To extend the service life of the membrane-based biogas purification equipment, please follow the following steps:
Core principle: Treat the membrane as the “heart” of the system
Failure of the membrane is rarely sudden; it usually occurs gradually as performance slowly deteriorates until it fails to meet the standards. The key to extending the lifespan lies in prevention rather than treatment.
Pre-treatment: The guarantee of the lifeline (>50% importance)
This is an important and fundamental point among all the suggestions. The sole purpose of pre-treatment is to provide “pure water” grade inlet air to the membrane.
Deep desulfurization – Defending against “chemical assassins”
Biological desulfurization, with low operating costs and high efficiency.
Alternative dry desulfurization (iron oxide), but strict monitoring of pressure drop and replacement frequency is required.
For high-sulfur biogas, wet desulfurization can be used as a pre-treatment step for rough removal.
Objective: Reduce H₂S concentration to < 10 ppm, ideally < 5 ppm.
Measures:
Deep dehydration – Defending against “physical killers”
Combined process: Cooler (condensation separation) + Adsorption dryer.
Regularly check the regeneration function of the dryer and replace the adsorbent (such as alumina, molecular sieve) in time.
Objective: Reduce the dew point of water to < -40°C to prevent any liquid water from forming within the membrane.
Measures:
Fine filtration – Defending against “particle attacks”
Use multi-stage filtration: Main pipeline filter → Precision filter → Ultra-precision filter.
Strictly follow the filter replacement cycle and replace the filter elements (such as alumina, molecular sieve) in time, not exceeding the service period for cost-saving purposes. Replace them promptly according to the pressure indicator.
Objective: Remove all particles > 0.01 μm, oil mist and aerosols.
Measures:
Removal of special pollutants (depending on the gas source)
Siloxanes, VOCs: Mainly from landfill gas and kitchen waste biogas. Must be equipped with activated carbon adsorption tanks or dedicated adsorbents, and replace them regularly.
Standard operation: Stable operation is key
Rough operation is the “chronic killer” of the membrane.
Stable pressure and load
Avoid: Operating under conditions exceeding the design pressure of the membrane module.
Avoid: Intermittent and drastic fluctuations in the inlet flow rate. The regulating valve should be operated slowly.
Recommendation: Set up a buffer tank between the compressor outlet and the membrane system inlet to stabilize pressure and gas volume.
Appropriate temperature
Strictly follow the operating temperature range recommended by the membrane manufacturer (usually 5°C – 45°C).
High temperature will accelerate the aging of membrane materials; low temperature may cause hydrocarbons to condense.
Standard start-up and shutdown
Before startup: Ensure that the pre-treatment system is working normally and the inlet gas indicators are qualified before introducing it to the membrane system.
During shutdown: Especially for long-term shutdown, use clean, dry nitrogen or qualified biogas to blow and maintain pressure for the membrane system to prevent air and moisture from entering.
Devout maintenance: Preventive measures before problems occur
Establish and implement a preventive maintenance plan
Daily: Record system pressure, temperature, purity and recovery rate, and observe trend changes.
Weekly/Monthly: Check the pressure difference of the filters, check the performance of the dryer.
Every half year/annually: Replace all filter elements, desulfurizers and adsorbents compulsorily according to the operating time and manufacturer’s recommendations, regardless of their apparent condition.
Regular “check-up”
Regularly (once a year) have the system performance evaluated by the equipment supplier or a third party, analyze the operating data to determine the health status of the membrane.
Maintain equipment cleanliness and dryness
Keep the environment in the equipment area clean, control the humidity of the environment, and prevent electrical control system failures and external corrosion.
Smart initial selection: Lay the foundation for longevity
Choose high-quality membrane modules
Select brands with long-term industrial application verification. High-quality membrane materials have better resistance to chemical degradation, plasticization and mechanical strength.
Choose reliable system integrators
An experienced integrator will design a redundant and reliable pre-treatment system for you, and provide on-site commissioning and lifetime technical support. This is much more important than simply comparing equipment quotations.
