(175c) Advanced Hydrogen Solutions in Decarbonizing Refineries

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.

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 targeted 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.

However, the “hard-to-abate” industrial sectors comprising mainly of refining, petrochemicals, cement, DRI etc. which involve high temperature processing thus requiring fuel firing, are expected to follow the “blue pathways” in terms of fossil-continuity with CCS. With various continued technological developments in post-combustion capture, mainly to improve the energy and capital intensity as well as process reliability, there is no clear cut and cost-effective process which is sufficiently deployed commercially. Thus, considering the proposed decarbonization targets of > 80% for a Refinery with its 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.

To address such emerging needs, the advanced solutions for decarbonizing especially the hard-to abate set-up of a Refinery, wrest on the pathway of first switching the refinery-wide fuel gas network to low-carbon or carbon-free fuel such as hydrogen or its compounded form as ammonia and secondly to find ways to (cost) effectively decarbonize such H2 generation effectively while using conventional hydrocarbon feedstock.

In addressing the above trends, the paper will also describe the innovative and distinctive developments by ZoneFlow reactor technologies, firstly in terms of their structured catalytic ZF reactors for steam reforming which by replacing the existing pellets, allows a capacity increase of 15-20% combined with enhanced efficiency, thereby also lowering the CO2 per unit H2. And secondly as a bigger breakthrough, a rearranged conventional H2 plant flowsheet called “ Z-H2” which allows >90% decarbonization only 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 all the carbon within the process while having the fuel for SMR firing as only H2 thereby fully eliminating the need for less desirable post-combustions capture. The larger H2 plant also provides the H2 fuel for rest of the refinery units replacing the refinery fuel gas thus achieving the targeted decarbonization along with centralized pre-combustion capture within the H2 plant, thus offering an effective way forward in addressing the imminent decarbonization targets.