Gas/gaseous

Flammable Limits The minimum and maximum concentration of fuel vapor or gas in a fuel vapor or gas/gaseous oxidant mixture (usually expressed in percent hy volume) defining the concentration range (flammable or explosive range) over which propagation of flame will occur on contact with an ignition source. See also Lower Flammable Limit and Upper Flammable Limit. 

Flash-liquid Liquid obtained from flash pyrolysis accomplished in a time of < 1 s Flash-gas Gaseous material obtained from flash pyrolysis within a time of < 1 s Hydropyrolysis Pyrolysis with water Methanopyrolysis Pyrolysis with methanol Ultrapyrolysis Pyrolysis with very high degradation rate... 

Sulphur and selenium unite when warmed with the metal 51 when sulphur is triturated with sodium, the reaction proceeds with explosive violence which can be moderated by dilution with common salt. Under boiling toluene, sulphur forms the trisulphide Na2S3. Selenium forms the monoselenide, Na2Se, when heated with sodium. Sodium is attacked by hydrogen sulphide at ordinary temp., and at the fusion point the metal bums in the gas. Gaseous ammonia reacts readily with sodium, and liquid ammonia forms blue soln.—the so-called alkali-ammoniums. 

Natural gas Gaseous hydrocarbons that are used as fuel. Natural gas is primarily methane, although other gaseous hydrocarbons (ethane and propane) may be present (compare with petroleum and oil). 

Oil expulsion from good oil-prone source rocks is very efficient, whereas oil expulsion from leaner source rocks is relatively inefficient. Probably, most of the oil generated in leaner oil-prone source rocks will remain in the source rock and be cracked to gas at higher temperatures and expelled as gas condensate followed by dry gas. Gaseous solution cem be an effective migration mechanism for oil generated from mature type III kerogen. The expulsion of gas is very efficient. 

The term metathesis literally means to transpose. The term double replacement is often used to describe these reactions because the cations switch places with each other. These are chemical reactions that involve an exchange of positive ions between two compounds and that generally take place between two ionic compounds in an aqueous solution. The driving force that causes these reactions to occur is a decrease in the number of ions from the reactants to products. This will occur when a stable product forms from the ionic reactants. The three types of stable products that can form are a precipitate (or an insoluble solid), a gas (gaseous materials will bubble out of the solutions and leave the reaction mixture), or a stable molecule (a weak electrolyte, or nonelectrolyte, such as water). A general equation for a double-replacement reaction is... 

Material contaminated with gaseous contamination only (no liquid contamination) will off-gas gaseous chemical agent for approximately 30 min after removal from a gaseous contaminated environment. 

Pyrophoric gas Gaseous materials that spontaneously ignite when exposed to air under ambient conditions. An example is trimethyl aluminum. 

The carbonate fuel cell utilizes both H2 and CO at the anode. The conunonly available fuels being considered for carbonate fuel cells include natural gas, gaseous fuels derived from biomass and coal, landfill gas, biomass-derived ethanol, propane, diesel, and bio-diesel. Important properties of these fuels from fuel cells viewpoint are listed in Table 1. Sulfur and halogens present in some of these fuels are eonsidered harmful to fuel processing catalysts and the fuel cell. Therefore, these undesired components need to be removed from the fuel stream. Other potential contaminants such as siloxane in the renewable fuels (biomass digester gas and landfill gas) also should be removed from the fuel prior to fuel processing for fuel cells. 

Figure 6 Change of phase for substrates entering the reactor in gaseous phase and consumed in liquid phase by the microorganism (gray ellipsis), aq = aqueous gas = gaseous.

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