Visit the website of our partner Eliopig to explore all the services dedicated to the design, installation, commissioning and start-up of biogas and biomethane plants.
Biomethane takes biogas one step further a renewable energy source with the same properties as natural gas, it can be injected into the distribution grid, used as transport biofuel or sold on the gas market. Synergy designs and builds complete biomethane plants from raw biogas upgrading to the grid injection unit supporting clients on every technical, regulatory and financial aspect.
Biomethane is produced by purifying the raw biogas from anaerobic digestion: the upgrading process removes carbon dioxide (CO₂), hydrogen sulfide (H₂S) and residual moisture, raising the methane content above 95% and bringing the gas in line with UNI EN 16723-1 standards for grid injection.
Compared to using biogas solely for cogeneration, biomethane production offers several key strategic advantages:
- Access to higher incentive tariffs (M.D. 15 September 2022 and NRRP)
- Independence from the electricity market and greater revenue stability
- Gas valorisation in the transport sector (advanced biomethane) through Certificates of Release for Consumption (CIC)
- Option to sell on the natural gas market via the distribution grid
- Recovery of liquid CO₂ for industrial and agri-food applications
Biomethane is the future of renewable gas in Italy — an energy source equivalent to natural gas, produced from organic waste and biomass and ready for direct injection into the distribution grid.
Visit the website of our partner Eliopig to explore all the services dedicated to the design, installation, commissioning and start-up of biogas and biomethane plants.
Choosing the right upgrading technology is one of the most important design decisions, and depends on plant size, raw biogas quality, output gas specifications and the available budget. Synergy works with each client to identify the best solution for their specific project.
Hollow-fibre membranes separate methane from carbon dioxide based on differential permeability. This is the most widely adopted technology for medium- and large-scale plants: it offers high separation efficiency (methane > 97%), a compact footprint, low maintenance and fast start-up. Particularly suited to plants from 300 Nm³/h upwards.
PSA uses adsorbent materials (zeolites or activated carbon) that selectively retain CO₂ at high pressure and release it during the regeneration phase. A well-established technology suited to medium-scale plants, it delivers high methane purity, though it requires moderate energy consumption and careful management of the adsorption cycles.
Water scrubbing relies on the higher solubility of CO₂ compared to CH₄ in water, using a counter-current high-pressure process. A robust technology with good methane recovery rates, it is particularly suited to medium- and large-scale plants with sufficient water availability. It has lower capital costs than membranes, though energy consumption is somewhat higher.
A highly selective technology delivering top methane recovery rates, based on the chemical absorption of CO₂ in an amine solution. Best suited to large-scale plants (>500 Nm³/h) where maximum output gas purity is required. It demands closer monitoring of operating parameters and careful management of the regenerant.
A biomethane plant doesn’t end at the upgrading unit. Synergy designs and builds the entire chain from raw biogas to grid injection:
- Biogas pre-treatment: H₂S and moisture removal upstream of the upgrading unit, protecting the membranes or adsorbents and ensuring end-product quality.
- Upgrading: CO₂/CH₄ separation using the selected technology, with continuous gas quality monitoring via an online analyser.
- Odorisation: addition of mercaptan as required by Italian regulations for gas distributed through the grid.
- Fiscal metering: installation of flow meters and metering systems required by the Italian energy regulator (ARERA) for grid injection.
- Delivery point: physical connection to the distribution grid, coordinated with the local grid operator — regulation and metering station (REMI) or private delivery point.
- SCADA (Supervisory Control and Data Acquisition): continuous remote monitoring of all critical plant parameters.
- Alternative: transport by tube trailer — for plants that cannot be connected to the grid, compressed biomethane can be transported by tube trailer to distribution stations or industrial customers.
Calls for applications are issued periodically. Synergy can assist you in preparing the necessary documentation and submitting your application to the GSE. Please contact us to check the deadlines and requirements applicable to your project.
Biomethane enjoys a more favourable incentive framework than electricity-only biogas production, reflecting its strategic role in decarbonising the gas and transport sectors.
The Decree provides incentives for biomethane injected into the natural gas grid or used in the transport sector, through competitive tender procedures managed by the GSE. Incentives are awarded through reverse auctions on the base tariff; the GSE either purchases the biomethane produced (all-inclusive tariff) or pays a feed-in premium calculated as the difference between the incentive tariff and the market gas price. The incentive period is 20 years. Both new-build plants and conversions of existing biogas plants are eligible.
Certificates of Release for Consumption (CIC) are available for biomethane intended for the transport sector, when produced from substrates listed in Annex 3 of M.D. 10 October 2014 (livestock manure, organic municipal solid waste, sewage sludge). The CIC reference value for advanced biomethane is €375/CIC (with possible top-ups) over a 10-year incentive period.
A capital grant covering up to 65% of eligible expenditure (maximum €600,000 per project) is available for existing agricultural plants undergoing efficiency upgrades or conversion. The grant is cumulative with other capital incentives and can be applied for through the GSE portal.
If you already operate a biogas plant, converting to biomethane offers access to a more favourable incentive regime, diversified revenue streams and a longer economic life for the plant. M.D. 15 September 2022 explicitly allows for incentivised conversion of existing agricultural biogas plants, with no requirement to demolish the digester.
Synergy assesses the condition of the existing plant, sizes the required upgrading unit, manages the conversion permitting process and integrates the new biomethane section with the existing infrastructure — minimising plant downtime during the works.
Biogas is the gas produced directly by anaerobic digestion: it contains approximately 50–70% methane (CH₄) and 30–50% carbon dioxide (CO₂), along with traces of H₂S and moisture. Biomethane is biogas purified through an upgrading process that raises the methane content above 95–97%, making it equivalent to the natural gas distributed through the grid.
The economic viability of a biomethane plant depends heavily on scale: below 150–200 Nm³/h of available biogas, the fixed costs of upgrading tend to make the project less competitive. Above this threshold, biomethane is almost always more profitable than cogeneration in terms of net return, thanks to the dedicated incentive tariffs.
Yes. The producer can sell biomethane injected into the grid through the feed-in premium paid by the GSE, or sell the gas directly to authorised traders on the natural gas market. Alternatively, for biomethane intended for transport, the producer can enter into contracts with CNG refuelling station operators or industrial customers.
Fats and waste oils generally offer the highest biomethane potential per tonne of fresh product (>800 Nm³ CH₄/t VS), followed by slaughterhouse sludge and lipid-rich food by-products. Among the most common agricultural substrates, maize silage and sweet sorghum deliver high yields, while livestock manure has lower yields but virtually zero cost.
Synergy supports you from feasibility through to commissioning: we verify substrate availability, size the optimal upgrading system and manage the entire incentive application process with the GSE.
