical to quantifying carbon and nitrogen sequestration, quantifying greenhouse gas emissions, and understanding key biogeochemical processes (i.e., soil carbon and nutrient cycling). Many studies have assessed soil organic matter and nutrients in different ecosystems. However, the spatial distribution of carbon and nitrogen and the key influencing factors in arid desert steppe remain unclear. Here, we investigated the soil organic carbon (SOC) and soil total nitrogen (STN) to a depth of 100 cm at 126 sites in a desert steppe in northwestern China.SOCandSTNcontents decreased with increasing depth; the highest averageSOCandSTNcontents were 12.70 and 0.65 g kg−1in the surface 5 cm, and the lowest were from 80 to 100 cm (4.49 and 0.16 g kg−1, respectively).SOCdensity (SOCD) andSTNdensity (STND) to a depth of 100 cm averaged 8.94 and 0.45 kg m−2, respectively. The top 1 m of the soils stored approximately 1,041 TgSOCand 52 TgSTNin the study area. Geostatistical analysis showed strong and moderate spatial autocorrelation forSOCDin different soil layers, but the autocorrelation forSTNDgradually weakened with increasing depth.SOCDandSTNDdecreased from southwest to northeast in the study area, along an elevation gradient. Both were significantly positively correlated with topographic variables, precipitation, and the normalized-difference vegetation index, but negatively correlated with temperature and aridity. More than 40% of theSOCDandSTNDspatial variation was explained by elevation, which was the dominant factor. The data and high-resolution maps from this study will support future soil carbon and nitrogen analyses.

Energy consumption and CO2 emissions of petroleum coke-to-methanol with/without carbon capture using process modeling and life cycle analysis

Petroleum coke is an important by-product of oil refineries. It is characterized by high carbon content and calorific value with increasing sulfur content due to the use of the inferior crude oil. The application of petroleum coke combustion will inevitably produce a large amount of greenhouse gas emissions. Gasification technology can efficiently convert it to syngas and then for methanol production. However, the petroleum coke-to-methanol also faces serious CO2 emissions when adjusting syngas composition. Therefore, this study establishes the model of the petroleum coke-to-methanol with/without carbon capture and compares their energy consumption and CO2 emissions from the production and life cycle aspect. The CO2 emissions of the petroleum coke conversion rates of 75%, 85%, and 95% without carbon capture are 2439 kg/t, 2269 kg/t, 2146 kg/t with exergy efficiencies of 38.35%, 45.31%, and 52.23%. With the help of the carbon capture devices, their CO2 emissions are reduced to 316 kg/t, 297 kg/t, and 285 kg/t with decreasing exergy efficiencies by about 1%. From the aspect of life cycle, the greenhouse gas emissions of the petroleum coke-to-methanol are 3602, 3299, and 3077 kg CO2 eq/t, which are reduced by about 54.58–55.79% with involving carbon capture.

Highly selective photocatalytic synthesis of ethylene-derived commodity chemicals on BiOBr nanosheets

The synthesis of ethylene-derived commodity chemicals is an important process in industry. However, the current manufacturing process is energy-intensive and contributes a significant amount of greenhouse gas emissions. Photocatalytic conversion of ethylene to target products is a more sustainable and green alternative. In this work, we designed a bromide-mediated photocatalytic approach for highly selective synthesis of ethylene oxide or ethylene glycol from ethylene. The bromine/hypobromous acid (Br2/HOBr) generated in photocatalytic process are effective active species for conversion of gaseous ethylene to liquid intermediates, bromoethanol and dibromoethane. These intermediates were further converted to ethylene oxide or ethylene glycol via a facile alkali treatment in different temperatures, giving rise to a high selectivity of 92% and 100%, respectively. Interestingly, the BiOBr could oxidize its crystal Br− to generate Br2/HOBr efficiently, which is a more favorable process thermodynamically than oxidation of aqueous Br−. Furthermore, long-term stability (> 40 h) of BiOBr is maintained by adding KBr in the reaction system to automatically replenish Br− in BiOBr. This work provides a potential alternative to current industrial method for green synthesis of ethylene-derived commodity chemicals.

Review of biowastes to energy in Malaysia: Current technology, scalability and socioeconomic analysis

Malaysia is experiencing rapid urbanisation leading to an increase in the demand of energy. The use of renewable energy can satisfy energy demands and mitigate environmental issues such as greenhouse gas (GHG) emission. Biogas produced from anaerobic digestion from different feedstock such as food waste (FW), palm oil mill effluent (POME), garden waste (GW), landfill, sewage sludge (SS) and animal manure can be utilised to reduce the need of fossil fuel. This review paper will focus on the current biogas technologies, their scalability and socio-economic analysis on biowastes to energy in Malaysia. If all FW generated in Malaysia (approximately 15,000 tonnes per day) could be converted to energy, it has a potential to replace fossil fuel totally, as it produces 10 times more than the annual requirement of energy. Consequently, there is a significant advantage obtained from offsetting huge amounts of GHG emissions that would otherwise be contributing to the global warming effect. Several issues and challenges have been identified for the scale-up of laboratory scale to industrial scale where parameters including pH, temperature, organic loading rate (OLR), hydraulic retention time (HRT) and mixing rate must be treated carefully. The socio-economic survey conducted as part of this study has revealed the strong acceptability of this technology and the readiness of the population in Malaysia to contribute and be part of this effort. However, the survey has also identified the limitations of the sorting and preparation facilities of food waste segregation for potential biogas generation.

A Review on the Feasibility of Deployment of Renewable Energy Sources for Electric Vehicles under Smart Grid Environment

Nowadays, Energy consumption in the field of transportation comes next to industrial consumption worldwide. If transportation is completely powered by renewable energy, the utilization of fossil fuels can be drastically reduced, which will result in a lesser amount of greenhouse gas emissions. Electric vehicles (EVs) can act as an alternative to make transportation pollution-free. Large-scale usage of EVs causes high electricity demand on the supply system. This problem can be overcome by utilizing renewable energy sources (RESs) for Electric Vehicle charging. Due to the unpredictability of RESs, coordinating EV charging with other loads and renewable generation is problematic. By using EVs as energy units, power fluctuations in the electric grid can be compensated. This paper presents a summary of recent research in the domain of integration of renewable energy sources with electric vehicles (EVs) under the smart grid environment. Electric vehicles-smart grid integrated systems face several issues related to communication, grid infrastructure and control in the future power system. Feasibility of integration of solar and wind energy systems with electric vehicles is discussed in section 2. The existing research articles in this area are classified into two based on the purpose: EVs integration into the electric grid and Vehicle to grid services. The function of V2G in the electricity market, as well as its management concerns, are investigated in section 3. Finally, the research gaps and future scope of incorporating electric vehicles with renewable energy sources and the Smart grid are highlighted.

Assessment of the Multiannual Impact of the Grape Training System on GHG Emissions in North Tajikistan

The overarching goal of agricultural sciences is to optimize production technology to rationalize the use of production resources, energy, and space. Due to its high fertilization and water requirements, the vine is a plant with a high potential for greenhouse gas (GHG) emissions. The modifying factor in the production technology is plantation management. To reach the assumed goal, a field experiment was conducted in the years 2001–2020, and the following training systems were used: multi-arm fan system (A) trunk height <30 cm, (B) 80 cm, (C) 120 cm, one-side multi-arm, paired planting (D) 120 cm, (E) 140 cm. The total amount of GHGs emitted in vine cultivation was calculated according to ISO 14040 and ISO 14044 standards. The system boundaries were: establishing the plantation, the production and use of fertilizers and pesticides, energy consumption for agricultural treatments, and gas emissions from the soil. The amount of GHG emissions for cultivation using the systems A, B, C ranged from 426.77 to 556.34 kg of CO2-eq Mg of yield−1, while in the case of D and E systems, the value was approx. 304.37 to 306.23 CO2-eq Mg of yield−1. When comparing this stage with total annual emissions related to cultivation (for 1 ha), the amount of emitted GHGs at this stage is from approx. 42% to 58% higher than from annual emission related to cultivation. Concrete poles are the main element related with GHG emission during stage of plantation establishment, from 97 to 98% of emission. In the case of annual production, nitrogen fertilizers are responsible for approx. 36%. Moreover, the results show that systems D and E increased the average annual fruit yield (per 19 years of research) by approx. 68% compared to the A, B, C systems. There was no difference in the yield of plants with different height of shoots in the D and E systems. The “one-side, multi-arm, paired planting system” was characterized by the highest production and environmental efficiency.

Examining the carbon footprint of rice production and consumption in Hubei, China: A life cycle assessment and uncertainty analysis approach

This study aimed to quantify greenhouse gas emissions derived from the production-consumption of rice in Hubei—a major rice-producing province in central China. This research employed primary and secondary data collection methods. Primary data sources included interviews and experimental observations from seven counties in Hubei collected from June 2016 to December 2016. Secondary data sources—including national datasets, inter-governmental reports, and peer-reviewed articles—were used to extract relevant data, such as emission factors, and national and provincial rice output. Life Cycle Assessment was employed to build a comprehensive inventory and map of the rice carbon footprint, including the following five stages: production inputs, farm management, growth period, processing and sale, and consumption. Uncertainty analysis was performed to validate the reliability of carbon footprint estimations. Results showed that the carbon footprint for every 1 ton of polished rice in Hubei ranged between 4.19–6.81 t CO2e/t and was 5.39 t CO2e/t on average. Greenhouse gas emissions were primarily produced from rice fields during the growth stage (over 60% of greenhouse gas emissions of the whole life cycle of rice), followed by the consumption stage, and the production and transportation of agricultural inputs. Uncertainty analysis estimations indicated acceptable levels of reliability. This study's results indicate that the production and consumption of rice is a significant contributor to agricultural carbon emissions in Hubei—consistent with national estimates that place China as the largest carbon dioxide emitter globally. This research provides further insight into future policies and targeted initiatives for the efficient use of low-carbon agricultural inputs for rice production and consumption stages in China.

