———————————————◆ Exhaust gas analysis ◆———————————————
Source of toluene waste gas
(1) toluene is an important chemical raw material. It is also the most important fuel. In the factories and gas stations where toluene is used, automobile exhaust is the main source of pollution. Toluene in urban air mainly comes from gasoline related emissions and solvent losses and emissions caused by industrial activities.
(2) accidents in the process of storage and transportation are another pollution source of toluene.
Characteristics of toluene waste gas
(1) it is flammable, and its vapor and air can form explosive mixture, which is easy to burn and explode in case of open fire and high heat.
(2) it can react strongly with oxidant. Too fast flow rate, easy to generate and accumulate static electricity.
(3) its vapor is heavier than air, and can spread to a considerable distance at a lower place, and will be ignited back in case of open fire.
(1) after the dust and granular substances are removed by pretreatment, the waste gas is sent to the activated carbon adsorber I and II. When the activated carbon adsorber I is close to saturation, the treatment gas is automatically switched to the activated carbon adsorber II (the adsorption operation of the activated carbon adsorber I stops), and then the activated carbon adsorber I is desorbed and desorbed with hot gas flow to desorb the organic matters from the activated carbon. In the desorption process, the organic waste gas has been concentrated, and the concentration has increased dozens of times than before, reaching more than 2000 ppm. The concentrated waste gas is sent to the catalytic decomposition unit, and finally discharged as CO2 and H2O.
(2) after the desorption, the activated carbon adsorber I will enter the standby state. When the activated carbon adsorber II is close to saturation, the system will switch back automatically, and at the same time, the activated carbon adsorber II will be desorbed and desorbed, so it will work in cycle.
(3) when the concentration of organic waste gas reaches more than 2000 ppm, the catalytic bed can maintain spontaneous combustion without external heating. The scheme not only greatly saves energy consumption, but also reduces equipment investment because the treatment capacity of catalytic decomposer only needs 1 / 5 of the original waste gas treatment capacity (60000m3 / h). This scheme is not only suitable for continuous work, but also suitable for intermittent work.