scholarly journals CFD Evaluation of Heat Transfer and NOx Emissions When Converting a Tangentially Fired Coal Boiler to Use Methane

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 246
Author(s):  
Kang-Min Kim ◽  
Gyu-Bo Kim ◽  
Byoung-Hwa Lee ◽  
Yoon-Ho Bae ◽  
Chung-Hwan Jeon
Keyword(s):  
Heat Transfer ◽  
Co2 Emissions ◽  
Power Plants ◽  
Stoichiometric Ratio ◽  
Nox Emissions ◽  
Heat Absorption ◽  
Input Source ◽  
Profile Changes ◽  
Coal Boiler ◽  
Carbon Dioxide Co2

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.

scholarly journals Desain Sistem On-Grid Energi Terbarukan Skala Rumah Tangga Menggunakan Perangkat Lunak HOMER

2019 ◽  
Vol 1 (3) ◽  
pp. 174-180 ◽  
Author(s):  
Bandiyah Sri Aprillia ◽  
Desri Kristina Silalahi ◽  
Muhammad Agung Foury Rigoursyah
Keyword(s):  
Renewable Energy ◽  
Co2 Emissions ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Energy System ◽  
Payback Period ◽  
Energy Sources ◽  
Grid Systems ◽  
Diesel Generators ◽  
Carbon Dioxide Co2

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.    

scholarly journals Observing carbon dioxide emissions over China's cities and industrial areas with the Orbiting Carbon Observatory-2

2020 ◽  
Vol 20 (14) ◽  
pp. 8501-8510 ◽  
Author(s):  
Bo Zheng ◽  
Frédéric Chevallier ◽  
Philippe Ciais ◽  
Grégoire Broquet ◽  
Yilong Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Global Climate ◽  
Large Cities ◽  
Independent Evaluation ◽  
Paris Climate Agreement ◽  
Carbon Dioxide Co2 ◽  
The Individual

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.

Utilization of Ocean Water for CO2 Capture via Amine Scrubbing

2020 ◽  
Author(s):  
Abhishek P. Ratanpara ◽  
Alexander Shaw ◽  
Sanat Deshpande ◽  
Myeongsub Kim
Keyword(s):  
Co2 Emissions ◽  
Co2 Capture ◽  
Carbon Capture ◽  
Power Plants ◽  
Fossil Fuel ◽  
Building Blocks ◽  
Ocean Water ◽  
Marine Animals ◽  
Co2 Capturing ◽  
Carbon Dioxide Co2

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.

scholarly journals A methodology to constrain carbon dioxide emissions from coal-fired power plants using satellite observations of co-emitted nitrogen dioxide

2020 ◽  
Vol 20 (1) ◽  
pp. 99-116 ◽  
Author(s):  
Fei Liu ◽  
Bryan N. Duncan ◽  
Nickolay A. Krotkov ◽  
Lok N. Lamsal ◽  
Steffen Beirle ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Power Plants ◽  
Operating Conditions ◽  
Satellite Observations ◽  
Nox Emissions ◽  
Bottom Up ◽  
Monitoring Instrument ◽  
The Us

Abstract. We present a method to infer CO2 emissions from individual power plants based on satellite observations of co-emitted nitrogen dioxide (NO2), which could serve as complementary verification of bottom-up inventories or be used to supplement these inventories. We demonstrate its utility on eight large and isolated US power plants, where accurate stack emission estimates of both gases are available for comparison. In the first step of our methodology, we infer nitrogen oxides (NOx) emissions from US power plants using Ozone Monitoring Instrument (OMI) NO2 tropospheric vertical column densities (VCDs) averaged over the ozone season (May–September) and a “top-down” approach that we previously developed. Second, we determine the relationship between NOx and CO2 emissions based on the direct stack emissions measurements reported by continuous emissions monitoring system (CEMS) programs, accounting for coal quality, boiler firing technology, NOx emission control device type, and any change in operating conditions. Third, we estimate CO2 emissions for power plants using the OMI-estimated NOx emissions and the CEMS NOx∕CO2 emission ratio. We find that the CO2 emissions estimated by our satellite-based method during 2005–2017 are in reasonable agreement with the US CEMS measurements, with a relative difference of 8 %±41 % (mean ± standard deviation). The broader implication of our methodology is that it has the potential to provide an additional constraint on CO2 emissions from power plants in regions of the world without reliable emissions accounting. We explore the feasibility by comparing the derived NOx∕CO2 emission ratios for the US with those from a bottom-up emission inventory for other countries and applying our methodology to a power plant in South Africa, where the satellite-based emission estimates show reasonable consistency with other independent estimates. Though our analysis is limited to a few power plants, we expect to be able to apply our method to more US (and world) power plants when multi-year data records become available from new OMI-like sensors with improved capabilities, such as the TROPOspheric Monitoring Instrument (TROPOMI), and upcoming geostationary satellites, such as the Tropospheric Emissions: Monitoring Pollution (TEMPO) instrument.

scholarly journals Observing carbon dioxide emissions over China's cities with the Orbiting Carbon Observatory-2

2020 ◽  
Author(s):  
Bo Zheng ◽  
Frederic Chevallier ◽  
Philippe Ciais ◽  
Gregoire Broquet ◽  
Yilong Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Global Climate ◽  
Large Cities ◽  
Independent Evaluation ◽  
Paris Climate Agreement ◽  
Carbon Dioxide Co2 ◽  
The Individual

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.

