Membrane separation skid-mounted device for tertiary oil and gas recovery at gas station

Membrane separation skid-mounted device for tertiary oil and gas recovery at gas station

The three times of oil and gas recovery at the gas station is the oil and gas discharged from the breathing valve of the oil storage tank. This part of oil and gas cannot be completely eliminated through primary unloading recovery and secondary refueling recovery, and an end treatment device is required. Skid-mounted membrane separation device is a mature technical route in the current industry. The combined process of "condensation membrane separation" is adopted to integrate the equipment on a steel base. The assembly and debugging are completed before leaving the factory. The site can be put into operation only by connecting the power supply and connecting pipelines.

Working principle

The device consists of a compression condensation unit and a membrane separation unit. Oil and gas come out of the breather valve of the storage tank, are pressurized by the compressor, and enter the condensing unit. The temperature is controlled between zero and minus ten degrees Celsius, and most of the heavy hydrocarbon components above C5 are liquefied into liquid gasoline, which flows back to the storage tank.

The uncondensed exhaust gas enters the membrane separation unit.gas separation membraneUsing the difference in the permeation rate of oil and gas molecules and air molecules in the membrane material-oil and gas molecules preferentially penetrate the membrane layer to form concentrated gas, which is sent back to the compressor inlet for circulation treatment. The whole system forms a closed cycle, and the emission concentration can stably meet the emission limit requirements stipulated by the GB20952-2020.

Skid-mounted advantages

The skid-mounted structure integrates the units on a steel base and has the following features:

Quick installation: complete assembly and commissioning before leaving the factory, the site only needs to be connected to the power supply and gas circuit to run, the installation cycle is short

Small footprint: the equipment covers an area of usually within a few square meters, suitable for gas station site conditions

Can be moved as a whole: can be lifted and moved as a whole according to the renovation needs of gas stations, and the equipment can be reused.

Automatic operation: automatically start and stop according to the pressure of the oil tank, work when there is gas, standby when there is no gas, no need for manual duty

Technical Features

High processing efficiency. The membrane separation unit further enriches and recycles the low boiling point components in the condensed tail gas, and the overall recovery rate can reach more than 99%, and the emission concentration is far below the national standard limit. The relevant invention patent shows that through the combination design of compression condensation and membrane separation, oil and gas can be recycled for many times, and impurities such as oil residue can be filtered to improve the purity of recovery.

Low operating costs. The equipment is driven by electricity, does not consume natural gas, and the unit energy consumption is about 0.43kW/m³. withactivated charcoalCompared with the adsorption process, membrane separation does not produce waste activated carbon and other secondary pollutants, without solid waste treatment.

Safe and reliable. The process is operated without open flame and has good applicability in explosion-proof places of gas stations. The system automatically starts and stops according to the pressure of the oil storage tank, runs automatically when the pressure rises to the set value, and stops automatically when the pressure drops to the set value to ensure safe operation.

Scope of application

The device is suitable for the three oil and gas recovery and transformation projects of gas stations, and the processing capacity covers gas stations of different sizes. The working condition test shall be completed before the type selection, and the equipment specifications shall be matched according to the parameters such as the daily average filling amount, storage tank volume and oil and gas production of the gas station. LuoyangWohong PetrochemicalEquipment Co., Ltd. focuses on the field of membrane VOCs recovery and provides design and manufacturing services for skid-mounted tertiary oil and gas recovery devices. Before selection, on-site working condition detection can be arranged and equipment specifications can be matched according to actual parameters.