0th the abundance of methane and the compara-B tive cheapness of chlorine favor the industrial utilization of chlorination for the preparation OF the chloromethanes. In most of the prior processes i t was necessary t o use some economically undesirable feature t o avoid an explosive o r burning reaction w h e n high concentrations OF chlorine w e r e employed. The present w o r k was undertaken in an effort t o apply the Hass-McBee chlorination technique t o methane. A hydrocarbon i s passed through a reactor w h i l e chlorine i s introduced through jets suitably spaced along the reactor. By this arrangement the momentary concentrations of chlorine are maintained b e l o w those w h i c h yield explosive mixtures, and the over-all mole ratio of reactants may b e any desired value-for example, 4 of chlorine t o I of methane t o produce carbon tetrachloride. Graphs of temperature gradients w e r e helpful i n selecting the most suitable bath temperature, spacings of chlorine jets, space velocity, etc. Most of the data w e r e obtained at 440" C. The ratios of the four chloromethanes in the product can b e varied from nearly 100 per cent methyl chloride t o carbon tetrachloride exclusively. HE four chloromethanes are important commercial T substances and are used in relatively large quantities.The supply of methane froni petroleum is enormous, and during peacetime chlorine is readily available a t a relatively lorn cost. These factors favor the chlorination of methane for the commercial preparation of all the chloromethanes. The large number of patents and other literature references in the field indicate extensive interest in this problem.The chlorination reaction is highly exothermic and requires careful control for successful operation. If the concentration of chlorine is within certain limits, there is danger of a violent and even explosive reaction. The approximate figures for the heats of reaction for the chlorination of methane at 400" C., calculated from the heats of combustion given by Bichomsky and Rossini, are as follows:CHh + Clz + . CHZCl + HC1 + 25 Cal. CHa + 2C12 + . CH2C12 + 2HC1 + 48 Cal. CH4 + 3 c 1 2 + . CHC13 + 3HCl + 72 Cal. CH4 + 4C12 + . CClr + 4HC1 + 96 Cal.When high reaction temperatures are attained, as by high concentration of chlorine, carbon and hydrogen chloride are 1 This paper 1s the fifteenth in a series on the subject of syntheses from natural gas hydrocarbons
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