Question

PERC replaced gasoline and kerosene in the dry-cleaning process.

(a) Describe any environmental problems or worker hazards that would be associated with these solvents.

(b) Would these same environmental problems or workers hazards be eliminated by the use of PERC?

(c) By the use of carbon dioxide?

(please typed answers)

Answer 1

ANSWER

a). Problem with gasoline or kerosene:- They are highly flammable petroleum solvents and can cause many fires and explosions. So workers have to be very careful while using then as clothes can easily catch the fire. They also leads to release harmful gases after burning so government had to ban it.

b). After using PERC many of such environmental problems were eliminated but not completely because these solvents were much less flammable than petroleum solvents and had improved cleaning power.

But PERC has different problem, it is carcinogenic in nature and  Perc has been shown to contaminate soil, water and air. So people use different reagent for dry cleaning.

c). Using CO2 as dry cleaning agents reduces many environmental problems. It is one of the most ecofriendly method of dry cleaning. It is used as Supercritical CO2. Advantages are:- It saves water and energy. It leads to less waste generation. No harmful gases are evolved.

Disadvantage of liquid Co2 is that, it is less powerfull than PERC and it requires expensive machinery for cleaning. Workers also have to be carefull while using co2.