Mixture of CO and H2, after removal of CO2 by washing with K2CO3, is passed over a Ni catalyst on pumice at 180°-250°. By using a mixture of 3 vol. H7 to 1 vol. CO, almost pure CH4 is obtained. The CH4 with or without addition of CO and H2 is passed over a catalyst of BF3, colloidal Pd, SbCl3, and AlCl3. The liquid obtained thus contains toluol, xylol, cyclohexane, and heptane. If the CH4 is passed through a tube heated to 390° over a Ni or V catalyst, a mixture of C2H2 and H2 is obtained, and over a Ni, Co, or Fe catalyst at 200°-300° a petroleum liquid distilling mostly up to 150°.