TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The methane rich product stream (S2) is contacted with hydrocarbon selective sorbent subsequent to the formation of first product stream (S1) so as to adsorb hydrocarbon having 4 carbon atom or more, in to stream (S2). The hydrocarbon selective sorbent preferentially adsorbs C3+ hydrocarbons. The nitrogen-selective sorbent (NSB) is periodically heated after formation of stream (S2) and purge stream, to drive off accumulated methane from NSB. The NSB is subsequently cooled by contacting with a gas stream containing at least 30 mol% of nitrogen, preferably at least 90 mol% of nitrogen and remaining methane. The nitrogen containing gas stream is fed to NSB counter current to the direction of feed stream. The stream (S2) is heated to 200degreesF, and the hot stream is contacted with NSB. The first pressure swing adsorption unit (20) (PSA) is concurrently depressurized to form a lower product stream. The stream (S1) is combined with lower pressure product stream and the combined stream is contacted with NSB. The pressure of stream (S1) is reduced to the pressure of low pressure product stream before combining. The second PSA (30) is depressurized to form a low pressure recycle stream having a pressure lower than stream (S2) and higher than purge stream. The low pressure recycle stream is combined with stream (S1), and the combined stream is passed to NSB. The pressure of low pressure recycle stream is raised and the pressure of stream (S1) is lowered so that the low pressure recycle stream and stream (S1) are at the same pressure before combination. Alternatively, first PSA unit is depressurized to form a low pressure product stream which is combined with stream (S1) and recycled stream, and contacted with NSB. The pressure of stream (S1) is lowered to the pressure of lower pressure product stream, and the pressure of lower pressure recycle stream is raised to the pressure of lower pressure product stream before combination. The pressure of second PSA after formation of low pressure recycle stream and before the formation of purge stream, is equal. Preferred Sorbents: The NSB is a crystalline titanium silicate having a pore size of 3-less than 4 Angstrom , preferably barium exchanged crystalline titanium silicate with barium comprising at least 30% of the exchangeable cations of titanium silicate. The NSB is silica. Preferred Composition: The natural gas stream contains 4 mol% of nitrogen. The stream (S1) is devoid of hydrocarbon having 4 or more carbon atoms, and has reduced level of propane relative to natural gas stream. The feed stream optionally contains water and/or carbon dioxide. EXAMPLE - (In lbs) A cake obtained by heating a gel formed by mixing 10 gpm of caustic solution (containing deionized water (2600), N-clear sodium silicate (6806) and sodium hydroxide solution (6766)) and 10 gpm of acidic solution (containing water (3819), titanium sulfate solution (8395) and sulfuric acid (631)), was reslurried with 75 gal of deionized water and heated to 170degreesF for 15 minutes to obtain a EST-4 cake. A solution of strontium chloride hexahydrate (7.84 kg) in 34 gal of deionized water, was added with the obtained EST-4 cake (39.7 kg). The resulting slurry was stirred at 50 rpm and reacted at 170degreesF for 90 minutes. The slurry was then filtered, washed and the strontium exchanged cake was dried. The strontium exchanged cake (in g) (1715) was mixed with bentonite cake powder (196.1) for 10 minutes. The blend was added with water (1550) in small portions, under low agitation. The blend was then vigorously rotated, and the beads formed were dried. The beads were again added with water (1260) under low agitation in portions, the resulting blend was vigorously rotated and the product was dried. The dried product was further dried to a dew point of -45degreesF, heated to 250degreesC for 10-12 hours and cooled to -45degreesF to prepare nitrogen-selective adsorbent CTS-1. A feed stream comprising (in moles) methane (0.8565), ethane (0.0296), propane (0.0079), n-butane (0.0027), nitrogen (0.1), carbon dioxide (0.0005), water (0.0001), helium (0.0011), n-pentane (0.0011) and n-hexane (0.0004), was passed to a pressure swing adsorption unit containing silica gel Sorbead AF125. The stream from first pressure swing adsorption unit was then passed to a second pressure swing adsorption unit comprising nitrogen-selective adsorbent CTS-1. A stream comprising methane (0.941448), ethane (0.02116), propane (0.001299), nitrogen (0.035) and helium (0.001093), was obtained as product stream from a pressure swing adsorption unit.