五彩湾煤半焦水热脱钠提质及其燃烧特性的演变

Investigation on the Na removal and combustion characteristics of the hydrothermal treated Wucaiwan coal char

利用电感耦合等离子体原子发射光谱仪(ICP-AES)分析新疆五彩湾原煤及其热解提质半焦中钠的赋存形式,考察了水热脱钠前后半焦的钠含量,采用热重分析仪和Flynn-Wall-Ozawa(FWO)方法建立五彩湾煤焦燃烧反应动力学模型,获得半焦燃烧动力学参数并分析脱钠对半焦燃烧特性的影响。结果表明:五彩湾原煤及其半焦中钠的赋存形式以水溶性钠为主,半焦总脱钠率高于原煤,水溶性钠的存在不利于半焦燃烧。600℃热解半焦的水热脱钠率高达82.59%,在所有实验焦样中,经水热脱钠后的半焦燃烧特性指数最高,燃烧活性最好。

The effect of the hydrothermal treatment on the Na removal and the combustion characteristics of Wucaiwan char was addressed in this paper.The sodium contained in the raw coal and the char was removed by hydrothermal treatment in a high-pressure autoclave.The content and occurrence modes of sodium contained in the samples before and after the hydrothermal treatment was determined using inductively coupled plasma atomic emission spectrometry（ICP-AES）.The combustion characteristics of the sample were investigated using a Thermal Gravimetric Analyzer（TGA）.Meanwhile,the oxidation reaction kinetics of the char was established using Flynn-Wall-Ozawa（FWO） method.The results indicate that the main occurrence modes of the sodium contained in the raw coal and the char samples is water-soluble species and the total sodium removal efficiency of the char by the hydrothermal treatment is higher than that of the raw coal.The appearance of the water-soluble sodium is disadvantageous to the char combustion.The sodium removal efficiency of the char prepared at 600℃ by hydrothermal treatment is 82.59%.The activation energy of the char hydrothermal treated is the lowest and the combustion characteristics index is the best among all char samples.