WU Hao;LIU Xia;CAO Xi;GUO Qinghua;YU Guangsuo;

• 1:Institute of Clean Coal Technology
• 2:East China University of Science and Technology

Abstract：

By blending municipal sewage sludge with coal to prepare sludge slurry, it is expected to achieve resourceful, harmless, and reducing disposal of sludge by using entrained-flow gasification technology. At present, there are few studies on the influence and mechanism of municipal sludge on the viscosity-temperature characteristics of gasification coal ash, which limits the application of sludge-coal water slurry in gasification. Ash of typical coal(YLA) for gasification was selected and mixed with different proportions of sewage sludge ash(SSA) to simulate the co-gasification ash of sludge and coal, and the ash fusion temperatures and viscosity-temperature curves of the raw and mixed ash samples were measured. XRD analysis and phase diagram theory were used to investigate the variation of crystallization tendency in slag during the cooling process, and FTIR was used to characterize the structural distribution of slag silica-oxygen units and to elucidate the mechanism by which municipal sludge ash content changed slag viscosity. The results show that 10% is the ideal SSA addition ratio and the slag discharge performance will be deteriorated if SSA content is above 30%. When SSA content is 10%, the flow temperature is sufficiently reduced and has an operable temperature range of 168 ℃. When the SSA content exceeds 30%, the flow temperature increases due to the significant increase in iron and phosphorus content in the ash, and the operable temperature range is narrowed. And the critical viscosity temperature is close to the lower limit of the operating temperature due to the increased crystallization tendency, which easily causes drastic changes in slag viscosity. FTIR analysis and peak fitting results show that the reduced polymerization of the silica-oxygen structure is the main reason for the decreasing viscosity of the slag with increasing SSA content.

Key Words： municipal sludge;coal;co-gasification;ash slag;viscosity-temperature characteristics

Abstract:

Keywords:

Foundation: 国家自然科学基金青年基金资助项目(22108080);国家自然科学基金联合基金资助项目(U21A20319)

Authors: WU Hao;LIU Xia;CAO Xi;GUO Qinghua;YU Guangsuo;

