scholarly journals Comparison of methane emission estimates from multiple measurement techniques at natural gas production pads

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Clay S. Bell ◽  
Timothy L. Vaughn ◽  
Daniel Zimmerle ◽  
Scott C. Herndon ◽  
Tara I. Yacovitch ◽  
...  
Keyword(s):  
Weighted Least Squares ◽  
Measurement Techniques ◽  
Flux Ratio ◽  
Methane Emissions ◽  
Gas Production ◽  
Test Method ◽  
Ratio Method ◽  
Emission Data ◽  
Direct Measurements ◽  
The Impact

This study presents the results of a campaign that estimated methane emissions at 268 gas production facilities in the Fayetteville shale gas play using onsite measurements (261 facilities) and two downwind methods – the dual tracer flux ratio method (Tracer Facility Estimate – TFE, 17 facilities) and the EPA Other Test Method 33a (OTM33A Facility Estimate – OFE, 50 facilities). A study onsite estimate (SOE) for each facility was developed by combining direct measurements and simulation of unmeasured emission sources, using operator activity data and emission data from literature. The SOE spans 0–403 kg/h and simulated methane emissions from liquid unloadings account for 88% of total emissions estimated by the SOE, with 76% (95% CI [51%–92%]) contributed by liquid unloading at two facilities. TFE and SOE show overlapping 95% CI between individual estimates at 15 of 16 (94%) facilities where the measurements were paired, while OFE and SOE show overlapping 95% CI between individual estimates at 28 of 43 (65%) facilities. However, variance-weighted least-squares (VWLS) regressions performed on sets of paired estimates indicate statistically significant differences between methods. The SOE represents a lower bound of emissions at facilities where onsite direct measurements of continuously emitting sources are the primary contributor to the SOE, a sub-selection of facilities which minimizes expected inter-method differences for intermittent pneumatic controllers and the impact of episodically-emitting unloadings. At 9 such facilities, VWLS indicates that TFE estimates systematically higher emissions than SOE (TFE-to-SOE ratio = 1.6, 95% CI [1.2 to 2.1]). At 20 such facilities, VWLS indicates that OFE estimates systematically lower emissions than SOE (OFE-to-SOE ratio of 0.41 [0.26 to 0.90]). Given that SOE at these facilities is a lower limit on emissions, these results indicate that OFE is likely a less accurate method than SOE or TFE for this type of facility.

scholarly journals Identification and characterization of high methane-emitting abandoned oil and gas wells

2016 ◽  
Vol 113 (48) ◽  
pp. 13636-13641 ◽  
Author(s):  
Mary Kang ◽  
Shanna Christian ◽  
Michael A. Celia ◽  
Denise L. Mauzerall ◽  
Markus Bill ◽  
...  
Keyword(s):  
Methane Emission ◽  
Oil And Gas ◽  
Methane Emissions ◽  
Gas Production ◽  
Mitigation Strategies ◽  
Gas Wells ◽  
Emission Data ◽  
Flow Rates ◽  
Abandoned Wells ◽  
Oil Gas

Recent measurements of methane emissions from abandoned oil/gas wells show that these wells can be a substantial source of methane to the atmosphere, particularly from a small proportion of high-emitting wells. However, identifying high emitters remains a challenge. We couple 163 well measurements of methane flow rates; ethane, propane, andn-butane concentrations; isotopes of methane; and noble gas concentrations from 88 wells in Pennsylvania with synthesized data from historical documents, field investigations, and state databases. Using our databases, we (i) improve estimates of the number of abandoned wells in Pennsylvania; (ii) characterize key attributes that accompany high emitters, including depth, type, plugging status, and coal area designation; and (iii) estimate attribute-specific and overall methane emissions from abandoned wells. High emitters are best predicted as unplugged gas wells and plugged/vented gas wells in coal areas and appear to be unrelated to the presence of underground natural gas storage areas or unconventional oil/gas production. Repeat measurements over 2 years show that flow rates of high emitters are sustained through time. Our attribute-based methane emission data and our comprehensive estimate of 470,000–750,000 abandoned wells in Pennsylvania result in estimated state-wide emissions of 0.04–0.07 Mt (1012g) CH4per year. This estimate represents 5–8% of annual anthropogenic methane emissions in Pennsylvania. Our methodology combining new field measurements with data mining of previously unavailable well attributes and numbers of wells can be used to improve methane emission estimates and prioritize cost-effective mitigation strategies for Pennsylvania and beyond.

Deriving anthropogenic CO2 emissions for combustion by application of the emission-ratio method to TROPOMI/S5P NO2 emission data.

