Search results for "Fuel gas"

Trends and Breaks in Per-Capita Carbon Dioxide Emissions, 1870-2028

2004

We consider per-capita carbon dioxide emission trends in 16 early industrialized countries over the period 1870-2028. Using a multiple-break time series method we find more evidence for very early downturns in per-capita trends than for late downturns during the oil price shocks of the 1970s. Only for two countries do downturns in trends imply downward sloping stable trends. We also consider trends in emission composition and find little evidence for in-sample peaks for emissions from liquid and gaseous fuel uses. These results lead us to reject the oil price shocks as events causing permanent breaks in the structure and level of emissions, a conclusion often made in analyses using shorter …

Experimental Determination of Liquefied Petroleum Gas–Gasoline Mixtures Knock Resistance

2014

The results of previous experimental researches showed that great advantages can be achieved, both in terms of fuel consumption and pollutant emissions, in bifuel vehicles by means of the double-fuel combustion, i.e., the simultaneous combustion of gasoline and a gaseous fuel, such as liquefied petroleum gas (LPG) or natural gas (NG). The substantial increase in knock resistance pursued by adding LPG to gasoline, which allowed to maintain an overall stoichiometric proportion with air also at full load, is not documented in the scientific literature and induced the authors to perform a proper experimental campaign. The motor octane number (MON) of LPG–gasoline mixtures has been hence determi…

An NTC zone compliant knock onset prediction model for spark ignition engines

2015

Abstract Pollutant emissions reduction and energy saving policies increased the production of Spark Ignition (SI) engines operated with gaseous fuels. Natural Gas (NG) and Liquefied Petroleum Gas (LPG), thanks to their low cost and low environmental impact represent the best alternative. Bi-fuel engines, which may run either with gasoline or with gas (NG or LPG), widely spread in many countries thanks to their versatility, high efficiency and low pollutant emissions: gas fueled vehicles, as example, are allowed to run in many limited traffic zones. In the last years, supercharged SI engines fueled with either gasoline or gaseous fuel, spread in the market. Thermodynamic simulations, widely …

The Effect of Combustion Dynamics on the Formation of Pollutant Emissions by Co-Firing the Wood Biomass with Gaseous Fuel

2008

Experimental model-based linearization of a S.I. engine gas injector flow chart:

2014

Experimental tests previously executed by the authors on the simultaneous combustion of gasoline and gaseous fuel in a spark ignition engine revealed the presence of strong nonlinearities in the lower part of the gas injector flow chart. These nonlinearities arise via the injector outflow area variation caused by the needle impacts and bounces during the transient phenomena that take place in the opening and closing phases of the injector and may seriously compromise the air-fuel mixture quality control for the lower injection times, thus increasing both fuel consumption and pollutant emissions. Despite the extensive literature about the operation and modelling of fuel injectors, there are …

Performance and combustion analysis of a supercharged double-fuel spark ignition engine

2019

In order to increase fuel economy and reduce pollutant emissions in the last decades light duty spark ignition (SI) engines have become smaller, supercharged and equipped with direct injection. A suitable alternative to oil derived fuel is represented by gaseous fuels, such as Natural Gas (NG) and Liquefied Petroleum Gas (LPG), whose higher knock resistance and better mixing capabilities substantially improve vehicle fuel economy and pollutant emissions. The simultaneous combustion of gasoline and gaseous fuel (Double-Fuel operation, DF) in a naturally aspirated SI engine has already been investigated in the past also by the same authors, proving remarkable results in terms of engine effici…

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 …