Brazil

A quantitative risk analysis to a central pressurized storage tank for gaseous hydrogen has been performed to attend requirements of licensing procedures established by the State Environment Agency of São Paulo State Brazil. Gaseous hydrogen is used to feed the reactor to promote hydrogenation at the surfactant unit. HAZOP was the hazard identification technique selected. System components failures were defined by event and fault tree analysis. Quantitative risk analysis was complied to define the acceptability concepts on societal and individual risks required by the State Environmental Agency to approve the installation operation license. Acceptable levels to public society from the analysis were reached. Safety recommendations to the gaseous hydrogen central were proposed to assure minimization of risk to the near-by community operators environment and property.

During the early phase of the transient process following a hydrogen leak into the atmosphere a contact surface appears separating air heated by the leading shock from hydrogen cooled by expansion. Locally the interface is approximately planar. Diffusion leads to a temperature decrease on the air side and an increase in the hydrogen-filled region and mass diffusion of hydrogen into air and of air into hydrogen potentially resulting in ignition. This process was analyzed by Li ˜nan and Crespo [1] for unity Lewis number and Li ˜nan and Williams [2] for Lewis number less than unity. We included in the analysis the effect of a slow expansion [3 4] leading to a slow drop in temperature which occurs in transient jets. Chemistry being very temperature-sensitive the reaction rate peaks close to the hot side of the interface where only a small fuel concentration present close to the warm air-rich side which depends crucially upon the fuel Lewis number. For Lewis number unity the fuel concentration due to diffusion is comparable to the rate of consumption by chemistry. If the Lewis number is less than unity diffusion brings in more fuel than temperature-controlled chemistry consumes. For a Lewis number greater than unity diffusion is not strong enough to bring in as much fuel as chemistry would burn; combustion is controlled by fuel diffusion. If the temperature drop due to expansion associated with the multidimensional jet does not lower significantly the reaction rate up to that point analysis shows that ignition in the jet takes place. For fuel Lewis number greater than unity chemistry does not lead to a defined explosion so that eventually expansion will affect the process; ignition does not take place [3 4]. In the current paper these results are extended to consider multistep chemical kinetics but for otherwise similar assumptions. High activation energy is no longer applicable. Instead results are obtained in the short time limit still as a perturbation superimposed to the self-similar solution to the chemically frozen diffusion solution. In that approximation the initiation step which consumes fuel and oxidant is taken to be slow compared with steps that consume one of the reactants and an intermediate species. The formulation leads to a two point boundary value problem for set of coupled rate equations plus an energy equation for perturbations. These equations are linear with variable co-effcients. The coupled problem is solved numerically using a split algorithm in which chemical reaction is solved for frozen diffusion while diffusion is solved for frozen chemistry. At each time step the still coupled linear problem is solved exactly by projecting onto the eigenmodes of the stiff matrix so that the solution is unaffected by stiffness. Since in the short time limit temperature is only affected at the perturbation level the matrix depends only on the similarity variable x t but it is otherwise time-independent. As a result determination of the eigenvalues and eigenvectors is only done once (using Maple) for the entire range of discretized values of the similarity variable. The diffusion problem consists of a set of independent equations for each species. Each of these is solved using orthogonal decomposition onto Hermite polynomials for the homogeneous part plus a particular solution proportional to time for the non-homogeneous (source) terms. That approach can be implemented for different kinetic schemes.

The Brazilian Fuel Cell Bus Project is being developed by a consortium comprising 14 national and international partners. The project was initially supported by the GEF/UNDP and MME/FINEP Brazil. The national coordination is under responsibility of MME and EMTU/SP the São Paulo Metropolitan Urban Transport Company that also controls the bus operation and bus routes. This work reports the efforts done in order to obtain the necessary licenses to operate the first fuel cell buses for regular service in Brazil as well as the first commercial hydrogen fueling station to attend the vehicles.

The maritime shipping sector is a major contributor to CO₂ emissions and this figure is expected to rise in coming decades. With the intent of reducing emissions from this sector this research proposes the utilization of the jet stream to transport a combination of cargo and hydrogen using airships or balloons at altitudes of 10–20 km. The jet streams flow in the mid-latitudes predominantly in a west–east direction reaching an average wind speed of 165 km/h. Using this combination of high wind speeds and reliable direction hydrogen-filled airships or balloons could carry hydrogen with a lower fuel requirement and shorter travel time compared to conventional shipping. Jet streams at different altitudes in the atmosphere were used to identify the most appropriate circular routes for global airship travel. Round-the-world trips would take 16 days in the Northern Hemisphere and 14 in the Southern Hemisphere. Hydrogen transport via the jet stream due to its lower energy consumption and shorter cargo delivery time access to cities far from the coast could be a competitive alternative to maritime shipping and liquefied hydrogen tankers in the development of a sustainable future hydrogen economy.

