Hydrogen. The Gas shall contain no carbon monoxide, halogens, or unsaturated hydrocarbons, and no more than four hundred parts per million (400 ppm) of hydrogen.
Hydrogen. 1) Keep hydrogen away from sources of ignition and do not permit any accumulation of gas. A sign must be posted: “HYDROGEN – FLAMMABLE GAS – NO SMOKING – NO OPEN FLAMES.”
2) Hydrogen is extremely cold (-420° F.) and can cause freeze xxxxx.
3) Use only equipment designated for use in hydrogen service.
Hydrogen i. Hydrogen and hydrogen-based energy supply chain studies
ii. Shaping international hydrogen standards
iii. Hydrogen research and development
Hydrogen. The percent combined hydrogen in a hydrocarbon fuel is a critical factor in controlling stack smoke levels. In general, the higher the hydrogen content in a liquid fuel the lower the smoke level will be. As an example: paraffinic hydrocarbons with high hydrogen contents (14-15%) have much less tendency to smoke than do aromatic hydrocarbons which can have 10% or less hydrogen. Hydrogen is usually determined by an accurate measurement of the amount of water produced in the controlled combustion of a weighed amount of fuel.
Hydrogen. It has been shown that efficient production of pure hydrogen can be achieved by dehydrogenation of cyclohexane or methylcyclohexane with catalysts consisting of 0.1-1.0 wt.% Pt supported on stacked-cone carbon nanotubes (SC-CNT). The SC-CNT were produced by catalytic dehydrogenation of propane. The catalysts exhibited 100 % selectivity for conversion of cyclohexane to hydrogen and benzene and methylcyclohexane to hydrogen and toluene. A 0.25 wt.% Pt/ SC-CNT catalyst had approximately the same activity as a commercial 1 wt.% Pt/Al2O3 catalyst. High resolution TEM showed the dispersion of the Pt catalyst particles on the SC-CNT support to be very high after 6.5 hours of reaction, with particle sizes ~ 1 to 2 nm. A 0.1wt% Pt/SC-CNT exhibited the highest efficiency (turnover-number (TON)) for hydrogen production per metal atom. A preliminary experiment on the aqueous-phase reforming of ethylene glycol using a 1 wt.% Pt-99 wt.% Al2O3 catalyst in a batch system has shown that significant amounts of hydrogen are produced, with very low production of carbon monoxide. New apparatus for the production of hydrogen by reforming of lower alcohols in supercritical water has been assembled and is working correctly. Depending on operating conditions, 3-4 moles of hydrogen are typically produced per mole of methanol or ethanol. 29Si and 13C solid state NMR methods were used to investigate several metal-loaded silica aerogel F-T catalysts. The results are as follows:
Hydrogen. Hydrogen has many qualities: − it is the most abundant atom on earth, as a constituent of water, 1 AFH2, Paris, E-mail: xxxxxxx.xxxxxx@xxxxxxx.xx − it is the most energetic molecule: 120MJ/kg, i.e. twice as much as natural gas, − it is neither polluting nor toxic, − its combustion produces no pollutant (only water), − it is the lightest of all gases, which is a positive factor in terms of security (it diffuses at high speed in the air), − it has numerous production modes, adapted to all forms of primary energy (electrolysis, thermal water decomposition, reforming), − its transport is easy and environment-friendly (in particular through pipes), − its modes of transformation are varied (fuel cell, thermal engine, turbine, combustion). Notwithstanding all these qualities, some flaws should be mentioned: − its lightness implies a volumetric energy density which is not in favour of its storage as gas, − its air inflammability and detonation limits are more extended that for natural gas (by a factor of 5), on the other hand in a ‘confined’ situation (i.e. trapped with air in a closed volume), these limits are more difficult to reach than with natural gas due to the speed of its diffusion in the air (4 times faster than natural gas), − it has a bad reputation in terms of security and its public acceptability is not obvious!
