Effect of catalysts on distribution of polycyclic-aromatic hydrocarbon (PAHs) in bio-oils from the pyrolysis of dewatered sewage sludge at high and low temperatures

被引：45

作者：

Hu, Yanjun ^{[1
]}

Yu, Wenjing ^{[1
]}

Wibowo, Haryo ^{[1
]}

Xia, Yuanyuan ^{[1
]}

Lu, Yanjun ^{[1
]}

Yan, Mi ^{[1
]}

机构：

[1] Zhejiang Univ Technol, Inst Energy & Power Engn, Liuhe Rd 288, Hangzhou 310023, Zhejiang, Peoples R China

来源：

SCIENCE OF THE TOTAL ENVIRONMENT | 2019年 / 667卷

基金：

中国国家自然科学基金;

关键词：

Sewage sludge; Pyrolysis; Catalysts; PAHs; Bio-oil; THERMOCHEMICAL CONVERSION; CANCER RISK; BIOMASS; FRACTIONS; KINETICS; MATTER;

D O I：

10.1016/j.scitotenv.2019.02.320

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

This study was aimed at investigating the effect of four types of catalysts on the distribution characteristics of 16 polycyclic-aromatic hydrocarbon (PAHs) in bio-oils from the pyrolysis of dry sewage sludge. The pyrolysis experiments of sewage sludge were conducted in a tubular reactor at the high and low temperatures of 850 degrees C and 450 degrees C, respectively. CaO, KCI, Na2CO3, and Fe2O3 were selected as catalysts for the catalyzed pyrolysis. In the non-catalyzed sludge pyrolysis, PAHs concentrations in bio-oil increased with temperature, reaching a maximum value of 15.25 mu g/g at 850 degrees C. This value was 4.5 times higher than PAHs concentration from the non-catalyzed pyrolysis at 450 degrees C. With the presence of catalysts at 850 degrees C, an evident reduction of PAHs concentration was observed for all the bio-oil samples. The added catalysts proved to effectively inhibit PAHs formation in bio-oil and reduce the toxic equivalent quantity (TEQ) of PAHs in the experiment at high temperature. The lowest observed PAHs concentration in bio-oil was 4.23 mu g/g, obtained with the use of KCI catalyst. However, an opposite trend was observed for catalyzed pyrolysis at 450 degrees C. The added catalysts promoted PAHs formation, up to the concentration of 8.89 mu g/g with the use of CaO catalyst. Catalyst loading also influenced PAHs concentration and TEQ with the lowest output found at 20% loading for all catalysts. Bio-oil yields, mass ratio of 16 PAHs concentrated into bio-oil, the TEQ of 16 PAHs and their subtotal group classified by ring number were separately examined to analyze their effects on fractional distribution of the total PAH amount. Overall, the presence of the selected catalysts was found to have the ability to inhibit PAHs production at higher pyrolysis temperature and to promote PAHs production at lower pyrolysis temperature. (C) 2019 Published by Elsevier B.V.

引用

页码：263 / 270

页数：8

共 48 条

[11] Formation of PAHs during the pyrolysis of dry sewage sludge [J].