University of Oulu

Koskela, Suopajärvi, Mattila, Uusitalo, & Fabritius. (2019). Lignin from Bioethanol Production as a Part of a Raw Material Blend of a Metallurgical Coke. Energies, 12(8), 1533.

Lignin from bioethanol production as a part of a raw material blend of a metallurgical coke

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Author: Koskela, Aki1; Suopajärvi, Hannu1; Mattila, Olli1;
Organizations: 1Process Metallurgy Research Unit, University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.9 MB)
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Language: English
Published: Multidisciplinary Digital Publishing Institute, 2019
Publish Date: 2019-09-13


Replacement of part of the coal in the coking blend with lignin would be an attractive solution to reduce greenhouse gas emissions from blast furnace (BF) iron making and for obtaining additional value for lignin utilization. In this research, both non-pyrolyzed and pyrolyzed lignin was used in a powdered form in a coking blend for replacing 5-, 10- and 15 m-% of coal in the raw material bulk. Graphite powder was used as a comparative replacement material for lignin with corresponding replacement ratios. Thermogravimetric analysis was performed for all the raw materials to obtaining valuable data about the raw material behavior in the coking process. In addition, chemical analysis was performed for dried lignin, pyrolyzed lignin and coal that were used in the experiments. Produced bio cokes were tested in a compression strength experiment, in reactivity tests in a simulating blast furnace shaft gas profile and temperature. Also, an image analysis of the porosity and pore shapes was performed with a custom made MatLab-based image analysis software. The tests revealed that the pyrolysis of lignin before the coking process has an increasing impact on the bio coke strength, while the reactivity of the bio-cokes did not significantly change. However, after certain level of lignin addition the effect of lignin pyrolysis before the coking lost its significance. According to results of this research, the structure of bio cokes changes significantly when replacement of coal with lignin in the raw material bulk is at a level of 10 m-% or more, causing less uniform structure thus leading to a less strong structure for bio cokes.

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Series: Energies
ISSN: 1996-1073
ISSN-E: 1996-1073
ISSN-L: 1996-1073
Volume: 12
Issue: 8
Article number: 1533
DOI: 10.3390/en12081533
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: This research is a part of BIOSTART project and mostly funded by SSAB. The funding of the project was partially conducted by Fundamentals of Formation and Properties of Metallurgical Coke project (grant decision number 296831), funded by Academy of Finland. The Jenny and Antti Wihuri Foundation is acknowledged for the personal incentive grant (00180164), granted for this research.
Academy of Finland Grant Number: 296831
Detailed Information: 296831 (Academy of Finland Funding decision)
Copyright information: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (