Comparative investigation on the chemical pre-desulfurization process of a high sulfur coal through orthogonal experiments: a case study

Abstract

ABSTRACT The effect of different chemical pre-desulfurization processes were compared to achieve the utilization of high sulfur coal efficiently and economically and its total sulfur content is 2.19%. The major influence factors were the reagent dosage, desulfurization temperature, and time. Compared with single-factor experiments, orthogonal experiments can greatly reduce the number of experiments and ensure the rationality of experimental data. The desulfurization rate of acid leach, alkali leach, oxidation, and catalytic reduction were 41.67%, 17.16%, 26.96%, and 27.45%, respectively, and the total sulfur after the pre-desulfurization process were 1.19%, 1.69%, 1.49%, and 1.48%, respectively. Range analysis and variance analysis were employed for the crucial operational parameters. In acid and alkali leaching desulfurization process, the acid/alkali concentration had the greatest influence on the desulfurization effect. In oxidation desulfurization process, the desulfurization time had the greatest influence on the desulfurization effect. In catalytic reduction desulfurization, the reducing agent dosage was the most important factor. The main factor for the results above was that the desulfurization mechanisms were different. Therefore, the research of different desulfurization mechanisms is the main direction of future work. The consequence of this paper would provide data support for the selection of the desulfurization method for high sulfur coal.