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Title: Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer

Abstract

Highlights: • Thermal gasification and co-gasification of sewage sludge and wheat straw is tested. • Two low-temperature-circulating-fluidized-bed gasifiers (100 kW and 6 MW) are used. • Influence of fuel type on ash P fertilizer quality and heavy metal fate is assessed. • Incubation study and plant pot experiment applied to examine ash fertilizer effect. - Abstract: The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100 kW and 6 MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw andmore » sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems.« less

Authors:
 [1];  [2];  [3];  [4]; ;  [1];  [5]
  1. Technical University of Denmark, Department of Chemical Engineering, DTU Ris ø Campus, Technical University of Denmark Building 313, Frederiksborgvej 399, 4000 Roskilde (Denmark)
  2. Roskilde University, Department of Environmental, Social and Spatial Change, 4000 Roskilde (Denmark)
  3. DONG Energy Thermal Power A/S, Nesa Allé 1, 2820 Gentofte (Denmark)
  4. Danish Fluid Bed Technology ApS, Industrivej 38, 4000 Roskilde (Denmark)
  5. University of Copenhagen, Department of Plant and Environmental Sciences, Plant and Soil Science, Thorvaldsensvej 40, Frederiksberg (Denmark)
Publication Date:
OSTI Identifier:
22742109
Resource Type:
Journal Article
Journal Name:
Waste Management
Additional Journal Information:
Journal Volume: 66; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0956-053X
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; ASHES; COMPARATIVE EVALUATIONS; FERTILIZERS; FLUIDIZED BEDS; GASIFICATION; HEAVY METALS; RECYCLING; SAMPLING; SEWAGE SLUDGE; TEMPERATURE RANGE 0065-0273 K; WASTE PROCESSING

Citation Formats

Thomsen, Tobias Pape, E-mail: ttho@kt.dtu.dk, Hauggaard-Nielsen, Henrik, Gøbel, Benny, Stoholm, Peder, Ahrenfeldt, Jesper, Henriksen, Ulrik B., and Müller-Stöver, Dorette Sophie. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer. United States: N. p., 2017. Web. doi:10.1016/J.WASMAN.2017.04.043.
Thomsen, Tobias Pape, E-mail: ttho@kt.dtu.dk, Hauggaard-Nielsen, Henrik, Gøbel, Benny, Stoholm, Peder, Ahrenfeldt, Jesper, Henriksen, Ulrik B., & Müller-Stöver, Dorette Sophie. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer. United States. doi:10.1016/J.WASMAN.2017.04.043.
Thomsen, Tobias Pape, E-mail: ttho@kt.dtu.dk, Hauggaard-Nielsen, Henrik, Gøbel, Benny, Stoholm, Peder, Ahrenfeldt, Jesper, Henriksen, Ulrik B., and Müller-Stöver, Dorette Sophie. Tue . "Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer". United States. doi:10.1016/J.WASMAN.2017.04.043.
@article{osti_22742109,
title = {Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer},
author = {Thomsen, Tobias Pape, E-mail: ttho@kt.dtu.dk and Hauggaard-Nielsen, Henrik and Gøbel, Benny and Stoholm, Peder and Ahrenfeldt, Jesper and Henriksen, Ulrik B. and Müller-Stöver, Dorette Sophie},
abstractNote = {Highlights: • Thermal gasification and co-gasification of sewage sludge and wheat straw is tested. • Two low-temperature-circulating-fluidized-bed gasifiers (100 kW and 6 MW) are used. • Influence of fuel type on ash P fertilizer quality and heavy metal fate is assessed. • Incubation study and plant pot experiment applied to examine ash fertilizer effect. - Abstract: The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100 kW and 6 MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems.},
doi = {10.1016/J.WASMAN.2017.04.043},
journal = {Waste Management},
issn = {0956-053X},
number = ,
volume = 66,
place = {United States},
year = {2017},
month = {8}
}