DOI: 10.13226/j.issn.1006-6772.AC23060701

References：

• [1] 王毅斌，冯敬武，谭厚章，等.市政污泥热化学处置中磷元素形态转变与回收利用研究进展[J].化工进展，2023,42(2):985-999.WANG Yibin,FENG Jingwu,TAN Houzhang,et al.Research progress on phosphorus speciation transformation and recovery during thermal chemical conversion of municipal sewage sludge[J].Chemical Industry and Engineering Progress,2023,42(2):985-999.
• [2] 段旺智，张凯华，张锴.城市污泥与煤矸石掺烧过程中汞的迁移转化特性[J/OL].洁净煤技术：1-9[2023-07-03].http://kns.cnki.net/kcms/detail/11.3676.TD.20230215.1417.002.html.DUAN Wangzhi,ZHANG Kaihua,ZHANG Kai.Migration and transformation characteristics of mercury during mixing of municipal sludge with coal gangue[J/OL].Clean Coal Technology:1-9[2023-07-03].https://kns.cnki.net/kcms/detail//11.3676.TD.20230215.1417.002.html.
• [3] 王鑫，凌鹏，安晓雪，等.典型污泥与煤泥混合燃烧及硫氧化物释放特性[J].洁净煤技术，2022,28(6):44-53.WANG Xin,LING Peng,AN Xiaoxue,et al.Co-combustion and sulfur oxide release characteristics of typical sludge and coal slime[J].Clean Coal Technology,2022,28(6):44-53.
• [4] 张自丽，孙光，段伦博.煤与污泥混燃及污染物逸出特性[J].洁净煤技术，2022,28(3):118-129.ZHANG Zili,SUN Guang,DUAN Lunbo.Combustion characteristic and pollutants emission behavior during co-combustion of coal and municipal sewage sludge[J].Clean Coal Technology,2022,28(3):118-129.
• [5] GAO Ningbo,KAMRAN K,QUAN Cui,et al.Thermochemical conversion of sewage sludge:A critical review[J].Progress in Energy and Combustion Science,2020,79:100843.
• [6] 李伟东，李明，李伟锋，等.污泥对水煤浆静态稳定性的影响研究[J].环境工程，2008,26(S1):267-271.LI Weidong,LI Ming,LI Weifeng,et al.The effect of sewage sludge on the static stability of coal-water slurries[J].Environmental Engineering,2008,26(S1):267-271.
• [7] 戴财胜，刘良良，马淞江.基于污泥煤浆的污泥调质与浓缩脱水实验研究[J].煤炭转化，2014,37(3):86-89.DAI Caisheng,LIU Lianglinag,MA Songjiang.Study on modifying and concentrated dewatering of sludge based on sludge-coal water slurry[J].Coal Conversion,2014,37(3):86-89.
• [8] 元宁，马洁，张天骄，等.污泥添加量对SiC耐火材料的腐蚀特性影响研究[J].煤化工，2022,50(5):87-90.YUAN Ning,MA Jie,ZHANG Tianjiao,et al.Stduy om corrosion characteristics of SiC refractory by sludge addition[J].Coal Chemical Industry,2022,50(5):87-90.
• [9] 马少莲，吴国光，孟献梁，等.污泥对分散剂的吸附及其对污泥水煤浆成浆特性的影响[J].煤炭学报，2017,42(6):1565-1571.MA Shaolian,WU Guoguang,MENG Xianliang,et al.Adsorption of dispersant onto sludge and its effect on preparation of coal sludge slurry [J].Journal of China Coal Society,2017,42(6):1565-1571.
• [10] 王健，何其慧，许仁富，等.掺混污泥对水煤浆性能的影响[J].洁净煤技术，2013,19(3):83-88.WANG Jian,HE Qihui,XU Renfu,et al.Effect of seage sludge addition on coal water slurry properties[J].Clean Coal Technology,2013,19(3):83-88.
• [11] 胡勤海，熊云龙，毛柯辉，等.城市污泥掺混水煤浆燃烧特性的热重分析[J].环境污染与防治，2008(1):60-63.HU Qinhai,XIONG Yunlong,MAO Kehui,et al.Combustion characteristics of sewage sludge coal water slurry and sludge-CWS mixtures by thermo gravimetric analysis[J].Environmental Pollution & Control,2008(1):60-63.
• [12] 李瑜煜，吴荣标，潘润锦，等.生物质煤浆制备技术研究[J].广东农业科学，2011,38(18):149-151.LI Yuyu,WU Rongbiao,PAN Runjin,et al.Research on preparation technology of bio-coal-water-slurry[J].Guangdong Agriculture Sciences,2011,38(18):149-151.
• [13] 于广锁，牛苗任，王亦飞，等.气流床煤气化的技术现状和发展趋势[J].现代化工，2004(5):23-26.YU Guangsuo,NIU Miaoren,WANG Yifei,et al.Application status and development tendency of coal entrained-bed gasification[J].Modern Chemical Industry,2004(5):23-26.
• [14] SYED-HASSAN S,WANG Yi,HU Song,et al.Thermochem-ical processing of sewage sludge to energy and fuel:Fundamentals,challenges and considerations[J].Renewable &Sustainable Energy Reviews 2017,80:888-913.
