scholarly journals A Comparative Analysis of EEDI Versus Lifetime CO2 Emissions

2020 ◽  
Vol 8 (1) ◽  
pp. 61 ◽  
Author(s):  
Nikoletta L. Trivyza ◽  
Athanasios Rentizelas ◽  
Gerasimos Theotokatos

The Energy Efficiency Design Index (EEDI) was introduced as a regulatory tool employed at the ship design phase to reduce the carbon dioxide (CO2) emissions and increase the vessel’s operational efficiency. Although it stimulated the greening of the shipping operations, its effectiveness is considerably criticised from various shipping industry stakeholders. The aim of this study is to investigate the EEDI effectiveness on accurately representing the environmental performance of the next-generation ships power plants for two representative ship types, in specific, an ocean-going tanker and a cruise ship. The performance of the optimal power plant solutions identified in previous studies is analysed according to the existing EEDI regulatory framework and compared with the lifetime CO2 emissions estimated based on an actual operating profile for each ship. The results indicate that the EEDI underestimates the effect of technologies for reducing carbon emissions in all the investigated cases. In this respect, it is concluded that EEDI is classified as a conservative metric, which however can be used as an approximation to compare alternative solutions early in the design phase.

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 278
Author(s):  
Ernest Czermański ◽  
Giuseppe T. Cirella ◽  
Aneta Oniszczuk-Jastrząbek ◽  
Barbara Pawłowska ◽  
Theo Notteboom

Container shipping is the largest producer of emissions within the maritime shipping industry. Hence, measures have been designed and implemented to reduce ship emission levels. IMO’s MARPOL Annex VI, with its future plan of applying Tier III requirements, the Energy Efficiency Design Index for new ships, and the Ship Energy Efficiency Management Plan for all ships. To assist policy formulation and follow-up, this study applies an energy consumption approach to estimate container ship emissions. The volumes of sulphur oxide (SOx), nitrous oxide (NOx), particulate matter (PM), and carbon dioxide (CO2) emitted from container ships are estimated using 2018 datasets on container shipping and average vessel speed records generated via AIS. Furthermore, the estimated reductions in SOx, NOx, PM, and CO2 are mapped for 2020. The empirical analysis demonstrates that the energy consumption approach is a valuable method to estimate ongoing emission reductions on a continuous basis and to fill data gaps where needed, as the latest worldwide container shipping emissions records date back to 2015. The presented analysis supports early-stage detection of environmental impacts in container shipping and helps to determine in which areas the greatest potential for emission reductions can be found.


2019 ◽  
Vol 1 (3) ◽  
pp. 174-180 ◽  
Author(s):  
Bandiyah Sri Aprillia ◽  
Desri Kristina Silalahi ◽  
Muhammad Agung Foury Rigoursyah

Electricity demand increases along with an increasing population. Renewable energy power plants are experiencing an increase in their use. This increase occurred because the world's electricity needs are rising every year, so the development of renewable energy power plants continues. Indonesia's state-owned power plants supply electricity more from non-renewable energy sources than renewable energy sources. Therefore, there is a need for renewable energy sources that can supply electricity in Indonesia. This research discusses an efficient renewable energy system for residential and the total installation costs for on-grid systems in Bandung, Indonesia. The research method used is collecting solar radiation data, equipment specifications and other data needed and then optimized. The simulation model uses HOMER software. HOMER is used to determine the best technically estimated cost, payback period, and NPC. Based on the optimization results, the system configuration can supply the electricity load 45.5% of daily load consumption with a total NPC cost is 75,300,000 million with a payback period of 7 years. In addition, the on-grid system produces 1400 kg of carbon dioxide (CO2) emissions per year from diesel generators, lower than the CO2 emissions from systems that only comprise diesel generators reaching 114 tons per year.    


2020 ◽  
Vol 20 (14) ◽  
pp. 8501-8510 ◽  
Author(s):  
Bo Zheng ◽  
Frédéric Chevallier ◽  
Philippe Ciais ◽  
Grégoire Broquet ◽  
Yilong Wang ◽  
...  

