Research On Innocent Incineration Processing Method Of Changzhou Acid Tar

This paper studied the emission characteristics of the pollutants experimentally while burning a typical liquid hazardous waste—acid tar from a coking plant in Changzhou China.We put forward the suggestion on comprehensive utilization of calcium carbide instead of lime as neutralizer,which was that the acid tar was mixed with calcium carbide residues to a certainty proportion and burned in the furnace. Meanwile,we should make sure the exhaust of waste gas comes up to the environment standard under given working conditions.The pyrolysis process of calcium carbide and the mixture were studied by TG-FTIR.Many components of the flue gas had been detected by the real-time FTIR during the whole process.Below 700℃the main components were H₂O,CH₄ and CO₂.With temperature increasing,the concentration of CO₂ elevated and reached the peak value around 840℃,accompanied by a little amount of CO.At high temperature section(above 850℃),SO₂ was first detected,corresponding to the weight loss peak of TG curve.The concentration increased quickly with the temperature higher.The experimental results in tube furnace showed that the emission of sulfur dioxide was strongly effected by incineration temperature.It was also found increasing airflow would promote the emission of sulfur dioxide.Mass ratio of calcium carbide and acid tar had a great influence on sulfur conversion rate.When the mass ratio was 1:1.2,sulfur conversion was the least.When incinerated in fludized bed at a low temperature condition the emission of SO₂ can be inhibited and sulphur capture efficiency was enhanced.The size had an important effect on the emission of SO₂.The smaller size had better sulphur capture efficiency.The main components of ash were CaSO₄,SiO₂ andCaO.The experimental results in rotary kiln indicated that primary chamber was under pyrolysis condition.The second chamber did good to decrease the emission of SO₂ and CH₄ siganificantly.The measured value of SO₂ and CH₄ were steady,but that of CO had slight fluctuation,between 350-400ppm. On the whole,combined with appropriate pretreatment,using rotary kiln to deal with acid tar was a ideal way.