European legislation in 1988 concerning gaseous emissions by stationary combustion installations places much greater constraints on the use of petroleum residues, which are generally rich in sulfur and nitrogen. The AUDE (AUtoDEpolluting) boiler, designed by lnstitut Francais du Petrole (IFP) and developed in collaboration with Babcock Entreprise, is initiated to meet the new needs of consumers of heavy fuel oils and residues among both refiners and industry. With its especially equipped desulfurization and denitrification chamber after the furnace, this boiler provides in situ treatment of flue gas, which gives it the advantage of holding down investments and of being easy to implement. The present article describes the research undertaken by IFP and Babcock Entreprise to develop this new piece of equipment, from the laboratory phase up to a 10 MW semi-industrial unit. It also describes the modeling support used to gain a better understanding of the exact operating of the desulfurization chamber, which will subsequently be used as a support for the sizing of industrial installations.