Impact of hydrogen refueling configurations and market parameters on the refueling cost of hydrogen

The cost of hydrogen in early fuel cell electric vehicle (FCEV) markets is dominated by the cost of refueling stations, mainly due to the high cost of refueling equipment, small station capacities, lack of economies of scale, and low utilization of the installed refueling capacity. Using the hydrogen delivery scenario analysis model (HDSAM), this study estimates the impacts of these factors on the refueling cost for different refueling technologies and configurations, and quantifies the potential reduction in future hydrogen refueling cost compared to today's cost in the United States. The current hydrogen refueling station levelized cost, for a 200 kg/day dispensing capacity, is in the range of $6–$8/kg H₂ when supplied with gaseous hydrogen, and $8–$9/kg H₂ for stations supplied with liquid hydrogen. After adding the cost of hydrogen production, packaging, and transportation to the station's levelized cost, the current cost of hydrogen at dispensers for FCEVs in California is in the range of $13–$15/kg H₂. The refueling station capacity utilization strongly influences the hydrogen refueling cost. The underutilization of station capacity in early FCEV markets, such as in California, results in a levelized station cost that is approximately 40% higher than it would be in a scenario where the station had been fully utilized since it began operating. In future mature hydrogen FCEV markets, with a large demand for hydrogen, the refueling station's levelized cost can be reduced to $2/kg H₂ as a result of improved capacity utilization and reduced equipment cost via learning and economies of scale.     

Air terminals and liquid hydrogen commercial air transports

An initial appraisal is made of results of two studies of the ground requirements of liquid hydrogen (LH₂) air transports. The studies were made for the NASA Langley Research Center by the Boeing Commercial Airplane Company and by the Lockheed California Company. Each hypothesized the use of a 400-passenger, 5500 nautical mile range subsonic commercial LH₂ transport. Two of the world's busiest commercial airports, Chicago O'Hare International and San Francisco International were selected for study; O'Hare by Boeing and San Francisco by Lockheed. The current and predicted wide-body traffic at these airports was assumed to simulate the LH₂ transport traffic at these airports in the 1990–1995 time period. Both studies produced conceptual designs for facilities to generate the required quantities of fuel from pipeline gaseous hydrogen and to deliver liquid hydrogen to the airplanes. Although the LH₂ and jet fuel facilities were kept apart, both study teams found it practical to converge the fuel supply lines so that with proper safety and operational procedures and specialized LH₂ equipment both LH₂ and jet fuel transports can use common ramp and gate facilities.     

A note on cylinder stress-intensity factors

A comparison is made between Shannon's finite element $\text{K}$ results for internally pressurised thick-walled cylinders with one and two radial cracks and Bowie and Freese's mapping-collocation results for the same geometries. The comparison is good except for shallow cracks relative to the cylinder wall thickness. Based on the nature of the two calculation techniques and on the comparison of the results for shallow cracks with the known result in the limit of very shallow cracks, the collocation results appear to be the better representation of $\text{K}$. The difference becomes particularly important when the $\text{K}$ results are to be used for predictions of cylinder fatigue lives, since shallow crack growth rates dominate fatigue life.     

Hydrogen in the seaward advancement of industrial societies

Since the initial impetus of Derek Gregory's landmark analysis of the Hydrogen Economy in 1972, most concepts for producing hydrogen offshore have assumed that the entire product utilization will be onshore. Although delivery to shore is undoubtedly one option, there is another, which is use at sea at or near the site of hydrogen generation.While many of us strive toward the development of hydrogen as tomorrow's fuel, another evolutionary bud is sprouting: our industry is beginning to move seaward. At the same time most signs point to a realization that we are on the threshold of a new social order; a society that is growth-limited by finite energy resources and one that may have to modify its techno-demographic patterns.Existing onshore energy infrastructures must convert to hydrogen at considerable expense and the conversion must be incremental and non-disruptive—no mean challenge. Offshore urban/industrial complexes, on the other hand, could be based upon hydrogen from the beginning. They could thus serve as test and demonstration beds for the eventual adoption of hydrogen as the storable, transportable and ecologically sound fuel base of highly efficient urban/industrial complexes everywhere.This paper explores this option and offers glimpses of future possibilities.     

