The hydrogen economy is not possible if the safety standards currently applied to liquid hydrogen and hydrogen gas by many laboratories are applied to devices that use either liquid or gaseous hydrogen. Methane and propane are commonly used by ordinary people without the special training. This report asks, "How is hydrogen different from flammable gasses that are commonly being used all over the world?" This report compares the properties of hydrogen, methane and propane and how these properties may relate to safety when they are used in both the liquid and gaseous state. Through such an analysis, sensible safety standards for the large-scale (or even small-scale) use of liquid and gaseous hydrogen systems can be developed. This paper is meant to promote discussion of issues related to hydrogen safety so that engineers designing equipment can factor sensible safety standards into their designs.

The employment of hydrogen has shown a lot of promises as an alternative for conventional fuel sources. However, if not handled properly, hydrogen content as low as 4%2can lead to a life-threatening catastrophe. Some sensors for hydrogen detection have already been built to address this safety issue. Unlike most of the traditional hydrogen sensors, the sensor developed in this study features high sensitivity, fast response, miniature size, and the ability to detect hydrogen under room temperature. The sensor template has a special nanoporous structure, coming from self assembled aluminum oxide after anodization process. Deposition of palladium particles into the nanopores brings superb hydrogen sensing ability by introducing a granular structure of sensing particles. The sensor prototype has been tested under controlled atmosphere with varying hydrogen concentrations.

The dispersion characteristics of hydrogen leaking through a small hole from a high-pressure reservoir are investigated numerically and experimentally to provide a guideline in determining the safety distances for hydrogen stations. The studies were carried out for the leaking holes with diameters of 0.5, 0.7 and 1.0mm and for the release pressures at 100, 200, 300 and 400 bar. Because Froude numbers in these realistic hydrogen leaking conditions are very large, it is reasonable to employ a 2-dimensional axisymmetric approach in the numerical simulations as well as in hydrogen samplings.

In this paper, safety, health and environmental risks of a typical installation handling anhydrous hydrogen chloride were assessed in an integrated approach. A four-step procedure was used as risk assessment framework for this integrated risk assessment. The safety risk was presented as individual risk while Hazard Quotients were calculated for health and environmental risks. Some advantages of such an integrated approach were identified through the exercise.

A liquid hydrogen target for high energy physics experiment, Crystal Ball Spectrometer, was recently built and operated at the Alternating Gradient Synchrotron (AGS) particle accelerator at the Brookhaven National Laboratory (BNL). The system safety design, operation, and control of the target was analyzed and evaluated during its two-month beam-taking experiment. This paper reports on this cryogenic project.

Recent growth in the development of hydrogen infrastructure has led to more requests for code officials to approve hydrogen-related projects and facilities. To help expedite the review and approval process, significant efforts have been made to educate code officials on permitting hydrogen vehicle fueling stations and facilities using stationary fuel cells (e.g., backup power for telephone cell tower sites). Despite these efforts, project delays continue because of several factors, including the limited experience of code officials with these types of facilities, submittals that lack the required information (including failure to adequately address local requirements), and submission of poor quality documents. The purpose of this paper is to help project proponents overcome these potential roadblocks and obtain timely approval for a project. A case study of an actual stationary application permitting request is provided to illustrate the value of addressing these issues. (C) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Canadian Hydrogen and Fuel Cell Association.

Hydrogen detection is priority for every launch vehicle where hydrogen is involved. Hydrogen sensors are necessary to monitor the detection of every possible leak. For space application is very challenging to pin point exact location of leaks and public acceptance of hydrogen fuel is require the integration of a reliable hydrogen safety sensor. For detecting leakage of cryogenic fluids in spaceport facilities, launch vehicle industry and aerospace agencies are currently relying heavily on the bulky mass spectrometers, which fill one or more equipment racks, and weigh several hundred kilograms. Recently new innovation in optical hydrogen makes these sensors intrinsically safe since they produce no arc or spark in an explosive environment caused by the leakage of hydrogen. Being a very small molecule, hydrogen is prone to leakage through seals and micro-cracks. This paper describes the development of fiber optic innovative technologies for detection of hydrogen in space applications. These systems consisted of Micro Mirror, Fiber Bragg grating, Evanescent Optical Fiber and Colorimetric Technology. The paper would discuss the sensor design and performance data under field deployment conditions.

