Dichlorofluoromethane
Encyclopedia
Dichlorofluoromethane or Freon 21 or R 21 is a halomethane
or hydrochlorofluorocarbon. It is a colorless and odorless gas.
Its critical point is at 178.5 °C (451.7 K) and 517 MPa (51.7 bar). At temperatures from 5 K to 105 K it has one phase in the space group
Pbca.
and refrigerant, but due to its ozone depletion
it has been set to be phased out. It has ozone depletion potential
0.04. Production and consumption has been since 2004 reduced to 15 % of level from 1989 and it is to be phased out in 2015 according to Montreal Protocol
.
Halomethane
Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms . Halomethanes are both naturally occurring, especially in marine environments, and man-made, most notably as refrigerants, solvents, propellants, and fumigants...
or hydrochlorofluorocarbon. It is a colorless and odorless gas.
Its critical point is at 178.5 °C (451.7 K) and 517 MPa (51.7 bar). At temperatures from 5 K to 105 K it has one phase in the space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
Pbca.
Uses
Dichlorofluoromethane was used as a propellantPropellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
and refrigerant, but due to its ozone depletion
Ozone depletion
Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere , and a much larger springtime decrease in stratospheric ozone over Earth's polar regions. The latter phenomenon...
it has been set to be phased out. It has ozone depletion potential
Ozone depletion potential
The ozone depletion potential of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane being fixed at an ODP of 1.0. Chlorodifluoromethane , for example, has an ODP of 0.055...
0.04. Production and consumption has been since 2004 reduced to 15 % of level from 1989 and it is to be phased out in 2015 according to Montreal Protocol
Montreal Protocol
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 believed to be responsible for ozone depletion...
.