Hydrogen is a promising commodity a renewable secondary energy source and feedstock alike to meet greenhouse gas emissions targets and promote economic decarbonization. A common goal pursued by many countries the hydrogen economy receives a blending of public and private capital. After European Green Deal state members created national policies focused on green hydrogen. This paper presents a study of energy transition considering green hydrogen production to identify Portugal’s current state and prospects. The analysis uses energy generation data hydrogen production aspects CO2 emissions indicators and based costs. A comprehensive simulation estimates the total production of green hydrogen related to the ratio of renewable generation in two different scenarios. Then a comparison between EGP goals and Portugal’s transport and energy generation prospects is made. Portugal has an essential renewable energy matrix that supports green hydrogen production and allows for meeting European green hydrogen 2030–2050 goals. Results suggest that promoting the conversion of buses and trucks into H2-based fuel is better for CO2 reduction. On the other hand given energy security thermoelectric plants fueled by H2 are the best option. The aggressive scenario implies at least 5% more costs than the moderate scenario considering economic aspects.

This study shows the results for the first time of an glycerol alkaline-acid electrolyzer. Such a configuration allows spontaneous operation producing energy and hydrogen simultaneously as a result of the utilization of the neutralization and fuel chemical energy. The electroreformer—built with a 20 wt% Pd/C anode and cathode and a Na+ -pretreated Nafion® 117—can simultaneously produce hydrogen and electricity in the low current density region whereas it operates in electrolysis mode at high current densities. In the spontaneous region the maximum power densities range from 1.23 mW cm−2 at 30 ◦C to 11.9 mW cm−2 at 90 ◦C with a concomitant H2 flux ranging from 0.0545 STP m−3 m−2 h −1 at 30 ◦C to 0.201 STP m−3 m−2 h −1 at 90 ◦C due to the beneficial effect of the temperature on the performance. Furthermore over a chronoamperometric test the electroreformer shows a stable performance over 12 h. As a challenge proton crossover from the cathode to the anode through the cation exchange Nafion® partially reduces the pH gradient responsible for the extra electromotive force thus requiring a less permeable membrane.

The emerging energy transition is particularly described as a move towards a cleaner lower-carbon system. In the context of the global shift towards sustainable energy sources this paper reviews the potential and roadmap for hydrogen energy as a crucial component of the clean energy landscape. The primary objective is to present a comprehensive literature overview illuminating key themes trends and research gaps in the scientific discourse concerning hydrogen production and energy policy. This review focuses particularly on specified geographic contexts with an emphasis on understanding the unique energy policies related to renewable energy in Brazil Austria and Germany. Given their distinct social systems and developmental stages this paper aims to delineate the nuanced approaches these countries adopt in their pursuit of renewable energy and the integration of hydrogen within their energy frameworks. Brazil exhibits vast renewable energy potential particularly in wind and solar energy sectors positioning itself for substantial growth in the coming years. Germany showcases a regulatory framework that promotes innovation and technological expansion reflecting its highly developed social system and commitment to transitioning away from fossil fuels. Austria demonstrates dedication to decarbonization particularly through the exploration of biomethane for residential heating and cooling.

The unbridled use of fossil fuels is a serious problem that has become increasingly evident over the years. As such fuels contribute considerably to environmental pollution there is a need to find new sustainable sources of energy with low emissions of greenhouse gases. Climate change poses a substantial challenge for the scientific community. Thus the use of renewable energy through technologies that offer maximum efficiency with minimal pollution and carbon emissions has become a major goal. Technology related to the use of hydrogen as a fuel is one of the most promising solutions for future systems of clean energy. The aim of the present review was to provide an overview of elements related to the potential use of hydrogen as an alternative energy source considering its specific chemical and physical characteristics as well as prospects for an increase in the participation of hydrogen fuel in the world energy matrix.

The world is undergoing a substantial energy transition with an increasing share of intermittent sources of energy on the grid which is increasing the challenges to operate the power grid reliably. An option that has been receiving much focus after the COVID pandemic is the development of a hydrogen economy. Challenges for a hydrogen economy are the high investment costs involved in compression storage and long-distance transportation. This paper analyses an innovative proposal for the creation of hydrogen ocean links. It intends to fill existing gaps in the creation of a hydrogen economy with the increase in flexibility and viability for hydrogen production consumption compression storage and transportation. The main concept behind the proposals presented in this paper consists of using the fact that the pressure in the deep sea is very high which allows a thin and cheap HDPE tank to store and transport large amounts of pressurized hydrogen in the deep sea. This is performed by replacing seawater with pressurized hydrogen and maintaining the pressure in the pipes similar to the outside pressure. Hydrogen Deep Ocean Link has the potential of increasing the interconnectivity of different regional energy grids into a global sustainable interconnected energy system.

The chances of a global hydrogen economy becoming a reality have increased significantly since the COVID pandemic and the war in Ukraine and for net zero carbon emissions. However intercontinental hydrogen transport is still a major issue. This study suggests transporting hydrogen as a gas at atmospheric pressure in balloons using the natural flow of wind to carry the balloon to its destination. We investigate the average wind speeds atmospheric pressure and temperature at different altitudes for this purpose. The ideal altitudes to transport hydrogen with balloons are 10 km or lower and hydrogen pressures in the balloon vary from 0.25 to 1 bar. Transporting hydrogen from North America to Europe at a maximum 4 km altitude would take around 4.8 days on average. Hydrogen balloon transportation cost is estimated at 0.08 USD/kg of hydrogen which is around 12 times smaller than the cost of transporting liquified hydrogen from the USA to Europe. Due to its reduced energy consumption and capital cost in some locations hydrogen balloon transportation might be a viable option for shipping hydrogen compared to liquefied hydrogen and other transport technologies.