微波协同化学助剂强化脱除煤中硫

Enhanced removal of sulphur from coal by microwave combined with chemical auxiliaries

硫是煤中主要有害元素,煤炭利用过程中硫的排放是酸雨的重要成因,脱硫是煤炭洁净利用的研究热点之一。微波具有促进反应发生、加快反应速率的作用,微波协同化学助剂脱硫是煤炭脱硫的重要手段。本文通过微波辐照结合3种化学助剂研究煤中硫的脱除效果,利用正交试验考察微波辐照时间、化学助剂种类和煤种对脱硫效果的影响。结果表明,煤种对微波协同不同助剂的脱硫效率影响较大,所选3种煤样的最佳辐照时间各不相同;硝酸与微波联合的脱硫效果最好,其中贵州(GZ)煤在微波协同硝酸作用下,全硫脱除率可达71.2%。形态硫测试分析表明煤样经脱硫后无机硫脱除效率较高,最高可达90.5%,有机硫脱除效率在20%~40%。XRD谱图分析显示微波协同化学助剂脱硫后,煤中主要矿物和煤质结构没有明显变化,微波在脱除煤中硫分的同时可保持煤炭基质稳定。XPS谱图分析表明,煤样硫醚(醇)类有机硫脱除效果较好,脱除率可达49.4%,亚砜类略低,脱除率为23%~28%,噻吩类有机硫脱除效果最差,脱除率在10%~20%。

Sulfur is the main harmful element in coal.The emission of sulfur during coal utilization is an important cause of acid rain.Desulfurization is one of the research hotspots for clean utilization of coal.Microwave has the function of promoting the reaction and accelerating the reaction rate.Microwave combined with chemical auxiliaries is an important means of coal desulfurization.In this paper,the effects of sulfur removal in coal were studied by microwave irradiation combined with three chemical additives.The effects of microwave irradiation time,chemical additives types and coal types on desulfurization were investigated by orthogonal test.The results show that the coal types have a great influence on the desulfurization efficiency of microwave assisted additives,and the optimum irradiation time of the selected three coal samples is different.Among the three chemical additives selected,the desulfurization effect of nitric acid combined with microwave is the best.The removal rate of total sulfur in Guizhou (GZ) coal can reach 71.2% under the action of microwave combining with nitric acid.The morphological sulfur test analysis shows that the removal efficiency of inorganic sulfur after coal desulfurization is higher,up to 90.5%,and the removal efficiency of organic sulfur is between 20% and 40%.XRD spectrum analysis shows that after the desulfurization of microwave assisting chemical additives,there is no significant change in the main minerals and coal structure in the coal.The microwaves can maintain the stability of coal matrix while removing sulfur from coal.Through the analysis of XPS spectrum,it is known that the removal of sulphur thioethers and organic sulphur from coal samples is better,the removal rate can reach 49.4%,the sulfoxides are slightly lower,the removal rate is 23%-28%,the removal of the thiophene organic sulfur is the worst,and the removal rate is between 10% and 20%.