State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources, Engineering Research Center of CO2 Emission Reduction and Resource Utilization-Ministry of Education of the People’s Republic of China, Shanxi University
Shanxi Hepo Power Generation Company Limited

热解是煤泥资源化利用的重要途径,硫的控制是煤泥热解利用的重要环节。为探究电石渣对煤泥热解中硫释放特性的影响,采用非等温热重分析法,利用SetaramSetsys同步热分析仪在N2气氛下研究了煤泥原样及电石渣添加量(电石渣在电石渣煤泥混合物中的质量分数)分别为10%,20%,30%,40%,50%的电石渣煤泥混合物在0℃~1000℃的热解特性,并利用Coats-Redfern积分法对热解过程进行了动力学分析,获得了反应级数、活化能和指前因子等动力学参数。同时采用等温热分析法,利用管式炉固定床反应器,对煤泥原样及电石渣添加量分别为10%,30%,50%电石渣煤泥混合物在550℃,650℃,750℃和850℃下恒温热解的硫释放规律进行研究,并利用Labinao硫释放反应动力学模型分析,获得了样品热解过程硫的释放动力学特征。结果表明:随着电石渣添加量的增加,电石渣煤泥混合物最大质量变化速率明显提高,从0.57%/min显著升高至2.49%/min,电石渣促进煤泥热解挥发分的释放;随着温度升高,硫的释放逐渐升高,样品中无机硫逐渐从FeS2分解为Fe1-xS,添加的电石渣与Fe1-xS反应生成CaS,电石渣的加入使得硫向固相产物转化,但当温度在850℃且电石渣添加量为50%时,硫不利于向固相转化;电石渣添加量为10%的电石渣煤泥混合物反应所需活化能最低,且提高了硫释放所需活化能,硫向固相转化,实验结果与动力学推断一致。

Pyrolysis is an essential method for coal slime resource utilization. Meanwhile, sulfur control is also a critical aspect for coal slime pyrolysis and its subsequent utilization. The effect of calcium carbide residue on sulfur release characteristic during coal slime pyrolyzation was investigated. Using non-isothermal thermogravimetry analysis method, the pyrolysis characteris-tics of the original coal slime as well as the mixture of coal slime and calcium carbide residue with 10%, 20%, 30%, 40%, and 50% calcium carbide residue additive amount (expressed as the mass fraction of calcium carbide residue in the mixture) at 0 ℃-1 000 ℃ were studied in N2 at-mosphere using Setaram Setsys synchronous thermal analyzer. Besides, the Coats-Redfern inte-gral method was used for kinetic analysis of the pyrolysis process, further obtaining kinetic pa-rameters such as reaction order, activation energy, and pre-exponential factor. At the same time, in a fixed bed reactor of tube furnace, the sulfur release properties during constant temperature pyrolysis of the original coal slime and the mixture with 10%, 30%, and 50% calcium carbide residue addition were researched at 550 ℃, 650 ℃, 750 ℃, and 850 ℃ through isothermal ther-mal analysis method. The kinetic characteristics of sulfur release during sample pyrolysis were further obtained by employing labinao kinetic model. The results show that the maximum mass change rate of the mixture increases significantly from 0.57%/min to 2.49%/min with calcium carbide residue addition increasing, which indicates that calcium carbide residue can promote the release of volatiles during coal slime pyrolysis; the findings indicate a progressive increase in sul-fur release as temperature rises. This can be attributed to the transformation from FeS2 into Fe1-xS, leading to stepwise decomposition of inorganic sulfur within the sample. Furthermore, the added calcium carbide residue can also undergo a reaction with Fe1-xS to produce CaS, resul-ting in the conversion of sulfur to solid phase product. However, the results reveal that this con-version is not favorable at a temperature of 850 ℃ and with 50% addition of calcium carbide resi-due; the activation energy for the reaction between calcium carbide residue and coal slime is the lowest when the calcium carbide residue additive amount is 10%. Both the experimental results and the kinetic results illustrate that increasing the activation energy necessary for sulfur release can promote the conversion of sulfur to solid phase product.

国家重点研发计划项目(2020YFB0606201)、国家自然科学基金项目(21908138)和山西省科技合作交流专项项目(202104041101014).

赵文鑫,张圆圆,李丽锋,等.电石渣对煤泥热解过程中硫释放特性及动力学的影响[J].煤炭转化,2023,46(6):70-79

ZHAO Wenxin,ZHANG Yuanyuan,LI Lifeng,et al.Influence of calcium carbide residue on sulphur release characteristics and kinetics during pyrolysis of coal slime[J].Coal Conversion,2023,46(6):70-79