Renewable natural gas (RNG) is a programmable renewable energy source, obtained by subjecting the biogas to an upgrading process and bringing the concentration of methane CH₄ to exceed 97%.
RNG makes it possible to get closer to the targets for reducing emissions and for decarbonization of transport at an accessible cost, exploiting the existing gas networks and promoting an economic model based on sustainability and circularity in the use of resources.
RNG is obtained from various raw materials: agricultural biomasses (by-products, agricultural waste and animal waste), agro-industrial waste (waste from the processing of the food chain) and from the organic fraction of urban solid waste (OFMSW).
Upgrading is a complex treatment, which is made up of different stages: a pre-treatment step precedes the actual processing which is divided into purification and separation of methane from carbon dioxide.
As it is produced from agricultural biomasses, agro-industrial waste and organic waste, RNG can be considered to all intents and purposes a renewable and sustainable source: in addition to reducing emissions into the atmosphere, it is carbon neutral, that is, it totally offsets the emissions produced, as it returns organic matter to the soil.
RNG adapts flexibly to multiple uses, from energy production to distributed generation and fuel for the transport sector. It is completely similar to natural gas and can therefore make use of existing transport and storage infrastructures.
In the agricultural sector, RNG can contribute to significantly reduce production costs and at the same time to increase competitiveness. The digestate (what remains after the anaerobic digestion process of agricultural matrices) can in fact be used as a natural fertilizer, capable of increasing the capacity of the soil to absorb and store carbon.