Is there a catalytic means to increase production from our hydrogen plant without a revamp or other significant capital outlay?Mar-2022
Barry Dallum, Alternative Petroleum Technology, email@example.com
There is a catalytic means to reduce existing demand for hydrogen to make it available for new, addition demand. This can be done by using oxidative desulfurization to replace some if not all hydrotreating. The multi-patented SULFEX process has much lower capital investment and much lower operating cost, while safer due to low pressure (1 atmosphere) and temperature (<100 C) operation than hydrotreating. It does not generate hydrogen sulfide nor greenhouse gases unlike SMR. It uses hydrogen peroxide with continuously recyclable weak and strong liquid acid commodity catalysts.
Tom Ventham, G. W. Aru, LLC and Unicat Catalyst Technologies, firstname.lastname@example.org
This question accurately illustrates the most popular query heard from refiners today. How can this vital future resource of hydrogen be enhanced from existing on-site refinery equipment without the need for expensive retrofits or brand new projects? What the question is missing is a time aspect to the problem, as refiners and syngas producers need these improvements now. This need is incompatible with the timeline to evaluate, cost, gain funding approval, design and engineer, and then construct and commission the revamp or new low-carbon (i.e., blue hydrogen) solution
A solution does already exist for this problem and is one that is known to a large number of refining companies and syngas producers who have shown an interest in enhancing production of hydrogen at their sites. A number of these companies are already taking advantage of the benefit of this MagCat SMR catalyst by producing 15% more hydrogen than their previous capacity. As a superior catalyst technology, MagCat from Unicat can also provide other benefits compared to conventional catalysts from other suppliers. This includes the ability to reduce fuel consumption in the reformer furnace and make CO2 reductions – both topics of very great importance at the current time.
MagCat achieves the benefits of a superior SMR catalyst by reimagining the size and shape of the physical carrier and by no longer being limited by the constraints of the traditional production processes used to produce the carriers (i.e. pellets) for conventional SMR catalysts. Optimising size and shape of a catalyst used in these gas-phase tubular reformer reactors unlocks multiple benefits. This includes the ability process more feed gas in the SMR without loss of conversion, which can be understood using fundamental principles of chemical engineering – fluid dynamics, heat transfer, and thermodynamics.
MagCat achieves multiple, step-out benefits for the SMR operator while avoiding complexities and inherent issues experienced with other, now defunct, high hydrogen production SMR catalytical solutions previously proposed to the industry by other suppliers. MagCat requires no changes to the operating, start-up, shutdown, or unloading procedures and in fact offers the ability to simplify loading procedures as it can be direct loaded to reformer tubes and does not require costly dense loading. As a real and proven solution with tangible functional improvements, MagCat offers refiners looking to improve hydrogen production an answer to this problem today. In view of current historic high natural gas prices many refiners are considering bringing forward catalyst change-outs to be able to load MagCat now in their steam methane reformers. Without exotic materials of construction or long lead-times this is possible. MagCat is compatible with all SMR unit designs and licences, all possible hydrogen plant configurations, and can be effectively used alongside any other upstream or downstream hydrogen plant catalysts and absorbents. Moreover, Unicat also supports uprating PSA units with high-performance Unicat absorbents to ensure any additional hydrogen production is effectively captured – a key consideration for all reformer operators considering increases to hydrogen production. MagCat is a truly innovative solution to catalytically increase hydrogen production as a cost- and time-wise alternative to retrofit installations such as a pre-reformer or post-reformer.
Rainer Rakoczy, Clariant Catalysts, Rainer.Rakoczy@clariant.com
Technip Energies and Clariant recently made a breakthrough in the productivity, efficiency, and sustainability of steam reforming. EARTH, an acronym for “enhanced annular reforming tube for hydrogen,” is a technology patented by Technip Energies that consists of an innovative, concentric tubular structure as a drop-in insert for the steam reformer tubes and contains tailor-made structured catalysts jointly developed with Clariant. This unique setup results in superior heat recovery, higher throughput, and significantly lower pressure drop than a conventional catalyst and catalytic tube layout.
