Methanol, a popular alternative fuel candidate, can theoretically be dissociated on-board a vehicle into a 2/1 molar mixture of hydrogen (H2) and carbon monoxide (CO) having a 14 percent greater heating value than that of methanol vapor. In this study, engine efficiency and fuel consumption with methanol vapor and dissociated methanol (simulated by a 2/1 mixture of Ha and CO) were compared in a single-cylinder engine at equivalence ratios (Φ’s) ranging from 0.5 to 0.9 and compression ratios (CR’s) from 11 to 14. Whan compared at the same Φ and CR, the reduction in fuel consumption for dissociated methanol compared to methanol (3-7 percent) was smaller than would be expected based on heating value alone. Indicated thermal efficiency with dissociated methanol was only 0.89-0.55 times that with methanol.Thermodynamic analyses were conducted to isolate the factors responsible for lower efficiency with dissociated methanol. The largest factor was dissociated methanol’s lower molecular weight (10.68 compared to 32.04 for methanol), causing an increase in compression work. Also, the higher heating value of dissociated methanol caused an increase in heat losses from the engine. Factors opposing the loss in efficiency with dissociated methanol were its faster burning rate and higher heat capacity per unit mass.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    A Comparison of Methanol and Dissociated Methanol Illustrating Effects of Fuel Properties on Engine Efficiency—Experiments and Thermodynamic Analyses


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE International Congress and Exposition ; 1985



    Publication date :

    1985-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English







    Engine Operation on Partially Dissociated Methanol

    Koenig,A. / Ellinger,K.W. / Korbel,K. et al. | Automotive engineering | 1985


    Engine Operation on Partially Dissociated Methanol

    König, Axel / Ellinger, Karl-Werner / Korbel, Kurt | SAE Technical Papers | 1985