A method for producing methanol and dimethyl ether using the air as the sole source of materials is disclosed. The invention relates to a method for separating the water (i.e., the moisture in the air) and carbon dioxide content of atmospheric air for their use in the subsequent production of methanol, dimethyl ether and derived synthetic hydrocarbons as products. The method includes the conversion of carbon dioxide and water under conditions sufficient to produce methanol and/or dimethyl ether. Methanol and/or dimethyl ether can be used as fuel or fuel additives or further converted to synthetic hydrocarbons and their products. Carbon dioxide is captured on a suitable absorbent, preferentially polyethyleneimine supported on nano-structured fumed silica. The process can also involve hydrogenation with hydrogen produced by electrolysis of water obtained from the air or from any other water source. Methanol can be dehydrated to produce dimethyl ether or further processed to produce synthetic hydrocarbons, polymers, and products derived from them by other known methods.