A system and a method for converting Natural Gas (NG) to high energy transportable liquid (such as gasoline) are disclosed. A semiconductor UV-source is used for initiate a photo lytic reaction between methane molecules and photons having energy equal or bigger than the energy of dissociation of the C—H bond in methane. The formed radicals are further react to produce higher molecular weight hydrocarbons, while hydrogen gas is separates from the reaction mixture in order to avoid reverse reactions.