Patent DE-102009038456-A1 (DE)
Title: Method for the separation of hydrocarbons in a plant for producing hydrocarbon from a hydrocarbon-containing element by splitting, comprises compressing and drying the product gas of splitting containing gaseous hydrocarbon material
Inventor: DUC TUAT PHAM
IPC: C07C7/11
Filed: 2009-08-21
Abstract: The method for the separation of hydrocarbons in a plant for producing hydrocarbon from a hydrocarbon-containing element by splitting (1), comprises compressing and drying the product gas of splitting containing gaseous hydrocarbon material emerging as raw gas (2) and then supplying as feedstock in a separation zone in which the raw gas is separated into a hydrocarbon fraction from hydrocarbon with maximum 3 carbon atoms, and a hydrocarbon fraction from hydrocarbon with 4 carbon atoms. The front end of C 3/C 4-separation consists of C4-absorber (4) and a column. The method for the separation of hydrocarbons in a plant for producing hydrocarbon from a hydrocarbon-containing element by splitting (1), comprises compressing and drying the product gas of splitting containing gaseous hydrocarbon material emerging as raw gas (2) and then supplying as feedstock in a separation zone in which the raw gas is separated into a hydrocarbon fraction from hydrocarbon with maximum 3 carbon atoms, and a hydrocarbon fraction from hydrocarbon with 4 carbon atoms. The front end of C 3/C 4-separation consists of C4-absorber (4) and a column in which hydrocarbons are drawn off with four hydrogen atoms as bottom product. The hydrocarbon fraction is supplied from hydrocarbon with maximum 3 carbon atoms in the separation zone, which consists of first column (12) and a second column. The second column has two separate sections. In the first column, the hydrocarbon fraction from hydrocarbon with maximum 2 carbon atoms is drawn off as main product. The bottom product of the first column is abandoned to the lower section of the second column. The C 4-absorber is operated in a pressure of 11-20 bar and the depropanizer (10) is operated in a pressure of 8-12 bar. The main product of the absorber is supplied to a further compressing zone. The main product of the C 4absorber is supplied over a hydration zone for hydrocarbon with maximum 3 carbon atoms in the first column. The top section of the second column is operated as demethanizer and the lower section of the second column is operated as deethanizer. The two columns are operated on a pressure of 9.5 bar. The main product of the first column is subjected to a deep cooling, in which a fraction is obtained that consists of 90% of methane, and a fraction is obtained that consists of 95% of hydrogen. The condensate obtained in the deep cooling is brought to the top section of the second column. The main product is brought to the top section of the second column in the deep cooling. The bottom product is supplied to the top section of the second column as raw material in a third column in which ethylene is obtained as main product and ethane is obtained as bottom product. The hydrocarbon fraction with 3 carbon atoms is drawn off from sump of the lower section of the second column and is brought as raw material in a fourth column in which propylene is obtained as main product and propane is obtained as bottom product. Cold required in deep cooling is produced with ethylene freezing agent and with recycled gas containing methane and hydrocarbon with 2 hydrocarbon atoms or with a mixture of freezing agent containing hydrocarbon with one, two or three carbon atoms.