Our proven and patented iLNG technology


The iLNG technology from Nordsol is essentially the use of conventional and proven technologies integrated into a less complex process scheme. While the technology for large-scale LNG production has been around for decades, it cannot be used for small-scale, decentralized production of bio-LNG. Nordsol has reinvented the process of making LNG by carefully considering the key differences between natural gas and biogas:

    • Required capacity of the installations
    • Fluctuations in biogas composition and flow
    • Complexity of the biogas composition
    • Importance of energy management for economic viability

The result is a compact, highly integrated system of biogas treating and liquefaction that makes small-scale bio-LNG production economically viable.


Gas treatment and liquefaction are integrated process steps in iLNG technology

Biogas treatment

Step one is to rid the feed gas of contaminants. iLNG solely utilizes membrane technology to remove carbon dioxide and any water. To obtain ultra-pure biomethane, this separation process is enhanced by sweeping the membrane with flash gas (“Flash-2-Sweep”). The key advantage of this separation process is that no amine treatment with its high heat demand or pressure-swing adsorption units are needed. The removed carbon dioxide can be liquefied for easy transport and reuse as bio-CO2.



The second step is the liquefaction. iLNG uses already produced biomethane as the only refrigerant. By creating conditions under which the methane has supercritical properties, the temperature in the heat exchangers can be higher than usual. This leads to less chance of residual carbon dioxide (or other residual contaminants) freezing out at this stage. Using methane as the refrigerant also makes it very easy to shift duty in the unit. Gas that flashes off during this second step in the process is used to sweep (or purge) the membrane in the first step.



iLNG technology in Amsterdam, The Netherlands

3,4 kton bio-LNG per year

Key advantages of iLNG

    • Small-scale, integrated system for bio-LNG production based on standard membrane technology
    • Increased membrane performance as a result of the patented ’Flash to Sweep’ configuration.
    • High energy efficiency through smart integration
    • No adsorbents, solvents and heat demand
    • Low equipment count, with standard off the shelf equipment
    • Robust process avoiding hydrogen, water and freeze up issues.
    • Continuous processes, closed system, no methane slip to atmosphere
    • Integrated CO2 liquefaction