Reducing NOx emissions by adding hydrogen-rich synthesis gas generated by a plasma-assisted fuel reformer using Saudi Arabian market gasoline and ethanol for different air/fuel mixtures

  • Dr. Ahmed Awadh Alharbi King Abdulaziz City for Science and Technology (KACST)
  • Dr. Feraih Sh. Aenazey KACST
  • Dr. Saud A. Binjuwair KACST
  • Dr. Ibrahim A. Alshunaifi KACST
  • Dr. Abdullah M. Alkhedair KACST
  • Dr. Abdullah J. Alabduly KACST
  • Mohammed S. Almurat KACST
  • Miqad S. Albishi KACST
Keywords: Plasma, Fuel reforming, Syngas production, Ethanol, Emissions, Nitrogen oxides


Environmental contamination poses a real threat to the environment and all organisms. Air pollution has increased markedly due to an increase in human activities and petroleum use for electricity generation, transportation, and industrial applications. Internal combustion engines play a significant role in society’s health and power requirements. However, automobiles are the main source of pollution and NOX emissions. This work presents a study of the performance and exhaust emissions of an internal combustion engine fuelled by gasoline available in the Saudi Arabian market, RON91/RON95, with an admixture of syngas and 5% by volume pure ethanol (E5) in the presence of different ultra-lean mixture regimes, including λ=1 for a stoichiometric mixture. The studied ranges were λ=1.13, λ=1.26, λ=1.43, and λ=1.67. An entirely automated engine and plasma converter system was developed for feeding the same type of fuel. The engine was modified for a more efficient operation by introducing a plasma-based fuel reformer. Syngas was produced through the partial oxidation of gasoline with air in a plasma-assisted fuel reformer in the presence of steam to reduce the amount of soot formed in the plasma reactor. The fuel consumption and related emissions were measured. The experimental results demonstrated a significant total reduction of NOx emissions compared with those from the original engine. The most obvious reduction (approximately 50%) of harmful pollution was observed under lean conditions, and the total gasoline consumption (including the gasoline required for the plasma-assisted converter) slightly increased. The results also showed that the NOx content for these new blends was lower using E5-gasoline 91 than that using E5-gasoline 95 and was generally lower using E5-gasoline 91 and syngas than that using E5-gasoline 95 and syngas.


Alharbi A, Alenazey F, Alexei M, Yuri D, Serguei Z. 2016. Reducing pollution emissions by adding syngas generated by a plasma-assisted gasoline converter in the intake manifold of a gasoline engine with electronic fuel injection system. Heat Transfer Research 47(11):1073-1082

Azhari A. 1990. So2 and Nox emission due to fossil fuel combustion in Saudi Arabia: Preliminary inventory. A tomospheric Environmental 24A(12):2917-2926

Stockholm University. 2005. Blending of Ethanol in Gasoline for Spark Ignition Engines – Problem Inventory and Evaporative Measurements.

Bechtold R, 1997. Alternative fuels guidebook. Society of Automotive Engineers Inc.

Bromberg L, Hadidi K, Cohn D. 2005. Experimental Investigation of Plasma Assisted Reforming of Methane I: Steady State Operation. Massachusetts Institute of Technology Plasma Science and Fusion Centre

Comas J, Mariño F, Laborde M, Amadeo N. 2004. Bio-ethanol steam reforming on Ni/Al2O3 catalysts. Chem Eng. 98:61– 68.

Alenazey F, Alharbi A, Chernukho A, Yuri D, Alexei M, Serguei Z. 2016. Syngas production from propane–butane mixtures using a high-voltage atmospheric pressure discharge plasma. Heat Transfer Research 47(11):1057–1072

Fierro V, Akdim O, Provendier H, Mirodatos C. 2005. Ethanol steam reforming over Ni-based catalysts. Power Sources 145:659–666

Hansen A, Zhang Q, Lyne P. 2005. Ethanol–diesel fuel blends – a review. Bioresour Technol 96:277–85.

Hsieh W, Chen R, Wu T, Lin T. 2002. Engine performance and pollutant emission of an SI engine using ethanol–gasoline blended fuels. Atoms Environ 36:403–10.

Ibrahim S. 1987. Automotive emission problem in Saudi Arabia, Environment International 13(4–5):335-338

Keunsoo K, Junghwan K, Seungmook O, Changup K, Yonggyu Ln. 2017. Evaluation of injection and ignition schemes for the ultra-lean combustion direct-injection LPG engine to control particulate emission. Applied Energy. 194: 123–135

Michael G, Robert G, Anatoliy P, Alexander R, Alexande G, Alexander F. 2010. On-board plasma-assisted conversion of heavy hydrocarbons into synthesis gas. Fuel 89: 1187–1192

Ni M, Leung D, Leung M. 2007. A review on reforming bio-ethanol for hydrogen production. Int. J. Hydrogen Energy 32:3238–3247

Olaf D. 2012. Catalytic reforming of logistic fuels at high-temperatures, Catalysis 24

Schfer F, Basshuysen R. 1995. Reduced emissions and fuel consumption in automobile engines. Altenburg: Springer-Verlag Wien and Society of Automotive Engineers, Inc.

Schweikert J. Gumbleton J. 1976. Emission Control With Lean Mixtures. SAE Technical Paper 760226

Xinli Z, Trung H, Lance L, Richard Ma. 2011. Plasma steam reforming of E85 hydrogen rich gas production. Heat Transfer Research 47(11):1073-1082

Chemical Engineering