Joint examination of fuel-related measures for the improvement of corn cob combustion properties

Dragutinovic, Natasa; Höfer, Isabel; Kaltschmitt, Martin

doi:10.15480/882.5190

Joint examination of fuel-related measures for the improvement of corn cob combustion properties

Citation Link: https://doi.org/10.15480/882.5190

Publikationstyp

Journal Article

Date Issued

2021-05-27

Sprache

English

Author(s)

Dragutinovic, Natasa

Höfer, Isabel

Kaltschmitt, Martin

Institut

Umwelttechnik und Energiewirtschaft V-9

TORE-DOI

10.15480/882.5190

TORE-URI

http://hdl.handle.net/11420/9847

Journal

Journal of renewable and sustainable energy

Volume

13

Issue

3

Article Number

033101

Citation

Journal of Renewable and Sustainable Energy 13 (3): 033101 (2021-05-27)

Publisher DOI

10.1063/5.0044971

Scopus ID

2-s2.0-85106906652

Publisher

American Institut of Physics

The aim of this paper is the production of a high-quality corn cob pellet which satisfies ISO 17225-6 requirements and addresses the ash melting behavior through additives kaolin and magnesium oxide. The effects of additives on the (1) physico-mechanical properties and (2) ash melting behavior of pellets were investigated. Before statistically analyzing the effect of additives on the mechanical durability and bulk density, pelletizing was conducted in two experimental series (full factorial design). In series 1, moisture content (18-20 wt. %), additive type (kaolin or MgO), and additive content (0-2 wt. %) were varied; in series 2, binding agent content (2-4 wt. %), additive type (kaolin or MgO), and additive content (0-2 wt. %) were varied, whereas moisture content was kept constant at 20 wt. %. The effect of additives on ash melting behavior was pre-evaluated: (1) in a laboratory scale, (2) using thermodynamic equilibrium calculations, and (3) fuel indices. Results show that without a binder, only pellets with MgO can reach durability threshold class B (≥96 wt. %) from ISO 17225-6, whereas using a binder, the mean value of all pellets complies with the durability class A (≥97.5 wt. %). Results of pre-evaluation tests are in agreement regarding kaolin but not regarding MgO. Experimental results show that corn cob ash starts sintering >800 °C, melt consisting primarily of K, Si, and O, and both additives prevent sintering. FactSage predicts K sorption in the ash using kaolin, and molar (Si + P + K)/(Mg + Ca + Al) ratio predicts the improvement of ash behavior with both additives.