DBPapers
DOI: 10.5593/sgem2017H/43/S19.065

THE CONTENT OF TOXIC ELEMENTS IN CHARS AFTER THE GASIFICATION OF LIGNITE

B. Bielowicz
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-28-7 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 43, 513-520 pp; DOI: 10.5593/sgem2017H/43/S19.065

ABSTRACT

Gasification is one of the methods of utilization of lignite. Studies on clean coal technologies are carried out on a wide scale in Poland and worldwide. One of the projects was "The Development of Coal Gasification Technology for High Production of Fuels and Energy” carried out under the framework of the National Centre for Research and Development. The project was based on the gasification of lignite from the Bełchatów deposit. For syngas production, a circulating fluidized bed reactor and CO2 as the gasifying agent were used. After the gasification, the content of harmful elements, including U, Th, Hg, Cd, and As, in lignite and chars was analyzed. The analysis was carried out by ICP-MS/OS. The content of U and Th in the tested samples was lower in lignite subjected to the gasification process and amounted to 0.6 and 1.1 ppm, respectively. The examined chars contained 1.3 ppm of U and 3.0 ppm of Th. The arsenic content in chars was higher than in ash (1.2 ppm and 0.5 ppm, respectively). Compared with the starting lignite, the Hg and Cd contents were lower for char. The analyzed lignite contained 0.03 ppm of Hg and 0.15 ppm of Cd. In chars, the content of Hg and Cd was 0.0005 ppm and 0.06 ppm, respectively. The lower content of Hg and Cd is linked with the volatility of these elements. However, it should be underlined that the examined lignites and chars were usually characterized by low levels of harmful elements.

Keywords: char, gasification, lignite, toxic elements, ash