Abstract: Coconut shell activated carbon was modified by quaternary ammonium salt ionic liquid, the ignition and explosion parameters of activated carbon before and after modification and before and after adsorption of toluene were compared to explore the ignition and explosion law of gas-solid heterogeneous mixture in VOCs adsorption process of activated carbon. The spontaneous combustion point of activated carbon increased from 319.3 oC to 345.7 oC, and the spontaneous combustion point of activated carbon increased from 307.7 oC to 327.1 oC after adsorption of toluene before and after modification. Using a 20 L spherical explosion test device, the lower limit of explosion of powder was increased from 1.5~2.5 g/m3 to 7~8 g/m3 before and after activated carbon modification. The lower explosive limit of the mixture adsorbed toluene by activated carbon before modification is less than 1.5 g/m3, and the lower explosive limit of the mixture adsorbed toluene by activated carbon after modification is 2~3 g/m3. Under the condition of 200 g/m3, the maximum explosion pressures are 0.57 MPa and 0.53 MPa, respectively, and the explosion pressures decrease. The results show that the activated carbon modified with quaternary ammonium salt ionic liquid has not only enhanced the adsorption capacity of VOCs, but also reduced the risk of ignition and explosion.

Key words: modified activated carbon, toluene, spontaneous combustion point, lower explosion limit, maximum explosion pressure