1-Pentene epoxidation in titanium silicalite-1 microchannel reactor - Experiments and modelling

ATS-1 coated, microchannel reactor was fabricated onto silicon substrate using selective seeding and regrowth. The preparation technique's ability to engineer the zeolite film microstructure and chemistry was used to prepare TS-1 coatings with different titanium-contents and crystal sizes. The zeolite microreactor was utilized for 1-pentene epoxidation to 1,2-epoxypentane with hydrogen peroxide. This exothermic reaction can benefit by good heat transfer and containment of the oxidizing agent. A computational model was employed to simulate the reaction in the microreactor using kinetic data from batch reactor experiments. The influence of reactor geometry, catalyst properties and reaction conditions was evaluated and the results compared with experimental data

Architectural design and performance of zeolite microreactors

Titanium silicalite-1 (TS-1)-coated, microchannel reactors were investigated for I-pentene epoxidation to 1,2 epoxypentane using hydrogen peroxide as oxidant. The microreactor architecture as well as catalyst coating affects the reaction performance. A single-channel microreactor was easier to operate and provide the highest product yield per unit reactor volume compared to the T-shaped and multichannel microreactors. Also, a narrow channel width favored the exothermic epoxidation reaction. The reaction rate increased with the increasing amount of tetrahedrally coordinated Ti(IV) but decreasing with the size of the zeolite crystal

Design and fabrication of zeolite-based microreactors and membrane microseparators

This paper demonstrates that zeolites (i.e., Sil-1, ZSM-5 and TS-1) can be employed as catalysts, membrane or structural materials in miniature chemical devices. Traditional semiconductor fabrication technology was employed in micromachining the device architecture. The fabricated miniature zeolite-based structures find applications as catalytic microreactors and membrane microseparators. Four strategies for the manufacture of zeolite catalytic microreactors were discussed: zeolite powder coating, uniform zeolite film growth, localized zeolite growth, and etching of zeolite-silicon composite film. These zeolites were deposited either as film or discrete islands with controlled particle size, crystal morphology, layer thickness (3-16 mum) and film orientation (e.g., highly oriented (101) and (200) films). Crystal intergrowth was also manipulated through the use of growth inhibitors. Silicalite-l was also prepared as free-standing membrane for zeolite membrane microseparators. (C) 2001 Elsevier Science B.V. All rights reserved

Incorporating zeolites in microchemical systems

Using a new fabrication method based on microelectronic fabrication and zeolite thin film technologies, MFI-type zeolites with engineered structures were incorporated as catalyst, membrane and structural material within the design architecture of a microreactor, membrane microseparator and microeletrochemical cell. Complex microchannel geometry and network (<5 mum), as well as zeolite arrays (<10 mum) were successfully fabricated onto highly orientated supported zeolite films. The zeolite micropatterns were stable even after repeated thermal cycling between 303 and 873 K for prolonged period of time. Blueprints for zeolite-based microchemical systems were presented, and test units were fabricated and the structural details of the microdevices' architecture were analysed. (C) 2002 Elsevier Science B.V. All rights reserved

1-pentene epoxidation in catalytic microfabricated reactors

Silicon-glass microreactors with TS-1 catalyst wall coatings were fabricated and used for 1-pentene epoxidation with hydrogen peroxide in continuous flow. Seeding of the microchannels before zeolite growth was necessary to obtain a small crystal size and a sufficient zeolite film thickness. Crystal size was further reduced by adjusting synthesis conditions and utilizing triethoxymethylsilane (TEMS) as a crystal growth inhibitor. Zeolite film morphology and crystal orientation did not show any significant effect on reactor performance. However, reaction rate was found to increase with decreasing TS-1 crystal size in the zeolite films and with increasing amount of tetrahedrally coordinated Ti(IV). Catalyst deactivation was observed, caused by the presence of organic compounds and Ti leaching from the microporous framework. (C) 2003 Elsevier Inc. All rights reserved

TS-1 zeolite microengineered reactors for 1-pentene epoxidation

A zeolite-based microengineered reactor was fabricated and tested for 1-pentene epoxidation over titanium silicalite-1 (TS-1) catalyst, which has been selectively incorporated within the microreactor channel using a new synthesis procedure