| 摘要 |
<p>PURPOSE:To carry out wet treatment of exhaust gas effectively by a method wherein phenol exhaust gas is contacted with a sodium hydroxide solution to absorb phenol and thereafter a sodium hydroxide solution is neutralized by carbon dioxide to separate and recover phenol. CONSTITUTION:While an NaOH solution is recirculated by a pump 3 from a absorbing tower 1 through a storage tank 2. A pipe 4, phenol exhaust gas is introduced to a lower portion of a absorbing tower 1 from a absorbing duct 6 to contact with an NaOH solution countercurrently and phenol is absorbed in an NaOH solution as sodium phenolate. A part of a recirculated NaOH solution is introduced into a neutralizing apparatus 9 and reacted with carbon dioxide gas according to a reaction scheme I to separate phenol and, in a phenol separating tank 13, an upper phenol layer is separated and recovered. A lower sodium bicarbonate layer is reacted with calcium hydroxide in a regenerating tank 15 according to a designated reaction scheme II to regenerate NaOH and this NaOH is again used as a absorbing solution.</p> |
