| 摘要 |
In endothermic reactions, such as the pyrolysis of hydrocarbons or halogenated hydrocarbons by contact with a combustion gas, preferably having a temperature above 2100 DEG C., there is added to the combustion gas a "temperature stabilizing substance" in a non-gaseous state whereby the substance is vaporized and later condensed during the subsequent endothermic pyrolysis. Suitable substances are BaF2, CaCl2, CsBr, LiBr, LiCl, LiF, LiI, MgBr2, MgCl2, KCl, KF, KI, NaCl, Sb2O3, BaO, Bi2O3, CdF2 and AgCl. The substance is preferably added in liquid form in amount sufficient to cool the combustion gas to within 300 DEG C. above is vaporization temperature and such that water is dissociated less than 2%, i.e. less than 1880 DEG C. at 0,5 atmosphere, 1980 DEG C. at 1 atmosphere and 2050 DEG C. at 2 atmospheres and preferably less than 1% (1700 DEG -1825 DEG C. according to pressure). In a preferred embodiment the substance, if liquid below 600 DEG C., is also used as a quench fluid, separated from the product gases in a cyclone and reused, being heated before adding to the combustion gases and cooled before use as quench fluid. Hydrocarbons may be pyrolysed to acetylene and ethylene.ALSO:In the pyrolysis of halogenated hydrocarbons, e.g. of dichloro-ethane to vinyl chloride and of carbon tetrafluoride to fluoro-ethanes, by contact with a combustion gas, preferably having a temperature above 2,100 DEG C., there is added to the combustion gas a "temperature stabilising substance" in a non-gaseous state whereby the substance is vapourised and later condensed during the subsequent endothermic pyrolysis. Suitable substances are BaF2, CaCl2, CsBr, LiBr, LiCl, LiF, LiI, MgBr2, MgCl2, KCL, KF, KI, NaCl,Sb2O3, BaO, Bi2O3, CdF2 and AgCl. The substance is preferably added in liquid form in amount sufficient to cool the combustion gas to within 300 DEG C. above its vapourisation temperature and such that water is dissociated less than 2%, i.e. less than 1880 DEG C. at 0.5 atmosphere, 1980 DEG C. at 1 atmosphere and 2050 at 2 atmospheres and preferably less than 1% (1700-1825 DEG C. according to pressure). In a preferred embodiment the substance, if liquid below 600 DEG C., is also used as a quench fluid, separated from the product gases in a cyclone and reused, being heated before adding to the combustion gases and cooled before use as quench fluid. |
