Product gaseous

The volume of the gaseous products liberated during an explosion by the mixed explosive composition at stp can be calculated from the equation for explosion as shown in Reaction 5.12. 

From Reaction 5.12 it can be seen that 0.03755 mol of gas is produced from 1 g of mixed explosive composition, which will occupy a volume of 0.841 dm3 g 1 as shown in Equation 5.22  

The mixed explosive composition containing 60% RDX with 40% TNT therefore has a Q value of 4720 kJ kg-1, a Vvalue of 0.841 dm3 g-1 and a power index equal to 147%. 

The heat of explosion Q can be increased by adding to the explosive composition another fuel which has a high heat of combustion Such fuels can be found with the lighter elements of the periodic table as shown in Table 5.17. 

Beryllium has the highest heat of combustion of the solid elements, followed by boron and aluminium. Aluminium is a relatively cheap and useful element, and is used to increase the performance of explosive compositions, such as aluminized ammonium nitrate and 

Analysts need consistent, reliable, and credible methodologies to produce analytical data about gaseous emissions (Pamaik, 2004). To fulfill this need in this book, this chapter is devoted to descriptions of the various analytical methods that can be applied to identify gaseous emissions from a refinery (ASTM, 2004 IP, 2001). Each gas is, in turn, referenced by its name rather than the generic term petroleum gas (ASTM D4150). However, the composition of each gas varies, and recognition of this is essential before testing protocols are applied. 

Some secondary explosives are so stable that rifle bullets can be fired through them or they can be set on fire without detonating. The more stable explosives which detonate at very high velocities exert a much 

Colour Grey, pale brown or white crystalline solid 

Mercury fiilmiiiiUe is sensitive to impact aiu liiclion. ami is easily detonated by sparks and flames. It is desensili/ed by the addition of water but is very sensitive to sunlight and ilccomposes with the evolution of gas. Some of the properties of meicury fulminate arc presented in Table 2.2. 

Cuhius added lead aeetate to a solution of sodium or ammonium azide resulting in the formation of lead azide. In 1893, the Prussian Government carried out an investigation into using lead azide as an explosive in detonators, when a fatal accident occurred and stopped all experimental work in this area. No further work was carried out on lead azide until 1907 when Wohler suggested that lead azide could replace mercury fulminate as a detonator. The manufacture of lead azide for military and commercial primary explosives did not commence until 1920 because of the hazardous nature of the pure crystalline material. 

Lead azide has a good shelf life in dry conditions, but is unstable in the presence of moisture, oxidizing agents and ammonia. It is less sensitive to impact than mercury fulminate, but is more sensitive to friction. Lead azide is widely used in detonators because of its high capacity for initiating other secondary explosives to detonation. On a weight basis, it 

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Winters H F and Houle F A 1983 Gaseous products from the reaction of XeF, with silicon J. Appl. Phys. 54 1218-... 

Solubility in concentrated sulphuric acid. Place 3 0 ml. of pure concentrated sulphuric acid in a dry test-tube and add 0 -10 g. of a solid or 0 -20 ml. of a liquid. If the compound does not dissolve immediately, agitate for some time but do not heat. Observe any change in colour, charring, evolution of gaseous products, polymerisation accompanied by precipitation etc. 

The relationship between heat transfer and the boundary layer species distribution should be emphasized. As vaporization occurs, chemical species are transported to the boundary layer and act to cool by transpiration. These gaseous products may undergo additional thermochemical reactions with the boundary-layer gas, further impacting heat transfer. Thus species concentrations are needed for accurate calculation of transport properties, as well as for calculations of convective heating and radiative transport. 

Because the gaseous products ate ia thermodynamic equiUbtium at the flame temperature, quite accurate calculatioas of gas compositioa, maximum... 

The original process of heating coal in rounded heaps, the hearth process, remained the principal method of coke production for over a century, although an improved oven in the form of a beehive was developed in the Durham-Newcastie area of England in about 1759 (2,26,28). These processes lacked the capabiHty to collect the volatile products, both Hquids and gases. It was not until the mid-nineteenth century, with the introduction of indirectiy heated slot ovens, that it became possible to collect the Hquid and gaseous products for further use. 

Fig. 2. Chemistry of (a) gasifier (b) hydrogasifier and (c) devolathation processes. The gaseous product of (a) is of low heating value that of (b) and (c) is...

Prior to the discovery of plentihil suppHes of natural gas, and depending on the definition of the resources (1), there were plans to accommodate any shortfalls in gas supply from soHd fossil fuels and from gaseous resources by the conversion of hydrocarbon (petroleum) Hquids to lower molecular weight gaseous products. 

The principal secondary variable that influences yields of gaseous products from petroleum feedstocks of various types is the aromatic content of the feedstock. For example, a feedstock of a given H/C (C/H) ratio that contains a large proportion of aromatic species is more likely to produce a larger proportion of Hquid products and elemental carbon than a feedstock that is predominantly paraffinic (5). 

The means by which synthetic gaseous fuels could be produced from a variety of biomass sources are variable and many of the known gasification technologies can be appHed to the problem (70,71,76—82). For example, the Lurgi circulatory fluidized-bed gasifier is available for the production of gaseous products from biomass feedstocks as well as from coal (83,84). 

Coal can be processed to H2 by heat from a high temperature, gas-cooled reactor at a process efficiency of 60—70%. Process steps are coal hquefaction, hydrogasification of the Hquid, and steam reforming of gaseous products (179). 

Pyrolysis. Heating in the absence of oxygen releases moisture at low temperatures, carbon dioxide at temperatures >200° C, and a variety of gaseous products at very high temperatures. Acid washing of the raw coal is used to remove extractable cations, followed by treatment with selected cations. Yields of CO2, CO, CH, H2, and H2O depend on the amounts of inorganic species in the coal (42). 

Gasification. Gasification converts soHd fuel, tars, and oils to gaseous products such as CO, H2, and CH that can be burned direcdy or used in synthesis gas (syngas) mixtures, ie, CO and mixtures for production of Hquid fuels and other chemicals (47,48) (see Coal conversion processes, gasification Euels, synthetic-gaseous fuel Hydrogen). 

Spent Sulfuric Field. Spent sulfuric acid recovered from petrochemical and refinery processes can be fed to a high temperature furnace at 870—1260°C, where it is transformed kito sulfur dioxide, water, and other gaseous products. After suitable scmbbkig and drykig, the gases are passed to a conventional contact sulfuric acid plant (263). 

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