Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

This review paper covers potential alternative fuels for automotive engine application for both spark ignition (SI) and compression ignition (CI) engines. It also includes applications of alternative fuels in advanced combustion research applications. The representative alternative fuels for SI engines include compressed natural gas (CNG), hydrogen (H 2 ) liquefied petroleum gas (LPG), and alcohol fuels (methanol and ethanol); while for CI engines, they include biodiesel, di-methyl ether (DME), and jet propellent-8 (JP-8). Naphtha is introduced as an alternative fuel for advanced combustion in premixed charge compression ignition. The production, storage, and the supply chain of each alternative fuel are briefly summarized, and are followed by discussions on the main research motivations for such alternative fuels. Literature surveys are presented that investigate the relative advantages and disadvantages of these alternative fuels for application to engine combustion. The contents of engine combustion basically consist of the combustion process from spray development, air–fuel mixing characteristics, to the final combustion product formation process, which is analyzed for each alternative fuel. An overview is provided for alternative fuels together with summaries of engine combustion characteristics for each fuel, in addition to its current distribution status and future prospects.

Alternative fuels for internal combustion engines

Increasing urbanization and industrialization have led to a phenomenal growth in transportation demand worldwide, coupled with a concentration of vehicles in metropolitan cities. With regard to increasingly stringent emission legislation natural gas is gaining interest as a transportation fuel with worldwide over 19 million natural gas vehicles in operation. This paper presents the worldwide background, prospects and challenges of natural gas fuel and natural gas fueled vehicles along with environmental and economic aspects of compressed natural gas as a transformation fuel. Technical aspects of compressed natural gas properties, storage, safety problems and its effect on engine performance, efficiency, emissions and barriers to natural gas vehicles adaptation are discussed in detail. The main indicators selected for the comparative assessment of natural gas as vehicular fuel are: economic, emission performance and safety aspect. The results showed that CNG has several advantages over both diesel and gasoline fuel, including considerable emission and cost reductions.

Haeng Muk Cho

Papers

Spark ignition natural gas engines—A review