Butane, flame speed

Broschka et al. (1983) report results of experimental tests on parallel plate flame arresters in piping systems. Tests were conducted on 3-inch and 6-inch diameter parallel plate flame arresters installed in 3-inch and 6-inch diameter piping sections using butane-air mixtures to generate a flame. The ignition source was varied from 3 to 43 feet from the flame arrester. The flame speed varied between 0 to 20 ft/s, and when the flame speed was 20 ft/s, the flame passed through the arrester (flame arrester failure). 

Hirasawa, T., Sung, C.J., Yang, Z., Joshi, A., Wang, H., and Law, C.K., Determination of laminar flame speeds of fuel blends using digital particle image velocimetry Ethylene, M-butane, and toluene flames, Proc. Combust. Inst., 29,1427, 2002. 

The presence of propylene and butylenes in liquefied petroleum gas used as fuel gas is not critical. The vapor pressures of these olefins are slightly higher than those of propane and butane and the flame speed is... 

Clearly, heat transfer, flammability and catalyst stability are the major concerns of fixed-bed technology. In the early 1990s, tests were conducted at a commercial plant to increase MA productivity by feeding butane concentrations beyond the flammability limit (which is nominally 1.8 vol% butane in air). Apparently, the butane feed concentration in the vessel approached 2.3 vol% before the reactor head lifted off the body of the vessel (the reactor was designed to allow for such an event). Many patents have been issued that claim the interior vessel walls can be passivated to reduce the frequency of free radical formation (or quench free radicals). Free radicals initiate thermal events that lead to combustion or deflagration and even to detonation when the flame front exceeds the speed of sound. 

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