Gas station membrane method for oil and gas recovery or condensation with membrane? How to choose between the two routes

Gas station membrane method for oil and gas recovery or condensation with membrane? Direct answer: There is no absolute superiority or inferiority between the two routes, depending on the station conditions and demands - the membrane method alone has a compact structure, simple operation and maintenance, and is suitable for stations with tight venues and peace of mind; Condensation with film is the process of first condensing and liquefying most of the oil and gas, and then enriching the film section at the bottom. It has stronger efficiency and resistance to fluctuations, and is suitable for high concentration and high load situations that require deep treatment. The selection is not more advanced than anyone else, and it is more closely related to the site's oil and gas volume, concentration, and site constraints. This article explains the selection logic from four dimensions: efficiency, land occupation, operation and maintenance, and cost.

The difference in mechanism between the two routes

The membrane method relies solely on the selective permeation of membrane components, where the intake is driven by pressure difference to allow oil and gas to pass through while air remains, resulting in enriched oil and gas flowing back. The process is short and has fewer components. The condensation and membrane addition process is two-stage: first, the oil and gas are cooled and liquefied by refrigeration, and most of the liquid oil is recovered. The remaining low concentration tail gas is then concentrated in the membrane section, resulting in a much smaller membrane load. The differences in mechanisms determine all subsequent comparisons: the single membrane process is simple but has weak resistance to concentration fluctuations, the condensation and membrane addition efficiency is stable but the system is complex, and it occupies more land and consumes more energy. Understanding this point, selection is no longer about comparing terms, but about matching working conditions.

Efficiency and resistance to fluctuations

In terms of efficiency, condensation with film is more stable: condensation first collects the oil from the large head, and the film section only processes the remaining low concentration exhaust gas. The overall recovery rate and emission concentration are more controllable, especially suitable for loading and unloading scenarios with large fluctuations in oil and gas volume. The performance of a single membrane under steady-state low concentration conditions is not poor, but when the inlet concentration fluctuates significantly, the membrane segment load fluctuates accordingly, and the stability of the index is weakened by one level. When selecting, the fluctuation range of the station's oil and gas volume should be put on the table: those with large fluctuations should be selected for more stable condensation and film addition, while those with small fluctuations can be handled by a single film without having to spend extra money on redundant capabilities.

Land occupation, operation and maintenance, and cost

Single film has the advantage of occupying space, and the whole machine is compact, suitable for tight venues; Adding a film to the condenser requires an additional set of refrigeration and condensing boxes, which requires a high amount of space and installation complexity. In terms of operation and maintenance, there are fewer single film actions and less manual labor. For condensation and film addition, multiple refrigeration units, refrigerants, and defrosting are required, with more maintenance points. In terms of cost, the initial investment of a single membrane is usually low and the operation and maintenance are economical, while the initial investment of a condensing membrane is high but the unit recovery cost is better under a large number of operating conditions. Weighing all four factors together, rather than just looking at initial investment or efficiency, is the key to a reliable conclusion.

How to get into the selection table

The practical operation of selection is to fill in a comparison table: the oil and gas volume range, concentration fluctuation, available space of the site, budget and operation and maintenance manpower of this station, four items are filled in one by one, and then compare the strengths of the two routes. For high concentration, high load, and deep treatment requirements, condensation and membrane addition are given priority; For low to medium load, tight space, and those who want to save on maintenance, priority should be given to single membrane. When unsure, follow the order of "first calculate the quantity, then compare the fluctuations, and then look at the venue" to avoid being misled by a single selling point. The renovation project also needs to incorporate existing pipelines and power sources, with more reuse resulting in greater savings.

Selection dimension comparison

Selection steps

1. Calculate the oil and gas volume and concentration range of this station;
2. Assess the amplitude of concentration fluctuations;
3. Measure the available site and power supply conditions;
4. Balancing the cost of land occupation and operation based on efficiency in four dimensions;
5. When uncertain, give priority to calculating the quantity rather than looking at the site based on fluctuations;
6. The renovation project includes the reuse of existing pipelines.

Frequently Asked Questions

Which is more cost-effective, single film or condensing film?

Depending on the operating conditions: For medium to low loads and those who want to save on maintenance, both the initial commissioning and maintenance of a single membrane can be saved; For high concentration and high load products that require deep treatment, the unit recovery cost of condensation and membrane addition is more optimal. However, compared to initial investment, there may be misjudgment, and the entire cycle should be considered.

Which option should I choose for renovating an old station?

First, determine how much existing pipelines and power sources can be reused, and then compare the site and load; Priority should be given to single membrane for areas with tight space and moderate load, while condensation and membrane addition should be considered for areas with large load and sufficient space. The more reuse, the more cost-effective the renovation.

Can the two routes be mutually changed in the later stage?

It is possible, but the cost is high: adding a single film for condensation increases equipment, while adding a film for condensation decreases capacity, both of which require the operation of pipelines and electrical control; The selection stage is more cost-effective than mutual modification in the later stage, don't treat modification as trial and error.

This article is organized by Luoyang Wohong Petrochemical Equipment Co., Ltd. The company provides design, manufacturing, installation, commissioning, and operation services for oil and gas recovery equipment, membrane separation recovery devices, and buried composite pipeline networks for gas stations, oil depots, and chemical enterprises. If you need scheme configuration or on-site investigation, please feel free to contact and exchange ideas.