Natural Gas Processing - Nitrogen Removal from Natural Gas

The growing demand on natural gas leads to the necessity to upgrade sub-quality gas. This sub-quality gas partly contains high amounts of nitrogen and/or carbon dioxide, sometimes helium is even a component of natural gas. To achieve pipeline and sales gas specification it is necessary to remove non desired components. Higher hydrocarbons such as ethane, propane, butane and pentane and he-lium can form valuable by-products. It is economically feasible to recover helium, if the amount in natural gas is higher than 0.1 mol%. Some of the recovery processes are well known from air separation: - Cryogenic single column. - Cryogenic double column. - Adsorption (Pressure Swing Adsorption, PSA). In the last decades three additional processes were introduced into gas processing industry: - Absorption (Mehra ProcessSM). - Adsorption (Molecular GateTM). - Membrane Separation. This book gives a short overview of above mentioned processes and compares the processes in technical and economical aspects.