The Thailand experience in natural gas development

We describe the development of Thailand's natural gas industry, including exploration, supply, transmission, and utilization. Activities in this area started more than 10 years ago with exploration for petroleum in the Gulf of Thailand. The main transmission pipeline for natural gas from the reserves in the Gulf of Thailand to two power plants in Bangkok has been completed. The natural gas that is being delivered and which is planned for up to 1990 has all been committed to supply domestic demand in order to save energy cost, reduce foreign currency outflow, reduce dependency on imported petroleum, and provide feedstock for basic petrochemical industries. These targets have been set and based on offshore gas reserves of 16 × 10¹² ft³ supplying gas at a rate of $\text{700 × 10}{}^6\text{ft}{}^3\text{/d}$ by 1990. However, the discovery of new gas and oil reserves onshore in the central part of Thailand may provide new opportunities for Thailand to earn foreign exchange through the export of excess petroleum in the future.     

Elastic analysis of cylindrical pressure vessels with various end closures

The well-known problem of the elastic analysis of cylindrical pressure vessels with hemispherical, torispherical and ellipsoidal heads, involving the partial differential equations for the classical theory of thin shells of revolution axisymmetric in character, is attempted here using a step-by-step integration procedure and a segmentation technique. The numerical results are obtained with a generalised computer program for a number of cases and for a given set of values of elastic moduli, Poisson's ratio and $\text{thickness}\text{diameter}$ ratio. The results are compared with the known results available in literature and also with the stresses predicted by the ASME Code.     

The application of adjoint sensitivity theory to a liquid fuels supply model

Adjoint sensitivity theory has been applied to a liquid fuels supply model to determine the sensitivity of calculated results to the parameters in the model. The power of the adjoint sensitivity methodology is that it provides, in principle, an efficient means of calculating the sensitivity, $\text{d}\text{R}\text{d}\text{x}$, of any calculated result R to every parameter x in the model. The liquid fuel supply model considered is one of a class of models that may be constructed from the Generalized Equilibrium Modeling System (GEMS) developed at Decision Focus, Inc., Los Altos, California. It is shown that for this class of models the lengthy development effort that is usually associated with applying the adjoint sensitivity methodology can be avoided by using the GEMS program to evaluate the large number of partial derivatives that are needed to apply the methodology.     

Effect of H2-injection on the thermodynamic and transportation properties of natural gas

Condensation of hydrocarbons due to temperature and pressure changes in the pipelines plays an important role in the transportation of natural gas. Injection of hydrogen might change this condensation behavior considerably. The influence of hydrogen on the thermodynamics upon injection, on the Joule–Thomson effect at the pressure reduction stations, on the energy density, on the Wobbe index, and on the pressure drop in the pipelines has been calculated. It has been shown that injection of 25% hydrogen may lead to a temperature drop of several degrees, the temperature drop at the pressure reduction stations reduces by $\text{1}\text{3}$, and the pressure drop in the transport lines increases only slightly. Moreover, at $\text{40}\text{bar}$ and $\text{258}\text{K}$ the amount of liquid condensate is slightly less in the case of hydrogen if the same amount of energy is transported.     

Mass transfer in turbulent flowTransfert massique dans un ecoulement turbulentStoffübergang in turbulenter strömungMaccooбмeн в тypбyлeнтнoм пoтoкe

The local mass transfer coefficient in turbulent duct flow was measured using a new experimental technique. The experimental results agreed quite well with a numerical solution to the turbulent diffusion equation in channel flow. Formulation of the diffusion equation provided a continuous solution from a point near the discontinuity in mass flux to the fully developed region. The Nusselt numbers obtained numerically agreed with Spalding's asymptotic solution at $\text{x}\text{D}{}_{\mathrm{h}}\text{< 0·02}$ and Hatton et al.' seigenvalue solution for symmetrical heat transfer which is valid for $\text{x}\text{D}{}_{\mathrm{h}}\text{> 1}$. Current asymmetric heat transfer results in the fully developed region fell between the eigenvalue and numerical solutions.     

