Slow pyrolysis of by-product lignin from wood-based ethanol production– A detailed analysis of the produced chars. (1st December 2018)

• Record Type: Journal Article
• Authors: Toloue Farrokh, Najibeh; Suopajärvi, Hannu; Mattila, Olli; Umeki, Kentaro; Phounglamcheik, Aekjuthon; Romar, Henrik; Sulasalmi, Petri; Fabritius, Timo
• Is Part Of: Energy. Volume 164(2018)
• Page Start: 112
• Page End: 123
• Publication Date: 2018-12-01
• Subjects: Biomass -- Lignin -- Slow pyrolysis -- Combustion; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2018.08.161
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Slow pyrolysis as a method of producing a high-quality energy carrier from lignin recovered from wood-based ethanol production has not been studied for co-firing or blast furnace (BF) applications up to now. This paper investigates fuel characteristics, grindability, moisture uptake and the flow properties of lignin chars derived from the slow pyrolysis of lignin at temperatures of 300, 500 and 650 °C (L300, L500 and L650 samples respectively) at a heating rate of 5 °C min −1 . The lignin chars revealed a high mass and energy yield in the range of 39–73% and 53–89% respectively. Pyrolysis at 500 °C or higher, yielded lignin chars with low H/C and O/C ratios suitable for BF injection. Furthermore, the hydrophobicity of lignin was improved tremendously after pyrolysis. Pyrolysis at high temperatures increased the sphericity of the lignin char particles and caused some agglomeration in L650. Large and less spherical particles were found to be a reason for high permeability, compressibility and cohesion of L300 in contrast to L500 and L650. L300 and L500 chars demonstrated high combustibility with low ignition and burnout temperatures. Also, rheometric analysis showed that L500 has the best flow properties including low aeration energy and high flow function. Highlights: First study on pyrolysis of lignin recovered from wood-based ethanol production. Pyrolyzed lignin has high mass/energy yield up to 73/89% and HHV up to 34.31 MJ/kg. Effect of temperature on Physico-chemical characteristics of chars investigated. Best lignin char to substitute coal in BF injection obtained in pyrolysis at 500 °C. Pyrolysis in lower temperatures resulted in high combustibility and low water uptake.