• Journal of the Korean Institute of Gas
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• v.19 no.3
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• pp.44-48
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• 2015

The equations of hydrocarbon dew points(DT) of the fuel gas mixtures have been derived using the multiple regression analysis. In QSDR(Quantitative Structure Dew-point Relationship), the principal descriptors are CN(average carbon number) and BI(the ratio of the branched isomers). QSDRs studied by changing the pressures of the fuel gas mixtures in the range of 100 kPa ~ 500 kPa are as follows; $$DT(^{\circ}C)=-683.1+1224.98CN-898.01CN^2+308.58CN^3-49.56CN^4+3.02CN^5-12.42BI$$ (at 100 kPa, $$R_{adj}{^2}=0.99$$) (1) $$DT(^{\circ}C)=-745.2+1351.66CN-978.1CN^2+332.7CN^3-52.96CN^4+3.20CN^5-12.84BI$$ (at 200 kPa, $$R_{adj}{^2}=0.99$$) (2) $$DT(^{\circ}C)=-795.4+1457.1CN-1051.1CN^2+357.53CN^3-57.07CN^4+3.46CN^5-13.10BI$$ (at 300 kPa, $$R_{adj}{^2}=0.99$$) (3) $$DT(^{\circ}C)=-868.1+1608.4CN-1156.0CN^2+393.38CN^3-63.06CN^4+3.85CN^5-13.39BI$$ (at 500 kPa, $$R_{adj}{^2}=0.99$$) (4) As the average carbon numbers in the mixed fuel being reduced or the ratio of the branched isomers having a boiling point lower increase, The hydrocarbon dew point becomes lower, The differences between the hydrocarbon-dew points determined by the multiple regression and those calculated by the commercial program, VMGSim are negligible.