Romania

Purpose- To present an overview of the research and development carried out in a European funded framework 7 (FP7) project called SafeHPower for the implementation of neutron radiography to inspect fatigue cracks in vehicle and storage hydrogen fuel tanks. Project background– Hydrogen (H2) is the most promising replacement fuel for road transport due to its abundance efficiency low carbon footprint and the absence of harmful emissions. For the mass market of hydrogen to take off the safety issue surrounding the vehicle and storage hydrogen tanks needs to be addressed. The problem is the residual and additional stresses experienced by the tanks during the continuous cyclic loading between ambient and storage pressure which can result in the development of fatigue cracks. Steel tanks used as storage containers at service stations and depots and/or the composite tanks lined with steel are known to suffer from hydrogen embrittlement (HE). Another issue is the explosive nature of hydrogen (when it is present in the 18-59% range) where it is mixed with oxygen which can lead to catastrophic consequences including loss of life. Monitoring systems that currently exist in the market impose visual examination tests pressure tests and hydrostatic tests after the tank installation [1] [2]. Three inspection systems have been developed under this project to provide continuous monitoring solutions. Approach and scope- One of the inspection systems based on the neutron radiography (NR) technology that was developed in different phases with the application of varied strategies has been presented here. Monte Carlo (MCNP) simulation results to design and develop a bespoke collimator have been presented. A limitation of using an inertial electrostatic Deuterium-Tritium (D-T) pulsed neutron generator for fast neutron radiography has been discussed. Radiographs from the hydrogen tank samples obtained using thermal neutrons from a spallation neutron source at ISIS Rutherford laboratory UK have been presented. Furthermore radiograph obtained using thermal neutrons from a portable D-T neutron generator has been presented. In conclusion a proof in principle has been made to show that the defects in the hydrogen fuel tank can be detected using thermal neutron radiography.

A novel Pd/templated carbon catalyst (Pd/TC) was developed characterized and tested in the dehydrogenation of formic acid (FA) under mild conditions with the possibility to control the H₂ generation rate in the absence or presence of HCOONa (SF) by adjusting the Pd:FA and/or FA:SF ratios. The characterization results of the templated carbon obtained by the chemical vapor deposition of acetylene on NaY zeolite revealed different structural and morphological properties compared to other C-based supports. Therefore it was expected to induce a different catalytic behavior for the Pd/TC catalyst. Indeed the TC-supported Pd catalyst exhibited superior activity in the decomposition of FA even at room temperature with turnover frequencies (TOFs) of up to 143.7 and 218.8 h⁻¹ at 60 °C. The H2 generation rate increased with an increasing temperature while the H₂ yield increased with a decreasing FA concentration. Constant generation of gaseous flow (H₂ + CO₂) was achieved for 11 days by the complete dehydrogenation of FA at room temperature using a 2 M FA solution and Pd:FA = 1:2100. The presence of SF in the reaction medium significantly enhanced the H₂ generation rate (535 h⁻¹ for FA:SF = 3:1 and 60 °C).

The climate changes that are becoming visible today are a challenge for the global research community. The stationary applications sector is one of the most important energy consumers. Harnessing the potential of renewable energy worldwide is currently being considered to find alternatives for obtaining energy by using technologies that offer maximum efficiency and minimum pollution. In this context new energy generation technologies are needed to both generate low carbon emissions as well as identifying planning and implementing the directions for harnessing the potential of renewable energy sources. Hydrogen fuel cell technology represents one of the alternative solutions for future clean energy systems. This article reviews the specific characteristics of hydrogen energy which recommends it as a clean energy to power stationary applications. The aim of review was to provide an overview of the sustainability elements and the potential of using hydrogen as an alternative energy source for stationary applications and for identifying the possibilities of increasing the share of hydrogen energy in stationary applications respectively. As a study method was applied a SWOT analysis following which a series of strategies that could be adopted in order to increase the degree of use of hydrogen energy as an alternative to the classical energy for stationary applications were recommended. The SWOT analysis conducted in the present study highlights that the implementation of the hydrogen economy depends decisively on the following main factors: legislative framework energy decision makers information and interest from the end beneficiaries potential investors and existence of specialists in this field.

