| 摘要 |
1,187,938. Separating hydrocarbon gases. CONTINENTAL OIL CO. 18 June, 1968 [10 Aug., 1967], No. 29058/68. Heading B1L. Condensables are removed from a hydrocarbon feed gas, e.g. natural gas, by sorption, the sorbent e.g. activated carbon, being subsequently desorbed and regenerated by means of a heated gas stream, a surge zone being provided which communicates both with the feed line and with the regeneration circuit. As shown, in a 3-phase cyclic process, feed gas is passed by lines 1 and 2B to sorbent bed in adsorber 6, effluent depleted of condensables and other constituents leaving by lines 7B and. 3. Meanwhile, adsorber 5 is being desorbed and regenerated by a heated gas stream which arrives by lines 8, 9A and 2A, the rich effluent which leaves by lines 10A, 11, 12 and 13 passing through coolers 14 and 15 to scrubber 16, the condensables condensed therein being withdrawn as product by line 17. The effluent gas therefrom passes by line 18, booster 19, line 20, heat exchanger 21 and line 22 to heater 23 before recirculation by line 8. Surge tank 24, filled with glass fibre or containing baffles, is connected to scrubber 16 by line 25 and to feed line 1 by line 26. At the same time as adsorber 5 is being desorbed, adsorber 4 is being cooled prior to coming on stream by means of a cool residue gas stream fed by lines 27, 30 and 2. The effluent heated gas then passes by lines 29 and 28 to heat exchanger 21 to heat gas in the regenerating phase leaving scrubber 16 and then passes by line 31 and either out of the system through lines 32 and 3, or is recirculated by lines 33, booster 34 and cooler 36, or both. At the end of the regeneration phase, coolers 14 and 15 and scrubber 16 are bypassed by opening valve 21 and closing valve 22 so as to displace hot gas from adsorber 5 to adsorber 6 until the displacing gas just reaches the outlet of adsorber 6; at this point, valve 21 is closed and valve 22 reopened, and the adsorbers switched so that adsorbers 6, 5 and 4 are operated in the regeneration, cooling and sorption phases respectively. If preferred, the displacement gas may be drawn from lines 27, 30A and 2A into adsorber 5, in which case coolers 14 and 15 and scrubber 16 are not by passed. The flow rates of feed and of the circulating gas stream in the regeneration circuit is controlled automatically at the points indicated by controller R.F.R.C. The inclusion of surge tank 24 provides a volume into which the gas in the regeneration circuit can expand when pressure therein rises quickly at the start of this phase because of the initial preferential desorption of non-condensables and this expansion may pass gas through the tank and back into the feed line, later in the phase, as condensables are desorbed and condensed, pressure drops and the gases which have expanded into the tank pass back into the regeneration circuit. |
