NOVELTY - Separation of butane and propane from a flow (1) containing liquefied petroleum gases and mercaptane, comprises: primary distillation (101) of the flow into a primary top flow (104) and bottom flow (106); secondary distillation (108) of the primary top flow into secondary top flow (112) and a secondary bottom flow (113); and recuperation of propane and butane at secondary-top flow and -bottom flow, respectively.    USE - The method is useful for the separation of butane and propane from a flow containing liquefied petroleum gases and mercaptanes (claimed).    ADVANTAGE - The method: reduces, avoids the production of disulfide oil (DSO) by concentrating the mercaptane in the condensate; is simple to operate; produces propane by satisfying the commercial specifications for mercaptanes; is adaptable to eliminate large quantity of disulfide oil; and does not operate in a very corrosive medium and does not require the usage of noble metallurgy for the equipments.    DETAILED DESCRIPTION - Process of separation of butane and propane from a flow (1) containing liquefied petroleum gases and mercaptane, comprises: primary distillation (101) of the flow into a primary top flow (104) containing propane and butane and a primary bottom flow (106) containing the condensates; the secondary distillation (108) of the primary top flow (containing propane and butane) into a secondary top flow (112) and bottom flow (113), where secondary distillation is carried out under conditions of reflux and/or a number of plates such that the secondary top flow containing propane is free of mercaptanes; and recuperation of propane and butane at the level of the secondary top and bottom flow, respectively. INDEPENDENT CLAIMS are also included for:    (1) method for the separation of butane and propane from a flow (1) containing liquefied petroleum gases and mercaptane comprising: primary distillation of the flow into a primary top flow containing propane and a primary bottom flow container the condensates, where the primary distillation being done under conditions of reflux and/or a number of plates such that the primary top flow (5) containing propane is free of mercaptane; secondary distillation of the primary bottom flow containing the condensates into a secondary top flow containing butane and a secondary bottom flow; third distillation of the secondary top flow containing butane into a third top flow and a bottom flow; recuperation of propane at the level of the primary top flow; and recuperation of butane at the level of the third bottom flow; and    (2) devices for the separation of butane and propane from a flow containing liquefied petroleum gases and mercaptane comprising: either a supply-tube of the flow, first distilling column of the flow (comprising a primary top outlet and bottom outlet), second distilling column connected at the level of its supply tube to the primary top outlet (comprising the secondary top and bottom outlet, where the second distilling column comprises a reflux and/or a number of plates such that the secondary top outlet containing propane is free of mercaptane), propane outlet at the level of the secondary top outlet, and a butane outlet at the level of the secondary bottom outlet; or supply-tube of the flow; first distilling column of the flow comprising a primary top outlet and a primary bottom outlet, where the first distilling column comprising a reflux and/or a number of plates such that the primary top outlet containing propane is free of mercaptane, second distilling column connected at the level of its supply tube to the primary bottom outlet (comprising a secondary top outlet containing butane and a secondary bottom outlet, third distilling column connected at the level of its supply tube to the secondary top outlet, comprising a third top outlet and a third bottom outlet, propane outlet at the level of the primary top outlet, and a butane outlet at the level of the third bottom outlet.    DESCRIPTION OF DRAWING(S) - The figure shows a device for the separation of butane and propane:    Flow; (1)    Primary distillation; (101)    Primary top flow; (104)    Primary bottom flow; (106)    Secondary distillation; (108)    Secondary top flow; (112)    Secondary bottom flow. (113)