Biomethane production: from the distillery to the national grid
In recent years, biomethane production has been steadily expanding in Italy, where an increasing number of companies are choosing to embrace the circular economy by using waste products from their manufacturing processes to produce clean energy.
While part of this is used to meet the needs of the factory itself, the rest can be sold on and made available to the national grid. One production process which is particularly suitable for generating the precious biogas is the distillation of grappa.
How does biomethane production work?
Biomethane is a renewable natural gas produced during the decomposition of organic waste, such as food scraps, leaves and other biodegradable materials. In general, the procedure necessary to obtain it can be divided into three distinct phases:
- the gathering of organic waste;
- the production of biogas;
- the purification of the biogas to extract the biomethane.
Once it has been gathered, the waste is transported to a composting centre or anaerobic digestion plant. Here, the decomposition process is started, using anaerobic bacteria to metabolise the waste and produce biogas.
The resulting mix consists of methane, carbon dioxide, water and other gases. The separation of the precious fuel from the various fluids contained in the mix requires another step: purification.
This can be carried out using several different methods, but the most common are:
- carbon absorption;
- the separation membrane;
- liquefaction.
With the right technological adjustments, (these processes were recently patented by Italian researchers and it took over 16 months for a Padua distillery to implement them), the by-products produced during grappa distillation have proved to be an excellent source matter for biomethane production.
In fact, the spent grape residue forms an ideal base material for that process, as the polyphenols it contains can be extracted. These natural substances are highly valued and are very nutritious. They are often used in the manufacture of nutritional supplements.
The advantages of a circular economy based on biogases
The production of biomethane brings many advantages. Firstly, it uses waste products as its raw materials, thereby reducing the quantity of waste destined for landfill. Furthermore, as it is a low carbon content fuel, its carbon footprint is smaller than that of fossil fuels such as coal and oil.
Another benefit which should not be overlooked is that it can be produced locally. This factor in particular has attracted the attention of European Community experts, who have proposed it as a key future energy source in the REPowerEU plan.
In addition to its low environmental impact, biomethane would allow the Europe to reduce its dependency on imported foreign natural gas and could potentially replace more than 25% of that gas, according to estimates, enabling Europe to rely less on other nations for its energy sources.
These are the reasons which make promoting a circular economy paramount, including the use of more unusual systems such as grappa distilleries. Of course, significant investment is needed in terms of innovation and the implementation of new technologies, but in the long term, the financial returns should prove considerable.
Companies who have already this kind of sustainable production have reported reduced energy costs, improved production-time ratios and regular extra earnings from the sale of any surplus biomethane to the national grid.
In other words, it is an unmissable opportunity, which has the potential to boost local production and contribute to the wellbeing of businesses and citizens at national and international levels.
Translated by Joanne Beckwith
