  Citation: Torres-Liñán, J.; Ruiz-Rosas, R.; Rosas, J.M.; Rodríguez-Mirasol, J.; Cordero, T. A Kinetic Model Considering Catalyst Deactivation for Methanol-to-Dimethyl Ether on a Biomass-Derived Zr/P-Carbon Catalyst. Materials 2022, 15, 596. https://doi.org/10.3390/ma15020596 Academic Editor: Nicolas Sbirrazzuoli Received: 3 December 2021 Accepted: 10 January 2022 Published: 13 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article A Kinetic Model Considering Catalyst Deactivation for Methanol-to-Dimethyl Ether on a Biomass-Derived Zr/P-Carbon Catalyst Javier Torres-Liñán, Ramiro Ruiz-Rosas , Juana María Rosas * , José Rodríguez-Mirasol and Tomás Cordero Chemical Engineering Department, Andalucía Tech, Universidad de Málaga, 29010 Málaga, Spain; javiertorres@uma.es (J.T.-L.); ramiro@uma.es (R.R.-R.); mirasol@uma.es (J.R.-M.); cordero@uma.es (T.C.) * Correspondence: jmrosas@uma.es; Tel.: +34-952-132-038 Abstract: A Zr-loaded P-containing biomass-derived activated carbon (ACPZr) has been tested for methanol dehydration between 450 and 550 ◦ C. At earlier stages, methanol conversion was complete, and the reaction product was mainly dimethyl ether (DME), although coke, methane, hydrogen and CO were also observed to a lesser extent. The catalyst was slowly deactivated with time-on-stream (TOS), but maintained a high selectivity to DME (>80%), with a higher yield to this product than 20% for more than 24 h at 500 ◦ C. A kinetic model was developed for methanol dehydration reaction, which included the effect of the inhibition of water and the deactivation of the catalyst by coke. The study of stoichiometric rates pointed out that coke could be produced through a formaldehyde intermediate, which might, alternatively, decompose into CO and H 2 . On the other hand, the presence of 10% water in the feed did not affect the rate of coke formation, but produced a reduction of 50% in the DME yield, suggesting a reversible competitive adsorption of water. A Langmuir–Hinshelwood reaction mechanism was used to develop a kinetic model that considered the deactivation of the catalyst. Activation energy values of 65 and 51 kJ/mol were obtained for DME and methane production in the temperature range from 450 ◦ C to 550 ◦ C. On the other hand, coke formation as a function of time on stream (TOS) was also modelled and used as the input for the deactivation function of the model, which allowed for the successful prediction of the DME, CH 4 and CO yields in the whole evaluated TOS interval. Keywords: methanol dehydration; dimethyl ether; biomass-derived carbon; zirconium phosphate; kinetic modelling; deactivation 1. Introduction Global warming, as well as fossil fuel depletion, are pushing the actual model of energy consumption to a more environmentally friendly scenario [1]. In this new renewable and sustainable environment, the use of waste biomass for the production of chemicals, liquid fuels and advanced catalysts could help to achieve a circular economy and expand the life cycle of the products. Dimethyl ether (DME), as an interesting renewable diesel substitute, has been widely studied in recent years. Its global market has been increasing and is expected to increase at a compound annual growth rate of 7.5% in the period 2021–2026 [2]. DME can be used as liquified petroleum gas-blending, aerosol propellant and low-soot emission diesel substitute [3–5]. In addition, DME is an interesting hydrogen vector [6]. The production of renewable DME comes from syngas obtained by biomass gasifi- cation. This production of DME can be carried out in two different ways. The first one is the direct route, in which a bifunctional catalyst is used to transform syngas into DME. The most common catalyst used in this is commercial Cu-Zn-Al 2 O 3 , physically mixed with γ-alumina or zeolite [7]. On the other hand, the most widespread process used to industrially obtain DME is the indirect method, in which methanol is synthetized from Materials 2022, 15, 596. https://doi.org/10.3390/ma15020596 https://www.mdpi.com/journal/materials