FAQ

CO₂ recovery from biogas upgrading captures and processes the CO₂-rich gas separated during biomethane production. Instead of releasing this stream, a recovery installation purifies and liquefies the carbon dioxide for storage, transport and use.

The commercial value depends on the recoverable volume, gas composition, operating costs and availability of a suitable CO₂ buyer.

Discover how CO₂ recovery from biogas upgrading works.

Biogas upgrading separates methane from carbon dioxide to produce biomethane, also known as renewable natural gas or RNG. CO₂ recovery processes the separated CO₂-rich stream into a usable product.

The upgrader and recovery installation therefore produce different outputs: biomethane and purified CO₂. Their gas flows, operating pressures and control systems must be coordinated.

Solveno’s CO₂ recovery systems for biogas upgrading are designed for this downstream recovery application.

Biogenic CO₂ is carbon dioxide originating from biomass, such as organic residues, manure or agricultural feedstocks. In a biomethane plant, anaerobic digestion produces biogas containing methane and CO₂. The upgrading process separates these gases to produce biomethane and a CO₂-rich off-gas.

Solveno Technologies processes this CO₂-rich stream through purification and liquefaction to produce liquid CO₂ for storage, transport and suitable end uses. Potential applications include dry ice production and industrial or food-related uses, subject to the required quality specifications and source qualification.

Biogenic origin describes where the carbon comes from, it does not establish product purity or a certified climate benefit. These require separate assessment of the production process, supply chain and final use.

Read more about biogenic versus fossil CO₂ and Solveno’s CO₂ recovery systems for biomethane plants.

CO₂ is recovered by treating the CO₂-rich gas separated during biogas upgrading, removing unwanted components and converting the purified CO₂ into a liquid.

A typical recovery process includes gas compression, treatment of trace contaminants, drying, refrigeration, liquefaction and separation of remaining impurities. The exact arrangement depends on the inlet gas and the required product specification.

Water must be removed to prevent freezing and operational problems. Residual methane, oxygen and nitrogen require appropriate separation because they affect product quality and the amount of CO₂ that can be recovered. Separated gas streams must have a defined return or treatment route.

Solveno Technologies combines these process steps in its modular biogas CO₂ recovery systems. The liquid product is transferred to suitable storage for collection or further processing.

Performance should be assessed as saleable liquid CO₂ output at the agreed specification, together with electricity consumption and recovery yield.

See Solveno’s CO₂ recovery systems for biogas upgrading.

Yes, CO₂ recovery can be integrated with different biogas upgrading technologies, provided that the separated gas stream is suitable for treatment. Compatibility depends on the actual off-gas conditions, rather than the upgrading technology name alone.

Membrane separation, pressure swing adsorption and solvent-based upgrading can produce different off-gas compositions, pressures and operating profiles. The assessment should therefore include CO₂ concentration, residual methane, oxygen, nitrogen, moisture, trace contaminants and variations in flow.

Solveno Technologies evaluates these conditions when selecting the recovery configuration. Integration also requires agreement on available pressure, allowable backpressure, control signals and the handling of methane-containing streams. Depending on the site, additional treatment or changes to the interface may be required.

For an existing plant, a representative gas analysis and operating data provide a stronger design basis than nominal upgrader specifications alone.

Explore CO₂ recovery from biogas upgrading and our project engineering services.

Yes. CO₂ recovery can be assessed as a retrofit to an existing biomethane plant. Important integration points include the off-gas connection, permitted backpressure, available electrical capacity, equipment layout, storage and control interfaces.

The design must also establish how the biomethane plant handles its off-gas when the CO₂ recovery installation is stopped or undergoing maintenance.

Solveno’s engineering services support project assessment and system integration.

Yes. CO₂ gas released when liquid CO₂ is expanded during dry ice production can be collected, compressed and reliquefied for reuse. This reduces the amount of fresh liquid CO₂ needed for a given dry ice output.

Solveno Technologies supplies recovery systems for this application. At IJsfabriek Strombeek in Belgium, a Solveno CR35 installation recovers CO₂ gas from dry ice production. The published project report records 1,000 tonnes of CO₂ recovered during its first two months of operation.

Recovery performance depends on the gas collection arrangement, production schedule, inlet conditions and integration with the liquid CO₂ system. Electricity consumption and the reduction in fresh CO₂ demand should be evaluated together.

This application differs from recovery at a biomethane plant, where the incoming gas generally requires a different purification approach.

