Influence of the reactant carbon-hydrogen-oxygen composition on the key products of the direct gasification of dewatered sewage sludge in supercritical water.

The supercritical water gasification of ten different types of dewatered sewage sludges was investigated to understand the relationship between sludge properties and gasification products. Experiments were performed in a high-pressure autoclave at 400°C for 60 min. Results showed that gasification of sewage sludge in supercritical water consists mainly of a gasification reaction, a carbonization reaction and a persistent organic pollutants synthesis reaction. Changes in the reactant C/H/O composition have significant effects on the key gasification products. Total gas production increased with increasing C/H2O of the reactant. The char/coke content increased with increasing C/H ratio of the reactant. A decrease in the C/O ratio of the reactant led to a reduction in polycyclic aromatic hydrocarbon formation. This means that we can adjust the reactant C/H/O composition by adding carbon-, hydrogen-, and oxygen-containing substances such as coal, algae and H2O2 to optimize hydrogen production and to inhibit an undesired by-product formation.

[1]  Mithat Yüksel,et al.  Biomass gasification in supercritical water: Part 1. Effect of the nature of biomass , 2007 .

[2]  X. Chai,et al.  Partial oxidative gasification of phenol for hydrogen in supercritical water , 2011 .

[3]  Andrea Kruse,et al.  Influence of Proteins on the Hydrothermal Gasification and Liquefaction of Biomass. 1. Comparison of Different Feedstocks , 2005 .

[4]  C. Schwarz,et al.  Thermodynamic modelling of supercritical water gasification: investigating the effect of biomass composition to aid in the selection of appropriate feedstock material. , 2014, Bioresource technology.

[5]  Andrea Kruse,et al.  Influence of Proteins on the Hydrothermal Gasification and Liquefaction of Biomass. 2. Model Compounds , 2007 .

[6]  J. A. Menéndez,et al.  Hydrogen rich fuel gas production from the pyrolysis of wet sewage sludge at high temperature , 2006 .

[7]  Organic reactions in subcritical and supercritical water , 2012 .

[8]  A. Kruse,et al.  Char and Coke Formation as Unwanted Side Reaction of the Hydrothermal Biomass Gasification , 2008 .

[9]  Lili Qian,et al.  Treatment of sewage sludge in supercritical water and evaluation of the combined process of supercritical water gasification and oxidation. , 2015, Bioresource technology.

[10]  Lili Qian,et al.  Treatment of municipal sewage sludge in supercritical water: A review. , 2016, Water research.

[11]  M. Gong,et al.  Quantitative analysis of polycyclic aromatic hydrocarbons in solid residues from supercritical water gasification of wet sewage sludge , 2013 .

[12]  Bo Xiao,et al.  Mechanism of wet sewage sludge pyrolysis in a tubular furnace , 2011 .

[13]  Linghong Zhang,et al.  Energy recovery from secondary pulp/paper-mill sludge and sewage sludge with supercritical water treatment. , 2010, Bioresource technology.

[14]  Paul T. Williams,et al.  Reactions of different food classes during subcritical water gasification for hydrogen gas production , 2012 .

[15]  Y. Matsumura,et al.  Acid-Catalyzed Char Formation from 5-HMF in Subcritical Water , 2011 .

[16]  Wei Zhu,et al.  Direct gasification of dewatered sewage sludge in supercritical water. Part 1: Effects of alkali salts , 2013 .

[17]  Wei Zhu,et al.  Influence of moisture content on the direct gasification of dewatered sludge via supercritical water , 2012 .

[18]  Chia-Lung Chen,et al.  Hydrothermal gasification of sewage sludge and model compounds for renewable hydrogen production: A review , 2014 .

[19]  Kazuo Yamamoto,et al.  Supercritical water gasification of sewage sludge using bench-scale batch reactor: advantages and drawbacks , 2014 .

[20]  J. R. Portela,et al.  Remediation of PAH spiked soils: concentrated H2O2 treatment/continuous hot water extraction-oxidation. , 2009, Journal of hazardous materials.

[21]  L. Fiori,et al.  Supercritical water gasification of biomass: A stoichiometric thermodynamic model , 2015 .

[22]  M. Gong,et al.  Influence of sludge properties on the direct gasification of dewatered sewage sludge in supercritical water , 2014 .

[23]  Liejin Guo,et al.  An experimental investigation of sewage sludge gasification in near and super-critical water using a batch reactor , 2013 .

[24]  Andrea Kruse,et al.  Supercritical water gasification , 2008 .

[25]  Liejin Guo,et al.  Hydrogen production by sewage sludge gasification in supercritical water with a fluidized bed reactor , 2013 .

[26]  Cheng-Han Lu,et al.  Characterization and comparison of biomass produced from various sources: Suggestions for selection of pretreatment technologies in biomass-to-energy , 2012 .