scholarly journals Comparative analysis and estimation of amounts of exhaust gas waste heat from the Tier III-compliant dual-fuel low-speed marine main engines

Pomorstvo ◽  
2021 ◽  
Vol 35 (1) ◽  
pp. 128-140
Author(s):  
Piotr Kamil Korlak
Keyword(s):  
Comparative Analysis ◽  
Co2 Emissions ◽  
Least Squares Method ◽  
Waste Heat ◽  
Emissions Reduction ◽  
Exhaust Gas ◽  
Ambient Conditions ◽  
Medium Speed ◽  
Technical Solutions ◽  
The Impact

Existing and future IMO restrictions on emission of harmful substances contained in exhaust gas have introduced an obligation to implement technical solutions to reduce NOX, SOX and CO2 emissions. Reduction in NOX and SOX emissions has been achieved by systems (i.e. SCR and EGR) ensuring Tier III-compliant exhaust gas composition. SCR and EGR systems have also affected the amount of exhaust gas waste heat. Therefore reduction in CO2 emissions has mostly been dependent on available amount of exhaust gas waste heat to produce electricity using waste heat recovery generator unit instead of medium-speed diesel generating set. Comparative analysis of amounts of exhaust gas waste heat in LNG and MGO modes under ISO ambient conditions has been carried out with particular emphasis on the impact of different variants of SCR and EGR systems. Formulae to estimate the amounts of exhaust gas waste heat have been determined using least squares method.

scholarly journals Localize the Impact of Global Greenhouse Gases Emissions under an Uncertain Future: A Case Study in Western Cape, South Africa

Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 111-123
Author(s):  
Bowen He ◽  
Ke J. Ding
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Co2 Emissions ◽  
Ghg Emissions ◽  
Future Climate ◽  
Emissions Reduction ◽  
Western Cape ◽  
Emissions Scenarios ◽  
Rcp 8.5 ◽  
The Impact

The growing impact of CO2 and other greenhouse-gas (GHG) emissions on the socio-climate system in the Western Cape, South Africa, urgently calls for the need for better climate adaptation and emissions-reduction strategies. While the consensus has been that there is a strong correlation between CO2 emissions and the global climate system, few studies on climate change in the Western Cape have quantified the impact of climate change on local climate metrics such as precipitation and evaporation under different future climate scenarios. The present study investigates three different CO2 emissions scenarios: Representative Concentration Pathway (RCP) 2.6, RCP 4.5, and RCP 8.5, from moderate to severe, respectively. Specifically, we used climate metrics including precipitation, daily mean and maximum near-surface air temperature, and evaporation to evaluate the future climate in Western Cape under each different RCP climate scenario. The projected simulation results reveal that temperature-related metrics are more sensitive to CO2 emissions than water-related metrics. Districts closer to the south coast are more resilient to severer GHG emissions scenarios compared to inland areas regarding temperature and rainfall; however, coastal regions are more likely to suffer from severe droughts such as the “Day-Zero” water crisis. As a result, a robust drying signal across the Western Cape region is likely to be seen in the second half of the 21st century, especially under the scenario of RCP 8.5 (business as usual) without efficient emissions reduction policies.

scholarly journals The impact of COVID-19 on CO2 emissions in the Los Angeles and Washington DC/Baltimore metropolitan areas 

2021 ◽  
Author(s):  
Anna Karion ◽  
Vineet Yadav ◽  
Subhomoy Ghosh ◽  
Kimberly Mueller ◽  
Geoffrey Roest ◽  
...  
Keyword(s):  
Los Angeles ◽  
Co2 Emissions ◽  
Atmospheric Co2 ◽  
Emissions Reduction ◽  
Washington Dc ◽  
Gas Consumption ◽  
Model Dependency ◽  
Carbon Dioxide Co2 ◽  
Urban Emissions ◽  
The Impact

