Title: Co-combustion of biocoal and lignite in a circulating fluidised bed combustor to decrease the impact on global warming

Authors: Babak Keivani; Hayati Olgun; Aysel T. Atimtay

Addresses: Solar Energy Institute, Ege University, 35100 Bornova, Izmir, Turkey ' Solar Energy Institute, Ege University, 35100 Bornova, Izmir, Turkey ' Department of Environmental Engineering, Middle East Technical University, 06800 Cankaya, Ankara, Turkey

Abstract: This work covers co-combustion of biocoal obtained from red pine wood chips with Orhaneli lignite in a 30 kW-thermal capacity circulating fluidised bed combustor (CFBC) system in air and oxygen-enriched atmosphere. The combustor was of 108 mm inside diameter and 6 m height. The combustion temperature was held at 850+50°C. Oxygen enriched combustion tests were carried out at different ratios of lignite and biocoal mixtures. Biocoal share in the fuel mixture was increased up to 50% by wt. It was found that the fuel mixtures up to 50% by wt. of biocoal were combusted effectively in the system. The oxygen concentration in the oxidant was varied between 21 and 27% by vol. for the oxygen-enriched combustion experiments. The results showed that biocoal can be a good additive fuel to lignite coal and oxygen-enriched co-combustion is an option for reducing flue gas emissions of SO₂, CO and N₂O.

Keywords: biomass; torrefaction; biocoal; oxygen enriched combustion; circulating fluidised bed combustion.

DOI: 10.1504/IJGW.2019.100313

International Journal of Global Warming, 2019 Vol.18 No.2, pp.120 - 137

Received: 19 Oct 2018
Accepted: 02 Mar 2019
Published online: 25 Jun 2019 *

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