GB719221A - Improvements in or relating to a process an apparatus for making carbon black and treating effluent gases therefrom and for making hydrogen-containing synthesis gas - Google Patents

Abstract

<PICT:0719221/III/1> Carbon black and a synthesis gas comprising carbon monoxide and hydrogen are made by pyrolytic decomposition by partial combustion of a hydrocarbon feed in a reaction zone wherein carbon black is separated from the effluent gases from the reaction zone and carbon dioxide is then removed to form said synthesis gas. Hydrocarbon gas or oil feed from tank 9 is fed through heater 13 and pipe 7 to cylindrical furnace 6 where it is heated by direct heat exchange with hot gases formed by introducing oxygen, with or without fuel gas, through a tangentially directed pipe 16. Air, oxygen, or inert gas, may also be added through 14. The effluent smoke is cooled to 1500 DEG F. by passage through water jacketted cooler 27 with quenching water spray 33, and then passes through heat exchanger 34 or air cooling pipe 36 to dry carbon black separator 41, e.g. bag filter, or electrical precipitators and cyclones. The temperature of the gas entering separator 41 may be adjusted to 300-600 DEG F. by adding water at 44 in amount controlled by temperature of gas (250-500 DEG F.) leaving separator 41 at 43. The dilute smoke passes through cooler 49 to separator 51 where it is washed with water from spray 53 to remove condensed water and residual carbon black. The washed gas passes through pipe 54 to absorber 58 where a spray of aqueous alkaline liquid, e.g. triethanolamine or potassium hydroxide, removes carbon dioxide, Some of the resulting H2-CO withdrawn at 61 may be recycled through pipes 111 and 108 to be either burnt at 114 in heater 13, and/or added to furnace hydrocarbon feed in 7 at 112, and/or through 111 and 109 with or without heating in 110 to furnace tangential inlet 16 at 22. Alternatively some or all of the gas from 61 may be passed to catalytic synthesis process 23 with addition of hydrogen or carbon monoxide, if necessary at 71, 72. Alternatively the ratio of H2 to CO may be adjusted by passing the gas from 61 through heat exchanger 34 to water gas shift reactor 79 with addition of water or steam at 81 to effect the reaction CO+H2O=CO2+H2 and returning the gas from 79 to pipe 43 for removal of water and carbon dioxide in 51 and 58. The gas from pipe 54 may also be withdrawn through pipes 56 and 57 and used in heater 13, or in feed 7, or in furnace 6 in place of or in addition to gas from 61, or gas may be vented for use at 55. The wash water in separator 51 is recycled through pipe 94 with addition, if desired, of a wetting agent, e.g. the condensation product of formaldehyde and naphthalene sulphuric acid, or sodium lignin sulphate, at 89 and of an anti-foaming agent, e.g. tetrachloroethylene, or Turkey red oil at 91, and some of the resulting carbon black slurry may be withdrawn at 100 and p injected through spray 33a or used as such. The wash liquor in absorber 58 is passed to heated stripper 64 and CO2 is vented at 66 while the wash liquid is recycled to absorber 58 through cooler 62. Additional fuel may be supplied to any of the heater burners. In an alternative arrangement (Fig. 2 not shown) air is used in the tangential feed to the furnace, nitrogen is vented from the system and the resulting gas is not used in a synthesis process. Specifications 607,296, 654,350 and 679,818 are referred to.