重质油添加量对低变质粉煤共热解过程产品组成的影响

摘要

进行了低变质粉煤(SJC)与重油(HS)、煤沥青(LQ)、焦煤(JM)的共热解实验,主要研究了 HS添加量对共热解过程中产品组成与结构的影响规律.利用傅立叶红外光谱(FTIR)和气相色谱-质谱联用(GC-MS)等对固体焦、热解焦油的结构和组成进行分析表征.研究表明:HS 的加入可有效改善低变质煤共热解过程中热解产品的产率与结构组成.随着 HS添加量的增加,固体焦收率逐渐降低,而焦油收率先增大后减小,煤气收率先减小后增大;固体焦表面酚类、醇类官能团质量分数有所增加;热解煤气中 CH4体积分数逐渐增大,H2体积分数则逐渐减少.当 HS 添加量为20%时,焦油收率达到最大值33%,煤气中 CH4与 H2体积分数分别增大到33.16%和19.61%, CO+CH4+H2总体积分数达到最大值65.54%.随着 HS 添加比例的增大,HS 中芳香结构的加氢裂解使得焦油中芳香烃含量骤减,同时烷烃和酚类质量分数有所上升,SJC与 HS之间的协同作用更加明显,酚类物质含量最大为21.87%,而芳香族物质则减少了24.20%.同时,焦油中轻质组分(C5~C10)含量逐渐增大,而C11~C19与C≥20质量分数则有所降低,HS添加量为20%时,轻质组分含量达到最大值28.81%,而中质组分和重质组分质量分数均达到最小值.%The co-pyrolysis experiments of low metamorphic pulverized coal(SJC),heavy oil (HS),coal tar pitch (LQ)and coking coal (JM)were carried out.The research focused on the composition and structure of co-pyrolysis products after adding the heavy oil (HS).FTIR and GC-MS were used to investigate the structure and composition of solid products and pyrolysis tar respectively.Results show that the addition of HS can effectively improve the distribution and structure of pyrolysis products in the process of co-pyrolysis of low-rank coal.The solid coke yield gradually decreases,while the tar yield first increases and then decreases,the gas yield first decreases and then increases;the contents of phenols and alcohols functional groups on the sur-face of solid coke increase;the pyrolysis CH4gas content gradually increases,while H2content gradually reduces.When the amount of HS is 20%,the yield of tar reaches 33%,the volume fraction of CH4and H2in gas increase to 33.16% and 19.61% respectively,and the total volume fraction of CO+CH4+H2reaches 65.54%.With the increase of the proportion of HS,the aromatics structure in HS is pyrolyzed and the content of aromatics in tar decreases sharply.With the increase of HS addition ratio,the hydrocracking of aromatic structures in HS causes a sharp decrease in aromatic hydrocarbon content in tar,while the contents of alkanes and phenols in-crease,and the synergy between SJC and HS becomes more pronounced.The maximum mass fraction is 21.87%,while the aromatics reduce by 24.20%.Meanwhile,the content of C5-C10in tar gradually increases,while the contents of C11-C19and C≥20decrease.The maximum amount of light components is 28.81%,when the addition of HS is 20%.However the contents of medium and heavy components reach their minimum values.