Environmental performance of end-of-life handling alternatives for paper-and-pulp-mill sludge: Using digestate as a source of energy or for biochar production

Ali Mohammadi, Maria Sandberg, G. Venkatesh, Samieh Eskandari, Tommy Dalgaard, Stephen Joseph and Karin Granström

Energy, 2019, vol. 182, issue C, 594-605

Abstract: This paper evaluates the environmental impacts of different alternatives for handling of sludge from paper and pulp mills in Sweden, using Life Cycle Assessment (LCA). The common practice of incineration of biosludge with energy recovery followed by landfilling of ash (System A) was compared with the alternative of digesting sludge anaerobically to produce biogas using different digestate residue management options. The digestate produced from anaerobic digestion (AD) was assumed to be incinerated for heat energy recovery in System B or pyrolyzed for biochar production in System C to be mixed with forest soils. The impact categories considered in this work are climate change, non-renewable energy use, mineral extraction, aquatic ecotoxicity, carcinogens and non-carcinogens. The LCA results demonstrate that the two proposed systems significantly reduce the environmental impacts of biosludge management relative to incineration. An 85% reduction in the aquatic ecotoxicity impact is achieved in System C, due to the reduced mobility of heavy metals in biochar relative to ash. System C, on the whole, outperformed the other two, leading the authors to the recommendation that the use of pulp and paper mill biosludge in biogas-biochar production systems is preferable to merely recovering energy from it.

Keywords: Anaerobic digestion; Ash; Biochar; Forest soils; Heavy metals (search for similar items in EconPapers)
Date: 2019
References: Add references at CitEc
Citations: View citations in EconPapers (5)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S036054421931196X
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:energy:v:182:y:2019:i:c:p:594-605

DOI: 10.1016/j.energy.2019.06.065

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

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