School of Coal Engineering,Shanxi Datong University

煤液化残渣所含沥青质和重油在热解时可产生大量自由基,如不能被及时稳定和缩聚将转化为大量焦油和气体,形成孔隙结构,从而影响所制冶金焦密度。为此,拟引入添加剂诱导其高效缩聚,提高聚合物密度,再经炭化后制备优质冶金焦。通过系统研究不同添加剂(糠醛、甲醇、呋喃和羟基丙酮)、温度(350、400、450、500和550℃)、停留时间(0、30、60和120min)和添加量(0、4、8和16g)对所制聚合物缩聚率、结构性质、密度、热稳定性和表面性质影响,获得煤液化残渣诱导缩聚的最优试验条件。在最优条件下,分别探讨所制聚合物和炭化物的表面形貌、微晶结构和元素变化情况,获得煤液化残渣诱导缩聚机理。结果表明,添加剂(糠醛)的诱导缩聚效果最佳,其次是羟基丙酮,因而理想添加剂至少应含有1个醛基或酮基。不同添加剂可促进煤液化残渣缩聚,提高所制聚合物比表面积、孔容、平均孔径和真密度。温度和停留时间对煤液化残渣/糠醛聚合物热稳定性和表面性质影响较大,温度升高和停留时间延长可促进煤液化残渣所含酚类基团和芳香物中H参与缩聚反应,提高聚合物的缩聚程度。煤液化残渣/糠醛(焦炭)整体呈片层密实状,并含更多无定形碳。

The asphaltene and heavy oil contained in coal liquefaction residue can generate a large number of free radicals during pyrolysis.If they cannot be stabilized and polycondensation in time, they will be transformed into a large number of tar and gas, forming pore structure, affecting the density of metallurgical coke. Therefore, a certain amount of additives to induce high efficiency polycondensation wasintroduced, polymer density was improved, high-quality metallurgical coke was prepared after carbonization. The effects of different additives (furfural, methanol, furan and hydroxyacetone), temperature (350, 400, 450, 500 and 550 ℃ ), residence time (0, 30, 60 and120 min) and addition amount (0, 4, 8 and 16 g) on the polycondensation rate, structural properties, density and thermal stability of theprepared polymer were systematically studied. The optimum experimental conditions for induced polycondensation of coal liquefaction residue were obtained. Under the optimal conditions, the surface morphology, microcrystal structure and element changes of the prepared polymer and carbonization were investigated respectively, and the induced polycondensation mechanism of coal liquefaction residue was obtained. The results show that the additive (furfural) have the best effect on inducing polycondensation, followed by hydroxyl acetone.Therefore, the superior additive should contain at least one aldehyde or ketone group. The different additives can promote the polycondensation of coal liquefaction residue and increase the specific surface area, pore volume, average pore size and true density of the polymer.The temperature and residence time have great influence on the thermal stability and surface properties of coal liquefaction residue/ furfuralpolymer. The increasing temperature and residence time can promote the phenolic groups and H of aromatic compounds in the coal liquefaction residue to participate in the polycondensation reaction and improve the polycondensation′ degree of polymer. The coal liquefactionresidue/ furfural (coke) is lamellar dense and contains more amorphous carbon.

山西省回国留学人员科研资助项目(2022174);山西省高校科技创新资助项目(2021L397)

罗化峰,李通达,魏征,等.煤液化残渣诱导缩聚制备冶金焦的影响因素[J].洁净煤技术,2024,30(4):205-211.

LUO Huafeng,LI Tongda,WEI Zheng,et al.Influencing factors of coal liquefaction residue induced polycondensation toprepare metallurgical coke[J].Clean Coal Technology,2024,30(4):205-211.