摘要
煤和生物质共热解过程中,填料方式会显著影响挥发分之间相互作用及产物分布。分析分隔放置(Case 1)、机械混合(Case 2)、煤在棉秆上层(Case 3)和煤在棉秆下层(Case 4)4种填料方式下淖毛湖煤(NMH)和棉秆(CS)共热解产物的分布、组成及性质,并结合分形理论研究共热解半焦的孔隙特征,探究共热解协同效应。结果表明,NMH和CS协同作用因填料方式不同而变化,填料方式对共热解产物分布及性质影响大。用Case 4方式时,共热解焦油产率最高,为15.94%,较理论计算值增加3.89%,正协同效应最显著。此时,CS热解产生的富氢组分及时与NMH热解挥发物发生交互作用,导致H_(2)、CH_(4)和C_(2)~C_(4)产量较理论值降低,共热解焦油产率增加。不同填料方式对共热解焦油中轻油馏分均产生负协同作用。含氧化合物相对含量减少可能是因为共热解过程促进脱氧反应(如脱羧和脱羰基化等),进一步生成脂肪烃,减少含氧官能团发生交联反应;在共热解中,·H自由基与活性含氧基团产生正协同作用,促使焦油中O、N、S原子向固体或气体产物转移。由半焦分形结果可知半焦分形维数D_(1)和D_(2)均在2~3间,说明半焦粗糙度和孔结构均满足分形结构基本特征。对于Case 3和Case 4方式,位于下层样品半焦的表面更粗糙。用Case 3方式所得CS-C孔隙更小;而Case 4方式所得NMH-C孔隙更不均匀,孔结构更复杂。
In the co-pyrolysis process of coal and biomass,the mixing mode significantly affects the interaction between volatile compo-nents,which in turn affects the distribution of products.In this study,the co-pyrolysis products distribution,composition,and properties of Naomaohu coal(NMH)and cotton stalks(CS)under four mixing modes,which is separated placement(Case 1),mechanical mixing(Case 2),coal in the upper layer of cotton stalks(Case 3),and coal in the lower layer of cotton stalks(Case 4).Combined with the fractal theory,the pore characteristics of co-pyrolysis char were studied,and the synergistic effect of co-pyrolysis was explored.The re-sults show that the synergistic effect of NMH and CS varies with different mixing modes,and the mixing mode has a significant impact on the distribution and properties of co-pyrolysis products.In Case 4 method,the co-pyrolysis tar yield is the highest,15.94%,which is 3.89%higher than the theoretical calculation value,and the positive synergistic effect is the most significant.At this point,the hydrogen rich components generated by CS pyrolysis interact with the volatiles of NMH pyrolysis in a timely manner,which result in a decrease in the yields of H_(2),CH_(4),and C_(2)-C_(4) compared to the theoretical values,and an increase in the co-pyrolysis tar yield.Different mix-ing modes have a negative synergistic effect on the light oil in co-pyrolysis tar.The decrease in the oxygen-containing compounds may be due to the co-pyrolysis process promoting deoxygenation reactions(such as decarboxylation and decarboxylation),further generating fatty hydrocarbons,and reducing the occurrence of cross-linking reactions of oxygen-containing functional groups.During the co-pyrolysis process,·H radicals and active oxygen-containing groups have a positive synergistic effect,promoting the transfer of O,N,and S atoms in tar to solid or gas products.From the fractal dimension of char,the fractal dimensions D_(1) and D_(2) of the char are between 2-3,indica-ting that the roughness and pore structure of the char meet the basic characteristics of the fractal structure.For Case 3 and Case 4 meth-ods,the surface of the sample char located in the lower layer is rougher.The CS-C obtained by Case 3 method has smaller pores;while the pores of NMH-C obtained by Case 4 method are more uneven and the pore structure is more complex.
作者
胡孟启
罗杰
刘洋
钟梅
代正华
靳立军
亚力昆江·吐尔逊
李建
HU Mengqi;LUO Jie;LIU Yang;ZHONG Mei;DAI Zhenghua;JIN Lijun;YALKUNJANG Tursun;LI Jian(State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources,School of Chemical Engineering and Technology,Xinjiang University,Urumqi830017,China;Xinjiang Key Laboratory of Coal Clean Conversion&Chemical Engineering,Xinjiang University,Urumqi830017,China;State Key Laboratory of Fine Chemicals,Institute of Coal Chemical Engineering,School of Chemical Engineering,Dalian University of Technology,Dalian116024,China)
出处
《洁净煤技术》
CAS
CSCD
北大核心
2024年第6期85-94,共10页
Clean Coal Technology
基金
新疆维吾尔自治区科技计划资助项目(2023D04025)
自治区高校基本科研业务费科研资助项目(XJEDU2023P021)
“天池英才”青年博士人才资助项目。
关键词
低阶煤
棉秆
填料方式
共热解
协同效应
low-rank coal
cotton stalk
mixing mode
co-pyrolysis
synergetic effect