This paper presents a case study concerning a plant for hydrogen production and storage having a daily capacity of 100kg. The plant is located in Cluj-Napoca Romania. It produces hydrogen by means of water electrolysis while the energy is provided using solar energy. We performed the calculations for four different technical solutions used for the hydrogen production and storage plant and also we considered three scenarios regarding the sub-systems of the hydrogen production and storage plant efficiency. The conclusion of this study is that one can maximize the conversion of solar radiation into chemical energy in the form of hydrogen by hybridizing the solar hydrogen production system namely using both electrical energy as well as thermal energy in the form of steam.

Considering the current environmental restrictions particularly those imposed on fossil fuel exploitation hydrogen stands out as a very promising alternative for the power and transportation sectors. This paper investigates the effects of the employment of hydrogen in a K9K automotive diesel engine. Experiments were conducted at a speed of 2000 min−1 with various engine load levels of 40% 55% 70% and 85%; several quantities were monitored to evaluate the performance with hydrogen use in terms of brake-specific energetic consumption (BSEC) fuel economy maximum pressure and heat-release characteristics. It was found that at 55% engine load the engine efficiency increased by 5.3% with hydrogen addition achieving a diesel fuel economy of 1.32 kg/h. The rate of increase of the peak pressure and maximum pressure started to increase as a consequence of the higher fuel quantity that burned in the premixed combustion phase while still remaining within reliable operational limits. The accelerated combustion and augmented heat release rate resulted in a combustion duration that was reduced by 3◦ CA (crank angle degree) achieving a mass fraction burned percentage of 10% to 90% earlier in the cycle and the combustion variability was also influenced. Hydrogen use assured the decrease of CO2 HC NOx and smoke emission levels in comparison with classic fueling.

Recent environmental and climate change issues make it imperative to persistently approach research into the development of technologies designed to ensure the sustainability of global mobility. At the European Union level the transport sector is responsible for approximately 28% of greenhouse gas emissions and 84% of them are associated with road transport. One of the most effective ways to enhance the de-carbonization process of the transport sector is through the promotion of electric propulsion which involves overcoming barriers related to reduced driving autonomy and the long time required to recharge the batteries. This paper develops and implements a method meant to increase the autonomy and reduce the battery charging time of an electric car to comparable levels of an internal combustion engine vehicle. By doing so the cost of such vehicles is the only remaining significant barrier in the way of a mass spread of electric propulsion. The chosen method is to hybridize the electric powertrain by using an additional source of fuel; hydrogen gas stored in pressurized cylinders is converted in situ into electrical energy by means of a proton exchange membrane fuel cell. The power generated on board can then be used under the command of a dedicated management system for battery charging leading to an increase in the vehicle’s autonomy. Modeling and simulation results served to easily adjust the size of the fuel cell hybrid electric powertrain. After optimization an actual fuel cell was built and implemented on a vehicle that used the body of a Jeep Wrangler from which the thermal engine associated subassemblies and gearbox were removed. Once completed the vehicle was tested in traffic conditions and its functional performance was established.

Hydrides have emerged as strong candidates for energy storage applications and their study has attracted wide interest in both the academic and industry sectors. With clear advantages due to the solid-state storage of hydrogen hydrides and in particular complex hydrides have the ability to tackle environmental pollution by offering the alternative of a clean energy source: hydrogen. However several drawbacks have detracted this material from going mainstream and some of these shortcomings have been addressed by nanostructuring/nanoconfinement strategies. With the enhancement of thermodynamic and/or kinetic behavior nanosized complex hydrides (borohydrides and alanates) have recently conquered new estate in the hydrogen storage field. The current review aims to present the most recent results many of which illustrate the feasibility of using complex hydrides for the generation of molecular hydrogen in conditions suitable for vehicular and stationary applications. Nanostructuring strategies either in the pristine or nanoconfined state coupled with a proper catalyst and the choice of host material can potentially yield a robust nanocomposite to reliably produce H2 in a reversible manner. The key element to tackle for current and future research efforts remains the reproducible means to store H2 which will build up towards a viable hydrogen economy goal. The most recent trends and future prospects will be presented herein.

