LOWER OLEFINS PRODUCTION PROCESS Russian patent published in 1999 - IPC

FIELD: petrochemical synthesis. SUBSTANCE: lower olefins are prepared by pyrolysis of hydrocarbon stock in tubular reactor in absence of steam and in presence of catalysts. Hydrocarbon stock can be preliminarily non-treated or purified straight- run kerosene-gas oil fraction with density 780 kg/cu. m. Method is distinguished by using, as catalyst, refractory iron-based alloy containing 15+/-1% chromium and 1.2+/-0.5% aluminum and molybdenum and made in the form of cuttings, wire, or Rashig rings at high specific surface of contact of hydrocarbons with catalytic charge in pyrolysis zone. At process temperature 800+/-20 C and flow rate 6.0 hr^-1, gas formation is 66.4+/-1.0% of the mass of stock and summary yield of unsaturated C₂-C₄-hydrocarbons is 50.8+/-1.0%, including up to 26.6% of ethylene, up to 14.8% of propylene, up to 8.3% of butenes, and up to 6.0% of divinyl, yield of coke being 0.08+/-0.01%. EFFECT: improved environmental condition, reduced power consumption, and extended choice of starting materials. 7 ex