scholarly journals Observations of atmospheric <sup>14</sup>CO<sub>2</sub> at Anmyeondo GAW station, South Korea: implications for fossil fuel CO<sub>2</sub> and emission ratios

2020 ◽  
Vol 20 (20) ◽  
pp. 12033-12045
Author(s):  
Haeyoung Lee ◽  
Edward J. Dlugokencky ◽  
Jocelyn C. Turnbull ◽  
Sepyo Lee ◽  
Scott J. Lehman ◽  
...  
Keyword(s):  
South Korea ◽  
Sulfur Hexafluoride ◽  
Fossil Fuel ◽  
Combustion Efficiency ◽  
Mean Value ◽  
Asian Continent ◽  
Air Masses ◽  
Air Samples ◽  
Carbon Dioxide Co2 ◽  
Emission Ratios

Abstract. To understand the Korean Peninsula's carbon dioxide (CO2) emissions and sinks as well as those of the surrounding region, we used 70 flask-air samples collected during May 2014 to August 2016 at Anmyeondo (AMY; 36.53∘ N, 126.32∘ E; 46 m a.s.l.) World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) station, located on the west coast of South Korea, for analysis of observed 14C in atmospheric CO2 as a tracer of fossil fuel CO2 contribution (Cff). Observed 14C ∕ C ratios in CO2 (reported as Δ values) at AMY varied from −59.5 ‰ to 23.1 ‰, with a measurement uncertainty of ±1.8 ‰. The derived mean value Cff of (9.7±7.8) µmol mol−1 (1σ) is greater than that found in earlier observations from Tae-Ahn Peninsula (TAP; 36.73∘ N, 126.13∘ E; 20 m a.s.l., 28 km away from AMY) of (4.4±5.7) µmol mol−1 from 2004 to 2010. The enhancement above background mole fractions of sulfur hexafluoride (Δx(SF6)) and carbon monoxide (Δx(CO)) correlate strongly with Cff (r>0.7) and appear to be good proxies for fossil fuel CO2 at regional and continental scales. Samples originating from the Asian continent had greater Δx(CO) : Cff(RCO) values, (29±8) to (36±2) nmol µmol−1, than in Korean Peninsula local air ((8±2) nmol µmol−1). Air masses originating in China showed (1.6±0.4) to (2.0±0.1) times greater RCO than a bottom-up inventory, suggesting that China's CO emissions are underestimated in the inventory, while observed RSF6 values are 2–3 times greater than inventories for both China and South Korea. However, RCO values derived from both inventories and observations have decreased relative to previous studies, indicating that combustion efficiency is increasing in both China and South Korea.

scholarly journals <sup>14</sup>C observations of atmospheric CO<sub>2</sub> at Anmyeondo GAW station, Korea: Implications for fossil fuel CO<sub>2</sub> and emission ratios

2020 ◽  
Author(s):  
Haeyoung Lee ◽  
Edward J. Dlugokencky ◽  
Jocelyn C. Turnbull ◽  
Sepyo Lee ◽  
Scott J. Lehman ◽  
...  
Keyword(s):  
South Korea ◽  
Sulfur Hexafluoride ◽  
Fossil Fuel ◽  
Combustion Efficiency ◽  
Mean Value ◽  
Asian Continent ◽  
Air Masses ◽  
Air Samples ◽  
Carbon Dioxide Co2 ◽  
Emission Ratios