2020 ◽  
Author(s):  
Jos de Laat ◽  
Ronald van der A
Keyword(s):  
South America ◽  
Iberian Peninsula ◽  
Ratio Method ◽  
Inversion Algorithm ◽  
Emission Data ◽  
Bottom Up ◽  
Satellite Platform ◽  
Direct Measurements ◽  
Combustion Emissions ◽  
Emission Ratios

<p>Anthropogenic CO<sub>2</sub> and NO<sub>2</sub> emissions from combustion processes usually have the same sources but different emission ratios. Because of their similar sources, combustion emissions of CO<sub>2</sub> and NO<sub>2</sub> are correlated in space and time. Or in other words: combustion emissions of NO<sub>2</sub> will generally be accompanied by CO<sub>2</sub> emissions, and vice versa.</p><p>This concept can be used for converting satellite-based emissions of NO<sub>2</sub> into CO<sub>2</sub> emissions by multiplying known emission ratios of CO<sub>2</sub> over NO<sub>2</sub> from established emission databases with satellite-derived NO<sub>2</sub> emissions.</p><p>As part of the H2020 CHE project (“CO<sub>2</sub> Human Emissions”) we have applied this method to TROPOMI/S5P NO<sub>2</sub> emission data and “bottom-up” emission databases from Dutch TNO. TROPOMI/S5P emissions using the inversion algorithm DECSO were derived for the Iberian Peninsula in Europe and an area over South America.</p><p>We find that, after accounting for naturally occurring soil NO<sub>x</sub> emissions, the spatial distribution of DECSO-TROPOMI based CO<sub>2</sub> emissions over the Iberian Peninsula and the South America region overall are very realistic, and within uncertainties CO<sub>2</sub> emissions budgets from both methods are not dissimilar.</p><p>We will also present and discuss some additional aspects and uncertainties of this ratio-method, including the influence of uncertainties in the TNO bottom-up emission database, like inter-country differences, and the relevance of applying emission ratios representative for the same time period as the TROPOMI/S5P measurements. We will also provide some recommendations for further improving this method.</p><p>Overall, at minimum this method appears to provide a “sanity check” for bottom-up (reported) CO<sub>2</sub> emissions, but potentially more than that, also evidenced by several new satellite mission proposals to combine direct measurements of CO<sub>2</sub> with direct measurements of NO<sub>2</sub> from the same satellite platform.</p>

scholarly journals Evaluation of Energy Absorption Capabilities of Polyethylene Foam under Impact Deformation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3613
Author(s):  
Baohui Yang ◽  
Yangjie Zuo ◽  
Zhengping Chang
Keyword(s):  
Energy Absorption ◽  
Failure Modes ◽  
High Strain ◽  
Early Stage ◽  
High Energy ◽  
Test Method ◽  
Test Theory ◽  
Strain Rates ◽  
Impact Properties ◽  
The Impact

Foams are widely used in protective applications requiring high energy absorption under impact, and evaluating impact properties of foams is vital. Therefore, a novel test method based on a shock tube was developed to investigate the impact properties of closed-cell polyethylene (PE) foams at strain rates over 6000 s−1, and the test theory is presented. Based on the test method, the failure progress and final failure modes of PE foams are discussed. Moreover, energy absorption capabilities of PE foams were assessed under both quasi-static and high strain rate loading conditions. The results showed that the foam exhibited a nonuniform deformation along the specimen length under high strain rates. The energy absorption rate of PE foam increased with the increasing of strain rates. The specimen energy absorption varied linearly in the early stage and then increased rapidly, corresponding to a uniform compression process. However, in the shock wave deformation process, the energy absorption capacity of the foam maintained a good stability and exhibited the best energy absorption state when the speed was higher than 26 m/s. This stable energy absorption state disappeared until the speed was lower than 1.3 m/s. The loading speed exhibited an obvious influence on energy density.

scholarly journals Laboratory experiment on the nano-TiO2 photocatalytic degradation effect of road surface oil pollution

2020 ◽  
Vol 9 (1) ◽  
pp. 922-933
Author(s):  
Qing’e Wang ◽  
Kai Zheng ◽  
Huanan Yu ◽  
Luwei Zhao ◽  
Xuan Zhu ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Oil Pollution ◽  
Road Surface ◽  
Test Method ◽  
Driving Safety ◽  
The Road ◽  
Road Surfaces ◽  
The Many ◽  
The Impact ◽  
Degradation Effect

