Natural Gas Gasoline Research Articles

NOX reduction and efficiency improvements by means of the Double Fuel HCCI combustion of natural gas–gasoline mixtures

Homogeneous Charge Compression Ignition (HCCI) and Double Fuel (DF) combustion represent two innovative processes sharing a strong potential for pollutant emissions and fuel consumption reduction. HCCI regards the auto-ignition of a homogeneous premixed charge of air and fuel, featuring very low NOX emissions and good efficiency. Double Fuel (DF) instead indicates the simultaneous combustion of gasoline and natural gas (or gasoline and LPG), premixed with air by the port injection of both fuels within same engine cycle. Since fuel mixtures enhances the HCCI performances widening the range of possible operating conditions, the authors tested the HCCI combustion process using natural gas–gasoline mixtures on a CFR engine, endowed with two injection systems for the accurate control of both fuel mixture composition and overall air-to-fuels ratio. Stable and knock-free DF-HCCI combustions were obtained by combining different intake temperatures and compression ratios, in a range of engine load between 20% and 54% of the maximum load obtained with normal Spark Ignition (SI) operation. Noticeable increment of engine efficiency (+23%) and a strong reduction of pollutant emissions were found in comparison to SI operation, above all in terms of NOx, which was reduced by 2 order of magnitude.

Influence of driving patterns on vehicle emissions: A case study for Latin American cities

On-board real-time emission experiments were conducted on 78 light-duty vehicles in Bogota. Direct emissions of carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and hydrocarbons (HC) were measured. The relationship between such emissions and vehicle specific power (VSP) was established. The experimental matrix included both gasoline-powered and retrofit dual fuel (gasoline–natural gas) vehicles. The results confirm that VSP is an appropriate metric to obtain correlations between driving patterns and air pollutant emissions. Ninety-five percent of the time vehicles in Bogota operate in a VSP between −15.2 and 17.7kWton−1, and 50% of the time they operate between −2.9 and 1.2kWton−1, representing low engine-load and near-idling conditions, respectively. When engines are subjected to higher loads, pollutant emissions increase significantly. This demonstrates the relevance of reviewing smog check programs and command-and-control measures in Latin America, which are widely based on static (i.e., idling) emissions testing. The effect of different driving patterns on the city’s emissions inventory was determined using VSP and numerical simulations. For example, improving vehicle flow and reducing sudden and frequent accelerations could curb annual emissions in Bogota by up to 12% for CO2, 13% for CO and HC, and 24% for NOx. This also represents possible fuel consumption savings of between 35 and 85million gallons per year and total potential economic benefits of up to 1400million dollars per year.

Octane Rating of Natural Gas-Gasoline Mixtures on CFR Engine

In the last years new and stricter pollutant emission regulations together with raised cost of conventional fuels resulted in an increased use of gaseous fuels, such as Natural Gas (NG) or Liquefied Petroleum Gas (LPG), for passenger vehicles. Bi-fuel engines represent a transition phase product, allowing to run either with gasoline or with gas, and for this reason are equipped with two separate injection systems. When operating at high loads with gasoline, however, these engines require rich mixtures and retarded combustions in order to prevent from dangerous knocking phenomena: this causes high hydrocarbon (HC) and carbon monoxide (CO) emissions together with high fuel consumption. With the aim to exploit the high knock resistance of NG maintaining the good performances of gasoline, the authors experienced, in a previous work [1], the simultaneous combustion of NG-gasoline mixtures on a series production Spark Ignition (SI) engine, obtaining, with respect to pure gasoline operation, strong reduction in pollutant emissions, noticeable efficiency increase and no significant power losses. In order to ascertain the knock resistance increase due to the addition of natural gas to gasoline, and given the total absence of such information in the scientific literature, the authors decided to carry out a dedicated experimental campaign: a standard Cooperative Fuel Research (CFR) engine, properly upgraded to inject both fuels in the intake duct, has been employed to determine the Motor Octane Number (MON) of several fuel mixtures following the ASTM Standard D2700. The results showed a non-linear relation between mixture knock resistance and natural gas concentration, correctly interpolated by a polynomial law. The correlation found can be usefully implemented in knock onset prediction sub-models for thermodynamic engine simulation, or used in future works involving the simultaneous combustion of natural gas and gasoline in a SI engine.

The Design and Construction of Air Intake System of a Gasoline-Natural Gas Dual Fuel Engine

The concept of this design is to replace a carburetor by an electronic controlled gasoline-natural gas dual fuel injection system, which mainly consists of a gasoline supply unit, a natural gas-air intake system, a single-chip electronic control unit and sensors. The retrofit design and construction of this system enables the engine working under several modes of a) gasoline combustion only, b) natural gas combustion only and c) gasoline-natural gas dual fuel combustion, hence make it possible to combust different fuels under the best air-fuel ratio. This leads to a low exhaust gas emissions and fuel-saving.

New carbon sorbents

The formation of the structural and absorption properties of carbon sorbents based on various carbon-containing materials was studied. Carbon sorbents and catalysts on carbon supports with a wide range of physicochemical properties and structural parameters were prepared and tested in air separation, natural gas-gasoline processing, direct oxidative degradation of hydrogen sulfide, and the recovery of noble metals from solutions and pulps. It was found that the targetoriented synthesis of a pore structure makes it possible to obtain carbon sorbents and catalysts on carbon supports, which are effective in gas decomposition, gas mixture separation, and the recovery of valuable components from liquid media.

Adsorption method for the recovery of hydrocarbons from natural gas and associated petroleum gas

Carbon sorbents were prepared based on various raw materials, and their sorption capacities for gasoline fraction were studied under static and dynamic conditions. A pilot batch of the most efficient sorbent was tested in a pilot plant under conditions similar to the operating parameters of commercial natural gas-gasoline processing plants. The dynamic adsorption capacity of a carbon sorbent was higher than this characteristic of imported silica gel, which is commonly used for natural gas stripping.

THE USE OF MIXED EFFECTS ANCOVA TO CHARACTERIZE VEHICLE EMISSION PROFILES

A mixed effects analysis of covariance model to characterize mileage dependent emissions profiles for any given group of vehicles having a common model design is used in this paper. These types of evaluations are used by the U.S. Environmental Protection Agency to certify whether or not new models conform to existing emissions standards. The statistical models introduced describe both the average emissions profile for a group of vehicles as well as an accounting for individual vehicle variability within the group. Realistic confidence bounds for an average emissions deterioration profile within a given group can also be provided to allow accurate emissions comparison of multiple groups. Sample of emissions data is presented for two types of vehicles: natural gas Dodge Ram vans and gasoline Dodge Ram vans (all from the 1992-94 model years). Additionally, the population profile for nonmethane hydrocarbons is explored.

Composition of Natural Gas Gasoline.

Composition of Natural Gas Gasoline.

Some Recent Developments in the Manufacture of Natural Gas Gasoline

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSome Recent Developments in the Manufacture of Natural Gas GasolineF. E. HOSMER and F. M. SEIBERTCite this: Ind. Eng. Chem. 1922, 14, 12, 1106–1110Publication Date (Print):December 1, 1922Publication History Published online1 May 2002Published inissue 1 December 1922https://doi.org/10.1021/ie50156a004RIGHTS & PERMISSIONSArticle Views47Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (818 KB) Get e-Alerts

Treating natural-gas gasoline to meet the “doctor test”

Treating natural-gas gasoline to meet the “doctor test”