Search results for "Natural Gas"
showing 10 items of 72 documents
Detailed Combustion Analysis of a Supercharged Double-Fueled Spark Ignition Engine
2021
The main goal of researches in the field of automotive engineering is to obtain a large-scale implementation of low- or zero-emissions vehicles in order to substantially reduce air pollution in urban areas. A fundamental step toward this green transition is represented by the improvement of current internal combustion (IC) engines in terms of fuel economy and pollutant emissions. The spark ignition (SI) engines of modern light-duty vehicles are supercharged, down-sized, and equipped with direct injection. Gaseous fuels, such as liquefied petroleum gas (LPG) or natural gas (NG), proved to be a valid alternative to gasoline in order to reduce pollutant emissions and increase fuel economy. In …
Molecular and isotopic composition of free hydrocarbon gases from Sicily, Italy
2004
Chemical and isotopic data have been used as geochemical tracers for a genetic characterization of hydrocarbon gases from a total of eleven manifestations located in Eastern and Central-Southern Sicily (Italy). The molecular analysis shows that almost all the samples are enriched in methane (up to 93.2% Vol.), with the exception of four gas samples collected around Mt. Etna showing high mantle-derived CO2 content. Methane isotope signatures suggest that these are thermogenic gases or a mixture between thermogenic gases and microbial gases. Although samples from some mud volcanoes in Southern Sicily (Macalube di Aragona) show isotope signatures consistent with a mixing model between thermoge…
Hydrogen underground storage—Petrographic and petrophysical variations in reservoir sandstones from laboratory experiments under simulated reservoir …
2018
Abstract Fluctuating energy production by renewables is one of the main issues in transition times of energy production from conventional power plants to an energy production by renewables. Using excess produced electricity (windy/sunny periods) to convert water to oxygen and hydrogen and storing the hydrogen in depleted oil-, gas fields or sedimentary aquifer structures would provide the option to recover and convert hydrogen to electricity in periods with an energy demand. Research focus is here the pore space in the geological underground where still few studies exist. In static batch experiments up to six weeks long, under different reservoir-specific conditions; regarding pressure, tem…
The impact of using project based learning in Natural Gas Engineering
2013
A methodology for selecting a sustainable development strategy for connecting low heat density consumers to a district heating system by cascading of…
2021
Abstract The paper presents a methodology for supporting the decision making on how to sustainably develop an existing district heating system when consumers located in a remote, low-heat consumption density area are connected to the system. Several scenarios are proposed where a multi-generative system is assessed by implementation of industrial heat pumps (HP), solar photovoltaic (PV) system, and low-temperature regime into an existing district heating system in various combinations. The methodology is based on multi-criteria analysis allowing for energy, economic, exergy, and environmental (4E) assessment. The research is based on a case study of an autonomous district heating system in …
Abiotic and biotic controls on methane formation down to 2.5 km depth within the Precambrian Fennoscandian Shield
2017
Abstract Despite a geological history characterised by high temperature and pressure processes and organic carbon deprived crystalline bedrock, large amounts of hydrocarbons are found in deep groundwaters within Precambrian continental shields. In many sites, methane comprises more that 80% of the dissolved gas phase reaching concentrations of tens of mmol l −1 . In this study, we used isotopic methods to study the carbon isotope systematics and sources of crustal methane within the Fennoscandian Shield. The main study sites were the Outokumpu Deep Drill Hole and the Pyhasalmi mine in Finland, both of which allow groundwater sampling down to 2.5 km depth and have been previously studied for…
Demand and Supply Model for the Natural Gas Supply Chain in Colombia
2018
Natural gas is considered the transitional fuel for excellence between fossil and renewable sources, considering its low cost, greater efficiency and lesser effects on the environment. This has led to increased demand levels worldwide, requiring the intervention of public and private actors to meet such demand. In this research, we study the natural gas supply chain in Colombia using system dynamics modelling. The results allow to contrast both the behaviour of the production and transport levels and the behaviour of the demand from the consumption sectors, allowing to identify capacity levels to be developed considering implementation times and percentages of coverage in the supply.
LNG cold energy use in agro-food industry: A case study in Sicily
2011
Abstract It is known how the complete gasification of liquefied natural gas (LNG) can return about 230 kWh/t of energy. Nevertheless out of fifty-one gasification plants in the world, only thirty-one of them are equipped with systems for the partial recovery of the available energy. At the moment most of these plants mainly produce electric energy; however the employment of the cold energy results very interesting, in fact, it can be recovered for agro-food transformation and conservation as well as for some loops in the cold chain. Cold energy at low temperatures requires high amounts of mechanical energy and it unavoidably increases as the required temperature diminishes. Cold energy reco…
Calibration of a knock prediction model for the combustion of a gasoline-natural gas mixture
2009
Gaseous fuels, such as Liquefied Petroleum Gas (LPG) and Natural Gas (NG), thank to their good mixing capabilities, allow complete and cleaner combustion than normal gasoline, resulting in lower pollutant emissions and particulate matter. Moreover natural gas, which is mainly constituted by methane, whose molecule has the highest hydrogen/carbon ratio, leads also to lower ozone depleting emissions. The authors in a previous work (1) experienced the simultaneous combustion of gasoline and natural gas in a bi-fuel S.I. engine, exploiting so the high knock resistance of methane to run the engine with an ‘overall stoichiometric’ mixture (thus lowering fuel consumption and emissions) and better …
A Comprehensive Model for the Auto-Ignition Prediction in Spark Ignition Engines Fueled With Mixtures of Gasoline and Methane-Based Fuel
2018
The introduction of natural gas (NG) in the road transport market is proceeding through bifuel vehicles, which, endowed of a double-injection system, can run either with gasoline or with NG. A third possibility is the simultaneous combustion of NG and gasoline, called double-fuel (DF) combustion: the addition of methane to gasoline allows to run the engine with stoichiometric air even at full load, without knocking phenomena, increasing engine efficiency of about 26% and cutting pollutant emissions by 90%. The introduction of DF combustion into series production vehicles requires, however, proper engine calibration (i.e., determination of DF injection and spark timing maps), a process which…