Volume 8, Issue 2, March 2019, Page: 18-27
Algorithm for Determining the Knock Resistance of LNG
Martijn Van Essen, DNV-GL Oil & Gas, Groningen, The Netherlands
Sander Gersen, DNV-GL Oil & Gas, Groningen, The Netherlands
Gerco Van Dijk, DNV-GL Oil & Gas, Groningen, The Netherlands
Maurice Van Erp, Shell Projects & Technology, Rijswijk, The Netherlands
En Howard Levinsky, Energy and Sustainability Research Institute, University of Groningen, Groningen, The Netherlands
Received: May 28, 2019;       Accepted: Jul. 10, 2019;       Published: Jul. 24, 2019
DOI: 10.11648/j.ijepe.20190802.12      View  40      Downloads  16
This paper reports the development of a next-generation algorithm to calculate the knock resistance for LNG compositions. This so-called PKI Methane Number is developed and tested for a lean-burn, medium-BMEP gas engine. The algorithm itself is a polynomial equation based on thousands of simulations performed using an experimentally verified engine knock model. Comparison of the PKI MN calculated using the gas-input-only algorithm and measurements on the test engine show very good agreement. A comparison with two existing methods for calculating the methane number (AVL and MWM Method as defined in EN 16726) with experimental engine data show reasonable agreement with predictions using AVL method but substantial differences with predictions from MWM method are observed. Additionally, the current methods such as AVL and MWM need a dedicated solver to calculate the methane number. In contrast, the algorithm described here is a polynomial equation that is very easy to implement in gas composition sensors for fast real-time methane number calculations. This opens possibilities for smart-phone methane number calculation during bunkering and fuel-adaptive control systems that could optimize engine performance for a broad range of fuel compositions. Furthermore, given the experimentally verified reliability and ease of implementation of the PKI MN algorithm, we assert that it is an excellent, open-source candidate for international standards for specifying the knock resistance of LNG.
LNG, Methane Number, Engine Knock, Algorithm
To cite this article
Martijn Van Essen, Sander Gersen, Gerco Van Dijk, Maurice Van Erp, En Howard Levinsky, Algorithm for Determining the Knock Resistance of LNG, International Journal of Energy and Power Engineering. Vol. 8, No. 2, 2019, pp. 18-27. doi: 10.11648/j.ijepe.20190802.12
Copyright © 2019 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The LNG industry GIIGNL Annual Report 2017,
M. van Essen, S. Gersen, G. van Dijk, H. Levinsky, T. Mundt, G. Dimopoulos and N. Kakalis, “The effect of boil off on the knock resistance of LNG gases”, CIMAC Congress, Helsinki, Finland, June 6-10, 2016, paper 123.
J. B. Heywood, International Combustion Engine fundamentals, McGraw-Hill, 1989.
M. Leiker, W. Cartelliere, H. Christoph, U. Pfeifer, and M. Rankl, (1972) Evaluation of Anti-Knock Property of Gaseous Fuels by Means of the Methane Number and Its Practical Application, ASME paper 72-DGP-4.
California Alternative Fuels for Motor Vehicle Regulations Appendix D: Methane Number and fuel composition,
Gary Choquette, “Analysis and estimation of stoichiometric air-fuel ratio and methane number for natural gas”, 23rd Gas Machinery Conference, Nashville, USA, October 5-8, 2014.
G. W. Sorge, R. J. Kakoczki, and J. E. Peffer, “Method for determining knock resistance rating for non-commercial grade natural gas”, US Patent 6,061,637, May 9, 2000.
R. T. Smith, G. W. Sorge, and J. R. Zurlo, “Systems and Methods for Engine Control Incorporating Fuel Properties”, European Patent EP 2 963 270 A1, 25th May 2015.
prEN16726: 2014 - Annex A.
C. Rahmouni, G. Brecq, M. Tazerout, O. Le Corre, (2004) Knock rating of gaseous fuels in single cylinder spark ignition engine, Fuel 83 (3) 327-336.
“Gas Methane Number Calculation MWM method”, April 2013 (documentation Euromot MWM tool).
Methane number calculation of natural gas mixtures,
GasCalc Software,
EUROMOT position paper, “Methane number as a parameter for gas quality specifications”, 2012.
International group of liquefied natural gas importers, “Position paper on the impact of including methane number in natural gas regulation”, 2015.
See, for example, ISO/TC 28/SC 4/WG 17 “LNG as a marine fuel”.
Patrik Soltic, Hannes Biffiger, Philippe Pretre and Andreas Kempe (2016) Micro-thermal CMOS-based gas quality sensing for control of spark ignition engines, Measurement 91, 661-679.
K. Saikaly, O. Le Corre, C. Rahmouni and L. Truffet (2010) Preventive Knock Protection Technique for Stationary SI Engines Fuelled by Natural Gas, Fuel Processing Technology 9 641-652.
S. Gersen, M. van Essen, H. Levinsky, and G. Dijk (2016) Characterizing Gaseous Fuels for Their Knock Resistance based on the Chemical and Physical Properties of the Fuel, SAE Int. J. Fuels Lubr. 9 (1), doi: 10.4271/2015-01-9077.
M. van Essen, S. Gersen, G. Dijk, T. Mundt, et al. (2016) The Effect of Humidity on the Knock Behavior in a Medium BMEP Lean-Burn High-Speed Gas Engine, SAE Int. J. Fuels Lubr. 9 (3), doi: 10.4271/2016-01-9075.
D. van Alstine, D. Montgomery, T. Callahan, and R. Florea, “Ability of the Methane Number Index of a Fuel to Predict Rapid Combustion In Heavy Duty Dual Fuel Engines for North American Locomotives”, Proceedings of the ASME 2015 Internal Combustion Engine Division Fall Technical Conference, November 8-11, 2015, Houston, TX, USA, paper ICEF2015-1119.
TKI LNG report, a correct ‘octane number’ for LNG, report No.: OGNL.113944, 30-11-2017.'octane_number'_for_LNG
Browse journals by subject