Engineering estimates of methane emissions from natural gas production have led to varied projections of national emissions. This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States (150 production sites, 27 well completion flowbacks, 9 well unloadings, and 4 workovers). For well completion flowbacks, which clear fractured wells of liquid ...

Sewage sludge is an important resource for the generation of electricity and heat within a wastewater treatment plant (WWTP). Taking a holistic approach to such use involves considering the greenhouse gas emissions. In particular, for anaerobic sludge treatment, methane emissions are a matter of concern. Therefore, the utilization of a carbon balance, based on the chemical oxygen demand (COD), ...

Production of unconventional gas resources commonly requires the use of hydraulic fracturing and chemical production well additives. Concern exists for the use of chemical compounds in gas wells due to the risk of groundwater contamination. This study focuses on a proposed method of identifying groundwater contamination from gas production. The method focuses on the classification of naturally ...

Depleted natural gas reservoirs are promising targets for carbon dioxide sequestration. Although depleted, these reservoirs are not devoid of methane, and carbon dioxide injection may allow enhanced production of methane by reservoir repressurization or pressure maintenance. Based on the favorable results of numerous simulation studies, we propose a field test of the Carbon Sequestration with E...

This study investigated pollutants emissions from filling stations and their impact on the air quality. Gas monitors were employed to identify the different pollutants present in the ambient air of the study areas. The results showed that the most prominent pollutants present in the ambient air are the volatile organic compounds followed by methane, then carbon monoxide. Measurements were taken...

The objective of this study was to determine the chemical compounds of Iranian propolis (IP) extracts and to show flavonoids and phenol effects on methane production, fermentation characteristics and rumen microbial population (in vitro). In this study two diets with different concentrate: forage ratios as (HC: high concentrate) and (MC: middle concentrate), respectively as non-supplemented or ...

The discovery that methane from dissociation of gas-hydrates could be an important factor in the global carbon cycle resolves the major discrepancy in estimates of the increase of terrestrial biomass from the Last Glacial period to the present. Carbon isotope budgeting using the marine carbon isotopic record results in an estimate centered around 500 GtC; whereas palaeovegetation reconstruction...

to study the potential of production of biogas, utilizing the wastes of rose distillation process, the wastes were mixed with cow manure at manure proportions of 5, 10, 15 and 20% and in temperatures at two levels of 35 and 45 °c. the treatments were carried out using a 2×4 factorial design (?=0.05). the volumes of produced gas and generated methane were recorded daily and modeled as functions ...

Introduction: The increase in greenhouse gas (GHG) emissions has changed the global temperature and had a negative impact on global climate conditions. Landfill gas is one of the major GHG contributors. With the knowledge of GHG inventory, it is possible to carry out disaster prevention measures. Materials and Methods: In this study, tow Landfill Gas Emissions Modeling (LandGEM) and Intergover...