Abstract: A smoking article which comprises tobacco treated with a high loading level of humectant and which has been expanded by a high level expansion process to produce expanded tobacco having a humectant loading level in the range of 4% to 15%. The particulate matter, water, nicotine and humectant free (PMWNHF) to nicotine delivery ratio of smoking articles according to the invention and smoked under standard machine smoking conditions is not more than 8 to 1.

Abstract: In a method of expanding tobacco the tobacco is contacted in a first vessel with an expansion agent and, with the vessel being closed and liquid phase expansion agent in the tobacco being at a temperature above the boiling point at a lower, release pressure, the first vessel is connected to a closed second vessel the interior of which is at the release pressure. When the tobacco is contacted in the first vessel with the expansion agent, the tobacco is maintained in a mobilized, particle separated condition by supplying gaseous mobilizing medium to a mobilizing zone of the first vessel via nozzles located at upwardly diverging walls bounding the zone and preferably supplying in addition gaseous accelerating medium to the zone in an upward direction from a lower region of the zone.

Abstract: Tobacco expansion apparatus comprises a transport duct in which can be established a flow of hot gaseous medium and into an upstream end of which can be fed particulate tobacco. The downstream end of the duct opens into the casing of a tobacco/gaseous medium separator comprising a separation screen.

Abstract: The method for expanding tabacco lamina comprises contacting the tobacco with an organic expansion agent, heating the thus contacted tobacco in a closed first vessel so that the temperature of the agent is above the boiling point of the agent at a lower release pressure, and suddenly venting the first vessel into a second vessel which is at said release pressure prior to the venting. By this means the fill volume of the tobacco is increased by a least 50%.

Abstract: A tobacco expansion agent capable of synergistic tobacco expansion comprises a first organic compound which is volatile, non-polar and substantially water insoluble and a second organic compound which is volatile, water soluble, oxygen containing and of a polarity in excess of that of the first compound.