CO2dominated

CO2-dominated is used to describe systems where carbon dioxide is the principal constituent by mole fraction or volume, often when xCO2 exceeds common thresholds. This term is used across fields to contrast with nitrogen-, methane-, or water-dominated mixtures. The exact threshold varies by field.

In planetary science, CO2-dominated atmospheres occur when CO2 is the major atmospheric gas; examples include Venus and Mars, as well as some exoplanets. In such cases CO2 controls radiative properties and climate.

In geology and geochemistry, CO2-dominated fluids or gas mixtures appear in natural CO2 reservoirs, geothermal systems, and during carbon capture and storage. CO2-rich plumes can affect rock dissolution, mineral precipitation, and subsurface pressure regimes; CO2 can be dissolved in brines or present as a free gas.

In industry, CO2-dominated streams arise in fermentation byproducts, natural CO2-rich gas fields, and after CO2 capture and compression. Handling requires corrosion-resistant materials and careful pressure management; health hazards include asphyxiation at high concentrations.

Measuring often uses mole fraction or partial pressure; thresholds vary by context. The term is avoided when CO2 is only a minor component. For climate and environmental assessment, "CO2-rich" or "CO2-laden" may be used as synonyms.