<div> <div> <div> <p>Responses to COVID-19 have resulted in unintended reductions of city-scale carbon dioxide (CO2) emissions. Here we detect and estimate decreases in CO2 emissions in Los Angeles and Washington DC/Baltimore during March and April 2020. Our analysis uses three lines of evidence with increasing model dependency. The first detects the timing of emissions declines using the variability in atmospheric CO2 observations, the second assesses the continuation of reduced emissions using CO2 enhancements, and the third employs an inverse model to estimate the relative emissions changes in 2020 compared to 2018 and 2019. Emissions declines began in mid-March in both cities. The March decrease (25%) in Washington DC/Baltimore is largely supported by a drop in natural gas consumption associated with a warm spring whereas the decrease in April (33%) correlates with changes in gasoline fuel sales, a proxy for vehicular emissions. In contrast, only a fraction of the March (17%) and April (34%) reduction in Los Angeles is explained by traffic declines, while the remainder of the emissions reduction remains unexplained. To help diagnose such observed changes in emissions, more reliable, publicly available emission information from all significant sectors needs to be made available. Methods and measurements used herein highlight the advantages of atmospheric CO2 observations for providing timely insights into rapidly changing urban emissions patterns that can empower cities to course-correct mitigation activities more efficiently.</p> </div> </div> </div>

scholarly journals Analysis of thermal parameters of heat storages for use in vehicles with combustion engines

2019 ◽  
Vol 179 (4) ◽  
pp. 119-125
Author(s):  
Przemysław MĘŻYK ◽  
Grzegorz PRZYBYŁA ◽  
Karolina PETELA
Keyword(s):  
Internal Combustion Engine ◽  
Waste Heat ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Winter Conditions ◽  
Military Vehicle ◽  
Combat Vehicle ◽  
The Impact

The propulsion system of a vehicle using an internal combustion engine generates a significant amount of waste heat during operation, which is almost entirely discharged into the environment without any useful effect. One of the ways of using waste heat is storing it, and then using, for example, when starting the engine in winter conditions. The application of the indicated solution, in particular for the combat vehicle will allow to reduce the effects of cold start and will shorten the time of preparing such a vehicle for combat operations. The article presents: types of heat accumulators that could be used in a military vehicle, the results of preliminary tests carried out on the test stand and the impact of an additional heat source on the time of heating the internal combustion engine and on emission of exhaust gas components.

scholarly journals Performance Analysis for Mechanical Draft Cooling Tower

2009 ◽  
Author(s):  
Si Y. Lee ◽  
James S. Bollinger ◽  
Alfred J. Garrett ◽  
Larry D. Koffman
Keyword(s):  
Water Droplet ◽  
Cooling Tower ◽  
Waste Heat ◽  
National Laboratory ◽  
Ambient Air ◽  
Savannah River ◽  
Ambient Conditions ◽  
Integral Test ◽  
Counter Current ◽  
The Impact

Industrial processes use mechanical draft cooling towers (MDCT’s) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT’s consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

scholarly journals The Impact of Direct and Indirect COVID-19 Related Demand Shocks on Sectoral CO2 Emissions: Evidence from Major Asia Pacific Countries

2021 ◽  
Vol 13 (16) ◽  
pp. 9312 ◽  
Author(s):  
Muhammad Jawad Sajid ◽  
Ernesto D. R. Santibanez Gonzalez
Keyword(s):  
Co2 Emissions ◽  
Negative Impact ◽  
Extraction Methods ◽  
Policy Implications ◽  
Asia Pacific ◽  
Emissions Reduction ◽  
Case Scenario ◽  
Worst Case ◽  
Demand Shocks ◽  
The Impact

