Study Of Chemical Looping Gasification And Nitrogen Migration Of High Nitrogen Wood Waste Based On Copper Slag Oxygen Carrier

The substantial increase in China's population has led to an increase in the demand for wood-based panels year by year,further increasing the content of high nitrogen wood waste produced by sanding of wood-based panels,and causing serious pollution to the environment.Based on high nitrogen wood waste recycling and harmless treatment guidelines,chemical looping gasification(CLG)technology is used for treatment.The copper slag selected in this paper is the remaining waste slag of copper smelting,which is calcined at high temperature to obtain redox metal oxides.The high-temperature calcined copper slag is used as an oxygen carrier and modified by alkali(earth)metal to realize the chemical looping gasification process of high nitrogen wood waste.High nitrogen wood waste is a kind of high nitrogen waste.At present,there are relatively few studies on its chemical looping gasification and nitrogen-containing pollutants.This article will comprehensively study Mechanism study of Chemical looping Gasification and Nitrogen Migration of high nitrogen wood waste Based on Copper Slag Oxygen Carrier.First,the waste copper slag was calcined at high temperature to enhance its activity.The impregnated method was used to modify the calcined copper slag by loading different quality alkali(earth)metals(K,Ca,Na).The best active oxygen carrier was obtained,and the gasification characteristics of high nitrogen wood waste and nitrogen migration rules were preliminary studied.The results show that the waste copper slag is calcined at 1100?(CS1100)and converted from olivine(Fe2SiO4)to Fe2O3,Fe3O4,and SiO2,so that the original copper slag has oxidation activity.With the increase of the load K,the oxidation activity first increased and then decreased.Selecting a load of 10%to modify CS 1100,the activity of different alkali(earth)metals was 10K-CS1100>1 OCa-CS 1100>10Na-CS 1100.The reactivity of 10K-CS1100 was significantly higher than that of CS1100.When obtain the same carbon conversion rate of 66.32%,it is equivalent to reduce the amount of oxygen carrier used by 40%.Secondly,in order to preliminary explore the chemical looping gasification process and nitrogen migration mechanism of high nitrogen wood waste,the effects of reaction time on the chemical looping gasification process and nitrogen migration were systematically studied in a fixed bed.Investigate the change of gas nitrogen,semi-coke nitrogen,carbon conversion rate.The study found:that when the reaction time was 15 minutes,the carbon conversion rate was 76.75%.Most of the high nitrogen wood waste was gasified.The release rate of ammonia gas is faster than that of hydrogen cyanide.Compared with pyrolysis,the chemical looping gasification reduces the ratio of NH3 to fuel nitrogen by 25.46%,while the ratio of HCN to total fuel nitrogen decreases by 5.84%.Oxygen carrier can change the existing form of semi-coke nitrogen.Promote the release of semi-coke nitrogen to generate NOX precursors.In the chemical looping gasification process,the initial nitrogen oxide content accounted for 11.04%of the semi-coke nitrogen,while the pyrolysis accounted for 5.08%.Finally,the nitrogen migration mechanism based on the 10K-CS1100 oxygen carrier high nitrogen wood waste was studied in depth on a fixed bed,and the nitrogen migration rules under different reaction conditions(oxygen equivalent coefficient,reaction temperature,gas purge flow rate,and water vapor content)were analyzed and summarized.Nitrogen migration mechanism during chemical looping gasification of high nitrogen wood waste.The study found that as the mass ratio of high-nitrogen wood waste and oxygen carrier gradually increased,the ratio of ammonia and hydrogen cyanide to fuel nitrogen increased.Especially when the mass ratio of high nitrogen waste wood to oxygen carrier is 3:7,ammonia and hydrogen cyanide account for the largest proportion of fuel nitrogen.As the reaction temperature increases,the contents of NH3 and HCN gradually increase.When the temperature exceeds 850?,HCN decreases.The Gas flow rate and water vapor leads to a gradual increase in the NOx precursor content.