低温等离子强化复合钙基吸附剂脱汞实验研究

在固定床吸附实验台上对低温等离子改性前后的复合钙基吸附剂进行脱汞实验，深入探究SO₂和O₂对具有较高孔隙率和比表面积的复合钙基吸附剂脱汞性能的影响.并通过多种表征手段和方法分析复合钙基吸附剂对Hg⁰的吸附机理.实验结果表明，由于等离子改性提高了吸附剂表面的含氧官能团的相对含量，经等离子改性的复合钙基吸附剂的脱汞效率有明显提高.在N₂+0.07% SO₂+6% O₂气氛下，吸附剂脱汞效率相比于无氧气氛由23.7%增至91.2%，吸附剂脱汞效率明显提高.此时吸附剂表面的羟基、酯基官能团作为主要反应活性位点，而羰基官能团的作用不明显.O₂的存在促使活性炭表面由碳原子不饱和键形成的活性位增加，促进了Hg⁰的吸附，同时生成多种汞化合物.随着SO₂浓度升至0.15%，改性复合钙基吸附剂表面活性位再次出现不足，此时SO₂抢夺Hg⁰的吸附位点，脱汞效率降至23.3%.

Experimental study of enhancement of demercuration from flue gas by calcium-based composite sorbent with non-thermal plasma treated

The influence of SO₂, O₂ and non-thermal plasma treatedon mercury removal by sorbent of high porosity and high specific surface area was investigated in a fixed bed bench. The mechanism of demercuration was analyzed by different characterization methods. As non-thermal plasma treatment increases relative content of oxygen-containing functional groups on the surface of sorbent, the study showed that the adsorption of mercury removal significant increases. In 0.07% SO₂+6% O₂atmosphere, the efficiency of mercury removal rose from 23.7% to 91.2% compared with which in the non-oxygen atmosphere. As active sites of the adsorption of Hg⁰, hydroxyl group and ester group improved the efficiency of demercuration. But the effect of carbonyl group was not obvious. It was due to the presence of O₂ that the unsaturated bonds of carbon atoms was increased. With the increase of SO₂ concentration to 0.15%, the competitive mechanism was the main effect. The efficiency of mercury removal dropped to 23.3%.