AbstractOil leak from vehicles is one of the most common pollution types of the road. The spilled oil could be retained on the surface and spread in the air voids of the road, which results in a decrease in the friction coefficient of the road, affects driving safety, and causes damage to pavement materials over time. Photocatalytic degradation through nano-TiO2 is a safe, long-lasting, and sustainable technology among the many methods for treating oil contamination on road surfaces. In this study, the nano-TiO2 photocatalytic degradation effect of road surface oil pollution was evaluated through the lab experiment. First, a glass dish was used as a substrate to determine the basic working condition of the test; then, a test method considering the impact of different oil erosion degrees was proposed to eliminate the effect of oil erosion on asphalt pavement and leakage on cement pavement, which led to the development of a lab test method for the nano-TiO2 photocatalytic degradation effect of oil pollution on different road surfaces.

scholarly journals Microbial drivers of methane emissions from unrestored industrial salt ponds

2021 ◽  
Author(s):  
Jinglie Zhou ◽  
Susanna M. Theroux ◽  
Clifton P. Bueno de Mesquita ◽  
Wyatt H. Hartman ◽  
Ye Tian ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Methane Flux ◽  
Methane Emissions ◽  
Metagenomic Data ◽  
Rrna Gene ◽  
Salt Ponds ◽  
Salt Pond ◽  
Reference Wetlands ◽  
Reference Wetland ◽  
The Impact

AbstractWetlands are important carbon (C) sinks, yet many have been destroyed and converted to other uses over the past few centuries, including industrial salt making. A renewed focus on wetland ecosystem services (e.g., flood control, and habitat) has resulted in numerous restoration efforts whose effect on microbial communities is largely unexplored. We investigated the impact of restoration on microbial community composition, metabolic functional potential, and methane flux by analyzing sediment cores from two unrestored former industrial salt ponds, a restored former industrial salt pond, and a reference wetland. We observed elevated methane emissions from unrestored salt ponds compared to the restored and reference wetlands, which was positively correlated with salinity and sulfate across all samples. 16S rRNA gene amplicon and shotgun metagenomic data revealed that the restored salt pond harbored communities more phylogenetically and functionally similar to the reference wetland than to unrestored ponds. Archaeal methanogenesis genes were positively correlated with methane flux, as were genes encoding enzymes for bacterial methylphosphonate degradation, suggesting methane is generated both from bacterial methylphosphonate degradation and archaeal methanogenesis in these sites. These observations demonstrate that restoration effectively converted industrial salt pond microbial communities back to compositions more similar to reference wetlands and lowered salinities, sulfate concentrations, and methane emissions.

scholarly journals Methane Emissions from Process Equipment at Natural Gas Production Sites in the United States: Liquid Unloadings

2014 ◽  
Vol 49 (1) ◽  
pp. 641-648 ◽  
Author(s):  
David T. Allen ◽  
David W. Sullivan ◽  
Daniel Zavala-Araiza ◽  
Adam P. Pacsi ◽  
Matthew Harrison ◽  
...  
Keyword(s):  
United States ◽  
Natural Gas ◽  
The United States ◽  
Methane Emissions ◽  
Gas Production ◽  
Process Equipment ◽  
Natural Gas Production

scholarly journals Aerosol distribution over Europe: a model evaluation study with detailed aerosol microphysics

2008 ◽  
Vol 8 (6) ◽  
pp. 1591-1607 ◽  
Author(s):  
B. Langmann ◽  
S. Varghese ◽  
E. Marmer ◽  
E. Vignati ◽  
J. Wilson ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Rural Areas ◽  
Regional Scale ◽  
Evaluation Study ◽  
Emission Data ◽  
Aerosol Model ◽  
Fire Emissions ◽  
Elevated Ozone ◽  
Emission Fluxes ◽  
The Impact

Abstract. This paper summarizes an evaluation of model simulations with a regional scale atmospheric climate-chemistry/aerosol model called REMOTE, which has been extended by a microphysical aerosol module. Model results over Europe are presented and compared with available measurements in surface air focusing on the European distribution and variability of primary and secondary aerosols. Additionally, model results obtained with detailed aerosol microphysics are compared to those based on an aerosol bulk mass approach revealing the impact of dry deposition fluxes on atmospheric burden concentration. An improved determination of elevated ozone and sulfate concentrations could be achieved by considering a diurnal cycle in the anthropogenic emission fluxes. Deviation between modelled and measured organic carbon concentrations can be mainly explained by missing formation of secondary organic aerosols and deficiencies in emission data. Changing residential heating practices in Europe, where the use of wood is no longer restricted to rural areas, need to be considered in emission inventories as well as vegetation fire emissions which present a dominant source of organic carbon.