Abstract. To understand Korea's carbon dioxide (CO2) emissions and sinks as well as those of the surrounding region, we used 70 flask-air samples collected during May 2014 to August 2016 at Anmyeondo (AMY, 36.53° N, 126.32° E; 46 m a.s.l.) World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) station, located on the west coast of South Korea, for analysis of observed 14C in atmospheric CO2 as a tracer of fossil fuel CO2 contribution (Cff). Observed 14C / C ratios in CO2 at AMY varied from −59.5 to 23.1 ‰ with the measurement uncertainty of ±1.8 ‰. The derived mean value Cff of (9.7 ± 7.8) μmol mol−1 (1σ) is greater than that found in earlier observations from Tae-Ahn Peninsula (TAP, 36.73° N, 126.13° E, 20 m a.s.l., 24 km away from AMY) of (4.4 ± 5.7) μmol mol−1 from 2004 to 2010. The enhancement above background of sulfur hexafluoride (Δx(SF6)) and carbon monoxide (Δx(CO)) correlate strongly with Cff (r > 0.7) and appear to be good proxies for fossil fuel CO2 at regional and continental scales. Samples originating from the Asian continent had greater Δx(CO) : Cff (RCO) values, (29 ± 8) to (36 ± 2) nmol μmol−1, than in Korean local air ((8 ± 2) nmol μmol−1). Air masses originating in China showed (1.8 ± 0.2) times greater RCO than a bottom-up inventory suggesting that China's CO emissions are underestimated in the inventory. However, both RCO derived from inventories and observations have decreased relative to previous studies, indicating that combustion efficiency is increasing in both China and South Korea.

scholarly journals Sub- and Supercritical Extraction of Slovenian Hops (Humulus lupulus L.) Aurora Variety Using Different Solvents

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1137
Author(s):  
Katja Bizaj ◽  
Mojca Škerget ◽  
Iztok Jože Košir ◽  
Željko Knez
Keyword(s):  
Sulfur Hexafluoride ◽  
Total Yield ◽  
Extraction Yield ◽  
Operating Conditions ◽  
Influence Of Process Parameters ◽  
Humulus Lupulus L ◽  
Bitter Acids ◽  
Temperature And Pressure ◽  
Carbon Dioxide Co2 ◽  
The Mathematical Model

This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO2), propane, sulfur hexafluoride (SF6), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated. The mathematical model based on Fick’s second law well described the experimental extraction results. Furthermore, HPLC analysis has been used to determine α- and β-acids in extracts. The yield of bitter compounds in hop extracts was largely influenced by the type of solvent, the temperature and pressure applied during extraction. The results show that CO2 and propane were roughly equivalent to DME in solvating power, while SF6 was a poor solvent at the same conditions. The highest yield as well as the highest concentration of bitter acids in extracts were obtained by using DME, where the optimal operating conditions were 40 °C and 100 bar for the extraction of α-acids (max. concentration 9.6%), 60 °C and 50 bar for the extraction of β-acids (4.5%) and 60 °C and 150 bar for the maximum extraction yield (25.6%).

scholarly journals Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

2005 ◽  
Vol 5 (11) ◽  
pp. 2989-3002 ◽  
Author(s):  
P. Guyon ◽  
G. P. Frank ◽  
M. Welling ◽  
D. Chand ◽  
P. Artaxo ◽  
...  
Keyword(s):  
Large Scale ◽  
Particle Number ◽  
Aerosol Particles ◽  
Secondary Growth ◽  
Combustion Efficiency ◽  
Vertical Transport ◽  
Airborne Measurements ◽  
Sampling Campaign ◽  
Wide Range ◽  
Emission Ratios

Abstract. As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign, we studied the emission of carbon monoxide (CO), carbon dioxide (CO2), and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN) relative to CO (ERCN/CO) fell in the range 14-32 cm-3 ppb-1 in most of the investigated smoke plumes. Particle number emission ratios have to our knowledge not been previously measured in tropical deforestation fires, but our results are in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependent on the fire conditions (combustion efficiency). Variability in ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2), which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, reflecting the fact that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF) for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC) fraction of emissions that are not sampled by the aircraft, which increased the EF by a factor of 1.5-2.1. Vertical transport of smoke from the boundary layer (BL) to the cloud detrainment layer (CDL) and the free troposphere (FT) was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non-precipitating clouds. The detrained aerosol particles released in the CDL and FT were larger than in the unprocessed smoke, mostly due to coagulation and secondary growth, and therefore more efficient at scattering radiation and nucleating cloud droplets. This process may have significant atmospheric implications on a regional and larger scale.

