Comparison of energy efficiency assessment process methods: Case Bio-SNG process

T. Kohl*, Timo Laukkanen, M. Tuomaala, T. Niskanen, S. Siitonen, Mika Järvinen, P. Ahtila

*Corresponding author for this work

    Research output: Contribution to journalArticleScientificpeer-review

    18 Citations (Scopus)


    The goal of biofuel production is to partially replace fossil fuels in energy generation and transport. For the evaluation of biofuel production processes different criteria are applied and usually they include costs, efficiency aspects and emissions. However, evaluation of the energy efficiency of biofuels production is difficult since no general standard method exists for that. This paper compares three different assessment methods of energy efficiency both qualitatively and quantitatively. The methods are: thermal efficiency, exergy analysis and primary energy analysis. The feasibility of the methods is tested on a Bio-SNG (synthetic natural gas) production process which was modelled in AspenPlus and MS Excel. The results show that the exergy analysis seems to be advantageous when it comes to detailed (sub-) process analysis whereas the primary energy analysis offers the advantage of showing how the system is influencing the global primary energy resources. The results obtained by the thermal efficiency analysis do not add any new information to the results obtained by exergy and primary energy analyses. Exergy and primary energy analyses should be the preferred means for process assessment. Especially a combination of the two methods could offer the chance to develop a more holistic energy efficiency indicator. (C) 2014 Elsevier Ltd. All rights reserved.

    Original languageEnglish
    Pages (from-to)88-98
    Number of pages11
    Publication statusPublished - 1 Sep 2014
    MoE publication typeA1 Journal article-refereed
    EventInternational Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems - Guilin, China
    Duration: 16 Jul 201319 Jul 2013
    Conference number: 26


    • Primary energy efficiency
    • Exergy analysis
    • Thermal efficiency
    • Method assessment
    • Bio-SNG (synthetic natural gas)
    • Aspen Plus
    • PLANT

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