Optical hydrogen sensors are intrinsically safe since they produce no arc or spark in an explosive environment caused by the leakage of hydrogen. Safety remains a top priority since leakage of hydrogen in air during production, storage, transfer and distribution creates an explosive atmosphere for concentrations between 4%2(v/v) - the lower explosive limit (LEL) and 74.5%2(v/v) - the upper explosive limit (UEL) at room temperature and pressure. Being a very small molecule, hydrogen is prone to leakage through seals and micro-cracks. Hydrogen detection in space application is very challenging; public acceptance of hydrogen fuel would require the integration of a reliable hydrogen safety sensor. For detecting leakage of cryogenic fluids in spaceport facilities, Launch vehicle industry and aerospace agencies are currently relying heavily on the bulky mass spectrometers, which fill one or more equipment racks, and weigh several hundred kilograms. This paper describes the successful development and test of a multi-point fiber optic hydrogen sensor system during the static firing of an Evolved Expandable Launch Vehicle at NASA's Stennis Space Center. The system consisted of microsensors (optrodes) using hydrogen gas sensitive indicator incorporated onto an optically transparent porous substrate. The modular optoelectronics and multiplexing network system was designed and assembled utilizing a multi-channel optoelectronic sensor readout unit that monitored the hydrogen and temperature response of the individual optrodes in real-time and communicated this information via a serial communication port to a remote laptop computer. The paper would discuss the sensor design and performance data under field deployment conditions.

Hydrogen is considered to be a hazardous gas since it forms a flammable mixture between 4 to 75%2by volume in air. Hence, the safety aspects of handling hydrogen are quite important. For this, ideally, highly selective, fast response, small size, hydrogen sensors are needed. Although sensors based on different technologies may be used, thin-film sensors based on palladium (Pd) are preferred due to their compactness and fast response. They detect hydrogen by monitoring the changes to the electrical, mechanical or optical properties of the films. We report the development of Pd-doped tin-oxide based gas sensors prepared on thin ceramic substrates with screen printed platinum (Pt) contacts and integrated nicrome wire heaters. The sensors are tested for their performances using hydrogen nitrogen gas mixtures to a maximum of 4 %2H(2) in N(2). The sensors detect hydrogen and their response times are less than a few seconds. Also, the sensor performance is not altered by the presence of helium in the test gas mixtures. By the above desired performance characteristics, field trials of these sensors have been undertaken. The paper presents the details of the sensor fabrication, electronic circuits, experimental setup for evaluation and the test results.

Optical hydrogen sensors are intrinsically safe since they produce no arc or spark in an explosive environment caused by the leakage of hydrogen. Safety remains a top priority since leakage of hydrogen in air during production, storage, transfer and distribution creates an explosive atmosphere for concentrations between 4%2(v/v) - the lower explosive limit (LEL) and 74.5%2(v/v) - the upper explosive limit (UEL) at room temperature and pressure. Being a very small molecule, hydrogen is prone to leakage through seals and micro-cracks. Hydrogen detection in space application is very challenging; public acceptance of hydrogen fuel would require the integration of a reliable hydrogen safety sensor. For detecting leakage of cryogenic fluids in spaceport facilities, Launch vehicle industry and NASA are currently relying heavily on the bulky mass spectrometers, which fill one or more equipment racks, and weigh several hundred kilograms. An optical sensor system can decrease pay load while monitoring multiple leak locations in situ and in real time. In this paper design of ormsoil approach for developing a completely reversible optical hydrogen sensors for aerospace application is being discussed.