Process and apparatus for the treatment of nitrogen containing natural gas

摘要

The process for working up N2-contg. natural gas, esp. with N2 contents of 40-90 mol.% and contents of S and higher hydrocarbons, comprises passing the gas through an appts. (2, 3, 22) to reduce pressure. The natural gas is relieved by throttling to 200-250 bar in a 1st expansion machine (3) and with a generator (7) to a pressure of 60-100, pref. 70-90, bar. The gas is subjected to a low temp. treatment to deposit 5 C hydrocarbons and then a purifying stage (10) to remove CO2 and acidic S components. The gas is then, after intermediate cooling in a heat exchanger (17), subjected to further purifying stages (18, 20) to remove acidic gas cpds., CO2, H2O and residual 6 C hydrocarbons. The gas is then relieved in a 2nd expansion machine (22) with generator to 20-60, pref. 30-50, bar. The appts. for performing the process is also claimed.