(27b) Catalyst Uniformity Requirements for Industrial Microchannel Applications | AIChE

(27b) Catalyst Uniformity Requirements for Industrial Microchannel Applications

Authors 

Daly, F. - Presenter, Velocys, Inc.
Mazanec, T. - Presenter, Velocys Inc.
Taha, R. - Presenter, Velocys Inc
Arora, R. - Presenter, Velocys, Inc.


The process intensification advantages offered by microchannel architecture are well documented but are not yet proven at commercially significant production levels. The transition from lab to industrial scale has been the failing of many promising technologies, but recent developmental successes make the future of microchannel process technology appear especially encouraging. These advances include cost effective manufacturing techniques to produce high quality microreactors, manifolding advancements that provide even flow within and between microchannel devices, and methods to uniformly deploy catalyst inside microchannel reactors. This presentation will review these advances for Velocys' steam methane reformer which is being developed for both hydrogen production and gas-to-liquid applications.

Microchannel architecture improves both mass and heat transfer, which makes it ideal for a number of catalytic reactions - both endothermic and exothermic. Microchannel devices are scaled up by numbering up. In other words, capacity is increased by adding more and more parallel channels rather than changing critical process dimensions, such as tube or vessel diameters. The numbering up method of increasing scale reduces risk by keeping the reaction physics and channel flow hydrodynamics the same, but introduces its own challenges for fabrication, uniform catalyst integration and fluid flow. Specific methodologies for achieving sufficiently uniform flow distribution in microchannel reactors have been demonstrated and will be discussed.

Integrating catalysts uniformly in microchannel devices poses a few key challenges. First, the proper catalyst form must be selected. Microchannel devices offer intensified performance, and therefore can use more active catalysts than conventional reactors. In many cases, the catalyst form currently used commercially is not appropriate for integrating in microreactors. Secondly, the integration scheme must ensure uniform deployment in each channel of the microreactor in order for the device to perform as designed. No distribution is perfect, but the method employed must be adequate to meet the microchannel device's design tolerances. Lastly, the need to refurbish or replace the catalyst must be considered. For the steam reformer and most other industrial applications, the catalyst life is far shorter than that of the reaction hardware. So, an effective means of reactivating or replacing the catalyst is essential.

Velocys has addressed each of these challenges by closely coupling the development of microchannel-adapted catalysts with the development of microreactors. Multiple catalyst forms have been formulated, deployed and demonstrated in microchannel hardware. These include powders, washcoats and inserted engineered forms. For each form, protocols have been developed and validated in prototype devices to achieve uniform integration. Selected forms will be demonstrated in commercial-scale microreactors. Refurbishment of select catalyst forms has also been tested with encouraging results.

Checkout

This paper has an Extended Abstract file available; you must purchase the conference proceedings to access it.

Checkout

Do you already own this?

Pricing

Individuals

AIChE Pro Members $150.00
AIChE Graduate Student Members Free
AIChE Undergraduate Student Members Free
AIChE Explorer Members $225.00
Non-Members $225.00