Thermo-Economic Analysis of Microalgae Co-Firing Process for Fossil Fuel-Fired Power Plants

2010 ◽  
Author(s):  
Jian Ma ◽  
Oliver Hemmers
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Power Plants ◽  
Fossil Fuel ◽  
Construction Materials ◽  
Ghg Emissions ◽  
Combustion Efficiency ◽  
Pure Oxygen ◽  
Firing Process ◽  
Microalgal Biomass

A thermoeconomic analysis of microalgae co-firing process for fossil fuel-fired power plants is studied. A process with closed photobioreactor and artificial illumination is evaluated for microalgae cultivation, due to its simplicity with less influence from climate variations. The results from this process would contribute to further estimation of process performance and investment. The concept of co-firing (coal-microalgae or natural gas-microalgae) includes the utilization of CO2 from power plant for microalgal biomass culture and oxy-combustion of using oxygen generated by biomass to enhance the combustion efficiency. As it reduces CO2 emission by recycling it and uses less fossil fuel, there are concomitant benefits of reduced GHG emissions. The by-products (oxygen) of microalgal biomass can be mixed with air or recycled flue gas prior to combustion, which will have the benefits of lower nitrogen oxide concentration in flue gas, higher efficiency of combustion, and not too high temperature (avoided by available construction materials) resulting from coal combustion in pure oxygen. Two case studies show that there are average savings about $0.386 million/MW/yr and $0.323 million/MW/yr for coal-fired and natural gas-fired power plants, respectively. These costs saving are economically attractive and demonstrate the promise of microalgae technology for reducing greenhouse gas (GHG) emission.

scholarly journals Evaluating the Causal Relations between the Kaya Identity Index and ODIAC-Based Fossil Fuel CO2 Flux

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6009
Author(s):  
YoungSeok Hwang ◽  
Jung-Sup Um ◽  
JunHwa Hwang ◽  
Stephan Schlüter
Keyword(s):  
Co2 Emissions ◽  
Fossil Fuel ◽  
Co2 Flux ◽  
Causal Relationships ◽  
Mediating Effects ◽  
Multiple Mediation ◽  
Open Source Data ◽  
Carbon Dioxide Co2 ◽  
The Individual ◽  
Kaya Identity

The Kaya identity is a powerful index displaying the influence of individual carbon dioxide (CO2) sources on CO2 emissions. The sources are disaggregated into representative factors such as population, gross domestic product (GDP) per capita, energy intensity of the GDP, and carbon footprint of energy. However, the Kaya identity has limitations as it is merely an accounting equation and does not allow for an examination of the hidden causalities among the factors. Analyzing the causal relationships between the individual Kaya identity factors and their respective subcomponents is necessary to identify the real and relevant drivers of CO2 emissions. In this study we evaluated these causal relationships by conducting a parallel multiple mediation analysis, whereby we used the fossil fuel CO2 flux based on the Open-Source Data Inventory of Anthropogenic CO2 emissions (ODIAC). We found out that the indirect effects from the decomposed variables on the CO2 flux are significant. However, the Kaya identity factors show neither strong nor even significant mediating effects. This demonstrates that the influence individual Kaya identity factors have on CO2 directly emitted to the atmosphere is not primarily due to changes in their input factors, namely the decomposed variables.