1.2.1. The present hydrogen market
Table 1.1. Yearly consumption of hydrogen in Europe and in the world
1.2.2. What are the present obstacles to the development of hydrogen?
1.2.3. Which solutions for the production of hydrogen?
Hydrogen. Hydrogen, a gas and an energy carrier, is used in many industries such as refining, metallurgy and electronics (Xxxxxxxx, Xxxxx, and Kamsah 2015) and in the transport sector (see below). Singh et al. (2015) even argue that hydrogen can be used in almost any field where conventional fossil fuels such as gas or oil are needed, thus offering significant substitution potential (Singh et al. 2015). In 2010, the European chemical industry was the largest consumer of hydrogen (63%) with the refining industry accounting for about 30% (Fraile et al. 2015). But while hydrogen itself is not harmful for the environment, its production methods generate emissions. Overall, hydrogen can either be produced by reforming steam methane or by splitting it from water by electrolysis (Xxxxxxx et al. 2018). The steam reforming process can furthermore be based on natural gas, methane, coal (Xxxxxxx et al. 2018) or biomass (Ni et al. 2006), but can be equipped with CCS fairly cost-effectively. The electrolysis process can be powered by fossil fuel-based electricity or renewable electricity. Currently, hydrogen is produced almost exclusively through natural gas-based steam methane reforming or even coal in some cases (Singh et al. 2015)(Xxxxxx 2004). Looking at more sustainable hydrogen pathways, Xxxx et al. (2015) consider hydrogen production from biofuels combustion, assessing three steam reforming technologies as between TRL 4 and TRL 6 (Xxxx et al. 2015). When it comes to hydrogen production by electrolysis using renewable electricity, sometimes called power-to-hydrogen (Götz et al. 2016), the need to adapt to increasingly intermittent power supply from renewables pushes most of power-to-hydrogen technologies towards TRL 5 to TRL 7 (Grond and Holstein 2014). Besides technological challenges, economic challenges remain as well, since power-to-gas is still an expensive and relatively inefficient technology (Götz et al. 2016), one source for example arguing that per unit of H2 more than 32 times the electricity would be needed than by using conventional steam methane reforming (Xxxxxxx et al. 2018) which raises doubts on whether there would be enough excess renewable electricity on the markets to satisfy this demand (Ball and Xxxxx 2015). The following sections explore the TRL of hydrogen in the transport sector, in the steel industry as well as (for some applications) in the chemical industry. Since our literature review did not yield any TRL assessment for the refining pathway (...
Hydrogen. Overall, according to its website, the FCH JU, a specialised institution set up to drive forward the hydrogen pathway, has a budget of €665 million while industrial stakeholders are expected to double that amount, pushing the envelope to about €1.3 billion in the period of 2014 to 2020. For the years 2014, 2015 and 2016, the annual report of the FCH JU speaks of €244.9 million of EU money spent on 46 hydrogen related R&D projects (FCHJU 2017). However, the large majority of R&D was spent under the reports energy and transport category with only 3% of the funding flowing into “cross cutting” projects, thus suggesting that hydrogen applications for the industrial sector were either included in other non-FCH JU funding streams (see above) or were not a R&D priority in the period scrutinised (ibid.).
Hydrogen. In the UK, various applications for low carbon hydrogen are being considered by the energy market participants in the UK, such as mobility, heating of buildings, high- temperature process heat for industry, energy storage, and electricity generation. These options involve different production technologies, different scales and have different market conditions and interdependencies. Given the complexity of the value chains, the UK government announced plans to take a disaggregated approach to business model design, with commercial frameworks developing over time.
Hydrogen. Developing the potential for hydrogen to support the transition to a low carbon economy; • Sharing information and expertise including in the framework of the Hydrogen Energy Ministerial Meeting; and • Working together to promote international cooperation on research, development and deployment of hydrogen technologies, including through the G20, Mission Innovation and the International Partnership for Hydrogen and Fuel Cells in the Economy.
