Abstract
The outline of ethylene production through naphtha cracking, especially by the Stone & Webster process, is gven.The process is to crack the naphtha at the fized condition of abovt 301bs/sq.in.g.and 700-800°C, then the pyrolysis gas is purified by removing the acetylene, carbon dioxide and hydrogen sulfide and fractionated into various products.The entire production process is made up of the cracking process, pre-fractionation process, gas treating process, low temperature fractionation process, and high temperature fractionation process.The low temperature fractionation process, where the frac tionation is carried out under the condition of low temperature below 0°C and high pressure, reouires a removal unit of contained water and a refrigeration unit with a large capacity.Beside the main product of ethylene, residue gas which is a mixture of hydrogen and methane, ethane, propylene, C4 fraction containing considerable amount of butadiene, pentane fraction, cracked gasoline which has a high octane value and is rich of benzene, toluene and xylene, and fuel oil are produced from this process.
