Lignin from Bioethanol Production as a Part of a Raw Material Blend of a Metallurgical Coke

Abstract

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.

Preparation of Formed Coke for Blast Furnace Using Kraft Lignin as a Binder

“…13,14) No studies have reported the successful production of good quality coke through the addition of lignin during coke production. [15][16][17] Florentino-Madiedo et al 18) studied briquetting of high volatile bituminous coal (70%) combined with four different biomasses (15%: lignin, pine sawdust, torrified pine sawdust and a solid from the hydrothermal carbonization) and four different binders (15%), followed by carbonization. Adding biomass decreased the strength of the coke, and lignin provided the best results among the four biomass samples tested.…”

The Reduction Reaction Behavior of Steelmaking Dusts with Lignin under Different Atmospheres

“…Lignin is a complex, oxygen-containing, highly branched bio polymer that forms the chief constituent of wood [15]. This is the second-most-abundant natural material on the Earth [16]. Generally, this is produced as a byproduct in the paper and bioethanol industries.…”

A Crucial Step Toward Carbon Neutrality in Pyrometallurgical Reduction of Nickel Slag

“…Since biomass absorbs CO 2 from the atmosphere during their growth, they release the absorbed CO 2 in the reduction process, thus creating a closed loop carbon cycle [15,16]. Several research groups have investigated the use of biomass or biochar as reductant in metal production [10,[17][18][19][20][21][22][23][24][25].…”