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Chlorofluorocarbons ( CFCs) and hydrochlorofluorocarbons ( HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane . The most common example is dichlorodifluoromethane (R-12). R-12 is also commonly called Freon ...
Retrospective video on the Montreal Protocol and the collaboration between policy-makers, scientists, and industry leaders to regulate CFCs. The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ...
Particulates or atmospheric particulate matter (see below for other names) are microscopic particles of solid or liquid matter suspended in the air. The term aerosol commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. [1] Sources of particulate matter can be natural or anthropogenic. [2]
These include chlorofluorocarbons and hydrofluorocarbons, both of which cause ozone depletion (although the latter much less so) and contribute to global warming. 'Freon' is the brand name for the refrigerants R-12 , R-13B1 , R-22 , R-410A , R-502, and R-503 manufactured by The Chemours Company, and so is not used to label all refrigerants of ...
Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. [ 1] It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological ...
Fluorocarbons are colorless and have high density, up to over twice that of water. They are not miscible with most organic solvents (e.g., ethanol, acetone, ethyl acetate, and chloroform), but are miscible with some hydrocarbons (e.g., hexane in some cases). They have very low solubility in water, and water has a very low solubility in them (on ...
As of 2021, measured atmospheric concentrations of carbon dioxide were almost 50% higher than pre-industrial levels. [32] [33] The main sources of greenhouse gases due to human activity (also called carbon sources) are: Burning fossil fuels: Burning oil, coal and gas is estimated to have emitted 37.4 billion tonnes of CO2eq in 2023. [34]
The main concern over the use of carbon dioxide in refrigeration is the increased pressure required for carbon dioxide to act as a refrigerant. Carbon dioxide requires higher pressures to be able to condense within the cooling system, meaning that it has to be pressurized more than the other natural refrigerants. [ 22 ]