Status quo of China hydrogen strategy in the field of transportation and international comparisons

This paper discusses the current development strategy, technology and industrialization of China's hydrogen energy industry in the transportation field, summarizes the characteristics and development experience, and makes a comparative study with the situation of some developed countries. The results show that the current development of hydrogen energy has formed a broad consensus in China and is becoming the overall development of China's national level consciousness. However, China's hydrogen energy industry is still facing problems such as high cost of comprehensive utilization, imperfect standards and regulations for hydrogen energy utilization, obvious tendency of industrial blind development and structural overcapacity risk. Therefore, some policy suggestions were proposed for the future development, such as strengthening top-level design, strengthening pilot demonstration, promoting the development of the whole hydrogen industry chain, and reducing the cost of hydrogen and fuel cell vehicles in the field of transportation.     

Hydrogen station siting optimization based on multi-source hydrogen supply and life cycle cost

Hydrogen station siting plays an important role in hydrogen-energy infrastructure construction, and it's different from gas station siting. A gas station has a unitary way of fuel transport and a unitary fuel supplier, hence no consideration given to factors like fuel supplier and way of fuel transport at the time of siting it. However, hydrogen for a hydrogen fueling station can be supplied jointly from a couple of different sources nearby. Since there is a diversity of hydrogen price and productivity between different sources, hydrogen fueling station siting also entails consideration of the effect of the proportions of hydrogen supplied by the sources on hydrogen's life cycle cost. With the purpose of minimizing hydrogen's life cycle cost, this paper creates a mathematical model for station siting, largely for the case that each station can get hydrogen supply from combined multiple sources, and considers the effect of geographical information factors on station siting. The effect of geographical information factors on such siting is described herein in two cases to avoid selecting a must-not-build location and rebuilding into a gasoline-hydrogen fueling station at an existing gas station location. The latter can reduce station construction and operating costs. By creating a particle swarm optimization (PSO) example for station siting with Shanghai-Nanjing Expressway and constructing a position particle swarm in the form of 5D vector in order to optimize 5 station locations at the same time as well a weight particle swarm in the form of 2D matrix in order to optimize the multi-source hydrogen supply programs, the paper works out optimal station construction locations on condition of multi-source hydrogen supply, multi-source hydrogen supply programs, ways of storage and transport and corresponding hydrogen's optimal life cycle cost.     

Lifecycle impacts of natural gas to hydrogen pathways on urban air quality

In this paper we examine the potential air quality impacts of hydrogen transportation fuel from a lifecycle analysis perspective, including impacts from fuel production, delivery, and vehicle use. We assume that hydrogen fuel cell vehicles are introduced in a specific region, Sacramento County, California. We consider two levels of market penetration where 9% or 20% of the light duty fleet are hydrogen fuel cell vehicles. The following three natural gas to hydrogen supply pathways are assessed in detail and compared in terms of emissions and the resulting changes in ambient air quality: (1) onsite hydrogen production; (2) centralized hydrogen production with gaseous hydrogen pipeline delivery systems; and (3) centralized hydrogen production with liquid hydrogen truck delivery systems. All the pathways examined use steam methane reforming (SMR) of natural gas to produce hydrogen. The source contributions to incremental air pollution are estimated and compared among hydrogen pathways. All of the hydrogen pathways result in extremely low contributions to ambient air concentrations of _NOx${\mathrm{NO}}_x$, CO, particulates, and _SOx${\mathrm{SO}}_x$, typically less than 0.1% of the current ambient pollution for both levels of market penetration. Among the hydrogen supply options, it is found that the central SMR with pipeline delivery systems is the lowest pollution option available provided the plant is located to avoid transport of pollutants into the city via prevailing winds. The onsite hydrogen pathway is comparable to the central hydrogen pathway with pipeline systems in terms of the resulting air pollution. The pathway with liquid hydrogen trucks has a greater impact on air quality relative to the other pathways due to emissions associated with diesel trucks and electricity consumption to liquefy hydrogen. However, all three hydrogen pathways result in negligible air pollution in the region.     

