Fuel gas prodn. from synthesis gas - using mixt. of zinc and/or copper catalyst and crystalline silicate catalyst

摘要

Prodn. of gaseous fuels with a heating value of =30 MJ/m3 from synthesis gas with a H2/CO ratio of 1 is carried out by contacting the gas with a mixt. of 2-catalysts (A and B) under conditions such that =70vol% conversion is obtd.; isolating the C4-fraction from the prod.; and removing CO2 from the C4-fraction. Catalyst A contains Zn and/or Cu and is capable of converting synthesis gas to acrylic O-contg. hydrocarbons (esp. MeOH and/or Me2O). Catalyst B is a crystalline silicate which, after calcination in air at 500 degrees C for 1 hr, has the following characteristics: (i) thermally stable at 600 degrees C; (ii) characteristic X-ray powder diffraction pattern; (iii) adsorbs =0.8 mmole/g of n-hexane and =0.5 mmole/g 2,2-dimethylbutane (DMB) at 8 x 10-2 bar and 100 degrees C after evacuation at 2 x 10-9 bar and 400 degrees C for 16 hr, with n-hexane/DMB adsorption ratio of =1.5; (iv) molar compsn. y (1.0 plus-or-minus 0.3) M2O:y(a Fe2O3. b Al2O3):SiO2 (where M=H and alkali metal; a+b=1; a =0; b =0; 0 y =0.1; with the proviso that y 0.005 and a = 0 when catalyst A is Cu-free). Process can be operated with synthesis gas produced by direct steam gasification without subsequent shift conversion. High C4-yields are obtd. (e.g. 58-63% of total hydrocarbons) together with a useful gasoline-range by-product.