Product Description


After the digester and pretreatment process, the compressed gas undergoes further filtration within the VALOPUR unit. This is a compact unit housed within a pre-equipped container and composed of three stages of membranes which separate CO2 from CH4 (patented EVONIK process).

This system allows to produce a RNG compliant to network specifications, with upgrading efficiency up to 99.5 %. Once purified, RNG is channelled towards the grid injection station, which is connected to the natural gas network. The three stages membrane system deliver operational flexibility, ensure optimal upgrading efficiency across the unit’s operating range.


  • Easy to operate and easy to upgrade
  • A containerized installation for real-time monitoring of the overall process performance
  • Automated operations management to facilitate operation and maintenance
  • Hypervision: Remote monitoring and maintenance by our technicians
  • Performance guarantees
  • Can meet any gas grid specification in North America, upgrading efficiency > 99.5%, power consumption, availability > 97%
  • Reliability and durability of the membrane process

The SEPURAN® Green Membranes range contains for all products:

  • Membrane with 316L stainless steel casing
  • 1 installation kit for 16 barg application
  • The model and configuration should be chosen according to the Biogas upgrading unit selected and the operating conditions

The difference in size of the molecules gives them different diffusion speeds through the walls of the membranes, thus separating methane (low diffusion speed) from other compounds (carbon dioxide, water, oxygen, etc.).

The Biogas Compressor unit contains for the whole range:

  • 1 Compressor integrated in its shelter, with a RAL supplier paint quality C3
  • 1 IE3 motor on the compressor)
  • 1 Variable Frequency Drive
  • The main components of the control-command system (Programmable Logic Controller – PLC – and Human-Machine Interface – HMI), excluding the control cabinet

1 Containerized and secured unit, painted RAL 6012 quality C3, including:

  • Wall insulation
  • Gas safety detection (Process room)
  • Smoke detection and air conditioning in the technical room
  • Ventilation
  • Safety markings on the whole installation

1 Membrane Biogas Upgrading unit, (compressor excl.) including:

  • Raw Biogas analysis (CH4, CO2)
  • Off-gas analysis (CH4)
  • Safety devices
  • Water and oil filtration downstream compression
  • RNG flow and quality control
  • Instrumentation without local display
  • Safety shut-off valves
  • RNG and off-gas recirculation valves in case of non-conformity
  • RNG flow metering
  • 304L stainless steel gas piping

1 control cabinet with an HMI (Human Machine Interface)


Contact Prodeval for more information or request product sheets!


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