COVID-19’s demand shocks have a significant impact on global CO2 emissions. However, few studies have estimated the impact of COVID-19’s direct and indirect demand shocks on sectoral CO2 emissions and linkages. This study’s goal is to estimate the impact of COVID-19’s direct and indirect demand shocks on the CO2 emissions of the Asia-Pacific countries of Bangladesh, China, India, Indonesia, and Pakistan (BCIIP). The study, based on the Asian Development Bank’s COVID-19 economic impact scenarios, estimated the impact of direct and indirect demand shocks on CO2 releases using input–output and hypothetical extraction methods. In the no COVID-19 scenario, China emitted the most CO2 (11 billion tons (Bt)), followed by India (2 Bt), Indonesia (0.5 Bt), Pakistan (0.2 Bt), and Bangladesh (0.08 Bt). For BCIIP nations, total demand shocks forced a 1–2% reduction in CO2 emissions under a worst-case scenario. Given BCIIP’s current economic recovery, a best or moderate scenario with a negative impact of less than 1% is more likely in coming years. Direct demand shocks, with a negative 85–63% share, caused most of the CO2 emissions decrease. The downstream indirect demand had only a 15–37% contribution to CO2 emissions reduction. Our study also discusses policy implications.

scholarly journals Waste heat recovery at the glass industry with the intervention of batch and cullet preheating

2016 ◽  
Vol 20 (4) ◽  
pp. 1245-1258 ◽  
Author(s):  
Ioannis Dolianitis ◽  
Dionysios Giannakopoulos ◽  
Christina-Stavrula Hatzilau ◽  
Sotirios Karellas ◽  
Emmanuil Kakaras ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
Glass Furnace ◽  
Specific Energy ◽  
Flue Gas ◽  
Waste Heat ◽  
Specific Energy Consumption ◽  
Container Glass ◽  
Gas Temperature ◽  
The Impact

A promising option to reduce the specific energy consumption and CO2 emissions at a conventional natural gas fired container glass furnace deals with the advanced utilization of the exhaust gases downstream the air regenerators by means of batch and cullet preheating. A 3-dimensional computational model that simulates this process using mass and heat transfer equations inside a preheater has been developed. A case study for an efficient small-sized container glass furnace is presented dealing with the investigation of the impact of different operating and design configurations on specific energy consumption, CO2 emissions, flue gas energy recovery, batch temperature and preheater efficiency. In specific, the effect of various parameters is studied, including the preheater?s dimensions, flue gas temperature, batch moisture content, glass pull, combustion air excess and cullet fraction. Expected energy savings margin is estimated to 12-15%.

scholarly journals Daily CO<sub>2</sub> emission for China's provinces in 2019 and 2020

2021 ◽  
Author(s):  
Duo Cui ◽  
Zhu Liu ◽  
CunCun Duan ◽  
Zhu Deng ◽  
Xiangzheng Deng ◽  
...  
Keyword(s):  
High Resolution ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Energy Transition ◽  
Emissions Reduction ◽  
Provincial Level ◽  
Industrial Sectors ◽  
Spring Festival ◽  
The Impact ◽  
First Time

Abstract. Tracking China's national and regional CO2 emission trends is becoming ever more crucial. The country recently pledged to achieve ambitious emissions reduction targets, however, high-resolution datasets for provincial level CO2 emissions in China are still lacking. This study provides daily CO2 emission datasets for China's 31 provinces, including for the first time, the province of Tibet. The inventory covers the emissions from three industrial sectors (power, industry and ground transport) during 2019 to 2020, with its temporal resolution at a daily level. In addition, the variations in CO2 emissions for seasonal, weekly and holiday periods have been uncovered at a provincial level for the first time. This new data was added to further analyze the impact that weekends and holidays have on China's CO2 emissions. Over weekend periods, carbon emissions are shown to reduce by around 3%. Spring Festival meanwhile, has the greatest impact on the reduction of China's CO2 emissions. This detailed and time-related inventory will facilitate a more local and adaptive management of China’s CO2 emissions during both the COVID-19 pandemic’s recovery and the ongoing energy transition. The data are archived at https://doi.org/10.5281/zenodo.4730175 (Cui et al., 2021).

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