煤直接液化残渣改性沥青的制备及其性能研究

发布时间：2018-04-10 22:49

本文选题：DCLR + THFS　；参考：《北京建筑大学》2017年硕士论文

【摘要】：煤直接液化残渣(Direct Coal Liquefaction Residue,DCLR)作为煤清洁利用过程中副产品,具备开发为道路用石油沥青改性剂的可能性。根据DCLR的材料特性,对DCLR采取了相应的预处理手段,确定利用DCLR中的四氢呋喃可溶物(Tetrahydrofuran Soluble,THFS)对沥青进行改性。首先,本文研究了THFS改性沥青的制备工艺并对其性能进行评价与表征。基于正交试验和灰关联分析法,确定THFS改性沥青的最佳制备工艺为剪切温度150oC,剪切时间为45min,剪切速率为4000 r/min。通过性能评价,发现THFS可提高沥青的高温性能,降低其低温性能,推荐THFS掺量为6%。通过组分分析、元素分析、凝胶渗透色谱和红外光谱等对THFS改性沥青的微观结构进行表征,发现随着THFS掺量的增加,改性沥青的分子量和胶体不稳定系数Ic越来越大,但其元素组成没有明显变化,也没有新官能团的产生,说明THFS对沥青的改性属于物理改性。其次,本文对THFS改性沥青的流变特性进行了研究。通过温度扫描和频率扫描试验,并结合CAM模型,发现THFS掺量越高,改性沥青的高温性能不断增强,低温性能和疲劳性能不断下降,改性沥青的适用范围越来越窄。当THFS掺量控制在6%之内,改性沥青可用于沥青路面的中、下面层(抗车辙结构层)。第三,采用多指标共同评价THFS改性沥青的感温性能,结果表明THFS的加入可改善沥青的感温性能。同时,本文还发现随THFS掺量的增加,改性沥青的残留针入度比(Residual Penetration Ratio,RPR)、残留延度(Residual Ductility,RD)不断减小,软化点增量(Softening Point Increment,SPI)、残留黏度比(Residual Viscosity Ratio,RVR)不断增大。基于老化动力学和THFS改性沥青的微观结构,发现THFS改性沥青的老化过程属于一级老化反应,建立了以软化点为参数的一级老化动力学方程。随THFS掺量的增加,改性沥青的老化反应速率k不断增大,反应活化能Ea不断减少,胶体不稳定系数Ic以及老化前、后羰基峰面积比值不断增大,说明THFS改性沥青的抗老化性能不断变差。最后,本文利用马来酸二辛酯(Dioctyl Maleate,DOM)对THFS改性沥青的低温性能进行改善,发现DOM可以改善沥青的低温、疲劳、感温和抗老化性能,但会损伤其高温性能。综合THFS改性沥青的各项性能,确定最佳复配方案为6%THFS+1%DOM。同时,通过经济和环境效益分析表明,THFS复合改性沥青不仅具有明显的经济优势,而且可以减少原油消耗、降低温室气体排放,经济社会效益显著。
[Abstract]:Direct Coal Liquefaction residuetion (DCLRR), as a by-product of coal clean utilization, has the possibility of being developed as a road asphalt modifier.According to the material properties of DCLR, the corresponding pretreatment method was adopted for DCLR. It was determined that Tetrahydrofuran SolubleTHFSin DCLR was used to modify asphalt.Firstly, the preparation process of THFS modified asphalt was studied and its properties were evaluated and characterized.Based on orthogonal test and grey correlation analysis, the optimum preparation process of THFS modified asphalt was determined as follows: shear temperature 150oC, shearing time 45min, shear rate 4000 rmin.Through the performance evaluation, it is found that THFS can improve the high temperature performance of asphalt and reduce its low temperature performance. The content of THFS is recommended to be 6%.The microstructure of THFS modified asphalt was characterized by component analysis, elemental analysis, gel permeation chromatography and infrared spectroscopy. It was found that the molecular weight and colloidal instability coefficient IC of modified asphalt increased with the increase of THFS content.However, there is no obvious change in the composition of THFS and no new functional group is produced, which indicates that the modification of asphalt by THFS belongs to physical modification.Secondly, the rheological properties of THFS modified asphalt were studied.Through temperature and frequency scanning tests and CAM model, it is found that the higher the content of THFS is, the higher the high temperature performance of modified asphalt is, the lower the low temperature performance and the fatigue property are, the narrower the application range of modified asphalt is.When the THFS content is controlled within 6%, the modified asphalt can be used in the middle and lower layer of asphalt pavement (rutting resistant structure layer).Thirdly, the temperature sensing performance of THFS modified asphalt is evaluated by using multiple indexes. The results show that the addition of THFS can improve the temperature sensing performance of asphalt.Based on the aging kinetics and microstructure of THFS modified asphalt, it is found that the aging process of THFS modified asphalt is a first-order aging reaction. The first-order aging kinetic equation with softening point as the parameter is established.With the increase of THFS content, the aging reaction rate k of modified asphalt increases, the activation energy EA decreases, the colloid instability coefficient IC and the ratio of carbonyl peak area after aging increase.It shows that the aging resistance of THFS modified asphalt is getting worse.Finally, the low temperature performance of THFS modified asphalt was improved by dioctyl maleate dioctyl maleate. It was found that DOM could improve the low temperature, fatigue, temperature sensitivity and aging resistance of THFS modified asphalt, but it would damage its high temperature performance.According to the properties of THFS modified asphalt, the optimum blending scheme was determined as 6%THFS 1 DOM.At the same time, the analysis of economic and environmental benefits shows that the modified asphalt has not only obvious economic advantages, but also can reduce the consumption of crude oil, reduce greenhouse gas emissions, and remarkable economic and social benefits.
【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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