The Production of Biogas and Digestate: An Alternative Sustainable Model for Reducing Energy Dependence on Russia

Dear Colleagues,

The Russia–Ukraine crisis is also a crisis that affects the energy supply model that Europe has on relied too much. Italy in particular, as everyone has learned in recent days, depends on Russia for about 40% of its gas supply.

This energy crisis seems to have resulted in the massive explotiation of fossil sources (such as coal to power thermoelectric power plants) or a push towards solutions such as generation IV nuclear power, which are based on technologies not yet mature enough.

In this Special Issue, we are looking for contributions that demonstrate the strategic role of renewable sources of energy, both on the environmental level—given that the climate crisis has not been resolved—and for greater energy autonomy in an increasingly complex geopolitical framework.

Disconnecting from Russian gas, oil, and coal imports well before 2030 is therefore the goal of the REpowewrEU action plan presented by the European Commission (it aims to produce 35 billion cubic meters (bcm) of biomethane by 2030). Energy efficiency and saving, renewables, and the diversification of supplies are the watchwords. Additionally, in mixingalternative energies to fossil fuels, an important role has been recognised in the production of biogas and biomethane, an exellent source of circular energy.

The production of biogas and biomethane is growing rapidly throughout Europe thanks to the recognition of our sector as one of the drivers for promoting innovation in companies and the enhancement of production, sustainability, and respect for the environment. According to data from the European Biogas Association (EBA—European Biogas Association), Europe currently has more than 1000 biomethane production plants thanks to the rapid growth of production in France, Italy, and Denmark. Italy is in second place, with more than 11 new plants starting up in 2020. According to the EBA’s Biomethane Map, Europe currently has about 20,000 units in operation (the total number of biogas and biomethane plants).

Today, the energy crisis and the conflict in Ukraine have put the development of renewable energies back at the center of the debate, both to achieve the environmental objectives that the country has set itself with even greater commitment, but also to be able to finally make our energy system independent.

We welcome contributions with a special emphasis on the use of agricultural by-products and biowaste to show the feasibility of the technology for the production of energy from biogas, with the aim of decarbonizing the economy. With this Special Issue, we would like to focus on biomethane that can be used as a renewable alternative to substitute fossil fuel-based natural gas, reducing energy dependence on Russia.

Moreover, there is the need to "seize the opportunities that come from the circular economy and provide countries with a sustainable energy reserve with the agricultural biomethane supply chain", with which it will be possible to meet a substantial share of the national needs for gas.

It will be possible to cover a good share of the current demand for gas through agricultural biomethane and that derived from the organic fraction of urban waste.

Another aspect of great importance and that is connected to the blocking of supplies and the increase in natural gas prices triggered by the conflict between Russia and Ukraine is the significant increase in the cost of fertilisers, both nitrogen-based (urea, ammonium nitrate ) and those based on potassium and phosphorus, which are essential for the agricultural sector to ensure food production.  A further advantage of biomethane production chains is the possibility of using the residue of the anaerobic digestion process of agricultural biomass (digestate) as an organic fertiliser instead of chemical fertilizers produced from fossil sources. Thanks to the use of forms of organic fertilisation, many farms are lightening the burden of the increasing costs of chemical fertilisers. Other processes, such as composting and vermicomposting, could contribute to replacing the dependency on chemical fertilisers within a sustainable and circular bioecnomy model.

We cordially invite and welcome all kinds of articles (full research manuscripts, review/mini-review articles, opinion papers, technical notes and commentaries) including but not limited to the following research areas:

• Anaerobic digestion of biowaste, agricultural wastes, and residues;
• Co-products of anaerobic digestion;
• Organic waste management;
• Biomethane;
• Circular Bioeconomy;
• Digestate valorisation;
• Energy efficiency;
• Renewable energy;
• Waste to energy;
• Agro-energy supply chain;
• Compost;
• Vermicompost.

Submitted contributions must imply a clear link to agronomy as a prerequisite for consideration in this Special Issue. We particularly welcome experimental studies; however, we also encourage studies comprising life-cycle assessments and socioeconomic evaluations on the outlined topics.

We are looking forward to receiving your valued contributions to our Special Issue of Agronomy, entitled "The production of biogas and digestate: an alternative sustainable model for reducing energy dependence on Russia".

Dr. Carlo Greco
Dr. Vito Armando Laudicina
Guest Editors

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• anaerobic digestion
• co-products of anaerobic digestion
• organic waste management
• biomethane
• circular bioeconomy
• digestate valorisation
• energy efficiency
• renewable energy
• waste to energy
• agro-energy supply chain
• compost
• vermicompost