Innovative Zoneflow® Catalyst Offers Unmatched Solutions in Steam Reforming for Syngas Based NG Conversion

Natural gas has been a prime, rather increasingly preferred contender for meeting current and future energy demand based on its abundance, lower carbon intensity and modes of distribution. With the advent of shale gas, it has not only driven a quick switchover from high carbon fuel sources like coal anf fuel oil to NG but also offered ample opportunities and potential for monetizing it through conversion to Syngas as a building block. Moreover curtailment of flare gas also offers lot of opportunities and incentives for gas conversion. The syngas based wide spectrum ranges from major petro-chemicals to fertilizers and futuristic clean power with concerted carbon capture.

The predominant technology for Syngas generation over all these years has been steam reforming of natural gas commonly called steam-methane reforming (SMR). This mature technology, however, has seen only incremental improvements in its catalyst design in aiming for better performance and operating life whihc otherwise plays a crucial role in its thermal design, overall performance, reliability and cost-effectiveness.

The conventional "pellet" steam reforming catalysts suffer from few inherent limitations and/or operational deficiencies. These mainly relate to a) uneven random packing voidage leading to undesired flow and temperature mal-distribution, b) catalyst attrition and breakage from thermal cycling leading to increasing pressure drop and related capacity limitations and c) pore-diffusion limited reaction path leading to curtailed intrinsic activity. Past attempts to develop structured steam reforming catalysts to overcome some of these limitations have suffered from the innate problems around differential expansion gaps leading to feed by-passing and disturbed boundary layer endotherm.

ZoneFlow^TM Reactor Technologies LLC (ZFRT) has developed proprietary, radically innovative and differentiating structured catalyst systems called ZoneFlow^™ (ZF) Reactors. These not only overcome the above-mentioned deficiencies but also offer an unmatched combination of higher heat transfer, lower pressure drop, higher geometric surface area (GSA), more uniform flow and heat distribution and long-term structural integrity compared to the current state-of-the-art pellet catalyst.

ZF Reactor's unique structure also imparts a high degree of proximal flexibility thus eliminating the differential thermal expansion gaps, while also having high (metal substrate) physical strength against breakage over its lifetime. Its nested modules provide much more geometric surface than pellets, and take away the diffusion-limited access to the layered catalyst thus resulting in much higher catalyst effectiveness.

ZF Reactors also offer the advantage that they can be loaded horizontally, which allows for in-situ 'convective pre-reforming' in the reformer convection section. Furthermore its annular casing design directly enables regenerative or "bayonet" reformer designs, while overcoming the major concerns and risks associated with the current pellet-based designs. The ZF Reactor product range covers radiant steam reforming, convective pre-reforming as well as recuperative reforming. Their performance parameters have been validated through advanced CFD modeling and bench scale test rigs, to be further confirmed in upcoming pilot plant in Belgium.

ZF Reactor designs can be customized for required optimization between heat transfer and pressure drop, and to fit in any commercial SMR tube size. These features of the ZF Reactor can translate into attractive benefits to the end-user ranging from relieving "stressed" reformers, debottlenecking and capacity upgrades as well as new plant SMRs. The use of ZF reactors enables significant capital and operating cost reduction

This paper will provide status update on ZF technology developments and also the upcoming pilot plant progress with its extensive test program under near commercial operating conditions as well as various case studies covering capacity revamps and new plant for enhancing the economics and reliability of steam reforming based syngas generation for Natural Gas conversion and monetization.