Methane lost with off-gas
Every percent lost is product you paid to make — and a heavier carbon footprint on the gas you sell.
CIRCULAR BIOGAS UPGRADING
Biogas upgrading with CO₂ conversion to potassium carbonate
CarboLoop C-300 is a containerised biogas upgrading system by Int-Energia and Metaplasma. It converts raw biogas into biomethane (renewable natural gas, RNG) and captured CO₂ into marketable potassium carbonate. Performance is defined for the agreed feed gas and project requirements.
300 Nm³/h
Raw biogas per module
>98% CH₄
Biomethane quality*
2 products
From one biogas stream
*For an agreed raw-biogas composition.
Pilot tests witnessed by Bureau Veritas · 2025 Pilot tested in Asturias, Spain Int-Energia Kft. × Metaplasma S.L.
01 / A NEW CHAPTER FOR BIOGAS
The economics of biogas have changed.
CarboLoop upgrades raw biogas to biomethane and converts captured CO₂ into liquid potassium carbonate. You can arrange carbonate sales directly or discuss a partner off-take agreement for your site.
02 / THE OPERATOR’S CHALLENGE
Where value slips away.
CO₂ becomes a cost
Venting or disposal can leave the carbon in your biogas without a commercial use.
Strict grids, costly rejection
Oxygen, nitrogen and other limits vary by network. Non-compliance can mean downtime and lost revenue.
Tighter post-subsidy margins
“Good enough” cleaning is no longer enough. The plant has to earn more from the same input.
03 / THE CARBOLOOP DIFFERENCE
More value. Same biogas.
An integrated approach that connects methane recovery, CO₂ conversion and the specific requirements of your plant.
Keep more methane
Near-complete methane recovery returns methane-bearing streams to the cycle and back to the product.
Give CO₂ a commercial use
Captured CO₂ is converted into marketable potassium carbonate — a second commercial product.
Build around your grid
CH₄ >98% and H₂S ≈1 ppm.* Add dedicated O₂/N₂ polishing where your network needs it.
Adapt your operating model
Market the carbonate yourself or explore an available reagent-supply and product off-take partner model.
*For an agreed raw-biogas composition. Grid requirements are assessed for each project.
04 / CIRCULAR ECONOMY, BUILT IN
One biogas stream.
Two commercial products.
RAW BIOGAS
Closed-loop capture & conversion
CH₄
Biomethane
The energy product your plant is built to deliver.
K₂CO₃
Marketable potassium carbonate
A second product, with potential use in potassium fertiliser applications.
Captured CO₂ is converted into marketable K₂CO₃ as an integral part of the CarboLoop process.
05 / OPTIONAL O₂ / N₂ POLISHING
Your grid is demanding.
Your configuration can be, too.
A separate, dedicated O₂/N₂ polishing module is available for projects with stringent oxygen and nitrogen specifications. Match the configuration to your network and reduce the risk of injection rejection.
Discuss your grid requirementsSeparate add-on module
O₂ / N₂
01Raw-gas assessment
02Network specification
03Tailored polishing
Performance is agreed for your raw-biogas composition and the applicable grid requirements.
06 / HOW IT WORKS
Three stages. One container.
CarboLoop C-300 upgrades raw biogas into biomethane and converts captured CO₂ into a marketable potassium carbonate product through an integrated alkaline capture and conversion process.
- 01
Capture
CO₂ and H₂S are chemically removed from the raw biogas in the alkaline absorption stage.
- 02
Convert
Captured CO₂ is converted into a marketable liquid potassium carbonate product within the integrated CarboLoop process.
- 03
Deliver
Biomethane leaves the system at >98% CH₄.* The liquid potassium carbonate product is withdrawn as a ready commercial product for use or sale.
07 / YOUR PLANT. YOUR MODEL.
Clean gas. A model that fits.
Send your gas flow and composition. We’ll estimate the module count, identify any additional treatment and prepare an indicative economic assessment for your plant.
01 / PRODUCT OWNERSHIP
Manage carbonate sales directly
Handle carbonate sales yourself and develop a second commercial outlet alongside biomethane.
For operators who want to manage both products.
02 / PARTNER MODEL
Discuss partner supply and off-take
Explore an available partner model for reagent supply and carbonate off-take. Scope and availability are agreed per project.
For operators who prefer a managed chemistry model.
CONFIGURATION FOR YOUR SITE
From your feed-gas data to a suitable configuration
Is CarboLoop suitable for your project?
CarboLoop combines raw-biogas upgrading to biomethane with captured CO₂ conversion to liquid potassium carbonate. Project assessment considers both the intended gas use and the carbonate product outlet. Suitability is assessed from your feed-gas data and site requirements.
