【摘要】 高碱煤直接燃烧/气化过程呈现严重的沾污和结渣等问题限制了新疆地区高碱煤大规模利用。煤热解分质利用技术不具备发生沾污和结渣的高温与氧化气氛,应用前景广阔。如何提高热解油气的收率和品质是高碱煤分质利用研究的重要方向,通过分选可实现高油产率组分富集的同时降低钠钙等碱和碱土金属的不利影响。笔者利用有机重液对富镜质组白石湖煤进行浮沉-离心分离,采用傅里叶红外光谱对不同密度级组分表面官能团进行表征,利用热重分析仪和格金低温干馏试验装置研究了热解特征参数和动力学参数变化规律和热解产物分布规律。结果表明,白石湖煤不同密度级组分氢含量与H/C原子比均先降低后增加,氧含量和O/C原子比逐渐增加。—OH官能团主要为羧酸官能团和酚羟基,在中密度级相对富集。随密度级增加,最大质量变化速率和失重率均逐渐降低,活化能和指前因子均呈先降低后升高趋势;焦油产率先降低后升高:BS_{<1. 3}焦油产率高达25. 25%,BS_{>1. 6}焦油产率与BS_{1. 3-1. 4}相当,约为15%。黏土矿物结晶水析出导致BS_{>1. 6}具有最高的水产率。更多还原

【Abstract】 The serious fouling and slagging derived from direct combustion or gasification of high-alkali-coal limit the large-scale utilization of high-alkali-coal in Xinjiang area.The technology of coal grading pyrolysis does not have the conditions of high temperature and oxidizing atmosphere to trigger fouling and slagging problems,so it has broad application prospects.How to improve the yield and quality of oil and gas during coal pyrolysis is an important direction of research on the utilization of high alkali coal.With coal separation,the components of high oil yield can be concentrated and the adverse effects of alkali and alkaline earth metals（ such as sodium and calcium） can also be reduced.In the paper,the vitrinite-rich coal in Baishihu with different density grades was separated by flotation and centrifugation with heavy organic liquid.Fourier infrared spectrum was used to characterize the surface functional groups of different density-level components.In addition,the thermogravimetric analyzer and Gray assay were used to study the change rule of pyrolysis characteristic parameters and dynamics parameters,and the distribution of pyrolysis products.The results show that for the components of Baishihu coal with different density grades,the hydrogen content and the H/C atomic ratio decrease first and then increase,while the oxygen content and O/C atomic ratio increase gradually.The functional groups of —OH are mainly carboxylic acid functional groups and phenolic hydroxyl groups,which are relatively enriched at the medium density fractions.With the increase of density level,the maximum pyrolysis rate and the rate of weight loss decrease gradually,and the activation energy and pre-exponential factors decrease first and then increase.The tar yield first decreases and then increases: the tar yield of BS_{<1. 3} is as high as 25.25% and BS_{>1. 6} is equivalent to that of BS_{1. 3-1. 4},about 15%.The vaporization of crystal water in clay minerals results in the highest moisture yield for BS_{>1. 6}.更多还原