LNG (short for Liquefied Natural Gas) is natural gas, a fossil fuel, that has been liquefied under cryogenic temperatures in order to simplify its transport. LNG consists of about 98% of methane, just like standard natural gas.

Liquefied Bio-Methane (LBM) has the same consistency, but is – in contrast to a fossil fuel, produced naturally from special energy plants, and – more and more so – from organic waste.

If natural gas is being compressed instead of being liquefied, the product obtained is called CNG (Compressed Natural Gas). Compressed bio-methane is called bio-CNG.

LBM: the gas from a biogas plant consists roughly of 50% of metane, and 50% of biogenic CO2, with traces of other compounds. This mixture is then dried, purified, and separated into its components. By using a refrigeration machine, the gases are cooled down to a stage where they liquefy. While carbon dioxide liquefies at about -80° C, it takes temperatures below –160°C for methane to become a liquid.

A by-product of this process is the residual from the fermentation process, which serves as a natural fertiliser.

LNG: fossil natural gas is usually dried as well, after that methane is separated from other gaseous and liquid components and liquefied in a cryogenic process. By-products of this process are usually petroleum, LPG (Liquefied Petroleum Gas), and CO2 as well as Nitrogen. The world’s largest exporters of LNG are Australia, Qatar, the US, and Russia.

LBM is the ideal substitute for diesel fuel (and fossil LNG) in the transport sector. The CO2 footprint is four times lower when used here than in direct power generation from biogas. At the same time, emmissions of nitrous oxides are reduced by more than 90%, compared to the use of diesel, while fine particulates go down by more than 99%

Biogenic CO2 is a much sought for gas in the food and beverage industry. Other uses include dry ice, the gassing of greenhouses to enhance plant growth, and – last but not least – the production of e-fuels The market for biogenic CO2 is expected to grow by a factor of 10 within the next 10 years.

Right now, there are more than 10,000 biogas plants in Germany. If all of these plants were to be converted to produce LBM, and if the CO2 would be used to produce e-LNG (which can be done with additional green hydrogen), then we could substitute 14 million tons of diesel quickly and in a sustainable way. This represents more than 40% of today’s demand.

The crucial fact is that LBM is produced in a de-centralised way, and thus is available at every biogas plant which has been converted accordingly. As a result, distances for ist distribution are reduced to a minimum.

Fossil LNG – in contrast – needs to be transported from one of the terminals, e.g. at a harbour in the Baltic Sea, to a filling station in upper Bavaria, which is a distance of almost 1,000 km

The conversion of heavy-duty vehicles is quite simple. On the other hand, many manufacturers are offering a range of LNG/LBM-powered vehicles as well. From a practical point of view, the filling time of one tank is directly comparable to filling a diesel tank, and the range of about 1,500 km is also the same. LBM can, by the way, also be used for agricultural vehicles, and in municipal services, such as snow clearing or waste collection.