2,3-吡啶二羧酸合成尾气吸收实验研究

2,3-吡啶二羧酸合成产生的尾气中含有氯气,必须完全除去氯气,尾气才可达标排放。采用亚硫酸钠溶液和氢氧化钠溶液作为尾气吸收液进行对照实验,并考察了影响尾气吸收效果的因素。实验结果表明,亚硫酸钠吸收氯气效果优于氢氧化钠,适当降低流速以及提高吸收液浓度有利于吸收氯气。用30%氢氧化钠溶液调节吸收液pH可最大程度发挥亚硫酸钠吸收氯气的能力,每50 g喹啉反应对应需要300 g 20%亚硫酸钠和500 g 30%氢氧化钠吸收尾气中的氯气。整个反应中尾气未检测到氯气及二氧化硫等有害气体,吸收效果较好。

Experimental study on tail gas absorption in synthesis of 2,3-pyridinedicarboxylic acid

The tail gas produced by synthesis of 2,3-pyridinedicarboxylic acid contains chlorine.Chlorine must be completely removed before the exhaust gas discharge to reach standard.Sodium sulfate solution and sodium hydroxide solution were used as tail gas absorption solution for controlled experiment.And the factors influencing the absorption effect of tail gas were investigated.The experimental results showed that sodium sulfate had a better absorption effect of chlorine than sodium hydroxide.And appropriate reducing the flow rate and increasing the concentration of absorption solution was beneficial to the absorption of chlorine.The absorption capacity of Na₂SO₃ can be maximized by adjusting the pH of absorption solution with 30% NaOH solution.For 50 g quinoline reaction,300 g 20% Na₂SO₃ and 500 g 30% NaOH were required to absorb Cl₂ in tail gas.In the whole reaction,no harmful gas such as Cl₂ and SO₂ was detected in the tail gas,and the absorption effect was well.