Study On Migration And Transformation Of Nitrogen Containing Pollutants In The Coal Chemical Industry Park

Coal consumption of China’s chemical industry reaches to 0.23 billion tons,ranking the highest in the world.The coal chemical industry has provided a guarantee for the development of the national economy.At the same time,it is also a typical high-pollution industry.The COD and ammonia nitrogen discharge of this industry reaches to 236 thousand tons and 31 thousand tons,accounting for 7.6% and 13.9% of the total discharge,respectively.In recent years,the new normal operation of the domestic economy and the implementation of the new environmental law in 2015 put forward higher requirements for pollutant reduction and supply side reform in the coal chemical industry.The aim of this thesis is to develop a method of static material flow analysis for the coal chemical industry park.The system boundary is the geographical boundary of the production system.The time scale is 2016.Nodes are divided according to different production processes.Then,data are collected and tested.The indices of the key flow,the node fluctuation,and the conversion efficiency are proposed.The proposed method is applied to the case coal chemical production park to study the migration and transformation of nitrogen containing pollutants.The results show that the input of nitrogen elements mainly comes from the nitrogen in coal,and coke and ammonium sulphate as the main output accounts for 61% and 29%,and a small amount of nitrogen discharge into the gas,tar and waste water.About 60% of the nitrogen in the gas enters the coke oven carbonization chamber in the form of recycled gas and enters the flue gas through combustion.The amount of nitrogen input from coal is 13000 and 500 tons,and the output is mainly of raw gas and ash,which are 8 thousand and 100 tons and 4000 and 100 tons respectively.There is also a small amount of nitrogen entering the waste water and being entrained in the external supply of hydrogen.About 30% of the nitrogen entering the gas sends into the combustion chamber of the gasifier through the form of the recycled gas,and enters the flue gas through combustion.The input of coal from coal to nitrogen is 21000 tons.The output is mainly waste residue and exhaust gas,which are 4000 tons and 17000 tons respectively.There is a small amount of nitrogen into the dust and the waste water.