Read the IJsfabriek Strombeek project reference and explore our CO₂ recovery systems for dry ice production.

Yes. CO₂ recovered from biomethane production can be converted into dry ice once it has been purified and liquefied to meet the requirements of the production equipment and intended application.

Solveno Technologies provides CO₂ purification and liquefaction technology, while Cold Jet provides dry ice production technology. Their partnership connects CO₂ recovery with an on-site product route for biomethane producers.

The business case should compare selling liquid CO₂ with producing and distributing dry ice. Dry ice production adds equipment, packaging, handling and distribution requirements. Demand, delivery distance and sublimation losses affect the net value received.

Not all liquid CO₂ becomes solid dry ice during production. The resulting CO₂ gas can be assessed for recovery and recycling as part of the overall installation.

A viable project therefore requires a suitable CO₂ source, a defined quality specification and a credible route to market.

Learn more about the Solveno Technologies and Cold Jet partnership.

Solveno Technologies' CO₂ recovery range covers approximately 350 kg to 4,500 kg of CO₂ per hour. The appropriate configuration depends on the available CO₂ flow, gas composition, operating profile and required product quality.

When comparing proposals, check whether the stated capacity refers to total inlet gas, contained CO₂ or liquid CO₂ output.

Explore the CO₂ recovery product range for biogas upgrading.

A complete CO₂ recovery installation includes the equipment needed to convert the available gas into a product that meets the agreed specification, together with the utilities, controls and storage interfaces required for operation.

The process equipment typically covers compression, purification, drying, refrigeration, liquefaction and separation of remaining impurities. Instrumentation and appropriate quality monitoring support process control and product verification.

Solveno Technologies combines modular recovery equipment with project-specific engineering. The overall project must also address electrical supply, foundations, pipework, liquid CO₂ storage, loading facilities and integration with the existing plant.

These items should be clearly allocated in the quotation and scope of supply. A recovery-unit quotation should not be assumed to include every item required for an operational site.

Where food or beverage applications are intended, source qualification, relevant impurity limits and quality procedures must also be addressed. An analyser alone does not establish food-grade compliance.

Explore our biogas CO₂ recovery product range and engineering services.

Solveno Technologies uses a modular approach, combining standard equipment configurations with project-specific engineering.

The required adaptations depend on inlet gas composition, product quality, ambient conditions, utilities, storage and integration with the existing plant. This provides a repeatable equipment basis while addressing the requirements of each installation.

See the standard biogas recovery systems and our engineering approach.

Residual methane must be separated and handled through an appropriate process route. Depending on the installation, a methane-containing stream may be returned to a suitable process point or directed to an approved treatment system.

Methane recovery performance should be assessed across the complete installation, including normal operation, purges, start-up and shutdown. Any recovery claim needs a defined system boundary and operating conditions.

Oxygen and nitrogen must be separated from the liquid CO₂ product. Higher concentrations can increase separation requirements and CO₂ losses in the stream used to remove these gases.

This can affect recovery yield, electricity consumption and product quality. Their impact therefore needs to be assessed separately from the bulk CO₂ concentration.

Gas composition is an important input to the engineering of a CO₂ recovery installation.

CO₂ recovery can be profitable when the value generated covers operating costs and provides a sufficient return on the total installed investment. The assessment should consider three potential sources of value separately:

• Revenue from selling recovered CO₂.

• Additional biomethane value where residual methane is recovered and returned to production.

• Any recognised commercial value associated with an improved biomethane carbon intensity, or CI score.

A better CI score does not automatically generate additional revenue. Its financial value depends on the applicable certification framework, market and commercial agreement. The same environmental benefit must not be counted twice.

The main cost drivers include electricity, maintenance, consumables, quality control, storage and transport. Annual operating hours, recovery yield, buyer specifications and seasonal demand determine how much CO₂ can actually be sold.

Solveno Technologies’ approach is to assess the complete project: saleable output, operating cost per tonne, total installed investment and the intended CO₂ outlet. Sensitivity analysis should test changes in electricity price, CO₂ selling price and annual utilisation.

Our engineering services support this project-specific evaluation.

There is no universal minimum profitable capacity. Smaller installations have fewer saleable tonnes over which to spread investment, maintenance, analysis and storage costs.

A nearby buyer, high annual utilisation and favourable electricity costs can improve feasibility. Technical availability of a small recovery unit does not automatically mean that the project is economically attractive.

