Continuous acylation of anisole by acetic anhydride in mesoporous solid acid catalysts: Reaction media effects on catalyst deactivation

2007 ◽  
Vol 245 (1) ◽  
pp. 184-190 ◽  
Author(s):  
V SARSANI ◽  
C LYON ◽  
K HUTCHENSON ◽  
M HARMER ◽  
B SUBRAMANIAM
Keyword(s):  
Acetic Anhydride ◽  
Media Effects ◽  
Solid Acid ◽  
Catalyst Deactivation ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Reaction Media

scholarly journals Counteracting Rapid Catalyst Deactivation by Concomitant Temperature Increase during Catalytic Upgrading of Biomass Pyrolysis Vapors Using Solid Acid Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 748
Author(s):  
Andreas Eschenbacher ◽  
Alireza Saraeian ◽  
Brent H. Shanks ◽  
Uffe Vie Mentzel ◽  
Jesper Ahrenfeldt ◽  
...  
Keyword(s):  
Solid Acid ◽  
Catalyst Deactivation ◽  
Fixed Bed ◽  
Product Yield ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Hydrothermal Conditions ◽  
Stable Production ◽  
Catalyst Temperature ◽  
Fixed Catalyst

The treatment of biomass-derived fast pyrolysis vapors with solid acid catalysts (in particular HZSM-5 zeolite) improves the quality of liquid bio-oils. However, due to the highly reactive nature of the oxygenates, the catalysts deactivate rapidly due to coking. Within this study, the deactivation and product yields using steam-treated phosphorus-modified HZSM-5/γ-Al2O3 and bare γ-Al2O3 was studied with analytical Py-GC. While at a fixed catalyst temperature of 450 °C, a rapid breakthrough of oxygenates was observed with increased biomass feeding, this breakthrough was delayed and slower at higher catalyst temperatures (600 °C). Nevertheless, at all (constant) temperatures, there was a continuous decrease in the yield of oxygen-free hydrocarbons with increased biomass feeding. Raising the reaction temperature during the vapor treatment could successfully compensate for the loss in activity and allowed a more stable production of oxygen-free hydrocarbons. Since more biomass could be fed over the same amount of catalyst while maintaining good deoxygenation performance, this strategy reduces the frequency of regeneration in parallel fixed bed applications and provides a more stable product yield. The approach appears particularly interesting for catalysts that are robust under hydrothermal conditions and warrants further investigations at larger scales for the collection and analysis of liquid bio-oil.

scholarly journals Acylation of aromatic compounds by acid anhydrides using Preyssler's anion [NaP5W30O110]14- and heteropolyacids as green catalysts

2011 ◽  
Vol 13 (2) ◽  
pp. 11-17 ◽  
Author(s):  
Ali Gharib ◽  
Manouchehr Jahangir ◽  
J. Scheeren
Keyword(s):  
Acetic Anhydride ◽  
Aromatic Compounds ◽  
Room Temperature ◽  
Solid Acid ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Keggin Heteropolyacids ◽  
Acid Anhydrides

Acylation of aromatic compounds by acid anhydrides using Preyssler's anion [NaP5W30O110]14- and heteropolyacids as green catalysts The Preyssler, Wells-Dowson and Keggin heteropolyacids are efficient and eco-friendly solid acid catalysts for the acylation of electron-rich aromatic compounds with acid anhydrides. The performance of different forms of heteropolyacids was compared. In all the cases, the best results were obtained using the Preyssler heteropolyacid as the catalyst. In the presence of 25 mol% (with respect to H+ equivalency) Preyssler catalyst, highly para-selective acetylation of anisole occurs using two equivalents of acetic anhydride, in 15 min at room temperature. The isolated yield of the p-methoxyacetophenone product is 98%.

Preparation of Strong Acid Catalysts by Sulfate Treatment of Calcined Boehmite

1992 ◽  
Vol 57 (11) ◽  
pp. 2241-2247 ◽  
Author(s):  
Tomáš Hochmann ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Aluminum Sulfate ◽  
Solid Acid ◽  
Strong Acid ◽  
Acid Strength ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Preparation Methods ◽  
Indicator Method

Solid acid catalysts with acid strength of -14.52 < H0 < -8.2 were prepared by sulfate treatment of the samples of boehmite calcined at 105-800 °C. Two preparation methods were used: impregnation of the calcined boehmite with 3.5 M H2SO4 or mixing of the boehmite samples with anhydrous aluminum sulfate, in both cases followed by calcination in nitrogen at 650 °C. The catalysts were characterized by measurements of surface area, adsorption of pyridine and benzene, acid strength measurements by the indicator method and by catalytic activity tests in the isomerization of cyclohexene, p-xylene and n-hexane. Properties of the catalysts prepared by both methods were comparable.

scholarly journals Metal–Organic Framework-Based Solid Acid Materials for Biomass Upgrade

2021 ◽  
Author(s):  
Yutian Qin ◽  
Jun Guo ◽  
Meiting Zhao
Keyword(s):  
High Efficiency ◽  
Solid Acid ◽  
Metal Organic Framework ◽  
Acid Sites ◽  
Solid Acid Catalysts ◽  
Future Research ◽  
Acid Catalysts ◽  
Metal Organic ◽  
Biomass Transformation ◽  
Organic Framework

AbstractBiomass is a green and producible source of energy and chemicals. Hence, developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded. Metal–organic framework (MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation. In this review, we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites. Then, the methods for the generation and adjustment of corresponding acid sites are overviewed. Next, the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed. Furthermore, based on our personal insights, the challenges and outlook on the future development of MOF-based solid acid catalysts are provided. We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.

scholarly journals Nonthermal Plasma Induced Fabrication of Solid Acid Catalysts for Glycerol Dehydration to Acrolein

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 391
Author(s):  
Lu Liu ◽  
Xiaofei Philip Ye
Keyword(s):  
Solid Acid ◽  
Nonthermal Plasma ◽  
Temperature Programmed Desorption ◽  
Argon Atmosphere ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Pyridine Adsorption ◽  
X Ray ◽  
Glycerol Dehydration ◽  
Temperature Programmed

The feasibility of fabricating better solid acid catalysts using nonthermal plasma (NTP) technology for biobased acrolein production is demonstrated. NTP discharge exposure was integrated in catalyst fabrication in air or argon atmosphere. The fabricated catalysts were characterized by Brunauer–Emmett–Teller surface area analysis, temperature-programmed desorption of ammonia, X-ray powder diffraction and Fourier-transform infrared spectroscopy of pyridine adsorption, in comparison to regularly prepared catalysts as a control. Further, kinetic results collected via glycerol dehydration experiments were compared, and improvement in acrolein selectivity was displayed when the catalyst was fabricated in the argon NTP, but not in the air NTP. Possible mechanisms for the improvement were also discussed.

Sign in / Sign up

Export Citation Format

Share Document