Effect of oil shale semi-coke on deposit mineralogy and morphology in the flue path of a CFB burning Zhundong lignite  

作　　者：Zhuo LIU Jianbo LI Mingming ZHU Xiaofeng LU Zhezi ZHANG Dongke ZHANG 

机构地区：[1]Key Laboratory of Low-grade Energy Utilization Technologies and Systems of the Ministry of Education,Chongqing University,Chongqing 400044,China [2]Centre for Energy(M473),The University of Western Australia,35 Stirling Highway,Crawley WA 6009,Australia

出　　处：《Frontiers in Energy》2021年第1期26-37,共12页能源前沿（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Grant No.51706028);the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2017-K01);the Joint Grants Scheme of Shanxi Province and National Science Foundation of China(Key Applied Projects U1610254);the Australia Research Council under the ARC Linkage Projects Scheme(Project No.LP100200135).

摘　　要：The effect of oil shale semi-coke(SC)on the mineralogy and morphology of the ash deposited on probes situated in the flue path of a circulating fluidized bed(CFB)which burns Zhundong lignite(ZD)was investigated.10 wt%or 20 wt%SC was added to ZD,which were then combusted in the CFB furnace at 950℃.Two probes with vertical and horizontal orientations were installed in the flue duct to simulate ash deposition.Both windward and leeward ash deposits on probes(P_(1)W,P_(1)L,P_(2)W and P_(2)L)were analyzed by using a scanning electron microscopy with energy dispersive X-ray(SEM-EDX),X-ray diffraction(XRD),an inductively coupled plasma optical emission spectrometry ICP-OES,and a particle size analyzer.When ZD was burned alone,the P1W deposit was comprised of agglomerates(<30µm)enriched in CaSO_(4)and Na_(2)SiO_(3),incurring significant sintering.The P1L and P2W deposits,however,were of both discrete and agglomerated particles in similar mineral phases but with coarser sizes.The P_(2)L deposit was mainly fine ash particles where Na_(2)SiO_(3)and Na_(2)SO_(4)were absent.As SC was added,the agglomerates in both P1W and P1L decreased.Moreover,SiO_(2)and Ca/Na aluminosilicates dominated the mineral phases whereas Na_(2)SiO_(3)and Na_(2)SO_(4)disappeared,showing a decrease in deposit stickiness.Likewise,the P2W deposit was found less spread on the probe,decreasing its deposition propensity.Na-bearing minerals turned into(Na,K)(Si_(3)Al)O_(8)and(Ca,Na)(Si,Al)4O8 in the P_(2)W deposit.Moreover,Na in the deposits decreased from 32 mg/g to less than 15 mg/g as SC presented.The addition of SC would therefore help alleviate the propensity of ash deposition in the flue path in the CFB combustion of ZD.

关 键 词：ash deposition circulating fluidized bed(CFB) mineral transformation oil shale semi-coke(SC) Zhundong lignite(ZD) 

分 类 号：P618[天文地球—矿床学]