Abstract. In order to track progress towards the global climate targets, the parties that signed the Paris Climate Agreement will regularly report their anthropogenic carbon dioxide (CO2) emissions based on energy statistics and CO2 emission factors. Independent evaluation of this self-reporting system is a fast-growing research topic. Here, we study the value of satellite observations of the column CO2 concentrations to estimate CO2 anthropogenic emissions with 5 years of the Orbiting Carbon Observatory-2 (OCO-2) retrievals over and around China. With the detailed information of emission source locations and the local wind, we successfully observe CO2 plumes from 46 cities and industrial regions over China and quantify their CO2 emissions from the OCO-2 observations, which add up to a total of 1.3 Gt CO2 yr−1 that accounts for approximately 13 % of mainland China's annual emissions. The number of cities whose emissions are constrained by OCO-2 here is 3 to 10 times larger than in previous studies that only focused on large cities and power plants in different locations around the world. Our satellite-based emission estimates are broadly consistent with the independent values from China's detailed emission inventory MEIC but are more different from those of two widely used global gridded emission datasets (i.e., EDGAR and ODIAC), especially for the emission estimates for the individual cities. These results demonstrate some skill in the satellite-based emission quantification for isolated source clusters with the OCO-2, despite the sparse sampling of this instrument not designed for this purpose. This skill can be improved by future satellite missions that will have a denser spatial sampling of surface emitting areas, which will come soon in the early 2020s.


Author(s):  
Abhishek P. Ratanpara ◽  
Alexander Shaw ◽  
Sanat Deshpande ◽  
Myeongsub Kim

Abstract As the consumption of fossil fuel resources has continuously increased to meet global fuel demands for power generation, atmospheric emissions of greenhouse gases, particularly carbon dioxide (CO2), have rapidly increased over the last century. Increased CO2 emissions have caused serious international concerns about global warming, sea-level rise, and ocean acidification. Although post-combustion carbon capture technology that separates CO2 from flue gas in fossil fuel-fired power plants has contributed to significant migration of atmospheric CO2 emissions, this approach generates considerable amounts of toxic wastewater containing a heavy chemical which is difficult to treat, raises concerns about acute corrosion of metal structures in the facility, and waste of significant amounts of freshwater. In this research, we are particularly interested in reducing the use of freshwater for CO2 capture and generating carbonate minerals, byproducts of CO2 with calcium (Ca2+) or magnesium ions (Mg2+) in ocean water which are useful building blocks for marine animals, such as seashells and coral reefs. In our experimental approach, we attempted to use ocean water with different monoethanolamine (MEA) concentrations and compared the CO2 capturing efficiency with that in DI water. We found that there are considerable benefits of the use of ocean water in CO2 dissolution, showing that a replacement of freshwater with ocean water would be a possible option. In the future, we will further enhance the dissolution of CO2 in ocean water by using nanoparticle catalysts without using MEA, which will be an environmentally friendly method for CO2 capture.


2020 ◽  
Author(s):  
Bo Zheng ◽  
Frederic Chevallier ◽  
Philippe Ciais ◽  
Gregoire Broquet ◽  
Yilong Wang ◽  
...  

Abstract. In order to track progress towards the global climate targets, the parties that signed the Paris Climate Agreement will regularly report their anthropogenic carbon dioxide (CO2) emissions based on energy statistics and CO2 emission factors. Independent evaluation of this self-reporting system is a fast-growing research topic. Here, we study the value of satellite observations of the column CO2 concentrations to estimate CO2 anthropogenic emissions with five years of the Orbiting Carbon Observatory-2 (OCO-2) retrievals over and around China. With the detailed information of emission source locations and the local wind, we successfully observe CO2 plumes from 60 cities and industrial regions over China and quantify their CO2 emissions from the OCO-2 observations, which add up to a total of 1.6 Gt CO2 yr−1 that account for 17 % of mainland China's annual emissions. The number of cities whose emissions are constrained by OCO-2 here is three to ten times larger than previous studies that only focused on large cities and power plants in different locations around the world. Our satellite-based emission estimates are broadly consistent with the independent values from the detailed China's emission inventory MEIC, but are more different from those of two widely used global gridded emission datasets (i.e., EDGAR and ODIAC), especially for the emission estimates for the individual cities. These results demonstrate some skill in the satellite-based emission quantification for isolated source clusters with the OCO-2, despite the sparse sampling of this instrument not designed for this purpose. This skill can be improved by future satellite missions that will have a denser spatial sampling of surface emitting areas, which will come soon in the early 2020s.


