Lifting hydrogen

Lu, T.F., Yoo, C.S., Chen, J.H., Law, C.K. Three-dimensitmal direct numerical simulation of a turbulent lifted hydrogen jet flame in heated coflow a chemical explosive mode analysis. J. Fluid Mech. 652, 45-64 (2010)... 

To prepare gas for evacuation it is necessary to separate the gas and liquid phases and extract or inhibit any components in the gas which are likely to cause pipeline corrosion or blockage. Components which can cause difficulties are water vapour (corrosion, hydrates), heavy hydrocarbons (2-phase flow or wax deposition in pipelines), and contaminants such as carbon dioxide (corrosion) and hydrogen sulphide (corrosion, toxicity). In the case of associated gas, if there is no gas market, gas may have to be flared or re-injected. If significant volumes of associated gas are available it may be worthwhile to extract natural gas liquids (NGLs) before flaring or reinjection. Gas may also have to be treated for gas lifting or for use as a fuel. 

The lifting power of 1 cubic foot of hydrogen gas is about 0.07 lb at OC, 760 mm pressure. 

Fig. 13. Exploded view of an OxyTech MDC-55 ceU a, end plate b, rim screen c, side screens d, tube sheet e, full-cathode tube f, half-cathode or end tube g, side plate h, lifting lug i, punched and coined stiffener strap j, bosses k, end plate, operating aisle end 1, hydrogen outiet m, connector bar n,...

Upon the United States entry into World War 1 in 1917, helium became a war material of first priority. Helium was sought to replace hydrogen as the lifting gas in lighter-than-air craft for military use. As a war material, helium became a government monopoly, was given a code name, and was shrouded in secrecy. By the war s end, quantities of helium had been produced, but none had reached combat. 

A mathematical model of the operating characteristics of a modem HLW storage tank has been developed (60). This model correlates experimental data for the rate of radiolytic destmction of nitric acid, the rate of hydrogen generation owing to radiolysis of water, and cooling coil heat transfer. These are all functions of nitric acid concentration and air-lift circulator operation. 

Experimental techniques to visualize flows have been extensively used to define fluid flow in pipes and air flow over lift and control surface of airplanes. More recently this technology has been appHed to the coating process and it is now possible to visualize the flow patterns (16,17). The dimensions of the flow field are small, and the flow patterns both along the flow and inside the flow are important. Specialized techniques such as utilizing small hydrogen bubbles, dye injection, and optional sectioning, are required to visualize these flows. 

It is reported [1] that the fluidization quality was drastically decreased when the hydrogenation of CO2 was carried out in a fluidized catalyst bed (FCB). Recently, the phenomena occurring in the bed were directly observed [2] and it was found that the upper part of the emulsion phase was defluidized and this packed particles was lifted up through the column like a moving piston. 

A sequence of STM images were obtained (Figure 7.2) of the Cu(l 10) surface before hydrogen exposure (A), at an ambient H2 pressure of 1 bar (B) and finally after evacuation under UHV conditions (C). It is clear that in the presence of H2 the surface reconstructs into the well-known (1x2) missing row structure and that an evacuation the surface reconstruction is lifted with the (2 x 1) structure observed. AES established that no impurities were present at the Cu(110) surface. 

The purple colonies of T. roseopersicina are lifted on a filter paper, transferred onto a stack of filter papers soaked with oxidised redox dye (benzyl viologen) under air. Following heat treatment, the cells containing heat stable, active enzyme turn blue under hydrogen atmosphere,those containing defected hydrogenase remain purple [Fodor et al., 2001],... 

Cationic ions and polyelectrolytes can stabilize the formation of the PS I monolayers at the air-water interface. These complex monolayers can be transferred onto the hydrophobic substrate surfaces by horizontal lifting method. The PS I/polyelectrolyte complex film may be used for the development of a biosystem for the studies on photoinduced electron transfer and for hydrogen evolution. 

Like almost any other technique, thermoelectric power, does however also have some of its own limitations. For example, thermoelectric power is a contact method, which means that if hydrogen content needed to be measured on the exterior of a coated pipeline, the coating would need to removed, however in-line pig inspection would allow for in-situ inspection of the pipeline inner wall. In these limited cases, alternative complimentary techniques can be utilized. Low frequency impedance measurements can provide an alternative non-destructive, non-contact method of measuring hydrogen through an entire specimen thickness, dependent upon lift-off. 

Similarly, transporting, storing at the station, and pumping liquid hydrogen at 21K is an even more formidable task. Everyone knows it well what kind of safety precautions are undertaken when a space shuttle lifting main rocket is fuelled with liquid hydrogen and oxygen. 

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