Granular iron ore direct redn. in blast furnace using natural gas - with high ethane content as source of methane for producing carbon mon:oxide and hydrogen@

摘要

Direct redn. of granular Fe ore is carried out in a blast furnace with a redn. gas contg. H2 and CO, produced from a CH4-rich gas (I) on an indirectly heated catalyst (II) at 800-1200 deg.C, the top gas from the blast furnace being used (partly) as fuel for indirect heating of (II). The novel features are as follows. Natural gas (III), contg. 50-80 (vol.)% CH4 and 20-45% C2H6 and propane and higher hydrocarbons is compressed to 20-40 bar, cooled to -40 to -80 deg.C in a heat exchange zone and passed to a first separator. A first condensate (IV) contg. C2H6 is discharged from the first separator, partly expanded by a pressure difference of 2-20 bar and passed to a second separator. A CH4 fraction (V) is discharged from the first separator and partly expanded by cooling. (I), contg. at least 75% CH4 and 5-20% C2H6 and having a temp. of -75 to -100 deg.C, is discharged from the second separator. (I) is heated in a heat exchange zone, then heated further and passed over (II). A second condensate (VI) contg. C2H6 is discharged from the second separator and vapourised in the heat exchange zone. ADVANTAGE - The process permits the use (III) with a high C2H6 content and minimis soot formation on (II).