C2H4 →C2H5-CI→C2H5OH →C2H4→CO4
CH2=CH2+HCl->CH3-CH2Cl CH3-CH2Cl+H2O->CH3-CH2OH+HCl CH3-CH2OH-(kH2SO4,t>160°C)->CH2=CH2+H2O CH2=CH2+3O2->2CO2+2H20