Method for production of carbon black and start-up thereof

#The present invention relates to a method of carbon black production. In another aspect, the present invention relates to a method for the start-up of carbon black production.

#Conventionally, carbon black is produced by burning a carbonaceous material in the presence of a combustion-supporting material in a highly specialized furnace or reactor, terminating the burning after a relatively short residence time by the addition of a quench fluid to produce a hot combustion gas containing carbon black, preferably recovering heat values from the hot combustion gas by passing the same in indirect heat exchange with water and/or one or more of the reactant materials to produce a combustion gas of reduced temperature, and recovering the carbon black from the combustion gas of reduced temperature.

#In one mode of operation, water is utilized as a quench fluid to terminate the burning. This quench water together with water produced in the burning step creates serious corrosion problems in equipment for recovering heat values from the hot combustion gas, as well as in the system for recovering the carbon black from the combustion gas of reduced temperature. This problem is particularly significant during start-up of the carbon black process. Normally, during start-up, a fuel gas is burned in the presence of the combustion-supporting material and all equipment downstream of the reactor is operated as it would conventionally be operated for the production of carbon black for a period of time sufficient to attain carbon black production temperatures in the equipment throughout the system. Thereafter, the feed material is substituted for part or all of the fuel gas and carbon black is recovered under production conditions. This line-out or start-up of the system is a rather lengthy procedure and the water utilized as a quench fluid as well, as that produced during the burning step, will condense on the metal parts of the equipment downstream of the reactor until the equipment reaches a temperature above the dew point of water and, of course, severe corrosion occurs.

#The single FIGURE of the drawings is a simplified flow diagram showing a carbon black production system utilizing the method of the present invention.

#When utilized in the present application, the term "carbonaceous material" is meant to include normally gaseous carbonaceous materials, such as natural gas, normally liquid carbonaceous materials, such as normally liquid fractions of petroleum, shale oils, oils derived from coal, lignite and the like, etc. and normally solid carbonaceous materials, such as powdered coals, lignite, etc.

#The term "combustion-supporting material", when utilized herein is meant to include any oxygen-containing material capable of supporting combustion, including oxygen, oxygen-enriched air, air and the like.

#Carbon black may be produced from any carbonaceous material having sufficient carbon atoms for the production of practical quantities of carbon black. In general, the higher the carbon to hydrogen ratio of the feed material, the more desirable the carbonaceous material for carbon black production. While normally gaseous carbonaceous materials, particularly natural gas, have been utilized to produce carbon black and considerable research has been conducted for the production of carbon black from normally solid carbonaceous materials, such as coal and lignite, the most conventionally utilized carbonaceous materials are heavy fractions derived from petroleum. These materials are most often utilized because of their higher carbon to hydrogen ratio than natural gas and the greater ease of transport through the reactor and component break down, as compared with coal, lignite and the like. However, during start-up of a carbon black process, it is the usual practice to employ a normally gaseous carbonaceous material, particularly natural gas, as a fuel gas because of its higher heating value and, thus, its ability to more rapidly bring the system up to operating temperatures. Once the system has been lined out with natural gas as a fuel gas, conventional practice is to then substitute normally liquid hydrocarbons for all or a part of the natural gas for carbon black production. A preferred technique involves utilizing natural gas for start-up and, thereafter, substituting liquid hydrocarbons for part of the natural gas for carbon black production.