Question

Let's discuss the disadvantage of CFCs and how it will affect our global environment. What are substitute refrigerants used to replace the CFCs in the Refrigeration system?

Answer 1

CFCs are chlorofluorocarbon compounds these are non reactive, non flammable ,non toxic organic molecules therefore used in refrigerators , air conditioners in the production of plastic foam. Once CFCs are released in the atmosphere, they mix with the normal atmospheric gases and eventually reach the stratosphere. In stratosphere, they get broken down by powerful UV radiations, releasing chlorine free radical.The chlorine radicals causes the breakdown of Ozone as follows:

Cl^. (g) + O₃(g) ClO^.(g) +O₂ (g)

Thus CFCs are transporting agents for continously generating chlorine radicals into stratosphere and damaging ozone layer. With the depletion of ozone layer, more UV radiation enters into troposphere this leads to ageing of skin, cataract, sunburn, skin cancer, killing of many phytoplanktons, damage to fish productivity. Plant proteins also get affected by UV radiations which leads to harmful mutation of cells.It also increases evaporation of surface water through the stomata of leaves and decreases the moisture content of the soil. Increase in UV radiations damage paints and fibres, causing them to fade faster.

CFCs are now substituted by HFCs.

HFCs are hydrofluorocarbons that contain C, F and H only.

They does not contain Cl thus Cl radicals does not form at all , thus prevents ozone depletion.