What data are needed for a calculation?
Provide raw-biogas flow, CH₄ and CO₂ content, H₂S level, location and intended gas use. Identify measurements and estimates. Where available, add operating ranges, a dated gas analysis, existing pretreatment and the receiving specification.
What is the standard configuration?
One C-300 module processes 300 Nm³/h of raw biogas in a 40-ft ISO container. Modules can operate in parallel for higher total flows. The published inlet basis is CH₄ 56% / CO₂ 44% / H₂S ≤300 ppm. Higher H₂S is assessed individually; O₂/N₂ polishing is a project-dependent option.
What is agreed for each project?
Module count, gas treatment, interfaces and operating personnel depend on the complete plant configuration. Performance guarantees apply for the agreed raw-biogas composition. Grid injection and carbonate off-take require their respective specifications and arrangements. Partner-model scope and availability are agreed per project.
THIRD-PARTY INSPECTIONSPAIN · 2025
08 / ENGINEERED. TESTED. VERIFIED.
Pilot tests witnessed by Bureau Veritas
Bureau Veritas witnessed the pilot tests in Olloniego, Asturias, Spain on 11 September 2025. Its conclusion, issued on 30 September, found the installation functional and suitable for industrial application.
99.1% CH₄ achieved on the pilot
<1% Residual CO₂ on the pilot
Modular from the start
Each CarboLoop C-300 module processes 300 Nm³/h of raw biogas in a 40-ft container, and additional modules are installed in parallel to provide the required total plant capacity.
09 / TECHNICAL OVERVIEW
The numbers behind the loop.
CarboLoop C-300 standard module. Guaranteed performance applies for an agreed raw-biogas composition.
C-300
300 Nm³/h
40-ft ISO container
| Parameter | CarboLoop C-300 |
|---|---|
| CH₄ in biomethane | >98% |
| H₂S at outlet | ≈1 ppm |
| Methane recovery | Near-complete — returned to product |
| CO₂ | Converted into marketable K₂CO₃ |
| Commercial products | Biomethane + potassium carbonate |
| Module capacity | 300 Nm³/h raw biogas |
| Format | 40-ft ISO container |
| Operators | Operating personnel requirements are determined for the complete plant configuration according to the number of modules, automation level and site operating conditions. |
| O₂/N₂ polishing | Optional add-on module |
Inlet basis: CH₄ 56% / CO₂ 44% / H₂S ≤300 ppm. Guarantees apply for an agreed raw-biogas composition. Higher H₂S is assessed case by case.
10 / LET’S TALK ABOUT YOUR PLANT
Make your next cubic metre count.
Send us your raw-biogas flow and composition. We will determine the required number of CarboLoop C-300 modules, the appropriate gas-treatment configuration and the indicative economics for your plant.
- Configuration matched to your raw biogas
- Module count and optional polishing
- A commercial model for your operation
No obligation. We use your data only to prepare your calculation.
11 / QUESTIONS, ANSWERED
Before we talk.
What is the difference between biomethane and RNG?
Biomethane is commonly called renewable natural gas (RNG) in North America. Both terms describe upgraded biogas used as a substitute for fossil natural gas. Suitability for a particular gas grid or end use depends on the agreed gas specification and project requirements.
What is CarboLoop C-300?
CarboLoop C-300 is a containerised system that upgrades raw biogas to biomethane and converts captured CO₂ into potassium carbonate.
What happens to the CO₂?
CO₂ is captured chemically and converted into marketable potassium carbonate. The carbon becomes a product with potential use in potassium fertiliser applications.
What makes the process circular?
CO₂ conversion is integrated directly into the CarboLoop upgrading process. A single raw-biogas stream yields both biomethane and a marketable carbonate product, combining biomethane production as a renewable energy source with carbon capture and the production of a marketable material product.
Will the biomethane meet my grid requirements?
We assess your feed gas against the receiving network’s specification. Where oxygen or nitrogen limits require further treatment, a dedicated O₂/N₂ polishing module is available.
Can CarboLoop handle a larger plant?
The standard module handles 300 Nm³/h of raw biogas in a 40-ft ISO container. Multiple modules can be installed in parallel for higher flows, with the configuration determined from your plant data.
Do we need to sell the carbonate ourselves?
You can manage product sales yourself or explore an available partner model for reagent supply and carbonate off-take. The model and its availability are agreed for each project.
What do you need to prepare a calculation?
Send your raw-biogas flow, CH₄ and CO₂ content, H₂S level and plant location. These inputs help the team assess module count, gas treatment and the commercial configuration.