• [15] ZHANG Qiang,LIU Haifeng,QIAN Yaping,et al.The influence of phosphorus on ash fusion temperature of sludge and coal[J].Fuel Processing Technology,2013,110:218-226.
• [16] SCHWITALLA D,REINM?LLER M,FORMAN C,et al.Ash and slag properties for co-gasification of sewage sludge and coal:An experimentally validated modeling approach[J].Fuel Processing Technology,2018,175:1-9.
• [17] SCHWITALLA D,GUHL S,K?RNER J,et al.Meta-study on the effect of P2O5 on single phase slag viscosity and the effect of P2O5 induced liquid phase immiscibility on dispersion viscosity[J].Fuel,2021,305:121501.
• [18] 修浩然，王云刚，白彦渊，等.准东煤/市政污泥混燃燃烧特性及灰熔融行为分析[J/OL].化工进展：1-14[2023-07-03].https://doi.org/10.16085/j.issn.1000-6613.2022-1494.XIU Haoran,WANG Yungang,BAI Yanyuan,et al.Combustion characteristics and ash melting behavior of Zhundong coal / municipal sludge blended combustion[J/OL].Chemical Industry and Engineering Progress:1-14[2023-07-03].https://doi.org/10.16085/j.issn.1000-6613.2022-1494.
• [19] LI Fenghai,FAN Hongli,WANG Xiaochuan,et al.Influences of phosphorus on ash fusion characteristics of coal and its regulation mechanism[J].Fuel,2019,239:1338-1350.
• [20] 魏砾宏，梁法光，房凡，等.磷对泥/煤混燃灰熔融特性的影响及矿物相演变规律[J] 燃料化学学报，2019,47(2):129-137.WEI Lihong,LIANG Faguang,FANG Fan,et al.Effect of phosphorus on ash fusion characteristics and mineral transformation during co-combustion of sewage sludge and coal[J].Journal of Fuel Chemistry and Technology,2019,47(2):129-137.
• [21] FOLGUERAS M,ALONSO M,FOLGUERAS J.Effect of sludge addition to coal on Na,K and S volatilisation in ashing process and ash fusibility[J].Fuel Processing Technology,2015,138:714-723.
• [22] HE Chong,BAI Jin,KONG Lingxue,et al.Effects of atmos-phere on the oxidation state of iron and viscosity behavior of coal ash slag[J].Fuel,2019,243:41-51.
• [23] WU Hao,WANG Jiajian,LIU Xia,et al.Synergistic effects andmechanism of the ternary flux system Fe2O3-CaO-MgO on the coal ash slag fluidity[J].Fuel,2023,343:127963.
• [24] 马晓彤，王志刚，潘彦宏，等.含钒气化熔渣对致密刚玉材料的侵蚀作用机理[J].洁净煤技术，2022,28(11):121-127.MA Xiaotong,WANG Zhigang,PAN Yanhong,et al.Interaction mechanism between gasification slag containing vanadium and corundum material[J].Clean Coal Technology,2022,28(11):121-127.
• [25] KONG Lingxue,BAI Jin,LI Wen.Viscosity-temperature pro-perty of coal ash slag at the condition of entrained flow gasification:A review[J].Fuel Processing Technology,2021,215:106751.
• [26] CAO Xi,KONG Lingxue,BAI Jin,et al.Measurement and simulation of viscosity characteristics of coal ash slag under water vapor condition in coal gasification[J].Fuel,2022,308:121882.
• [27] VARGAS S,FRANDSEN F,DAM-JOHANSEN K.Rheological properties of high-temperature melts of coal ashes and other silicates[J].Progress in Energy and Combustion Science,2001,27(3):237-429.
• [28] WANG Hao,CHEN Ziwei,LIU Lili,et al.Roles of P2O5 addi-tion on the viscosity and structure of CaO-SiO2-Al2O3-Na2O-P2O5 melts[J].ISIJ International,2018,58(9):1644-1649.
• [29] SUN Yongqi,ZHENG Kai,LIAO Junlin,et al.Effect of P2O5 addition on the viscosity and structure of titanium bearing blast furnace slags[J].ISIJ International,2014,54(7):1491-1497.
• [30] WANG Z J,SHU Q F,SRIDHAR S,et al.Effect of P2O5 and FetO on the viscosity and slag structure in steelmaking slags[J].Metallurgical and Materials Transactions B:Process Metallurgy and Materials Processing Science,2015,46(2):758-765.
• [31] GE Zefeng,KONG Lingxue,BAI Jin,et al.Effect of CaO/Fe2O3ratio on slag viscosity behavior under entrained flow gasification conditions[J].Fuel,2019,258:116129.