Solveno can assess these factors through its project engineering and economic evaluation.

Compare electricity consumption per tonne of saleable liquid CO₂ together with the percentage of incoming CO₂ recovered as product. Both figures must refer to the same operating conditions and product specification.

Specific electricity consumption is the electricity used within the agreed system boundary divided by the tonnes of on-spec liquid CO₂ produced.

CO₂ recovery yield is the mass of CO₂ recovered as on-spec product divided by the mass of CO₂ entering the recovery system over the same period.

A comparison should state whether electricity consumption includes compression, purification, drying, refrigeration, cooling equipment and auxiliaries. Inlet pressure, gas composition, ambient temperature and operating load must also be specified.

A lower electricity figure may not deliver a lower production cost if more CO₂ is lost during separation or if essential equipment is excluded from the stated consumption.

Solveno Technologies evaluates energy consumption and recovery yield together when assessing a project. The relevant commercial measure is the cost of producing a saleable tonne at the required quality.

Explore our biogas CO₂ recovery systems and engineering approach.

CO₂ recovery can improve the carbon intensity, or CI score, of biomethane when the applicable calculation methodology recognises the resulting emissions savings. Carbon intensity expresses lifecycle greenhouse gas emissions per unit of fuel energy, commonly in gCO₂e/MJ.

The assessment must consider the destination of the recovered CO₂, any change in methane emissions and the additional energy required for recovery, liquefaction and transport.

Some methodologies recognise qualifying replacement of fossil CO₂ or permanent geological storage under specific conditions. Using CO₂ to produce dry ice is not permanent carbon storage: the CO₂ returns to the atmosphere when the dry ice sublimates.

Where integration also reduces methane emissions, that effect must be quantified against the existing plant configuration. Returning methane to production and reducing atmospheric methane emissions are related but distinct outcomes.

For a Solveno project, the recovery configuration and operating data provide inputs to the assessment. The recognised CI improvement must be established under the applicable certification methodology and verification process.

Discuss the required technical inputs through our project engineering services.

Compare suppliers on the cost and reliability of producing saleable CO₂ at the required specification, using the same inlet conditions and scope of supply.

The main comparison points are:

• Liquid CO₂ output and recovery yield at the specified gas composition.

• Total electricity consumption per tonne of saleable product.

• Performance at minimum, normal and maximum operating load.

• Product specification, quality monitoring and acceptance testing.

• Maintenance requirements, spare parts and service arrangements.

• Installed project cost, including utilities, storage and site integration.

• Operating references relevant to the proposed application.

For biomethane plants, also assess residual methane handling and the interfaces with the existing upgrader.

Solveno Technologies combines modular equipment with project-specific process engineering. Our operating reference at IJsfabriek Strombeek demonstrates CO₂ recovery from dry ice production. Biogas projects require a separate assessment because their gas composition and purification requirements differ.

Review our biogas recovery systems as the starting point for a project-specific comparison.

The main inputs are minimum, normal and maximum gas flow; CO₂, methane, oxygen and nitrogen concentrations; pressure; temperature; and moisture content. Relevant trace contaminants, including hydrogen sulphide (H2S) and volatile organic compounds (VOC's), should also be identified.

Gas analyses should state the measurement units and whether concentrations are reported on a wet or dry basis. Flow rates in Nm³/h should include the reference conditions.

You can send your available gas data to Solveno for an initial assessment.

An initial feasibility study needs information about the available gas, operating conditions, site infrastructure and intended CO₂ outlet. These inputs determine the suitable process configuration, recoverable output and economic potential.

Please provide, where available:

• Minimum, normal and maximum off-gas flow, with annual operating hours.

• CO₂, methane, oxygen and nitrogen concentrations, moisture and relevant trace contaminants.

• Gas pressure, temperature and expected operating variations.

• Upgrading technology and available interface information.

• Electricity price, available electrical capacity and site location.

• Required CO₂ quality, intended application and potential buyer.

• Storage, collection or on-site consumption requirements.

Gas analyses should state whether concentrations are on a wet or dry basis. Flow rates in Nm³/h should include their reference conditions.

For an assessment involving biomethane carbon intensity, also identify the applicable certification framework and available emissions data.

Solveno uses these inputs to assess the process configuration and project assumptions. Missing information should be identified explicitly so that preliminary estimates can be distinguished from confirmed design data.

Contact Solveno Technologies to discuss your project and our engineering services.