Odorization of Natural Gas: What are the Challenges?

Modern natural gas (NG) has little or no odor, so other compounds, usually mercaptans and thiols, are added as warning odorants. Federal regulations state that NG must be odorized so that it is readily detectable by people with normal senses of smell at one fifth the lower explosive limit, but regulations don't define "readily detectable" or "normal senses of smell." Methods to measure human odor detection have been available for decades. However, most previous work on NG odorants has underestimated human sensitivity, and measurements need to be repeated using the latest methods. More work is also needed to determine how odor sensitivity measured under optimal laboratory conditions is affected by real-world factors such as distraction and exposure to other odors in the environment. Regarding a "normal sense of smell," healthy people vary over orders of magnitude in the concentrations they can detect, so samples of subjects should be chosen to reflect the range of differences in the population.

Use of explosibility diagrams in potentially explosive atmospheres

Although the first research in the field was carried out by Davy in 1816, the first discovery emerged in 1891 when Le Chatellier defined the law for determining the explosive limits. Lower Explosive Limit (LEL) represents the lowest concentration of gas or vapours in air which is able to generate the explosion in the presence of an efficient ignition source. It is considered to be the same as the Lower Flammability Limit (LFL). Upper Explosive Limit (UEL) represents the highest concentration of gas or vapours in air which is able to generate the explosion in the presence of an efficient ignition source. It is considered to be similar with the Upper Flammability Limit (UFL) [1]. For the optimal management of underground or surface industrial environments, confined, obstructed or open environments, is required to know the point which defines the monitored atmosphere in relation with the explosion triangle. For confined underground environments, monitoring the atmosphere and using the explosibility diagrams are required during the closure process and also for re-opening the area. For underground environments specific to active mine workings and for industrial environments located on the surface, monitoring the atmosphere and using explosibility diagrams are required permanently.

Analysis Of The Normative Requirements For Ensuring The Safety Of Powder Coating Booths In Terms Of The Risk Of Explosion

During the process of electrostatic powder coating in coating booths, there is a probability of the risk of explosion. Compliance with the normative requirements referred to in the legislation in force minimize the hazards associated with the risk of explosion. This article focuses on the analysis of the current security level of coating booths in terms of the risk of explosion in relation to the lower explosive limit of the selected powder paints.

Influence of the Mixing Ratio on Combustion Parameters for Mixed Refuse Derived Fuel

This paper is devoted to the analysis of the effect of the percentage mixture of refuse derived fuels created from industrial waste on selected combustion parameters resulting from the mixture of the fuels, whose principal component is coal. The selected combustion parameters are; the lower explosive limit (LEL), maximum explosion pressure (pmax), maximum rate of the rise in pressure (dp/dt)max) and the cubic constant (KSt). The paper also includes a description of the test equipment and methods by which the tests of the combustion variables were carried out.

Impact Analysis of Ignition Energy for Gas Explosive Limit

Under the different experimental condition of ignition energy, the variations of gas explosive limit were obtained. The explosive limit ranges from 4.86% to 16.72%, under the condition of high ignition energy of 450 J. The result is quite different from the theoretical explosion limit range from 5% to 16%, thus providing a new basis to effectively prevent the gas explosion accidents.