| 摘要 |
<p>PURPOSE:To enable regeneration of P, Mo, V type catalyst of which catalytic activity is deteriorated due to the use for producing methacrylic acid by gas phase oxidation of methacrolein by heat-treating the deteriorated catalyst under passing a gas containing oxygen of the prescribed amount at prescribed temp. CONSTITUTION:After the catalyst containing at least P, Mo and V is used to produce methacrylic acid by gas phase catalytic oxidation of methacrolein with molecular oxygen, the catalyst of which catalytic activity is deteriorated is regenerated in a reaction pipe. In such a case, heat treatment is executed under passing oxidative gas containing at least 0.1vol.% molecular oxygen at 300-410 deg.C for 0.5-50hr. In addition, ammonium nitrate, ammonium carbonate and/or ammonium bicarbonate is added by below 20wt.% based on deteriorated catalyst to execute the heat treatment. In such a way, considerable level regeneration of activity is attained by this convenient method.</p> |
