Deactivation of a Biomass-Derived Zirconium-Doped Phosphorus-Containing Carbon Catalyst in the Production of Dimethyl Ether from Methanol Dehydration
| Autor: | Miguel García-Rollán, José Rodríguez-Mirasol, Juana M. Rosas, Tomás Cordero, Javier Torres-Liñán |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
General Chemical Engineering
Energy Engineering and Power Technology chemistry.chemical_element Biomass Catalysis chemistry.chemical_compound medicine Dimethyl ether Dehydration Deposition Coke Coque Zirconium Oxidos Catalysts Chemistry Doping Catalizadores Oxides medicine.disease Fuel Technology Alcohols Methanol Alcohol Carbon Nuclear chemistry |
| Zdroj: | RIUMA. Repositorio Institucional de la Universidad de Málaga instname |
| Popis: | Dehydration of methanol to produce dimethyl ether (DME) was studied at relatively high temperatures (400–600 °C) on biomass-derived phosphorus-containing carbon impregnated with a zirconium salt. Highly thermally stable zirconium phosphate surface groups could be obtained on the final catalyst, which were responsible for the high stability and selectivity to DME of the catalyst at temperatures lower than 400 °C. However, harder operation conditions, closer to those of the industrial process, were evaluated to analyze the changes of the catalyst surface properties with the reaction temperature and the possible causes of deactivation. Thus, high methanol conversion and selectivity to DME were also observed in the temperature range of 400–600 °C, although deactivation was detected. Coke deposition was responsible for a decrease in microporosity and surface concentration of zirconium and phosphorus of the catalyst. Temperature-programmed desorption, 31P magic angle spinning nuclear magnetic resonance, and X-ray photoelectron spectroscopy results suggest that the Zr–O–P groups from zirconium phosphate species were responsible for the long-term stability of the catalyst and that the C–O–P-type active sites were deactivated very fast. However, coke deposition on Zr–O–P-type active sites caused a slow and irreversible deactivation, while deposited coke on the C–O–P-type active sites was easily eliminated by the oxidative treatment in air. A reaction scheme that accounted for the gas product distribution and the production of coke was proposed. A kinetic model for coke formation as a function of time on stream that successfully represents the experimental results was also propounded, which yielded a value for the activation energy for the production of coke of 124 kJ/mol. Funding for open access charge: Universidad de Málaga / CBUA. This work was supported by the Spanish Ministry of Economy and Competitiveness and Junta de Andalucia through CTQ2015-68654-R, RTI2018-097555-B-I00, and UMA18- FEDERJA-110 projects. Javier Torres-Liñán also acknowledges the assistance of the Spanish Ministry of Economy, Industry and Competitiveness for the award of a predoctoral contract to become a Ph.D. (BES-2016-079237). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|