Advanced Solutions for Decarbonizing Hydrogen Generation and then the Refineries

Based on the current and imminent global drive for tackling climate change, hydrogen is finding its newer evolving and expanded role as an enabler for the imminent energy transition. With the strong push towards ‘near-zero’ and then to ‘net-zero’ carbon targets, efforts are gearing up for the projected transforming of the conventional Grey H2 to Blue H2 (with added CO2 capture), with Green H2 (based on water electrolysis using renewable power) expected to catch up in the longer term.

Moreover, hydrogen has been carrying its crucial role in petroleum refining for catering to the increasingly stringent requirements for cleaner and lighter product slate. Accordingly, it has drawn focal attention in terms of advanced hydrogen management as well as optimized on-purpose H2 generation for enhancing overall refinery profitability.

Over the years, the objective targets have progressed from H2 management towards CO2 management, more so since H2 generation itself caries quite a large C-footprint (of 9-12 ton per ton H2). Such efforts however led to only to a marginal reduction in CO2, while not governed by any statuary framework.

However, the “hard-to-abate” industrial sectors like refining and other which involve high temperature processing and requiring fuel firing, are expected to follow the “blue pathways” in support of fossil-continuity with CCS. Based on various continuing technological developments for Post-combustion CO2 capture, mainly to relax its energy and capital intensity as well as to improve process reliability, there is no clear cut and cost-effective process as yet which is also sufficiently deployed commercially. Thus, considering the proposed decarbonization targets of > 85% for a Refinery inherently having multiple fuel-fired heaters, the underlying need for post-combustion CO2 capture makes it quite a challenging and perhaps risky venture on a larger scale.

In addressing the above trends, the paper will describe the innovative and distinctive developments by ZoneFlow Reactor Technologies, firstly in terms of their ZF structured catalyst for steam reforming which by replacing the existing pellets, allow a capacity increase of 15-25% combined with enhanced efficiency, thereby also lowering the CO2 per unit H2 both for retrofits as well as new SMRs. And secondly as a bigger breakthrough, a rearranged conventional H2 plant flowsheet called “Z-H2” which allows >95% decarbonization through deploying only the well-proven and cost-effective pre-combustion CO2 removal from high pressure clean syngas.

The Z-H2 concept is based on recycling and retaining the total carbon input within the process while having full SMR firing with nearly pure H2. The H2 plant capacity though becoming much larger, also for catering for the H2 fuel requirements for rest of the refinery units replacing the refinery fuel gas, the overall economics remains attractive in the wake of eliminating the post-combustion CO2 capture while also achieving the required refinery-wide net carbon avoidance.

The paper will include comparative techno-economical assessment and NPV analysis for CO2 capture in decarbonizing hydrogen generation using natural gas feedstock in conjunction with utilization of refinery off gases and expanded hydrogen network for the targeted decarbonization of the refinery.

Decarbonizing the hydrogen generation and having centralized pre-combustion capture within the expanded and new H2 plants using Z-H2 process technology for producing extra hydrogen for blending or replacing the hydrocarbon fuels in the refinery heaters will prove to be an effective, proven, and economical route for decarbonization of a refinery. Z-H2 It offers an attractive, easy to execute, reliable and efficient way forward in realizing the imminent and future carbon avoidance mandates.