Experiments conducted to investigate the reaction between a laboratory-prepared atmospheric residue (oil) and elemental sulphur are described. Results of the reaction between 10 and 50 wt y/, sulphur-in-oil mixtures, conducted on a thermogravimetric balance under controlled conditions of temperature and heating rate are presented. Data obtained from a batch reactor used to prepare a 2.0 kg batch of a SO/50 wt/wt mix is also included and analyses of products and residues are shown. The reaction, carried out at 473 K for a period of about 5 h, results in the loss of volatile reaction products in the first hour and of hydrogen sulphide and elemental sulphur continuously. The product yield increases with increased sulphur content in the original reaction mixture and is optimised at 50 wt y0 sulphur in oil. The chemical analyses indicate that the extent of reaction achieved by a 20 wt % sulphur-oil mixture is similar to that from a 50 wt '4 sulphur-oil mixture, but that fixation of carbon when the reaction product is heated to 873 K is strongly affected by the presence of the additional sulphur. Refluxing of condensed reaction products does not affect the final yield which is greater than 90% for a 50/50 sulphur-oil mixture. Nitrogen and carbon dioxide BET surface areas of the 873 K char, measured at 77 K and 192 K are 67.3 and 203.8 m* g-' respectively.