energies Article Modeling of the Chemical Looping Combustion of Hard Coal and Biomass Using Ilmenite as the Oxygen Carrier Anna Zylka 1, * , Jaroslaw Krzywanski 1 , Tomasz Czakiert 2 , Kamil Idziak 2 , Marcin Sosnowski 1 , Marcio L. de Souza-Santos 3 , Karol Sztekler 4 and Wojciech Nowak 4 1 Faculty of Science and Technology, Jan Dlugosz University in Czestochowa, 42-200 Czestochowa, Poland; j.krzywanski@ujd.edu.pl (J.K.); m.sosnowski@ujd.edu.pl (M.S.) 2 Department of Advanced Energy Technologies, Czestochowa University of Technology, 42-201 Czestochowa, Poland; tczakiert@is.pcz.czest.pl (T.C.); k.idziak@is.pcz.pl (K.I.) 3 Department of Energy, School of Mechanical Engineering, University of Campinas, Campinas, SP 13083-970, Brazil; dss@csfmb.com 4 Faculty of Energy and Fuels, AGH University of Science and Technology, 30-059 Cracow, Poland; sztekler@agh.edu.pl (K.S.); wnowak@agh.edu.pl (W.N.) * Correspondence: a.zylka@ujd.edu.pl Received: 15 September 2020; Accepted: 12 October 2020; Published: 15 October 2020   Abstract: This paper presents a 1.5D model of a fluidized bed chemical looping combustion (CLC) built with the use of a comprehensive simulator of fluidized and moving bed equipment (CeSFaMB) simulator. The model is capable of calculating the effect of gas velocity in the fuel reactor on the hydrodynamics of the fluidized bed and the kinetics of the CLC process. Mass of solids in re actors, solid circulating rates, particle residence time, and the number of particle cycles in the air and fuel reactor are considered within the study. Moreover, the presented model calculates essential emissions such as CO 2 , SO X , NO X , and O 2 . The model was successfully validated on experimental tests that were carried out on the Fluidized-Bed Chemical-Looping-Combustion of Solid-Fuels unit located at the Institute of Advanced Energy Technologies, Czestochowa University of Technology, Poland. The model’s validation showed that the maximum relative errors between simulations and experiment results do not exceed 10%. The CeSFaMB model is an optimum compromise among simulation accuracy, computational resources, and processing time. Keywords: chemical looping combustion; CeSFaMB; ilmenite; oxygen carrier; hard coal; biomass 1. Introduction Global climate change caused by the greenhouse effect is the main reason to look for new solutions for burning solid fuels. One of the most promising combustion methods with inherent CO2 separation is chemical looping combustion (CLC) technology, which uses oxygen carriers (OCs) in the fuel combustion process. This technology requires two separate fluidized bed reactors: air reactor (AR) and fuel reactor (FR) with circulating and bubbling fluidized bed, respectively. In the AR the OCs are oxidized. In contrast, the OCs are reduced in the FR’s reaction chamber, as shown in Figure 1 [1,2]. Energies 2020, 13, 5394; doi:10.3390/en13205394 www.mdpi.com/journal/energies