Variable renewable energy (VRE) has seen rapid growth in recent years. However VRE deployment requires a fleet of dispatchable power plants to supply electricity during periods with limited wind and sunlight. These plants will operate at reduced utilization rates that pose serious economic challenges. To address this challenge this paper presents the techno-economic assessment of flexible power and hydrogen production from integrated gasification combined cycles (IGCC) employing the gas switching combustion (GSC) technology for CO₂ capture and membrane assisted water gas shift (MAWGS) reactors for hydrogen production. Three GSC-MAWGS-IGCC plants are evaluated based on different gasification technologies: Shell High Temperature Winkler and GE. These advanced plants are compared to two benchmark IGCC plants one without and one with CO₂ capture. All plants utilize state-of-the-art H-class gas turbines and hot gas clean-up for maximum efficiency. Under baseload operation the GSC plants returned CO₂ avoidance costs in the range of 24.9–36.9 €/ton compared to 44.3 €/ton for the benchmark. However the major advantage of these plants is evident in the more realistic mid-load scenario. Due to the ability to keep operating and sell hydrogen to the market during times of abundant wind and sun the best GSC plants offer a 6–11%-point higher annual rate of return than the benchmark plant with CO₂ capture. This large economic advantage shows that the flexible GSC plants are a promising option for balancing VRE provided a market for the generated clean hydrogen exists.

Hydrogen may represents a good alternative fuel that can be used to fuel internal combustion engines in order to ameliorate energetic and emissions performance. The paper presents some experimental aspects registered at hydrogen use to fuel a diesel engine different substitute ratios being use in the area of 18–34% at 40% engine load and speed of 2000 rev/min. The engine is equipped with an open ECU and the control of the cyclic dosses of diesel fuel and hydrogen are adjusted in order to maintain the engine power performance. The in-cylinder pressure diagrams show the increase of the maximum pressure with 17% from 78.5 bar to 91.8 bar for the maximum substitute ratio. Also values of maximum pressure rise rate start to increase for hydrogen addition in correlation with the increase of fuel amount burned into the premixed stage without exceed the normal values with assure the normal and reliable engine operation. Higher Lower Heating Value and combustion speed of hydrogen assure the increase in thermal efficiency the brake specific energy consumption decreases with 5.4%–7.8% at substitute ratios of 20–27%. The CO2 emission level decreases with 20% for maximum hydrogen cyclic dose. In terms of pollutant emission level at hydrogen use the emission level of the NOx decreases with 50% and the smoke number decreases with 73.8% comparative to classic fuelling at the maximum hydrogen cyclic dose.

Despite being the lightest element in the periodic table hydrogen poses many risks regarding its production storage and transport but it is also the one element promising pollutionfree energy for the planet energy reliability and sustainability. Development of such novel materials conveying a hydrogen source face stringent scrutiny from both a scientific and a safety point of view: they are required to have a high hydrogen wt.% storage capacity must store hydrogen in a safe manner (i.e. by chemically binding it) and should exhibit controlled and preferably rapid absorption–desorption kinetics. Even the most advanced composites today face the difficult task of overcoming the harsh re-hydrogenation conditions (elevated temperature high hydrogen pressure). Traditionally the most utilized materials have been RMH (reactive metal hydrides) and complex metal borohydrides M(BH4 )x (M: main group or transition metal; x: valence of M) often along with metal amides or various additives serving as catalysts (Pd2+ Ti4+ etc.). Through destabilization (kinetic or thermodynamic) M(BH4 )x can effectively lower their dehydrogenation enthalpy providing for a faster reaction occurring at a lower temperature onset. The present review summarizes the recent scientific results on various metal borohydrides aiming to present the current state-of-the-art on such hydrogen storage materials while trying to analyze the pros and cons of each material regarding its thermodynamic and kinetic behavior in hydrogenation studies.