Methodology of CO₂ Emission Factor Verification and Quantitative Assessment in Ethylene Product Processes

2018 ◽  
Vol 9 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Soo Kyung Youk ◽  
Eui-Chan Jeon ◽  
Kyung Seun Yoo
2021 ◽  
Vol 21 (11) ◽  
pp. 8557-8574
Author(s):  
Elizabeth B. Wiggins ◽  
Arlyn Andrews ◽  
Colm Sweeney ◽  
John B. Miller ◽  
Charles E. Miller ◽  
...  

Abstract. Recent increases in boreal forest burned area, which have been linked with climate warming, highlight the need to better understand the composition of wildfire emissions and their atmospheric impacts. Here we quantified emission factors for CO and CH4 from a massive regional fire complex in interior Alaska during the summer of 2015 using continuous high-resolution trace gas observations from the Carbon in Arctic Reservoirs Vulnerability Experiment (CRV) tower in Fox, Alaska. Averaged over the 2015 fire season, the mean CO / CO2 emission ratio was 0.142 ± 0.051, and the mean CO emission factor was 127 ± 40 g kg−1 dry biomass burned. The CO / CO2 emission ratio was about 39 % higher than the mean of previous estimates derived from aircraft sampling of wildfires from boreal North America. The mean CH4 / CO2 emission ratio was 0.010 ± 0.004, and the CH4 emission factor was 5.3 ± 1.8 g kg−1 dry biomass burned, which are consistent with the mean of previous reports. CO and CH4 emission ratios varied in synchrony, with higher CH4 emission factors observed during periods with lower modified combustion efficiency (MCE). By coupling a fire emissions inventory with an atmospheric model, we identified at least 34 individual fires that contributed to trace gas variations measured at the CRV tower, representing a sample size that is nearly the same as the total number of boreal fires measured in all previous field campaigns. The model also indicated that typical mean transit times between trace gas emission within a fire perimeter and tower measurement were 1–3 d, indicating that the time series sampled combustion across day and night burning phases. The high CO emission ratio estimates reported here provide evidence for a prominent role of smoldering combustion and illustrate the importance of continuously sampling fires across time-varying environmental conditions that are representative of a fire season.


2020 ◽  
Author(s):  
Elizabeth B. Wiggins ◽  
Arlyn Andrews ◽  
Colm Sweeney ◽  
John B. Miller ◽  
Charles E. Miller ◽  
...  

Abstract. With recent increases in burned area within boreal forests that have been linked to climate warming, there is a need to better understand the composition of emissions and their impact on atmospheric composition. Most previous studies have estimated boreal fire emission factors from daytime samples collected via aircraft near fire plumes or at the surface near actively burning fires. Here we quantified emission factors for CO and CH4 from a massive regional fire complex in interior Alaska during the summer of 2015 using continuous high-resolution trace gas observations from the CRV tower (Fox, AK). Averaged over the 2015 fire season, the CO/CO2 emission ratio was 0.138±0.048 and the CO emission factor was 145±50 g CO per kg of dry biomass consumed. The CO/CO2 emission ratio was about 35 % higher and more variable than most previous aircraft-based estimates for fresh wildfire emissions. The mean CH4/CO2 emission ratio was 0.010±0.003 and the CH4 emission factor was 6.05±2.09 g CH4 per kg of dry biomass consumed, with means similar to previous reports. CO and CH4 emission factors varied in synchrony, with higher CH4 emission factors observed during periods with lower modified combustion efficiency (MCE). By coupling a fire emissions inventory with an atmospheric model, we identified that at least 35 individual fires contributed to trace gas variations measured at the CRV tower, representing a significant increase in sampling compared to the number of boreal fires measured in all previous boreal forest fire work. The model also indicated that typical mean transit times between trace gas emission and tower measurement were 1–3 days, indicating that the time series sampled combustion across day and night burning phases. The high and variable CO emission factor estimates reported here provide evidence for a more prominent role of smoldering combustion, highlighting the importance of continuously sampling of fires across time-varying environmental conditions that are representative of typical burning conditions.


2017 ◽  
Vol 8 (2) ◽  
pp. 163-169
Author(s):  
Garam Song ◽  
Changsang Cho ◽  
Deakyeom Lee ◽  
Eui Chan Jeon
Keyword(s):  

2020 ◽  
Author(s):  
José‐Carlos Delgado‐González ◽  
Carlos‐de‐la Rosa Prieto ◽  
Nuria Vallejo‐Calcerrada ◽  
Diana‐Lucía Tarruela‐Hernández ◽  
Sandra Cebada‐Sánchez ◽  
...  

VASA ◽  
2017 ◽  
Vol 46 (5) ◽  
pp. 383-388 ◽  
Author(s):  
Henrik Christian Rieß ◽  
Anna Duprée ◽  
Christian-Alexander Behrendt ◽  
Tilo Kölbel ◽  
Eike Sebastian Debus ◽  
...  

Abstract. Background: Perioperative evaluation in peripheral artery disease (PAD) by common vascular diagnostic tools is limited by open wounds, medial calcinosis or an altered collateral supply of the foot. Indocyanine green fluorescent imaging (ICG-FI) has recently been introduced as an alternative tool, but so far a standardized quantitative assessment of tissue perfusion in vascular surgery has not been performed for this purpose. The aim of this feasibility study was to investigate a new software for quantitative assessment of tissue perfusion in patients with PAD using indocyanine green fluorescent imaging (ICG-FI) before and after peripheral bypass grafting. Patients and methods: Indocyanine green fluorescent imaging was performed in seven patients using the SPY Elite system before and after peripheral bypass grafting for PAD (Rutherford III-VI). Visual and quantitative evaluation of tissue perfusion was assessed in an area of low perfusion (ALP) and high perfusion (AHP), each by three independent investigators. Data assessment was performed offline using a specially customized software package (Institute for Laser Technology, University Ulm, GmbH). Slope of fluorescent intensity (SFI) was measured as time-intensity curves. Values were compared to ankle-brachial index (ABI), slope of oscillation (SOO), and time to peak (TTP) obtained from photoplethysmography (PPG). Results: All measurements before and after surgery were successfully performed, showing that ABI, TTP, and SOO increased significantly compared to preoperative values, all being statistically significant (P < 0.05), except for TTP (p = 0.061). Further, SFI increased significantly in both ALP and AHP (P < 0.05) and correlated considerably with ABI, TTP, and SOO (P < 0.05). Conclusions: In addition to ABI and slope of oscillation (SOO), the ICG-FI technique allows visual assessment in combination with quantitative assessment of tissue perfusion in patients with PAD. Ratios related to different perfusion patterns and SFI seem to be useful tools to reduce factors disturbing ICG-FI measurements.


Sign in / Sign up

Export Citation Format

Share Document