机构地区:[1]太原理工大学安全与应急管理工程学院,山西太原030024 [2]山西焦煤集团有限责任公司,山西太原030024
出 处:《煤炭学报》2023年第8期3229-3239,共11页Journal of China Coal Society
基 金:国家自然科学基金联合基金资助项目(U1810206);山西省应用基础研究计划资助项目(202103021223115)。
摘 要:甲烷排放产生的温室效应是同体积二氧化碳的25倍,矿井乏风中的低体积分数甲烷排放量巨大且直排大气,不仅造成能源浪费,还加剧了温室效应。将矿井乏风通入燃煤锅炉,在高效催化剂的催化作用下实现矿井乏风中低体积分数甲烷和锅炉燃煤的催化共燃,不仅可以实现乏风中低体积分数甲烷的完全燃烧,减少甲烷排放带来的温室效应,还可以进一步促进燃煤的充分燃烧,增加燃煤锅炉热值。基于此,首先采用配位聚合物方法合成了高效Co_(3)O_(4)/SiO_(2)催化剂。具体地,通过调变焙烧温度可控制备了Co_(3)O_(4)纳米颗粒尺寸不同的系列Co_(3)O_(4)/SiO_(2)催化剂,利用XRD、BET、H_(2)-TPR、O_(2)-TPD等进行表征,建立催化剂结构与催化低体积分数甲烷燃烧性能之间的构效关系,筛选出最优催化剂。在此基础上,将最优催化剂应用于催化低体积分数甲烷与褐煤共燃体系,进一步揭示低体积分数甲烷与褐煤催化共燃机理。结果表明,Co_(3)O_(4)/SiO_(2)-500由于其Co_(3)O_(4)颗粒尺寸最小、Co^(3+)物种含量丰富以及氧传递能力优良,表现出最优的催化低体积分数甲烷燃烧活性。此外,在低体积分数甲烷和褐煤催化共燃体系中,Co_(3)O_(4)/SiO_(2)-500催化剂的加入有效促进了褐煤挥发分的快速析出与燃烧,其燃烧放出的热量提供了甲烷燃烧必要的高温条件,使低体积分数甲烷完全燃烧温度由900℃降至700℃。该研究为矿井乏风中低体积分数甲烷的高效、大规模利用与节能减排奠定了一定的理论基础。The greenhouse effect of methane is 25 times that of the same volume of carbon dioxide.The low-concentra-tion methane(especially the ventilation air methane)emitted from coal mining is huge and discharged into the atmosphere,which wastes energy and intensifies the earth greenhouse effect.The catalytic co-combustion of the low-concentration methane in the mine exhaust air and the coal in the boiler under high efficiency catalyst can be achieved,which can not only realize the complete combustion of the low-concentration methane in the mine exhaust air,but also reduce the green-house effect caused by methane emission.Furthermore,it promotes the full combustion of coal in the boiler,which in-creases the heating value of coal-fired boiler.A Co_(3)O_(4)/SiO_(2)-x catalyst with con-trollable particle size of Co_(3)O_(4)and sup-ported on silicon dioxide was prepared by using piperazine and pyromellitic acid hydrate as linker at different calcination temperatures.A series of characterization methods such as XRD,BET,H_(2)-TPR and O_(2)-TPD were used to study the phys-ical structure and chemical properties of the catalysts and establish the structure-activity relationship between the physical and chemical properties of the catalyst and the catalytic combustion performance of low-concentration methane.On this basis,the optimal catalyst was selected and its catalytic performance of low-concentration methane and lignite co-combus-tion was investigated to reveal the catalytic co-combustion mechanism of low-concentration methane and lignite.The res-ults show that the Co_(3)O_(4)/SiO_(2)-500 has the best catalytic activity in the same series of catalysts due to its smallest Co_(3)O_(4)particle size,rich Co3+species content and excellent oxygen transfer ability.In the catalytic co-combustion system of low-concentration methane and lignite,the addition of the Co_(3)O_(4)/SiO_(2)-500 catalyst effectively promotes the rapid precipitation and combustion of lignite volatiles,and the heat released from combustion provides the necessary
分 类 号:TD712[矿业工程—矿井通风与安全]
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