consisting of liquid hydrocarbon and alcohol will be described in this example first gasoline containing 30 by volume of ethanol e30 gasoline as a blended fuel was supplied from the first conduit 3 to the first separating device 2 water in an amount of 3 5 by weight of the blended fuel was supplied from the first water conduit 4 and the blended fuel and the water were mixed thus in the first separating device 2 an ethanol water mixture as the alcohol water mixture 21 and gasoline as the liquid hydrocarbon 22 were separated and the gasoline and the ethanol water mixture were obtained in upper and lower layers respectively the gasoline was about 63 by weight of the total amount and the ethanol water mixture was about 37 by weight of the total amount then part of the ethanol water mixture drawn from the first separating device 2 was supplied to the reforming device 13 through the fifth conduit 10 at a flow rate of 10 kg h the catalyst device 31 in the reforming device 13 was charged with about 1 kg heteropolyacid as acid catalyst and the opening degree of the control valve 36 was adjusted to heat the acid catalyst in the catalyst device 31 to about 210 u00b0 c thus the ethanol in the ethanol water mixture was dehydrated and condensed to generate diethylether and the ethanol water mixture was modified to the ether water.