| 摘要 |
A process for recovery of liquefied petroleum gas from a raw natural gas feed stream. The process includes: passing the feed stream through an indirect heat exchanger; separating the feed stream into a first vapor fraction and a first liquid fraction; transferring the first liquid fraction to the indirect heat exchanger; transferring the first vapor fraction to a direct heat exchanger absorber column; transferring the first liquid fraction to a distilling unit; distilling the first liquid fraction in the distilling unit to yield a second vapor fraction and a second liquid fraction; cooling the second vapor fraction in the indirect heat exchanger; separating the second vapor fraction into a third vapor fraction and a third liquid fraction; returning at least a portion of the third liquid fraction to the distilling unit; passing the third vapor fraction through an the indirect heat exchanger, at least a portion of the third vapor fraction condensing to a liquid phase; decreasing pressure of the third vapor fraction such that at least a portion of the liquid phase flashes; transferring the third vapor fraction to the direct heat exchanger absorber column such that the third vapor fraction mixes with the first vapor fraction, yielding a fourth vapor fraction and a fourth liquid fraction; transferring the fourth liquid fraction to the indirect heat exchanger; transferring the fourth liquid fraction to the distilling unit to distill the fourth liquid fraction; and transferring the fourth vapor fraction to the indirect heat exchanger, such that, the feed stream exchanges heat with the first liquid fraction, the fourth vapor fraction, and the fourth liquid fraction, all four streams being in parallel. Also, the third vapor fraction exchanges heat with the fourth vapor fraction and the fourth liquid fraction, all three streams being in parallel and the second vapor fraction exchanges heat with, the fourth vapor fraction and the fourth liquid fraction, all three streams being in parallel. Heat is also exchanged between the feed stream and the fourth liquid fraction, after the fourth liquid fraction has exchanged first with the third vapor fraction, and then with the second vapor fraction.
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