Data on sulphur retention, combustion efficiency, NO/sub x/ emissions, heat transfer and elutriation in PFB combustors are collected in one report for future reference. The sulphur retention section comprises relevant experimental data from most of the published sources, whilst other sections are limited mainly to results obtained under contract to the United States DOE in a 3 ft x 2 ft combustor operating at 6 atm pressure and a 1 ft x 1 ft combustor operating at 6 to 20 atm pressure. The data are discussed, and correlations applied where appropriate. 29 refs., 26 figs., 19 tabs.