RNG/e-NG

While RNG and e-NG are the same in their molecular composition and usage, they are different in terms of feedstock and production process.

RNG is produced from syngas made from biomass gasification. Before the next step, called methanation, the syngas needs to be cleaned to remove harmful impurities that could damage the catalysts used later in the process. To get the right balance of gases needed for the methanation process, the syngas can be adjusted in a few ways: by adding hydrogen, removing CO₂ or through a CO shift.

e-NG is produced by using renewable electricity from sources like solar energy, wind, hydro, or nuclear energy to generate hydrogen. Our SOEC electrolysis solution leverages high-temperature electrolysis within this process, making it able to produce more hydrogen per unit of power than traditional alkaline and PEM methods. The hydrogen is then combined with carbon dioxide (CO₂). While e-NG has a lower carbon footprint compared to conventional natural gas, it is not completely carbon-neutral.

Our proven TREMP™ technology can help you produce either RNG or e-NG, depending on your current needs and feedstock. With a track record of being used in 15 plants around the world over the past 40 years, TREMP is tried-and-tested and ready to be deployed.

The profitable production of high quality, clean renewable natural gas requires the most energy-efficient process possible. Topsoe’s TREMP™ process stands for Topsoe Recycle Energy-efficient Methanation Process and uses a methanation process to convert either green hydrogen and renewable carbon dioxide (CO₂) or syngas from biomass gasification into e-NG or RNG. The end-product meets pipeline specifications, ensuring easy distribution of the product.

While the use of TREMP technology to produce RNG/e-NG is relatively new, the technology itself is not new. TREMP has been successfully deployed for decades in the production of substitute natural gas (SNG). Our first pilot TREMP plants went online in Germany in 1979, and since then we have won contracts for over 15 large-scale SNG plants across the world, including China, South Korea, and Sweden.

In the production of SNG, the TREMP technology was used for coal gasification – a much more or equally challenging feedstock than syngas or green hydrogen and CO₂ used for RNG/e-NG production. While the feedstock may differ, the use of TREMP for RNG/e-NG production is a more manageable process than what we have previously encountered.

When our proven TREMP process is combined with our stable high temperature catalysts, it is guaranteed to deliver optimal performance. This enables our customers to produce more renewable natural gas, at a higher quality, from the same number of natural resources, using less energy, while minimizing environmental impact.

This is made possible by the unique high-temperature stability of the MCR catalyst family. This proprietary catalyst family MCR can operate in the temperature range 250ºC-700ºC (475-1,300°F), which allows us to offer our TREMP™ technology with the unique feature of recovering the reaction heat at a high temperature. This makes the TREMP™ technology a very efficient technology to produce RNG/e-NG.