Power abd Energy Engineering |
|
|
|
|
Physicochemical analysis on hydrothermal upgrading of sewage sludge with lignite for solid fuel |
LI Jian, LIU Meng, DUAN Yu feng, XU Chao |
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China |
|
|
Abstract Hydrothermal treatment of municipal sewage sludge with low rank lignite was conducted in order to solve the problems of high ash content, low resource utilization rate and calorific value of sewage sludge hydrothermal carbonization. The physicochemical characteristics of the solid fuel,including fuel characteristics, pore structure and the changes of chemical structure were analyzed. Results show that the carbon content and calorific value of the solid fuel greatly promoted and the atomic ratio of n(H)/n(C) and n(O)/n(C) significantly descend with the temperature increasing when the quality ratio of sewage sludge and lignite is 1∶9. Relative absorption intensity of —OH in hydroxyl or carboxyl groups and —CO in amide or carboxyl groups were significantly reduced, indicating that dehydration and decarboxylation reactions occurred during the upgrading process. The 13C NMR spectrum showed that the relative content of methoxyl carbons and carboxyl/carbonyl groups diminished from 5.76% to 1.31% and 9.03% to5.64%, respectively, which suggested that oxygen loss not only corresponds to dewatering, but a significant correlation with conversion of CO and COOH and change of methoxyl carbons. The relative content of aromatic carbon was greatly improved, which indicated that the degree of aromatization and coalification deepened.
|
Published: 01 February 2016
|
|
污泥掺混褐煤水热制固体燃料的理化特性
为了解决污泥单独水热碳化灰分高、热值和资源化利用率低等问题,通过水热处理的方法对城市污泥掺混低阶褐煤进行提质处理,对水热提质固体燃料的燃料特性、孔隙结构以及化学结构的变化等理化特性进行研究.结果表明,当污泥与褐煤质量添加比为1∶9时,随着水热温度的提高,固体燃料中碳含量以及热值大幅度提高,且原子个数比n(H)/n(C)和n(O)/n(C)显著下降.固体燃料羟基或羧基官能团中—OH和酰胺官能团或羧基官能团中—CO的相对光谱吸收强度显著降低,表明提质过程中污泥与褐煤发生了显著的脱水和脱羧反应.通过13C核磁共振波谱分析,发现随着提质温度的升高,甲氧基减少的速率最快,摩尔分数从5.76%减少到了1.31%,羧基和羰基的摩尔分数从9.03%减少到5.64%,说明固体燃料中氧元素的丢失不仅与脱水作用有关,与羰基和羧基的转化以及甲氧基的变化也密切相关;芳香化碳的摩尔分数显著增加,表明固体燃料的芳香化程度加深,煤质特性提升.
|
|
[1] JIANG J,DU X,YANG S.Analysis of the combustion of sewage sludge derived fuel by a thermogravimetric method in China [J].Waste Management,2010,30(7):1407-1413.
[2] NAMIOKA T, MOROHASHI Y, YAMANE R, et al.Hydrothermal treatment of dewatered sewage sludge cake for solid fuel production [J].Journal of Environment and Engineering, 2009,4(1): 68-77.
[3] LIU Z, QUEK A,HOEKMAN S K, et al.Production of solid biochar fuel from waste biomass by hydrothermal carbonization [J]. Fuel, 2013, 103: 943-949.
[4] ZHAO P T, CHEN H F,GE S F, et al.Effect of the Hydrothermal pretreatment for the reduction of NO Emission from sewage sludge combustion [J].Applied Energy,2013,111: 199-205.
[5] RULKENS W. Sewage sludge as a biomass resource for the production of energy: Overview and assessment of the various options [J]. Energy & Fuels,2007,22(1): 9-15.
[6] LEBLANC, RONALD J, MATTEWS P, et al. Global atlas of excreta,wastewater sludge,and biosolids management: Moving forward the sustainable and welcome uses of a global resource [M]. [S.l.]Un habitat, 2009.
[7] YU Y J, LIU J Z, WANG R K, et al. Effect of hydrothermal dewatering on the slurryability of brown coals [J]. Energy Conversion and Management, 2012, 57: 8-12.
[8] 王知彩,水恒福,张德祥,等.水热处理对神华煤质的影响 [J].燃料化学学报,2006,34(5): 524-529.
WANG Zhi cai,SHUI Heng fu,ZHANG De xiang, et al. Effect of hydrothermal treatment on some properties of S henhua coal [J].Journal of fuel Chemistry and Techn ology,2006,34(5): 524-529.
[9] 葛立超,张彦威,应芝,等.水热处理对我国典型褐煤气化特性的影响[J].中国电机工程学报,2013, 33(32): 1420+11.
GE Li chao, ZHANG Yan wei, WANG Zhi hua, et al. Inf luence of the hydrothermal dewatering on the gasification
characteristics of typical Chinese lignite [J]. Proceedings of the CSEE, 2013, 33(32): 1420+11.
[10] 虞育杰,钟晶亮,刘建忠.水热提质条件下褐煤脱氧 过程的量子化学研究 [J].中国电机工程学报,2014,34(32): 5757-5762.
YU Yu jie, ZHONG Jing liang, LIU Jian zhong. A quantum chemistry study of deoxidization process of brown coal during hydrothermal dewatering treatment [J]. Proceedings of the CSEE, 2014,34(32): 5757-5762.
[11] THAPA K B,YING Q,HOADLEY A F A.Interaction of polyelectrolyte with digested sewage sludge and lignite in sludge dewatering [J].Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2009, 334(113): 66-73.
[12] NONAKA M,HIRAJIMA T,SASAKI K.Upgrading of low rank coal and woody biomass mixture by hydrothermal treatment [J].Fuel,2011,90(9): 2578-2584.
[13] VAN KREVELEN D W.Graphical statistical method for the study of structure and reaction processes of coal [J].Fuel,1950,29(12): 269-284.
[14] 谢克昌. 煤的结构和反应性[M].北京: 科学出版社,2002: 101.
[15] 赵卫东.低阶煤水热改性制浆的微观机理及燃烧特性研究 [D]. 浙江:浙江大学,2009.
ZHAO Wei dong. Micromechanism and combustion characteristics of low rank coal water slurry upgraded by hot water treatments [D]. Hangzhou: Zhejiang University, 2009.
[16] LIU Z G, ZHANG F S, WU J Z.Characterization and application of chars produced from pinewood pyrolysis and hydrothermal treatment [J]. Fuel, 2010, 89(2): 510-514.
[17] TAHMASEBI A, YU J L, HAN Y N, et al. A study of chemical structure changes of Chinese lignite during fluidized bed drying in nitrogen and air [J]. Fuel Processing Technology, 2012, 101(0): 8593.
[18] ERDENETSOGT B, LEE I, LEE S K, et al. Solid state C 13 CP/MAS NMR study of Baganuur coal, Mongolia: Oxygen loss during coalification from lignite to subbituminous rank [J]. International Journal of Coal Geology, 2010, 82(1): 37-44.
[19] JACKSON M J,LINE M A.Organic composition of a pulp and paper mill sludge determined by FTIR, 13C CP MAS NMR, and chemical extraction techniques [J].Journal of Agricultural and Food Chemistry, 1997, 45(6): 2354-2358.
[20] MURSITO A T, HIRAJIMA T, SASAKI K, et al. The effect of hydrothermal dewatering of Pontianak tropical peat on organics in wastewater and gaseous products [J].Fuel,2010,89(12): 3934-3942. |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|