摘要 |
C2-C4 paraffins or hydrocarbon mixtures comprising more than 50%w of C2-C4 paraffins are converted into an aromatic hydrocarbon mixture over a crystalline gallium silicate having a SiO2/Ga2O3 molar ratio of 25-250 and a Y2O3/Ga2O3 molar ratio lower than 1 (Y = Al, Fe, Co and/or Cr), and having an X-ray powder diffraction pattern after one hour's calcination in air in which pattern the strongest lines are shown at interplanar spacings d( ANGSTROM ) of 11.2 +/- 0.2; 10.0 +/- 0.2; 3.84 +/- 0.07; 3.72 +/- 0.06. The silicate has been subjected at least once to a two-step treatment comprising a coke deposition and a coke-burn off with an oxygen-containing gas at 350-700 DEG C. |