A method for recovery of spent lubricating oil, the method comprising steps of: passing the spent lubricating oil having a temperature ranging between 25°C to 30°C and a pressure ranging between 150 to 1030 mbar through a first evaporator having a heat exchanger with a heating media at a temperature ranging between 230°C to 380°C for heating the spent lubricating oil at a temperature ranging between 70°C to 240°C, thereby forming vapours of light hydrocarbon, water, and ethylene glycol form the spent lubricating oil at the heat exchange surface; condensing vapours received from the first evaporator in a first condenser; separating vapours and liquid from the vapours received from the first condenser in a first separator; compressing the vapours from the first separator in a first compressor; passing the spent lubricating oil pumped from the first evaporator having a temperature ranging between 70°C to 240°C through a second evaporator at a pressure ranging between 6 to 30 mbar, the second evaporator having heat transfer tubes arranged vertically for heating the spent lubricating oil, which is distributed to form a flowing film passing over a surface of the heat transfer tubes which have a heating media at a temperature ranging between 230°C to 380°C for heating the spent lubricating oil at a temperature ranging between 200°C to 290°C, thereby forming vapours of light vacuum gasoil from the spent lubricating oil at the heat exchange surface; condensing the vapours received from the second evaporator in a second condenser; separating vapours and liquid from the condensed vapours received from the second condenser in a second separator; compressing the vapours received from the second separator in a second compressor; passing the spent lubricating oil pumped from the second evaporator having a temperature ranging between 200°C to 290°C through a third evaporator at a pressure ranging between 0.5 to 15 mbar, the third evaporator having heat transfer tubes arranged vertically for heating the spent lubricating oil, which is distributed to form a flowing film passing over a surface of the heat transfer tubes which have a heating media at a temperature ranging between 300°C to 380°C for heating the spent lubricating oil to a temperature ranging between 250°C to 320°C, thereby forming vapours of vaporising heavy gasoil from the spent lubricating oil; condensing the vapours received from the third evaporator in a third condenser; separating vapours and liquid from the condensed vapours received from the third condenser in a third separator; compressing the vapours received from the third separator m the third compressor, thereby recovering the spent lubricating oil. passing the spent lubricating oil having a temperature ranging between 25°C to 30°C and a pressure ranging between 150 to 1030 mbar through a first evaporator having a heat exchanger with a heating media at a temperature ranging between 230°C to 380°C for heating the spent lubricating oil at a temperature ranging between 70°C to 240°C, thereby forming vapours of light hydrocarbon, water, and ethylene glycol form the spent lubricating oil at the heat exchange surface; condensing vapours received from the first evaporator in a first condenser; separating vapours and liquid from the vapours received from the first condenser in a first separator; compressing the vapours from the first separator in a first compressor; passing the spent lubricating oil pumped from the first evaporator having a temperature ranging between 70°C to 240°C through a second evaporator at a pressure ranging between 6 to 30 mbar, the second evaporator having heat transfer tubes arranged vertically for heating the spent lubricating oil, which is distributed to form a flowing film passing over a surface of the heat transfer tubes which have a heating media at a temperature ranging between 230°C to 380°C for heating the spent lubricating oil at a temperature ranging between 200°C to 290°C, thereby forming vapours of light vacuum gasoil from the spent lubricating oil at the heat exchange surface; condensing the vapours received from the second evaporator in a second condenser; separating vapours and liquid from the condensed vapours received from the second condenser in a second separator; compressing the vapours received from the second separator in a second compressor; passing the spent lubricating oil pumped from the second evaporator having a temperature ranging between 200°C to 290°C through a third evaporator at a pressure ranging between 0.5 to 15 mbar, the third evaporator having heat transfer tubes arranged vertically for heating the spent lubricating oil, which is distributed to form a flowing film passing over a surface of the heat transfer tubes which have a heating media at a temperature ranging between 300°C to 380°C for heating the spent lubricating oil to a temperature ranging between 250°C to 320°C, thereby forming vapours of vaporising heavy gasoil from the spent lubricating oil; condensing the vapours received from the third evaporator in a third condenser; separating vapours and liquid from the condensed vapours received from the third condenser in a third separator; compressing the vapours received from the third separator m the third compressor, thereby recovering the spent lubricating oil.