Preliminary Study on Combustion of Biodiesel for Power Generation

2006 ◽  
Author(s):  
Ee Sann Tan ◽  
Kumaran Palanisamy ◽  
Ibrahim Hussein ◽  
Farid Nasir Ani
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Fossil Fuel ◽  
Alternative Fuel ◽  
Waste Cooking Oil ◽  
Combustion Efficiency ◽  
Test Facility ◽  
Animal Fats ◽  
Cooking Oil ◽  
Crude Oil Prices

In the recent wake of escalating crude oil prices due to depletion of fossil fuel, biodiesel has generated a significant interest as an alternative fuel for the future. The use of biodiesel to fuel microturbines or gas turbine application is envisaged to solve problems of diminishing supplies of fossil fuel reserves and environmental concerns. This paper examines the combustion of biodiesel derived from Malaysian Waste Cooking Oil (WCO) in a combustion test facility to study the feasibility of using the designated fuel at five various volumetric ratios for gas turbine application. Biodiesel was produced from waste cooking oil in Malaysia, mainly from palm oil sources and animal fats. The oil burner was able to fire the five blends of fuel without any modification or pretreatment. The combustion performance of Malaysian WCO biodiesel and distillate blends was examined with respect to the combustion efficiency. The results indicated biodiesel combustion required less air for stoichiometric combustion due to presence of oxygen in the fuel. Indeed biodiesel stand as a potential alternative fuel for power generation application with the best efficiency at blended ratio of 20% biodiesel and 80% distillate.

S. I. Engine Pollution Control Using Low-Cost Palletized Catalytic Converter

Volume 2 ◽  
2004 ◽  
Author(s):  
Madhuri Jakkaraju ◽  
Vasudha Patri
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Pollution Control ◽  
Noble Metals ◽  
Fossil Fuel ◽  
Catalytic Converter ◽  
Low Cost ◽  
Hydrocarbon Emissions ◽  
Oxides Of Nitrogen ◽  
Carbon Dioxide Co2

I. C. Engines consume large amounts of fossil fuel emitting harmful pollutants like carbon monoxide (CO), unburnt hydrocarbons (UBHC), and oxides of nitrogen (NOx). By using a catalytic converter (CC), the carbon monoxide, hydrocarbon emissions can be transformed into less harmful carbon dioxide (CO2) & water vapor (H2O). Currently available CC’s are using costly noble metals like platinum (pt), palladium (pd), rhodium (rh) etc., hence making them expensive. This paper deals with the use of low-cost palletized silver coated alumina as the catalyst element in a CC. In this study, alumina and silver were used in the ratio of 10:1. All tests have been conducted on a stationary S.I. Engine at a constant speed of 1500 r.p.m with and without CC. Also, the performance of the palletized CC in combination with promoters like Bismuth, Cerium and Lanthanum was tested which have shown better results than silver alone as the coating element. It has been experimentally determined that the CO emissions have dropped from 7.25 (% vol) to 3.03(% vol) and the HC values have reduced from 350 ppm to 190 ppm.

scholarly journals Late Pleistocene-Recent Atmospheric δ13C Record in C4 Grasses

Radiocarbon ◽  
1993 ◽  
Vol 35 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Laurence J. Toolin ◽  
Christopher J. Eastoe
Keyword(s):  
Fossil Fuel ◽  
Secular Trend ◽  
Ice Cores ◽  
Mean Value ◽  
Herbarium Specimens ◽  
C4 Grasses ◽  
Polar Ice ◽  
Fossil Fuel Burning ◽  
Fuel Burning ◽  
The Mean

Samples of Setaria species from packrat middens, herbarium specimens and modern plants preserve a record of δ13C of atmospheric CO2 from 12,600 BP to the present. No secular trend is detected between 12,600 and 1800 BP, when the mean value of δ13C during that period was −6.5 ± 0.1‰ (the error is the standard deviation of the mean). Our value agrees with δ13C averages of pre-industrial CO2 from polar ice cores, and differs significantly from modern regional (-8.2 ± 0.1‰) and global (-7.7‰) values, which are higher because of fossil fuel burning.

scholarly journals Measurement of 14C Concentrations of Stratospheric CO2 by Accelerator Mass Spectrometry

