Patent GB-346680-A (GB)
Title: Improvements in the manufacture and production of carbon black
IPC: C09C1/54
Filed: 1929-10-12
Abstract: <PICT:0346680/III/1> In the production of carbon black by the catalytic thermal decomposition of gaseous or vaporous unsaturated hydrocarbons at temperatures below 500 DEG  C., the upper limit of temperatures employed is so much below that which leads to a complete decomposition of the converted unsaturated hydrocarbons to carbon black that not more than 90 per cent of the carbon contained in the converted unsaturated hydrocarbons is so transformed, the remainder being transformed into saturated hydrocarbons.  Some of the initial unsaturated hydrocarbon may remain unconverted.  This upper limit of temperature will depend upon the particular catalyst employed and the nature of the initial unsaturated hydrocarbons; preferably, the temperature should not be more than 50 DEG  below this upper limit. As catalysts, cobalt, iron or nickel may be employed.  The catalysts may be diluted with catalytically inactive substances such as calcium or zinc oxides; the catalysts may also contain activators, such as the compounds of chromium or the alkali metals.  The unsaturated hydrocarbons referred to are ethylene, butylene, propylene and acetylene.  They may be employed in admixture and may also be diluted with nitrogen, water vapour, carbon dioxide or saturated hydrocarbons.  The temperature may be controlled by the provision of cooling means such as tubes through which water or other liquids circulate, by leading the gases at a lower temperature into the reaction chamber or by effecting only a partial conversion during the first introduction of the gases, the conversion being completed by a second introduction of the gases into the reaction chamber. According to one example, ethylene enters a doublewalled semi-circular cross-sectioned chamber R (shown in the Figure), maintained at 350 to 370 DEG  C., at O and passes out at H.  The catalyst, obtained by the reduction of a mixture of cobalt, zinc and barium oxides, is introduced through a feed-pipe F and is spead out by means of a scraper K.  The carbon black formed is removed by the scraper K into a collection box V. The carbon black is freed from metallic impurities by treatment with hydrochloric or nitric acids. Hot water flows through cooling coils S.  Two other forms of apparatus are described. Catalysts for the process may also be prepared by precipitating a mixture of zinc and cobalt carbonates from their nitrates, washing the precipitate, adding a solution of potassium nitrate, and reducing the dried mixture with hydrogen or by precipitating a solution of cobalt nitrate and zinc nitrite with ammonium carbonate, adding a solution of potassium nitrite to the precipitate, and reducing the mixture.  The carbon black may be used as a filler in the vulcanization of rubber or the products obtained by the polymerization of diolefines such as butadiene or isoprene. Specifications 321,402, 324,959, and 326,913, [all in Class 1 (i) Chemical processes &c.], are referred to.ALSO:<PICT:0346680/IV/1> In the production of carbon black by the catalytic thermal decomposition of gaseous or vaporous unsaturated hydrocarbons at temperatures below 500 DEG  C., the upper limit of temperatures employed is so much below that which leads to a complete decomposition of the converted unsaturated hydrocarbons to carbon black that not more than 90 per cent of the carbon contained in the converted unsaturated hydrocarbons is so transformed, the remainder being transformed into saturated hydrocarbons.  Some of the initial unsaturated hydrocarbon may remain unconverted.  This upper limit of temperature will depend upon the particular catalyst employed and the nature of the initial unsaturated hydrocarbons; preferably, the temperature should not be more than 50 DEG  below this upper limit.  As catalysts, cobalt, iron or nickel may be employed.  The catalysts may be diluted with catalytically inactive substances such as calcium or zinc oxides; the catalysts may also contain activators such as the compounds of chromium or the alkali metals.  The unsaturated hydrocarbons referred to are ethylene, butylene, propylene and acetylene.  They may be employed in admixture and may also be diluted with nitrogen, water vapour, carbon dioxide or saturated hydrocarbons.  The temperature may be controlled by the provision of cooling means such as tubes through which water or other liquids circulate, by leading the gases at a lower temperature into the reaction chamber or by effecting only a partial conversion during the first introduction of the gases, the conversion being completed by a second introduction of the gases into the reaction chamber.  According to one example, ethylene enters a double walled semicircular cross-sectioned chamber R (Fig. 1), maintained at 350 to 370 DEG  C., at O and passes out at H. The catalyst, obtained by the reduction of a mixture of cobalt, zinc and barium oxides is introduced through a feed-pipe F and is spread out by means of a scraper K.  The carbon black formed is removed by the scraper K into a collection box V.  Hot wat<\>aer flows through cooling coils S.  Two other forms of apparatus are p  described. Specifications 321,402, 324,959 and 326,913, [all in Class 1 (i), Chemical processes &c.], are referred to.ALSO:In the production of carbon black by the catalytic thermal decomposition of gaseous or vaporous unsaturated hydrocarbons at temperatures below 500 DEG  C., the upper limit of the temperatures employed is so much below that which leads to a complete decomposition of the converted unsaturated hydrocarbons to carbon black that not more than 90 per cent of the carbon contained in the converted unsaturated hydrocarbon is so transformed, the remainder being transformed into saturated hydrocarbons.  The carbon black may be used as a filler in the vulcanization of rubber or the products obtained by the polymerization of diolefines such as butadiene or isoprene. Specifications 321,402, 324,959, and 326,913, [all in Class 1 (i), Chemical processes &c.], are referred to.