Experiments are performed on continuous detonation combustion of ternary hydrogen liquid propane air mixture in a large-scale annular combustor 406 mm in outer diameter with an annular gap of 25 mm. Liquid propane is fed into the combustor at the time when sustained continuous-detonation combustion of hydrogen air mixture is attained therein. Mass flow rates of hydrogen, propane and air in the experiments ranged from 0.1 to 0.5 kg/s (hydrogen), 0.1 to 0.5 kg/s (propane), and 5 to 12 kg/s (air). Continuous-detonation combustion of liquid propane in air is obtained for the first time due to addition of hydrogen rather than due to enrichment of air with oxygen. Combustor operation with a single continuously rotating detonation wave (DW) for about 0.1 s has been obtained when the flow rates of propane and air remained constant while the flow rate of hydrogen was rapidly decreasing. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.