The Experiment on Soil Water Characteristic Curve Considering the Effect of Urea Concentration

2014 ◽  
Vol 919-921 ◽  
pp. 795-799
Author(s):  
Gai Qing Dai ◽  
Dong Fang Tian ◽  
Yao Ruan ◽  
Lang Tian ◽  
You Le Wang
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Urea Concentration ◽  
Test Method ◽  
Materials Selection ◽  
Valuable Data ◽  
Soil Water Characteristic Curve ◽  
Concentration Test ◽  
The Impact

A new soil water characteristic curve (SWCC) experiment contemplating urea concentration is presented in the paper. We focus on the impact of the SWCC considering urea concentration test method for materials selection and introduction, experimental results, and finally, we have conducted some experiments of SWCC and obtained some valuable data which could affect urea concentration. By using linear fitting, an exponential function between water content and suction and urea concentration is established.

scholarly journals A double-blind, placebo-controlled, cross-over study to establish the bifidogenic effect of a very-long-chain inulin extracted from globe artichoke (Cynara scolymus) in healthy human subjects

2010 ◽  
Vol 104 (7) ◽  
pp. 1007-1017 ◽  
Author(s):  
Adele Costabile ◽  
Sofia Kolida ◽  
Annett Klinder ◽  
Eva Gietl ◽  
Michael Bäuerlein ◽  
...  
Keyword(s):  
Gastrointestinal Symptoms ◽  
Gas Production ◽  
Globe Artichoke ◽  
Daily Consumption ◽  
Healthy Human ◽  
Double Blind ◽  
Cynara Scolymus ◽  
The Impact ◽  
Long Chain

There is growing interest in the use of inulins as substrates for the selective growth of beneficial gut bacteria such as bifidobacteria and lactobacilli because recent studies have established that their prebiotic effect is linked to several health benefits. In the present study, the impact of a very-long-chain inulin (VLCI), derived from globe artichoke (Cynara scolymus), on the human intestinal microbiota compared with maltodextrin was determined. A double-blind, cross-over study was carried out in thirty-two healthy adults who were randomised into two groups and consumed 10 g/d of either VLCI or maltodextrin, for two 3-week study periods, separated by a 3-week washout period. Numbers of faecal bifidobacteria and lactobacilli were significantly higher upon VLCI ingestion compared with the placebo. Additionally, levels ofAtopobiumgroup significantly increased, whileBacteroides–Prevotellanumbers were significantly reduced. No significant changes in faecal SCFA concentrations were observed. There were no adverse gastrointestinal symptoms apart from a significant increase in mild and moderate bloating upon VLCI ingestion. These observations were also confirmed byin vitrogas production measurements. In conclusion, daily consumption of VLCI extracted from globe artichoke exerted a pronounced prebiotic effect on the human faecal microbiota composition and was well tolerated by all volunteers.

Passenger aircraft emissions analysis at Ordu-Giresun International Airport, Turkey in 2017

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilkay Orhan
Keyword(s):  
Aircraft Engine ◽  
Civil Aviation ◽  
Exhaust Emission ◽  
Aircraft Emissions ◽  
Emission Data ◽  
Emission Analysis ◽  
Content Type ◽  
International Airport ◽  
Engine Emission ◽  
The Impact

Purpose The purpose of this study is to present the pollutant gas produced by hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx) and the quantity of fuel burned from commercial aircraft at Ordu-Giresun International Airport, Turkey during the landing and take-off (LTO) cycles in 2017. Design/methodology/approach The flight data recorded by the General Directorate of State Airports Authority and the aircraft engine emission data from International Civil Aviation Organization (ICAO) Engine Exhaust Emission Databank were used for calculation. The aircraft and engine types used by the airlines for flight at Ordu-Giresun International Airport were determined. To evaluate the effect of taxi time on emission amounts, analysis and evaluations were made by taking different taxi times into consideration. Findings As a result of the emission analysis, the amount of fuel consumed by the aircraft were calculated as 6,551.52 t/y, and the emission amounts for CO, HC and NOx were estimated as 66.81, 4.20 and 79.97 t/y, respectively. Practical implications This study is aimed to reveal the effect and contribution of taxi time on the emitted emission at the airport during the LTO phase of the aircraft. Originality/value This study helps aviation authorities explain the importance of developing procedures that ensure the delivery of aircraft to flights in minimum time by raising awareness of the impact of taxi time on emitted emissions, and contributes to the determination of an aircraft emission inventory at Ordu-Giresun International Airport.

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