2017 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Luiz Fernando Rosa Mendes ◽  
Marcelo Silva Sthel

Brazil has abundant water resources and depends on them for hydroelectric power generation. In 2011, 81.9% of the electricity in the country was produced by hydropower. A significant change in the Brazilian hydrological cycle reduced this percentage to 64% in 2015. The scarcity of rain decreased the volumes in the reservoirs of the hydroelectric power plants located mainly in the Southeast, Center-West and Northeast regions. In this scenario, the National Operator System authorized the use in full load of thermoelectric plants powered by natural gas, biomass and coal. As a result, thermoelectric generation grew 329%, increasing carbon dioxide (CO2) emissions. The intensification in the use of thermoelectric energy leads to a vicious energy–environment cycle, as it increases the CO2 emissions. Brazilian government is aware of the necessity of electricity generation, and future uncertainties generated by the instabilities of hydrological cycles may jeopardize the country’s energy security. The country has proposed programs to encourage energy generation by other renewable sources (wind and solar) and avoid the use of thermoelectric plants, which increase the generation costs and environmental impacts. This could compromise the goals of reducing carbon emissions signed by Brazil at Paris Conference (COP21).


2020 ◽  
Vol 8 (3) ◽  
pp. 221 ◽  
Author(s):  
Joel R. Perez ◽  
Carlos A. Reusser

Nowadays, marine propulsion systems based on thermal machines that operate under the diesel cycle have positioned themselves as one of the main options for this type of applications. The main comparative advantages of diesel engines, compared to other propulsion systems based on thermal cycle engines, are the low specific fuel consumption of residual fuels, and their higher thermal efficiency. However, its main disadvantage lies in the emissions produced by the combustion of the residual fuels, such as carbon dioxide (CO2), sulfur oxide (SOx), and nitrogen oxide (NOx). These emissions are directly related to the operating conditions of the propulsion system. Over the last decade, the International Maritime Organization (IMO) has adopted a series of regulations to reduce CO2 emissions based on the introduction of an Energy Efficiency Design Index (EEDI) and an Energy Efficiency Operational Indicator (EEOI). In this context, adding a Shaft Generator (SG) to the propulsion system favoring lower EEDI and EEOI values. The present work proposes a selective control system and optimization scheme that allows operating the shaft generator in Power Take Off (PTO) or Power Take In (PTI) mode, ensuring that the main engine operates, always, at the optimum fuel efficiency point, thus ensuring minimum CO2 emissions.


Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 246
Author(s):  
Kang-Min Kim ◽  
Gyu-Bo Kim ◽  
Byoung-Hwa Lee ◽  
Yoon-Ho Bae ◽  
Chung-Hwan Jeon

The need to reduce global carbon dioxide (CO2) emissions is driving the conversion of coal-fired power plants to use methane, which can reduce CO2 emissions by >40%. However, conducting gas firing in coal boilers changes the heat transfer profile; therefore, preliminary evaluations using computational fluid dynamics are required prior to conversion. Here, methane was used as a heat input source in the simulation of an existing coal boiler, and combustion, nitrogen oxides (NOx) emission characteristics, and heat transfer profile changes inside the boiler were analyzed. Furthermore, changes in the burner zone stoichiometric ratio (BZSR) were simulated to restore the decreased heat absorption of the furnace waterwall, revealing that air distribution could change the heat absorption of the waterwall and tube bundles. However, this change was smaller than that caused by conversion from coal to methane. Therefore, to implement gas firing in coal boilers, alternatives such as output derating, using an attemperator, or modifying heat transfer surfaces are necessary. Despite these limitations, a 70% reduction in NOx emissions was achieved at a BZSR of 0.76, compared with coal. As the BZSR contributes significantly to NOx emissions, conducting gas firing in existing coal boilers could significantly reduce NOx and CO2 emissions.


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