Other Gaseous Fuels

There are direct substitutions of possible interest that would not be feasible without drastic changes in the feed system or pressure. Thus if the available substitute for natural gas is, eg, a manufactured gas containing much CO, there would almost always be a mismatch of the WIs unless the fuel could be further modified by mixing with some other gaseous fuel of high volumetric heating value (propane, butane, vaporized fuel oil, etc). Moreover, if there are substantial differences in eg, as a result of the presence of considerable H2 as well as CO in the substitute gas, the variation in dame height and dashback tendency can also make the substitution unsatisfactory for some purposes, even if the WI is reproduced. Refinements and additional criteria are occasionally appHed to measure these and other effects in more complex substitution problems (10,85). 

The limits of flammability for propane and butane are much narrower than most other gaseous fuels, making LPG safer in this respect. 

Freedom from carbon monoxide makes it less hazardous. The fire hazards are, however, as much as for any other gaseous fuel. 

Diffusion. Hydrogen diffuses through air much more rapidly than other gaseous fuels. With a diffusion coefficient in air of. 61 cm2/s, the rapid dispersion rate of hydrogen is its greatest safety asset. 

S 10.4 sugar C 15.6% burns about 3.3 times slower than the pdr contg charcoal) U)H.H. Holmes W.E.Lawson,USP 2414465(1947) CA 41,2578(1947)(A faster-burning BkPdr suitable for fuses may be obtd by replacing charcoal by a special type of C black produced by incomplete cotnbn of natural gas or other gaseous fuel. For inst, the compn KNOa 74,... 

Hydrogen internal combustion engines can be classified, like any other gaseous-fueled engines, into three basic engine concept categories [56] ... 

However, it should be made clear that, all things considered, hydrogen is no more dangerous, and in some respects it is rather less dangerous than other commonly used fuels. Table 8.10 gives the key properties relevant to safety of hydrogen and two other gaseous fuels widely used in homes, leisure, and business - methane and propane. 

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