Organic waste, in general, is an environmental and economic problem. Large companies from the most diverse sectors often spend significant amounts of resources to correctly dispose of the waste generated in their production. Biogas is a sustainable and renewable energy source, obtained through biodigestion, an old and well-known process. However, it is still little applied for the treatment of organic waste and energy production.

The technology can be applied in the most diverse segments, and can be used from small rural properties to large agribusinesses. The process itself is an aerobic digestion of organic matter, resulting in biogas, digestate and sludge, the main fermentation products. Biogas is mainly formed by methane, a combustible gas, which can be applied more directly, replacing cooking gas.

For this use, biogas can be used directly from the biodigester outlet, only needing to go through a process of cleaning unwanted gases, such as hydrogen sulfide gas. The purified biogas results in biomethane, which can be used to replace natural gas, as its composition will be very similar to the gas that comes from petroleum. Biogas can still be used to produce electricity, which is currently the main application. Digestate and sludge are excellent mineral sources, and their composition will depend on which raw material/waste was used to generate biogas, and they can be used to replace fertilizers.

Biodigestion technology is already very mature for large plants that use waste, for small properties, as these are plants that cannot have a lot of technology, as they need to be low cost. There is still a need for studies that enable a more efficient process in the production of biogas. Also, there is a need for research to consolidate plants that use dedicated raw materials. It is important to remember that, despite Brazil's great potential for waste treatment and biogas production, the technology never gained visibility and was, for many years, neglected. Until recently, biogas was talked about as the technology of the future.

I asked myself: why is a centuries-old technology touted as being the technology of the future? And the answers were things like: there is no interest, or the true potential of this technology was not known. Yes, because it makes no sense for a process that, in addition to treating waste, also generates income with the production of energy and biofertilizer, which allows the complete closure of the production cycle, not to be used massively in all sectors.

In Brazil, the use of biodigestion is concentrated in the sanitation and swine waste treatment sector. The reason is mainly for environmental reasons. Until recently, the benefits of investing in more efficient plants that maximize biogas production were not seen. However, with the development of more efficient technologies and a growing demand for clean and sustainable energy, Brazil turned to rescuing anaerobic digestion. Recently, I saw an interview with Tamar Roitman, executive manager of the Brazilian Biogas Association, in which she states that biogas is no longer a technology of the future, but that it is already a reality.

I believe that this reality has only been possible because large companies have managed to see the true potential of biodigestion, especially in the current context from an environmental point of view, in which we are looking for cleaner and more sustainable technologies. Biodigestion, for me, is not just a clean technology, but a technology that cleans. As mentioned at the beginning of the article, the amount of organic waste generated, whether in industry or in large cities, is gigantic. Urban waste alone in Brazil amounts to around 80 million tons per year.

If, instead of landfills, or even landfills, this waste was treated through the biodigestion process, we would have cleaner cities, we would put an end to the problems of landfills and, in addition, it would be a source of income, since the The energy generated could be used for the benefit of the population.

Still from the perspective of Tamar's statement, and, therefore, moving on to the facts, if today biogas is a reality in Brazil, this is mainly because the sugar and alcohol industry has increasingly invested in this technology to treat vinasse and sugar cake. filter, generating more energy without losing the nutrients that were already incorporated into the soil through vinasse irrigation in the field.

The interest of this important industrial segment strengthens biodigestion. It is important to remember that this technology was rescued, as this had already been attempted in the past. In the 80s, however, as already mentioned, the time was different. Current conditions are much more favorable and the chances of things going wrong no longer exist. It became a path of no return.

The sugar and alcohol sector's investment in waste treatment through anaerobic digestion is still likely to expand a lot in the coming years, as few biodigestion plants (in the sector) are under construction, and even fewer are already in operation, compared to the number of plants of ethanol we have. In other words, within the sugar and alcohol industry itself there is enormous potential for expansion, but I see beyond that.

I imagine that, given the success that is already happening and with the tendency to be even greater, other segments, such as the dairy industry, juice production companies, breweries, among others, which, compared to the sugar and alcohol sector, are smaller, but together they generate a very large amount of organic waste, they will reproduce this initiative, as the environmental gains are notable and the economic gains tend to be increasingly more significant, since products, such as energy and biofertilizer They are already traditional, but the trend of financial gains from the carbon market tends to expand.

Biogas is certainly here to stay, it is a clean and sustainable source of energy, which is not competitive with other renewable sources, since its main source is waste, without a doubt, it will add more sustainability to the Brazilian energy matrix, which is already the most renewable on the planet.