The Net Impact of Wind Energy Generation on Emissions of Carbon Dioxide in Texas

2012 ◽  
Author(s):  
Colin Meehan ◽  
Michael Webber ◽  
Kazunori Nagasawa
Keyword(s):  
Wind Energy ◽  
Co2 Emissions ◽  
Power Plants ◽  
Energy Generation ◽  
Energy Output ◽  
Wind Generation ◽  
Total System ◽  
Nox Emissions ◽  
Thermal Generation ◽  
Wind Energy Generation

This analysis will examine the relationship between increased levels of wind energy generation and emissions per unit of electricity produced using historical data for electricity output and CO2, SO2 and NOx emissions in the Electric Reliability Council of Texas (ERCOT). Renewable Portfolio Standards (RPS) are generally seen in part as a policy tool for reducing overall system CO2 emissions, although renewable energy goals do not directly regulate such emissions. Limiting this analysis to ERCOT provides two important advantages: transmission of wind energy output is constrained by the physical boundaries of the ERCOT grid, simplifying the analysis and avoiding associated ‘leakage issues’; and ERCOT has the highest level of wind generation as a percentage of total system demand of any grid in the continental U.S. The intermittent nature of wind generation has resulted in the need to ramp conventional thermal generation up and down to compensate for variability in wind output. Such ramping leads to inefficiencies in many fossil-fueled power plants that increase emissions of CO2, SO2, and NOx relative to a respective unit’s peak efficiency emissions rate. Using EPA’s Clean Air Markets hourly emissions data, we calculate the total combustion emissions of CO2, SO2 and NOx per MWh of electricity output for the ERCOT system from 2003–2011. The EPA database includes CO2, SO2 and NOx emissions reported by facility owner and operators on an hourly basis in a manner that incorporates facility inefficiencies during ramping periods, allowing us to fully evaluate the CO2 emissions reductions achieved in ERCOT as a result of increased wind generation. The study is ongoing as we wait for emissions statistics from the final quarter of 2011 to be released by the EPA in early 2012.

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
Keyword(s):  
Co2 Emissions ◽  
Environmental Performance ◽  
Power Plants ◽  
Design Phase ◽  
Cruise Ship ◽  
Shipping Industry ◽  
Optimal Power ◽  
Energy Efficiency Design Index ◽  
Carbon Dioxide Co2 ◽  
Alternative Solutions

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.

Thermoelectric Power Plant for Compensation of Hydrological Cycle Change: Environmental Impacts in Brazil

2017 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Luiz Fernando Rosa Mendes ◽  
Marcelo Silva Sthel
Keyword(s):  
Environmental Impacts ◽  
Co2 Emissions ◽  
Power Plants ◽  
Hydrological Cycle ◽  
Hydroelectric Power ◽  
Brazilian Government ◽  
Energy Environment ◽  
Generation Costs ◽  
Hydrological Cycles ◽  
Carbon Dioxide Co2

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).

scholarly journals A methodology to constrain carbon dioxide emissions from coal-fired power plants using satellite observations of co-emitted nitrogen dioxide

2019 ◽  
Author(s):  
Fei Liu ◽  
Bryan N. Duncan ◽  
Nickolay A. Krotkov ◽  
Lok N. Lamsal ◽  
Steffen Beirle ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Operating Conditions ◽  
Satellite Observations ◽  
Nox Emissions ◽  
Ozone Monitoring Instrument ◽  
Total Uncertainty ◽  
Monitoring Instrument

Abstract. We present a novel method to infer CO2 emissions from individual power plants based on satellite observations of co-emitted nitrogen dioxide (NO2) and demonstrate its utility on US power plants, where accurate stack emission estimates of both gases are available for comparison. In the first step of our methodology, we infer nitrogen oxides (NOx) emissions from isolated power plants using Ozone Monitoring Instrument (OMI) NO2 tropospheric vertical column densities (VCDs) averaged over the ozone season (May–September) and a "top-down" approach that we previously developed. Second, we determine the relationship between NOx and CO2 emissions based on the direct stack emissions measurements reported by continuous emissions monitoring system (CEMS) programs, accounting for coal type, boiler firing type, NOx emission control device type, and changes in operating conditions. Third, we estimate CO2 emissions of the ozone season for a plant using the OMI-estimated NOx emissions and the CEMS NOx / CO2 emission ratio. We find that the CO2 emissions estimated by our satellite-based method during 2005–2017 are in reasonable agreement with the CEMS measurements, with a relative difference of 8 % ± 41 % (mean ± standard deviation) for the selected US power plants in our analysis. Total uncertainty in the inferred CO2 estimates is partly associated with the uncertainty associated with the OMI NO2 VCD data, so we expect that it will decrease when our method is applied to OMI-like sensors with improved capabilities, such as TROPOspheric Monitoring Instrument (TROPOMI) and geostationary Tropospheric Emissions: Monitoring Pollution (TEMPO). The broader implication of our methodology is that it has the potential to provide an additional constraint on CO2 emissions from power plants in regions of the world without reliable emissions accounting. We explore the feasibility by applying our methodology to a power plant in South Africa, where the satellite-based emission estimates show reasonable consistency with other estimates.

Sign in / Sign up

Export Citation Format

Share Document