Knowledge Base

The CO₂ released when biogas is combusted is biogenic: it originates from organic material that recently absorbed CO₂ from the atmosphere during growth. Releasing it returns that carbon to the cycle rather than adding fossil carbon that has been out of circulation for millions of years. For this reason, biogenic CO₂ is treated as carbon-neutral in most regulatory frameworks.

A complete picture requires a lifecycle perspective. The energy used to heat the digesters, run pumps, and process the gas does carry an emissions cost, which is why internal heat recovery and energy efficiency are design priorities for HoSt plants. With good design and feedstock selection, the net greenhouse gas balance of a biogas system is more favorable than fossil gas.

The picture improves further when CO₂ is captured during upgrading and utilized as a valuable end product rather than vented to the atmosphere. The separated biogenic CO₂ can be purified to food-grade quality and used in the food and beverage industry, in greenhouse horticulture for crop stimulation, or for industrial applications such as welding. This transforms a process by-product into a commercial output and reduces the overall emissions footprint of the plant. All HoSt CO₂ technologies are food-grade CO₂ compliant. However, if you want to sell food-grade CO₂ as a valuable end product, you will need a CO₂ gas analyzer to validate and certify that the CO₂ complies with food-grade quality levels.