USO DA TÉCNICA DE BOOSTING PARA PREVISÃO DE CONSUMO DE COMBUSTÍVEL DE UMA FROTA DE NAVIOS

Forecasting fuel consumption is of great importance for shipping, as it allows for more efficient fuel management, being an excellent tool to assist in decision making regarding operational measures to improve the energy efficiency of the fleet. Companies linked to shipping are increasingly under pressure to reduce the cost of travel while increasing energy efficiency and reducing the amount of greenhouse gas emissions. The purpose of this paper is to present models to predict the fuel oil consumption of a fleet of vessels, with low forecast errors, using the machine learning technique boosting.

Optimal design of a sustainable natural gas supply chain network under uncertainty

This study proposes a multi-objective mathematical model to design a natural gas supply chain network with a focus on sustainable development goals. Based on the economic objective of the proposed model, an attempt is made to minimize the whole supply chain costs. The environmental objective minimizes the amount of greenhouse gas emissions, electricity consumption, gas consumption, water consumption, and wastewater generation. The social objective also considers balanced employment, balanced economic development, employee welfare, employee safety, customers cost risk, and operational environment risk. Because parameters in the real world are uncertain and can rarely be estimated precisely, the uncertainty of the model parameters is taken into account. A four-stage solution approach is used to solve the proposed model. In the first step, the best-worst method is used to weight the layers in geographic information system (GIS) software. In the second step, the suggested city gate stations are determined in GIS software. In the third step, a robust possibilistic programming method is used to deal with the uncertainty of the parameters. Finally, in the fourth step, the Torabi–Hassini method is used to transform the multi-objective model into a single-objective one. In order to evaluate the efficiency of the proposed model, a real case study is conducted on Fars Province Gas Company. Numerical results confirm the efficiency of the proposed model, revealing that the uncertainty associated with the model parameters cannot be ignored because system costs are significantly affected under uncertainty. Moreover, the capacity parameter of the suggested city gate station could have a significant effect on system costs while the largest share of supply chain costs is related to transmission fixed costs.

건설부문의 온실가스 배출량 산정 및 배출 특성 연구

Global warning and climate change adaptation policies have become a major issue for all nations. To establish and implement a GHG (Greenhouse gas) reduction plan in the construction sector, we need to secure data for actual GHG emissions. However, information on energy consumption and GHG emissions in the construction sector is lacking. The purpose of this study is to calculate 1) GHG emissions generated in the construction sector, 2) the annual variation in emissions, and 3) emission characteristics from emission intensity of the construction sector. This study provides information on the amount of GHG emissions and its characteristics within the construction industry and in the overall view. As a result of GHG emissions calculations from the construction sector, GHG emissions in 2007 were 2.51 million ton CO<SUB>2-eq</SUB>, almost the same as the emission reported by the government. Annual GHG emissions have decreased at a mean rate of (-)1.2% from 2006 until 2019. The calculated emission intensity of the construction sector was about 0.02 ton CO<SUB>2-eq</SUB>/million KRW, showing a continuously decreasing tendency until 2019, at an annual mean rate of (-)0.3%.

Emission Abatement Technology Selection, Routing and Speed Optimization of Hybrid Ships

This paper evaluates the effect of a large-capacity electrical energy storage, e.g., Li-ion battery, on optimal sailing routes, speeds, fuel choice, and emission abatement technology selection. Despite rapid cost reduction and performance improvement, current Li-ion chemistries are infeasible for providing the total energy demand for ocean-crossing ships because the energy density is up to two orders of magnitude less than in liquid hydrocarbon fuels. However, limited distance zero-emission port arrival, mooring, and port departure are attainable. In this context, we formulate two groups of numerical problems. First, the well-known Emission Control Area (ECA) routing problem is extended with battery-powered zero-emission legs. ECAs have incentivized ship operators to choose longer distance routes to avoid using expensive low sulfur fuel required for compliance, resulting in increased greenhouse gas (GHG) emissions. The second problem evaluates the trade-off between battery capacity and speed on battery-powered zero-emission port arrival and departure legs. We develop a mixed-integer quadratically constrained program to investigate the least cost system configuration and operation. We find that the optimal speed is up to 50% slower on battery-powered legs compared to the baseline without zero-emission constraint. The slower speed on the zero-emission legs is compensated by higher speed throughout the rest of the voyage, which may increase the total amount of GHG emissions.