Indoor pollutants
As early as in the middle of the last century 60's indoor air pollution already appeared, along with the improvement of people's living standard, decoration industry is rising, the problem of indoor air pollution is becoming more and more serious. Human have 90% of time living and working indoors, which is about 60% of the time at home. According to the survey of relevant international organizations, there are 2.8 million people die directly or indirectly from the decoration pollution around the world each year, 30% new and rebuilt buildings of the world there are indoor air pollution which is harmful to the health, so it is more and more important to purify indoor air. Activated carbon is a kind of excellent adsorbent, has the excellent adsorption capacity to the indoor pollutants.
Main indoor pollutants and their sources
Pollutant | Source |
Aerosol | combustion, smoking, people body |
Asbestus | heat insulating materials |
Formaldehyde | building materials, furniture |
CO | combustion, smoking |
Microorganism | domestic animal, people body |
Ozone | modern electronic office equipment |
Tobacco smoke | smoking |
Radon | wall and foundation |
VOCS | paint, cleaning agents, building materials |
CO2 | combustion, breath |
Allergens | animal, hair, insects, pollen |
Ammonia | antifreezer |
Benzene series | solvent, polyester fibre, adhesive tape, adhesive, wallpaper, paint, carpet |
Activated carbon pore classification
Classification | micropore | mid-hole | big hole |
Aperture nm | <2.0 | 2.0～50 | >50 |
Air Purification Activated Carbon is made of wood, coal or coconut shell, granular or cylindrical appearance. For air purification, the best is coconut shell.
The adsorption process of activated carbon
The adsorption characteristics of activated carbon depend on its pore structures and the surface chemical properties, and surface chemical properties determine the chemical adsorption of active carbon. Activated carbon for gas adsorption includes physical adsorption and chemical adsorption, generally both been accompanied by simultaneous. Physical adsorption simply via attractive forces between molecules adsorbs adsorbate on the surface of the adsorbent. Physical adsorption is reversible, reducing adsorbent partial pressure in the gas phase, increasing the adsorption temperature, adsorbent quickly desorption, without changing its chemical composition. Chemical absorption has high selectivity, and a kind of adsorbent only has the effect to the specific substance. Chemical adsorption is irreversible, after adsorption adsorbent has changed the original characteristics.
The difference between physical adsorption and chemical adsorption
Physical Adsorption | Chemical Adsorption | |
Adsorption Temperature | Can’t be far higher than the boiling point of the adsorbate | No connection with the boiling point of the adsorbate |
Adsorption Rate | Don't need any activation energy, adsorption rate is very high | Adsorption rate is influenced by activation energy and temperature in a very wide range |
Selectivity | No selectivity | Strong selectivity |
Adsorption Method | Multimolecular layer adsorption | Monomolecular layer adsorption |
Application
Air purification activated carbon has big specific surface area, abundant pore structure, high mechanical strength, strong adsorption capacity, easy regeneration. It can efficaciously adsorb methanol, ammonia, radon, benzene, xylene, exhaust gas, lampblack, especially aromatic compound.
Widely used for purification of carbon dioxide, hydrogen, nitrogen, chlorine hydride, ethyne, ethylene, cracking gas, inert gases, atomic equipment; As the packing of antigas mask, poison gas filter; For dropping off air pollutants and classification purification of mixed gas.
