Study On Preparation Of Catalyst-sorbent From Lignite And Its Performance Of Desulphurization And Denitrification

With the development of industry and improvement of living standard, the fuel gas has become one of the main sources of air pollutions due to increase of coal consumption for a long time in China. The principal contaminants in coal smoke are mainly smoke dust, sulfur dioxide (SO₂), nitrogen oxide (NO_x) and so on. In China, effective removal of SO₂ and NO_x from fuel gas is one of necessary measures to solve air pollution. At present, fuel gas desulphurization equipments have only been installed in a few areas and industries in China. However, researches on simultaneous removal of SO₂ and NO_x from coal smoke have been little concerned. Therefore, it is one of the urgent tasks to search a kind of economical and effective process method about removal of SO₂ and NO_x from coal smoke. In the study, catalyst-sorbent from lignite, as a kind of cheap sorbent and catalyst, was developed by utilizing lignite from Shenyang, Liaoning Province, and the experiments to remove SO₂ and NO₂ simultaneously by using the catalyst-sorbent from lignite were also researched.In the study, the raw material mixture-ration, the process conditions for preparing a catalyst-sorbent from lignite and their influence on the performance of the catalyst-sorbent from lignite were involved. Furthermore, the technology process and optimum conditions of preparing catalyst-sorbent from lignite were given. The optimum process conditions were as follows: 65:25:10 of the ratio of raw material mixture of lignite half coke, charred coal and tar oil; lignite carbonization temperature 600℃, nitrogen as carbonization gas medium, activation temperature 850⁹50℃, activation time 60⁹0min, vapor as activation gas medium.Besides having similar advantages of activated carbon, the catalyst-sorbent from lignite is characterized by low price and good mechanical strength. The crucial factors of desulphurization efficiency were catalytic activities of the catalyst-sorbent from lignite catalysis. To improve the desulphurization and denitrification characteristics of the catalyst-sorbent from lignite, the experiment of catalyst-sorbent from lignite to be modified with metal oxidation and metal salt were carried out. The results indicatedthat catalyst-sorbent from lignite modified by Fe₂(SO₄)₃ can remove SO₂ and NO_x more effectively.The experiments to remove SO₂ and NO₂ simultaneously with the catalyst-sorbent from lignite were carried out. The results indicated that the catalyst-sorbent developed with the main material lignite has good desulphurization and denitrification...