Energy & Green Tech

Improving carbon capture efficiency to help net zero emissions

As the UK's National Metrology Institute, NPL has a significant role to play in supporting climate change mitigation action and enabling the innovations which will help industry deliver on their goals of reducing greenhouse ...

Energy & Green Tech

Will the new E10 petrol be beneficial?

The introduction of a new type of petrol, E10, in the UK may create some extra costs for owners of older cars, but the aim is to reduce carbon dioxide emissions.

Energy & Green Tech

The case for onboard carbon dioxide capture on long-range vehicles

When people talk about how to eliminate vehicles' carbon dioxide (CO2) emission, often the conversation often focuses on electrifying cars, trucks and buses. Yet cargo and tanker ships, which are responsible for 3% of all ...

Energy & Green Tech

Touted as clean, 'blue' hydrogen may be worse than gas, coal

"Blue" hydrogen—an energy source that involves a process for making hydrogen by using methane in natural gas—is being lauded as a clean, green energy to help reduce global warming. But Cornell and Stanford University ...

Energy & Green Tech

Electrifying cars and light trucks to meet Paris climate goals

On Aug. 5, the White House announced that it seeks to ensure that 50 percent of all new passenger vehicles sold in the United States by 2030 are powered by electricity. The purpose of this target is to enable the U.S to remain ...

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Carbon dioxide

Carbon dioxide (chemical formula: CO2) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state.

Carbon dioxide is used by plants during photosynthesis to make sugars, which may either be consumed in respiration or used as the raw material to produce other organic compounds needed for plant growth and development. It is produced during respiration by plants, and by all animals, fungi and microorganisms that depend either directly or indirectly on plants for food. It is thus a major component of the carbon cycle. Carbon dioxide is generated as a by-product of the combustion of fossil fuels or the burning of vegetable matter, among other chemical processes. Large amounts of carbon dioxide are emitted from volcanoes and other geothermal processes such as hot springs and geysers and by the dissolution of carbonates in crustal rocks.

As of March 2009[update], carbon dioxide in the Earth's atmosphere is at a concentration of 387 ppm by volume. Atmospheric concentrations of carbon dioxide fluctuate slightly with the change of the seasons, driven primarily by seasonal plant growth in the Northern Hemisphere. Concentrations of carbon dioxide fall during the northern spring and summer as plants consume the gas, and rise during the northern autumn and winter as plants go dormant, die and decay. Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared.

Carbon dioxide has no liquid state at pressures below 5.1 atmospheres. At 1 atmosphere (near mean sea level pressure), the gas deposits directly to a solid at temperatures below −78 °C and the solid sublimes directly to a gas above −78 °C. In its solid state, carbon dioxide is commonly called dry ice.

CO2 is an acidic oxide: an aqueous solution turns litmus from blue to pink. It is the anhydride of carbonic acid, an acid which is unstable and is known to exist only in aqueous solution.

CO2 is toxic in higher concentrations: 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour.

This text uses material from Wikipedia, licensed under CC BY-SA