What is biomethane

Biogas can be produced from a wide variety of biological substrates, such as agricultural residues (intermediate crops, manure, straw, etc.), sludge in sewage, domestic and industrial organic waste, energy crops, etc.

The biogas production process is the result of an anaerobic digestion in the absence of oxygen of certain bacteria on these substrates. From this process a first untreated biogas arises whose composition consists of 50 to 75% methane (CH4), 25 to 50% carbon dioxide (CO2) and small amounts of water vapor (H20), nitrogen ( N2), oxygen (O2), and hydrogen sulfide (SH2). From this generated primary gas, the water vapor, hydrogen sulfide or some other component can be extracted. The most common use of biogas is to produce heat and electricity.

However, for some uses of biogas, such as injecting it into the natural gas network or using it as fuel for vehicles, it is necessary to go through a purification process . This process consists of eliminating the carbon dioxide in its composition, so that the percentage of methane gas increases . Typically, the methane content reaches 96% , so that it meets the standards to be used as natural gas . From this moment on, the biogas becomes known as biomethane .

We will tell you more about biogas in this other AgroCorrn article on What is biogas and its uses .

Biomethane achieves a composition and energy power very similar to that of natural gas , so it can already be used for the same purposes, such as injecting it into gas networks and using it as natural gas in different proportions or as fuel for vehicles.

Biomethane production is more sustainable , since a wide variety of raw materials are used, so its environmental characteristics are also varied, but in general better than with the use of fossil fuel sources . When digestates (semi-liquid by-product of anaerobic digestion) are used, such as organic fertilizers and soil improvements, the cost of producing mineral fertilizers is saved and the emissions associated with their production are avoided. It is estimated that with the use of digestates instead of mineral fertilizers, up to 13 kg of CO2 could be reduced in equivalents per ton.

The truth is that there are several advantages that biomethane gas offers. Specifically, biomethane is commercially viable , it can use existing infrastructures for natural gas, and its purification technology is already proven and feasible. The use of this gas will provide other advantages, such as helping to meet climate objectives by reducing CO2 emissions, providing improvements to air quality (NOx and particle emissions are reduced) or giving greater energy independence compared to other countries. .

In addition, its production would generate green jobs in agricultural areas and it is an energy efficient fuel.

Currently, there are 15 European countries that produce and use biomethane , with some 200 treatment plants throughout Europe. Most of this biomethane is used in the production of heat and electricity, although its use in transport is increasingly important. For example, in Sweden, the use of biomethane as a fuel has already surpassed compressed natural gas with a market of 57%, and in Germany it has gone from 6% to more than 15% in 2012.

In Europe, a current biogas production equivalent to 14 billion m3 of natural gas is calculated. The EBA ( European Biogas Association ) estimates that by 2020, the volume of biogas produced will be substantially higher, without any negative effect on farmland used in food and feed production. Even the rotation of crops and the recycling of nutrients in the ecosystem improve productivity through digestates.

If you want to read more articles similar to What is biomethane , we recommend that you enter our Renewable Energies category .