Hydrolysis of sodium borohydride with steam

Marrero-Alfonso, Eyma Y.; Gray, Joshua R.; Davis, Thomas A.; Matthews, Michael A.

doi:10.1016/j.ijhydene.2007.07.066

Cited by 88 publications

(54 citation statements)

References 15 publications

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“…For example, with highly concentrated aqueous solutions capacities of about 7 wt.-% were obtained while with solid NaBH 4 capacities up to 9.0 wt.-% were observed. The thermodynamically stable form of NaBO 2 is the dihydrated one [34,35], which means a maximum GHSC of 7.3 wt.-%. For obtaining higher capacities, the NaBO 2 hydration issue should be addressed.…”

Section: Discussionmentioning

confidence: 99%

“…Despite this failure, the idea of using solid NaBH 4 was considered one more time. Marrero-Alfonso et al [34,35] reported that the reaction of NaBH 4 with steam produced H 2 and a hydrated solid, and that up to 95% yield of H 2 was obtained with pure steam without any catalyst. Thermogravimetry and X-ray diffraction analysis revealed that the solid by-product was a hydrated borate corresponding to NaBO 2 Á2H 2 O.…”

Section: Powdermentioning

confidence: 99%

“…The amount of water (liquid or vapour) should determine the H 2 -controlled generation [34,35]. Using the catalyst either as a powder or supported over a substrate (resin, Ni foam, Cu plate, C cloth or paper and so on) are two different solutions that can be envisaged.…”

Section: Catalyst Shapesmentioning

confidence: 99%

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Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

et al. 2010

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Today there is a consensus regarding the potential of NaBH4 as a good candidate for hydrogen storage and release via hydrolysis reaction, especially for mobile, portable and niche applications. However as gone through in the present paper two main issues, which are the most investigated throughout the open literature, still avoid NaBH4 to be competitive. The first one is water handling. The second one is the catalytic material used to accelerate the hydrolysis reaction. Both issues are objects of great attentions as it can be noticed throughout the open literature. This review presents and discusses the various strategies which were considered until now by many studies to manage water and to improve catalysts performances (reactivity and durability). Published studies show real improvements and much more efforts might lead to significant overhangs. Nevertheless, the results show that we are still far from envisaging short‐term commercialisation.

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Section: Discussionmentioning

confidence: 99%

Section: Powdermentioning

confidence: 99%

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Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

et al. 2010

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“…Nowadays, the most hydrogen production is by reforming natural gas process (Pohl, 1995). In addition, pure hydrogen from water electrolysis is produced by fossil fuel burning generated electricity (Marrero-Alfonso et al, 2007), hydroelectric, wind energy and solar energy (Khaselev and Turner, 1998). Among such renewable resources, biomass conversion is also a technique usually used for hydrogen production (Cortright et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Gaseous Emissions and Combustion Efficiency Analysis of Hydrogen-Diesel Dual Fuel Engine Under Fuel-Lean Condition

Chaisermtawan

Jarungthammachote

Chuepeng

et al. 2012

American Journal of Applied Sciences

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Exhaust gas emissions from diesel engine combustion using alternative fuel may change in their quantities that can affect exhaust gas after-treatment devices and environmental ambient. This study presents theoretical analysis of combustion generated emissions and efficiency of hydrogen-diesel duel fuel in fuel-lean condition. A chemical equilibrium method by minimizing Gibbs free energy is employed to estimate exhaust gas products from diesel and hydrogen-diesel mode combustion. The combustion products, e.g., unburned hydrocarbons (CH 4 ), hydrogen (H 2 ), carbon dioxide (CO 2 ), carbon monoxide (CO) are comparatively investigated, based upon similar specific energy input. Subsequently, the obtained combustible products (CH 4 , H 2 and CO) are used to calculate combustion efficiency, based upon chemical energy left in waste exhaust gases. The main findings are associated with the reduction in CO 2 corresponding to the increase in combustion efficiency in hydrogen-diesel combustion mode, depending on relative air-to-fuel ratios. Meanwhile, the CH 4 , H 2 and CO contents in the flue gas increase in the operating conditions used.

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“…Nevertheless, there has been some recent interest in designing a hydrogen storage system based on NaBH 4 without the need for a catalyst, as summarised in Table 2.6. The high-temperature steam concept was further investigated in 2007; although the yield was lower, it was found that the reaction rate could be increased by adding methanol or acetic acid as a promoter [110]. hydrolysis systems with higher yields and GHSCs [116].…”

Section: Catalytic Hydrolysis Of Nabh 4 Solutionsmentioning

confidence: 99%

Sodium borohydride production and utilisation for improved hydrogen storage

Muir¹

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Sodium borohydride (NaBH 4 ) has been the subject of extensive investigation as a potential hydrogen storage material. Its advantages include its ability to be stored as a stabilised aqueous solution and hydrolysed catalytically on demand, providing hydrogen safely, controllably, and at mild conditions. However, several drawbacks were identified by the US Department of Energy (DOE) in their "No-Go" recommendation in 2007; namely, the limitations on its gravimetric hydrogen storage capacity (GHSC) and its prohibitive manufacturing cost.This thesis aims to address some of the major issues associated with the use of NaBH 4 for hydrogen storage. Efforts have been spread across three key research areas, which were identified in a review of the recent literature: Synthesising an efficient, durable, and inexpensive catalyst for the hydrolysis of aqueous NaBH 4 solution  The design of a hydrogen storage system based on NaBH 4 which can overcome the GHSC constraints imposed by the solubility of its hydrolysis by-product, NaBO 2  The development of a novel recycling process for regenerating NaBH 4 from NaBO 2 , with the goal of reducing its production cost to within the DOE's target range of $2-4 per gallon of gasoline equivalent (gge) To achieve the first goal, a new electroless plating method was developed for preparing cobalt-boron (Co-B) catalysts supported on shaped substrates. This method involves mixing the plating solutions at low temperature (<5 o C), in contrast to previously employed methods, which are generally carried out at room temperature or higher. The new method requires only one plating step to achieve the desired catalyst loading, and has higher loading efficiency than processes requiring multiple plating steps, due to reduced catalyst wastage. The catalysts produced by this method show significantly higher NaBH 4 hydrolysis activity than those prepared by conventional methods, with a hydrogen generation rate over 24000 mL/min/g recorded at a temperature of 30 o C and a NaBH 4 concentration of 15 wt%. The improved activity of these catalysts was thought to be due to their increased boron content and nanosheet-like morphology, both of which are products of the low temperature preparation method.ii The stability of these catalysts was examined over several usage and deactivation cycles, which involved long-term exposure to alkaline solution. It was found that the deactivated catalysts were able to recover 80-90% of their initial activity even after 10 cycles, if operated at 40 o C or higher. Characterisation of the deactivated catalysts revealed that a layer of NaBO 2 had formed on the surface, blocking the catalytically active Co sites. The improved cyclic stability is most likely due to the dissolution of this layer at higher temperatures.A new reactor design for a NaBH 4 -based hydrogen storage system was developed, with the goal of overcoming the GHSC limitations encountered by conventional system designs. The new design is based on a fed-batch configuration in which solid NaBH 4 is added ...

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Hydrolysis of sodium borohydride with steam

Cited by 88 publications

References 15 publications

Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

Gaseous Emissions and Combustion Efficiency Analysis of Hydrogen-Diesel Dual Fuel Engine Under Fuel-Lean Condition

Sodium borohydride production and utilisation for improved hydrogen storage

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