Catalytic hydrodesulfurization (HDS) and hydrodechlorination (HDC) of chloroethyl ethyl sulfide (CEES) is carried out over a Ni-Mo/gamma-Al2O3 catalyst and Ni and/or Mo supported on active carbon (AC) catalysts. The reactions are as follows: C2H5-S-C2H4Cl + H-2 --> 2C(2)H(4) + HCl + H2S C2H5-S-C2H4Cl + 3H(2) --> 2C(2)H(6) + HCl + H2S At 300 degrees C and 0.1 MPa, complete conversion of GEES is achieved in a fixed bed microreactor over Ni-Mo/gamma-Al2O3 for 100 h with gas molar composition of H-2 : GEES : He = 10 : 0.33 : 89.7 and 24,000 cm(3)/h/g.cat space velocity. The reaction is 98.0% selective to pure hydrocarbons (ethylene and ethane; Reaction (i) and (ii)) and 2% to ethyl mercaptan on Ni-Mo/gamma-Al2O3. Over Ni-Mo/AC, the reaction is more selective toward pure hydrocarbons with >99.5% selectivity. The activity order converting GEES to pure hydrocarbons at 300 degrees C is Ni-Mo/AC > Ni-Mo/gamma-Al2O3 > Mo/AC > Ni/AC. For all catalysts, the concentration of chlorinated hydrocarbon (chloroethane) is much less than the concentration of sulfur-containing compounds (diethyl sulfide [DES] and ethyl mercaptan) in the product stream, suggesting that hydrodechlorination (HDC) is faster than hydrodesulfurization (HDS) of GEES. Two sulfur-containing compounds - 1,2 bis(ethylthio) ethane and 1,4 dithiane - are detected at short residence times. This indicates the reaction pathway is more complicated than simple HDS and/or HDC reactions. (C)2000 Elsevier Science B.V. All rights reserved.