Abstract: Process for prolonging the effectiveness of a pyrolytic cracking tube which has been treated with an antifoulant for inhibiting the formation of coke during the cracking of hydrocarbons. The benefits of such treatment are enhanced by the desulfurization of a sulfur-containing feedstock prior to charging it to the treated pyrolytic cracking tube.

Abstract: The incremental yield of hydrocarbons having five or more carbon atoms in a cracked product from a thermal cracking process is increased by contacting or treating the tubes of a thermal cracking furnace with a composition comprising tin and silicon.

Abstract: For a given percentage decomposition, the decomposition temperature of an organosilicon compound is reduced by admixing with the organosilicon compound a decomposition promoting organotin compound. The amount of decomposition promoting organotin compound admixed with the organosilicon compound is sufficient to effectively lower the decomposition temperature of the organosilicon required for a given percentage decomposition.

Abstract: A novel method for treating the radiant tubes of a fired pyrolysis heater with an antifoulant composition for inhibiting the formation and deposition of coke thereon. Such novel method includes introducing the antifoulant into the crossover conduit between the convection tubes and radiant tubes of the fired pyrolysis heater.

Abstract: The rate of formation of carbon on the surfaces of thermal cracking tubes and the production of carbon monoxide during thermal cracking of hydrocarbons are inhibited by the use of cracking tubes treated with an antifoulant, including tin compound, silicon compound and sulfur compounds in the presence of a reducing gas such as hydrogen. Additionally, the concentration of carbon monoxide in a pyrolytic cracking process product stream is reduced by the treatment of the thermal cracking tubes of such process with a reducing gas having a concentration of a sulfur compound.

Abstract: The rate of formation of carbon on the surfaces of thermal cracking tubes and the production of carbon monoxide during thermal cracking of hydrocarbons are inhibited by the use of cracking tubes treated with an antifoulant, including tin compound, silicon compound and sulfur compounds in the presence of a reducing gas such as hydrogen. Additionally, the concentration of carbon monoxide in a pyrolytic cracking process product stream is reduced by the treatment of the thermal cracking tubes of such process with a reducing gas having a concentration of a sulfur compound.

Abstract: A method of injecting a liquid tin-containing antifoulant into a saturated hydrocarbon feed stream for a thermal cracking reactor comprises providing a first open-ended tube, a second open-ended tube which concentrically surrounds the first tube, and a third tube which concentrically surrounds the first and second tubes; passing a liquid antifoulant stream through the first tube, a dispersing gas stream through the second tube, and a hydrocarbon gas stream (preferably containing ethane and steam) through the third tube; injecting the liquid antifoulant through the open end of the first tube and the dispersing gas through the open end of the second tube into the hydrocarbon gas stream; and passing the mixture of dispersed antifoulant, dispersing gas and hydrocarbon gas into a thermal cracking reactor.