Gas treatment facility comprising: - a circuit for treating gas that is to be denoxified, in which is placed a gas denoxification catalytic reactor which: -- has a first inlet for gas that is to be denoxified communicating with a supply pipe for gas that is to be denoxified and a first outlet for denoxified gas communicating with a pipe for removing at least partially denoxified gas, -- and contains a catalyst (5a, 5b, 5c, 5d) able to denoxify at least some of the gas that has entered the catalytic reactor and with which at least some of the said entering gas comes into contact, - a circuit for regenerating at least some of the catalyst of the catalytic reactor, this circuit having a first inlet admitting regeneration gas into the catalytic reactor communicating upstream with a supply pipe for regeneration gas suited to regenerating the catalyst and a first outlet for gas derived from the regeneration communicating with a pipe (23, 39) for removing gas derived from the regeneration, the regeneration-gas supply pipe communicating with a gas outlet (25, 27) of gas heating means, a gas inlet of which communicates with the pipe supplying gas that is to be denoxified, characterized in that the gas heating means comprise a gas/gas exchanger through which there circulate, without mixing with one another, at a first temperature, at least some of the gas derived from the regeneration and, at a second temperature lower than the first, gas derived from the pipe for supplying gas that is to be denoxified. - a circuit for treating gas that is to be denoxified, in which is placed a gas denoxification catalytic reactor which: -- has a first inlet for gas that is to be denoxified communicating with a supply pipe for gas that is to be denoxified and a first outlet for denoxified gas communicating with a pipe for removing at least partially denoxified gas, -- and contains a catalyst (5a, 5b, 5c, 5d) able to denoxify at least some of the gas that has entered the catalytic reactor and with which at least some of the said entering gas comes into contact, -- has a first inlet for gas that is to be denoxified communicating with a supply pipe for gas that is to be denoxified and a first outlet for denoxified gas communicating with a pipe for removing at least partially denoxified gas, -- and contains a catalyst (5a, 5b, 5c, 5d) able to denoxify at least some of the gas that has entered the catalytic reactor and with which at least some of the said entering gas comes into contact, - a circuit for regenerating at least some of the catalyst of the catalytic reactor, this circuit having a first inlet admitting regeneration gas into the catalytic reactor communicating upstream with a supply pipe for regeneration gas suited to regenerating the catalyst and a first outlet for gas derived from the regeneration communicating with a pipe (23, 39) for removing gas derived from the regeneration, the regeneration-gas supply pipe communicating with a gas outlet (25, 27) of gas heating means, a gas inlet of which communicates with the pipe supplying gas that is to be denoxified, characterized in that the gas heating means comprise a gas/gas exchanger through which there circulate, without mixing with one another, at a first temperature, at least some of the gas derived from the regeneration and, at a second temperature lower than the first, gas derived from the pipe for supplying gas that is to be denoxified.