Non-toxic hydride energy source for biochemical and industrial venues: ORP and NAD+ reduction analyses

A recently described novel compound, silica hydride, was used to investigate potential alternative hydrogen energy sources for use in industry, pharmacology and biochemistry. Acting as an anionic hydride, the silica hydride does not react violently with water and produces stable oxidation-reduction potential readings of greater than $\text{−860}\text{mV}$ for extended periods providing capacity as an alternative for current transfer, hydrogen production and fuel cell applications in industrial arenas. In a biological venue, the silica hydride definitively reduces the pyridine NAD⁺ to the NADH form, indicating potential for use as a biochemical fuel cell. Subsequent analyses of the compound indicate no induced cytotoxicity as a result of the silica hydride and the increased NADH in a cell.     

The stability of crack growth in pipes subject to tensile loads

This paper presents a simple analysis for the stability of crack growth in 304 stainless steel pipes subject to tensile loads. The model of two identical part-through and part-circumference cracks, symmetrically situated with regard to the pipe cross-section, is examined for crack stability under displacement control tensile loading. Irrespective of the crack depth, the instability condition for a wide range of crack lengths, i.e. except for very short cracks and long cracks, is: $\text{2σ}{}_0\text{L}\text{πER}{}_{\mathrm{\chi }}\text{≡}\text{2L}\text{πR}\text{·}\text{1}\text{T}{}_{\mathrm{MAT}}\text{> 1}$ where σ₀ is the flow stress, E is Young's modulus, L is the pipe length, R is the pipe radius, χ is the crack tip opening angle, CTOA, associated with the crack growth and T_MAT is the material's tearing modulus. With a CTOA of 20° (i.e. T_MAT ～ 200), $\text{L}\text{R}$ must exceed 300 for instability. Since this number is far in excess of the $\text{L}\text{R}$ values for typical piping systems, the stability of cracks in pipes subject to tensile loads is essentially demonstrated.     

Measuring the effects of boron mass addition to V–Fe hydrogen storage alloys on their hydrogen absorbing–desorbing characteristics and loss of boron by hydrogenation by employing new analysis methods; hybrid of Sieverts' method,inert gas fusion method,and gravimetric method

(V_0.85Fe_0.15)_100?xB_x alloys (x = 0.5–15 atomic %) were synthesized by arc melting. 5 atomic % addition of boron to alloys markedly increased the hydrogen absorbing reaction rate to 50 times. However, the maximum hydrogen absorbing capacity decreased with the increasing boron addition. Even when it is very difficult to measure the exact amount of desorbed hydrogen by Sieverts' method, a new analysis method “iGFS hybrid method” which combines the inert gas fusion method with the Sieverts' method can estimate approximate amount of usable hydrogen ${{\text{H}}_{\text{H/M}}}^{\text{usable}}$ rapidly. With this method, by only 0.5% addition of boron, ${{\text{H}}_{\text{H/M}}}^{\text{usable}}$ increased significantly. The nature of hydrogen-alloy system was considered to change from “Compound type” to “Electron flow type” by only 0.5% addition of boron. We have designed a new analysis method “iGFG hybrid method” which combines the inert gas fusion method with the gravimetric method. With this iGFG method, the tendency of increasing boron evaporation by hydrogenation with the increasing boron addition may be observed, although quantitativity is not enough.     

A hydrogen-powered mass transit system

Hydrogen's application to mass transit systems is considered. A 21-passenger bus is converted to hydrogen using a Dodge engine which has been modified for high compression operation. Backfiring and nitric oxide pollution formation are controlled by a water injection technique. Hydrogen fuel storage for the experimental prototype is accomplished by two metal hydride containers using an iron-titanium alloy. Data are presented regarding equipment conversion and design, energy resource utilization, economics, and safety.