Method and system for separating and purifying helium in natural gas

• Main Authors: XU YIXIAO, XI RENJIE, LIU HUABIN, LI HESHENG, WEI XIN, LIU YIQUN
• Format: Patent
• Language: Chinese; English
• Published: 07.05.2024
• Subjects: ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE ORUNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; CHEMISTRY; FIRELIGHTERS; FUELS; FUELS NOT OTHERWISE PROVIDED FOR; LIQUEFIED PETROLEUM GAS; LUBRICANTS; METALLURGY; NATURAL GAS; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BYSUBCLASSES C10G, C10K; TECHNICAL GASES CONTAINING CARBON MONOXIDE; TRANSPORTING

The invention relates to the technical field of separation and purification of natural gas, and discloses a method and system for separating and purifying helium in natural gas, and the method comprises the following steps: (1) dehydrating and deacidifying natural gas raw material gas to obtain pretreated gas; (2) pressurizing the pretreated gas, then carrying out VOC membrane separation, and carrying out shallow cold oil absorption on the obtained permeation side gas to obtain C2 and above organic matter components; (3) pressurizing the retentate side gas obtained by the VOC membrane separation, and then carrying out one-stage or multi-stage helium membrane separation to obtain crude helium with the purity of 70% or above; (4) carrying out PSA (pressure swing adsorption) on the crude helium to obtain high-purity helium with the purity of 99.9% or above; wherein the natural gas raw material is 0.1-1% by volume of low-concentration helium. The VOC membrane separation technology, the shallow cold oil absorption