Fast and isothermal hydrothermal liquefaction of sludge at different severities: Reaction products, pathways, and kinetics

Lili Qian, Shuzhong Wang and Phillip E. Savage

Applied Energy, 2020, vol. 260, issue C, No S0306261919319993

Abstract: Hydrothermal liquefaction has emerged as a preferred means of converting wet biomass to biocrude. In this study, we examined the hydrothermal conversion of sludge over a large range of conditions (300–600 °C, 1–60 min) that included both nominally isothermal processing and non-isothermal processing (rapid heating, short times). An empirical severity index was employed to combine the effects of reaction temperature and holding time into a single parameter. The highest biocrude yields (20.1–30.9 wt%) were achieved at 10−1 < severity index < 102 and about 32% and 63% of the nitrogen in sludge transferred into the biocrude and aqueous phase products, respectively. A Van Krevelen diagram illustrated that dehydration and decarboxylation pathways were important for biocrude and light biocrude formation whereas dehydration paths were more important for heavy biocrude. We developed a quantitative kinetics model that faithfully correlated the effects of time and temperature on the yields of biocrude, aqueous phase products, solid, gas, and volatiles. It also accurately predicted the yields of the product fractions from hydrothermal liquefaction at 350 °C.

Keywords: Sludge; Biocrude; Hydrothermal liquefaction; Severity index; Kinetic modeling (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (5)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261919319993
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:260:y:2020:i:c:s0306261919319993

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2019.114312

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().