Slagging And Corrosion Characteristics Of Slurry Fuel Prepared By Multi-source Organic Solid Waste And Coal

In the context of the dual era of "dual carbon" goals and green development,the governance of solid waste,especially industrial organic solid waste,is related to the sustainable development of society and the health and safety of the people.The composition of industrial organic solid waste is complex and diverse.Traditional biochemical and other disposal methods generally have problems such as high cost,long cycle or easy to cause secondary pollution.Combined with my country’s energy pattern of "a lot of coal,lack of oil,and exhausted gas".Therefore,the mature coal water slurry technology（CWS） is used to couple industrial organic solid waste and coal to prepare slurry fuel.On the one hand,it fully utilizes the energy in industrial organic solid waste and plays a role in replacing coal combustion and gasification to "reduce carbon".On the other hand,it has also realized the "reduction,resource utilization and harmlessness" of solid waste disposal.In recent years,this technology has carried out basic research on the mechanism of slurry formation and rheological characteristics,but it is very important for combustion and gasification.The process and slagging corrosion situation are rarely explored.Therefore,this paper systematically studied the combustion and gasification characteristics of three kinds of industrial organic solid wastes and Shenhua coal in the preparation of slurry fuel（CWSS）,as well as the slagging and corrosion of gasifier refractories.In this paper,three organic solid wastes with different components,including ocean activated carbon,traffic resin,and Jinkang medicine residue,but all containing a calorific value of more than 18MJ/kg,and Shenhua coal are used to synergize the preparation of slurry fuel.The combustion characteristics of waste slurry fuel and the slagging characteristics and mineral conversion mechanism shown in the laboratory GF1400 atmosphere furnace.The experimental results show that,compared with Shenhua coal slurry,the addition of resin and slag promotes the thermogravimetric curve to move to the left（low temperature area）,while the addition of activated carbon makes the thermogravimetric curve move to the right（high temperature area）,and the magnitude of the movement is The addition ratio W is positively correlated;the calculation results show that the combustion characteristic index S of the 20% medicine residue coal slurry and resin coal slurry is increased by 15.85% and 7.67% compared with the Shenhua raw coal slurry,while the 20% activated carbon coal slurry S slightly decreases.The melting temperature results show that T_Resin>T_{Shenhua coal}>T_{Activated carbon}>T_{Medicine residue},activated carbon and slag contain more AAEM（alkali metal and alkaline earth metal）elements,resin contains more high melting point substance Al₂O₃ After adding medicine residue and activated carbon,the ash melting point of coal ash is significantly reduced,and it is positively correlated with the addition ratio W value.The resin increases the ash melting point of coal ash;with the continuous increase of the addition ratio,the activated carbon coal slurry shows "no Slagging → slight slagging → obvious slagging → melting slagging" trend,medicine residue coal slurry has a tendency of slagging when W=5%,and it is quite serious at 10%.Under the value of W,they all have a good non-slagging tendency.XRD results show that the solid waste coal slurry combustion ash sample after adding activated carbon and medicine residue contains more lowmelting minerals such as potassium/albite（K/NaAlSi₃O₈） and nepheline（NaAlSiO₄）,and increases with the W value.Increased,the diffraction peaks of this type of substance increase and strengthen.A large amount of stable mineral mullite（3Al₂O₃·2SiO₂） with a melting point of 1850°C is distributed in the resin coal slurry.In addition,aluminum phosphate（AlPO₄） is also present in the chemical slag coal slurry.Phosphate minerals easily form a low-temperature eutectic with other components in the ash,which further promotes slagging;SEM results also support the above phenomenon.The TL1400 vacuum tube furnace built by the laboratory is used to simulate the gasification experiment of slurry fuel under the atmosphere of CO₂ as the gasification agent.The gasification thermogravimetry-infrared combined experiment results show that the three W=20% CWSS are the same as CWS-SH,and there are three obvious weight loss peaks in the gasification process:moisture drying and precipitation process,volatilization analysis reaction With coke formation process and the main reaction process of fixed carbon gasification,the maximum gasification rate temperature T_max is about 1050°C,and the critical reaction temperature T_end is about 1110°C;the calculation result of the gasification reaction index Rs: CWSS-YZ>CWSS-HXT>CWS-SH>CWSS-SZ,indicating that the Na and K in the slag and activated carbon have obvious catalytic effects on the gasification reaction.The results of three-dimensional infrared spectroscopy show that the gasification products of solid waste coal slurry and Shenhua coal slurry are mainly CO,with a small amount of CH₄ and H₂O,and the relative height of the CH₄ absorption peak is CWSS-SZ > CWS-SH > CWSS-HXT > CWSS-YZ,CO absorption peak extreme value Amax: CWSS-YZ,>CWSS-HXT>CWS-SH>CWSS-SZ.In addition,the FTIR results of the four raw materials show that there is an absorption peak with a wave number of 1530¹590 cm^-1 in the activated carbon and medicine residue.Cationic reaction increases the gasification reaction index.The macro morphology of the gasification ash and the scanning electron microscopy analysis show that at 1150 ℃,the resin coal slurry shows good antislagging characteristics,and the gasification ash is independent and fluffy.The activated carbon coal slurry and the chemical slag coal The molten slag phenomenon of the slurry is obvious,W>10%,the gasification ash under the electron microscope shows a massive glassy slag structure,EDS proves that it contains higher components of Na,K,Ca and other fluxing elements;heavy metals Cr,The immobilization effect of Cd,Cu,Mn,Pb and Zn in the gasification slag is good,the immobilization rate is as high as 75%,and the addition of solid waste has almost no effect on the heavy metal immobilization rate of the coal slurry gasification slag.The research results of the erosion of multi-source organic solid waste on refractory high chromium bricks of Texaco gasifier show that after about 12 months of operation,the high chromium bricks at 10 points inside the furnace have been scoured and corroded;EDS surface scanning The results showed that there was no significant difference in the element distribution at each location.About 10% of Na elements were detected.The Na₂O content in the gasification slag collected on site was as high as 11.57%.The eroded thickness of high chromium bricks at different depths is different.The eroded thickness of high chromium bricks tends to increase first and then decrease with the increase of depth;polynomial fitting is performed on the erosion curve,which is about 300 cm away from the furnace top The erosion peak appears at the depth position,reaching 95 mm.The results of the longitudinal section of the high chromium brick show that there are three different structures: the slag reaction layer,the permeable layer and the uneroded layer.There are cracks in the slag reaction layer,while the permeable layer has a microporous structure,and the uneroded layer has a smooth structure.EDS results show that the uneroded layer mainly contains Cr₂O₃ and a small part of Al₂O₃.The permeable layer contains elements such as Na,K,Ca,P,Si,etc.,but the content of the corresponding elements is lower than that in the slag reaction layer,and the content of Cr is obvious Lower than the uneroded layer;from the permeable layer to the uneroded layer,the energy spectrum scan results show that the content of Na and P elements gradually decrease to zero,and the content of Cr element gradually increases to a fixed value.