Destruction of residual fumigant using a plasma reactor

Methyl bromide is amply used as a fumigant for soil conditioning in greenhouses, as well as for storage grain conditioning. The treatment is carried out in a confined place and after treatment the residual gas is vented to the atmosphere. Although this gas is not harmful to humans, because it is vented in open places, it is very detrimental for the atmosphere, because its reaction with high energy photons in the stratosphere reduces the ozone concentration. In this way, the present investigation is concerned with the study of the feasibility for destruction of the residual fumigant. One of the nonthermal plasma techniques: packed-bed ferroelectric reactor was applied for destruction of mixtures of methyl bromide in nitrogen or air. The performance of the process was studied by analyzing the influence and effect of the operating variables on the process efficiency. The results obtained showed the residence time and the applied voltage as the most significant variables. When nitrogen is employed as carrier gas destruction efficiencies as high as 80% are obtained. The reaction products were mainly CO, CO₂ and N₂O in a concentration not exceeding 409 ppm, 200 ppm and 700 ppm respectively