1Kindler Klaus, Puhl Hubert . Method for separating a C4- hydrocarbon mixture. US Pat Appl, US 6337429. 2002.
2Bohner Gerd, Kindler Klaus. Method for recovering crude 1,3 -butadiene by extractive distillation from a C4 cut.EP Pat Appl, EP 1366065. 2002.
3Bohner Gerd, Kindler Klaus. Method and device for obtaining 1,3 - butadiene from 1,3 - raw butadiene by distillation. WO Pat Appl, WO 200240434. 2002.
4Meyer Gerald, Kaibel Gerd. Method and device for treating a C4 fraction. US Pat Appl, US 2003181772. 2003.
5Arimori Yasuhiko, Nakano Toshihiro. Apparatus for separation and purification of saturated hydrocarbon and method for separation and purification. JP Pat Appl, JP 11349499. 1999.
6Suzuki Terutoshi, Aoyama Masutoshi. Method for separating hydrocarbon blend. JP Pat Appl, JP 63 - 27441.1988.