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Toshio Nakamura ◽  
Takakiyo Nakazawa ◽  
Nobuyuki Nakai ◽  
Hiroyuki Kitagawa ◽  
Hideyuki Honda ◽  
...  
Keyword(s):  
Transport Mechanism ◽  
Sampling Method ◽  
Lower Stratosphere ◽  
Mass Movement ◽  
Vertical Mixing ◽  
Air Transport ◽  
Air Mass ◽  
Air Masses ◽  
Air Samples ◽  
Accelerator Mass Spectrometer

In order to measure the concentrations of anthropogenically influenced gases in the stratosphere, we have collected air samples from the lower stratosphere since 1985, by a balloon-borne cryogenic sampling method, developed at the Institute of Space and Astronautical Science (ISAS). Air samples of ≃16 liters at STP were collected in the stratosphere at altitudes from 18.6 to 30.4 km, over the northeastern part of Japan (39.5°N, 139–142°E), on 1 September 1989. We conducted 14C analyses to study the vertical and horizontal air-mass movement in the stratosphere, and to investigate the air transport mechanism between troposphere and stratosphere. Carbon dioxide (containing a few mg carbon) was separated cryogenically from the air samples, and the 14C concentration of the CO2 was measured by a Tandetron accelerator mass spectrometer, using Fe-graphite targets prepared by reducing CO2 on Fe-powder with hydrogen in a Vycor tube at 650°. The 14C concentrations, expressed as Δ14C, of CO2 were 267–309‰ at altitudes of 21–30 km, and 134‰ at 19–20 km. The Δ14C values at 21–30 km were higher than those of the current tropospheric CO2, of around 80–200‰. The observed 14C concentrations, higher in the stratosphere than the troposphere, seem to be explained by large bomb-produced 14C inventories and/or high 14C production by cosmic rays, as well as weak vertical mixing of air masses in the stratosphere.

scholarly journals Atmospheric radiocarbon measurements to quantify CO<sub>2</sub> emissions in the UK from 2014 to 2015

2018 ◽  
Author(s):  
Angelina Wenger ◽  
Katherine Pugsley ◽  
Simon O'Doherty ◽  
Matt Rigby ◽  
Alistair J. Manning ◽  
...  
Keyword(s):  
High Frequency ◽  
Fossil Fuel ◽  
Atmospheric Model ◽  
Nuclear Industry ◽  
Air Masses ◽  
Background Site ◽  
Large Measurement ◽  
Gas Measurements ◽  
The Uk ◽  
Co Observations

Abstract. We present 14CO2 observations and related greenhouse gas measurements at a background site in Ireland and a tall-tower site in the east of the UK that is more strongly influenced by fossil fuel sources. These data have been used to calculate the contribution of fossil fuel sources to atmospheric CO2 mole fractions from the UK and Ireland. Corrections were calculated and applied for 14CO2 emissions from the nuclear industry and other sources such as biospheric emissions that are in disequilibrium with the atmosphere. Measurements at both sites were found to only be marginally affected by 14CO2 emissions from nuclear sites. Over the study period of 2014–2015, the biospheric correction and the correction for nuclear 14CO2 emissions were similar, at 0.4 and 0.3 ppm fossil-fuel CO2 (ffCO2)-equivalent, respectively. The observed ffCO2 at the site was not significantly different from simulated values based on the EDGAR 2010 bottom-up inventory. We explored the use of high-frequency CO observations as a tracer of ffCO2 by deriving a constant COenhanced / ffCO2 ratio for the mix of UK fossil fuel sources. This ratio was found to be 5.7 ppb ppm−1, close to the value predicted using inventories and the atmospheric model of 5.1 ppb ppm−1. The site in the east of the UK was strategically chosen to be some distance from pollution sources so as to allow for the observation of well-integrated air masses. However this, and the large measurement uncertainty in 14CO2, lead to a large overall uncertainty in the ffCO2, being around 1.8 ppm compared to typical enhancements of 2 ppm.

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