The outstanding internal heat recovery of the EARTH technology presents several major advantages for hydrogen and syngas producers. Firstly, it significantly reduces external heat flux demand through firing. Hence, producers can increase plant throughput and capacity by up to 20% while maintaining their current costs and process conditions. Alternatively, producers can choose to significantly lower their operating costs at equal yield while reducing CO2 emissions by up to 10% per unit of syngas produced.
Our EARTH technology is designed as a drop-in solution compatible with new or existing steam reformers tubes with inlet and outlet sections at opposing ends of the furnace. Its installation requires no additional plot space and is comparable to a typical catalyst changeout. In addition, the tubes can be delivered preloaded with catalysts on request.
Jumal Shah, Johnson Matthey, email@example.com
To increase production, it is important to initially understand the existing limitations of the hydrogen plant. This is typically achieved using performance evaluations of each catalyst unit against kinetic models, thermographic surveys of the steam methane reformer, and equipment specifications and design limit. Common factors that constrain production rates in a hydrogen plant include steam reformer tube temperature limits or other furnace constraints, carbon formation margins in the steam reformer pressure drop across the plant, and poor conversion in the water gas shift section.
Steam reforming of methane is an endothermic reversible reaction. Thus, the catalyst activity and heat transfer from the burners to the catalyst are important for maximising production. The formulation and the manufacturing process determine the intrinsic activity of the catalyst. Katalco 57-6 series has a patented manufacturing technique that makes the active metal on the pellet more accessible to the gas and enables performance deeper into the operating cycle. The size and shape of the catalyst will impact the tube-side laminar film layer and, therefore, the overall heat transfer coefficient. Catalysts such as Johnson Matthey’s QuadraLobe catalysts can provide better packing characteristics, more tube wall contact points, and radial gas mixing, thereby improving the heat transfer properties. Uniformity of the catalyst loading, reliable tube wall temperature monitoring, and balancing for better utilisation of firing capacity are also important controls for easing limits caused by tube temperature limits or other furnace constraints, such as limited combustion airflow or flue gas temperature limits.
Due to the temperatures at which steam reformers operate, carbon is constantly being formed from the hydrocarbon feed. However, carbon gasification reactions simultaneously occur that remove the carbon laid down, meaning there is no net accumulation of carbon in a well-run plant. The rate of carbon laydown depends on a number of conditions, such as the catalyst activity, degree of sulphur poisoning, and heat input to the tubes. As the steam reformer catalyst ages, the gradual deactivation of the catalyst can increase the tube wall temperatures and the potential for carbon formation. High activity, good thermal stability, and alkali promotion can ensure the carbon removal rate is faster than the carbon formation rate. Promoted catalysts, such as Katalco 25-series and Katalco 46-series, maximise protection against carbon formation and allow higher production rates to be maintained through the life of the catalyst.
For higher production rates, the catalyst should allow for the lowest possible pressure drop, as this will enable the highest possible plant throughput before compressor limits are reached. The catalyst breakage characteristics are important for the steam reforming catalysts as all pelleted steam reforming catalysts will break due to the forces exerted on them when reformer tubes expand in operation and then contract during plant shutdowns. QuadraLobe shaped catalyst pellets are specifically designed to avoid generating small pellet fractions when breaking and hence minimise pressure drop increase over the catalyst’s lifetime. Grades range from the highest activity shape mini QuadraLobe (MQ) to the low pressure drop extra-large QuadraLobe (XQ) catalyst, allowing a tailored selection to optimise between activity and pressure drop.
The water gas shift section of the hydrogen plant typically contributes around 15% of the hydrogen produced. High temperature shift catalyst with a higher activity, better thermal stability, and improved poisoning resistance can also enable an increase in hydrogen production. Premium catalysts such as Katalco 71-6 have enhanced activity, improved in-service strength, and more wetting resistance. The water gas shift reaction is an exothermic and equilibrium reaction. A higher activity catalyst allows operation at lower optimal temperatures and thus a more favourable equilibrium position for higher conversion. The improved strength ensures a consistently low pressure drop throughout the operating life, and simple StreamLine technology can be installed to reduce further the pressure drop across a water gas shift vessel.
In summary, many factors limit the production rate of a hydrogen plant. To maximise the production rate, a good understanding of the plant limits is needed, and selection of the right catalyst is required to enable maximum production capacity whilst maintaining reliability and efficiency.