Low energy method of pyrolysis of hydrocarbon materials such as rubber

Abstract

A low energy method of pyrolysis of rubber or other hydrocarbon material is provided. The hydrocarbon material is heated while maintaining a vacuum, using a clay catalyst. In an additional embodiment, also under a vacuum and optionally with or without the catalyst, the temperature of the reaction chamber and corresponding fuel input is varied either over time or spatially within the reaction chamber, to take advantage of the exothermic properties of the reaction. With the method of the present invention, an improved solid reaction product can be achieved.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. §119(e) to provisional application Ser. No. 60 / 224,405, filed Aug. 10, 2000, and provisional application Ser. No. 60 / 224,029, filed Aug. 10, 2000.FIELD OF THE INVENTION [0002] The present invention relates to a low energy method of pyrolysis of hydrocarbon materials such as rubber, coal, tar sands and the like. The method uses a clay catalyst and negative pressure to achieve lower energy input requirements, and produces improved solid carbonaceous material, oil, and combustible gas products. The system design profiles the energy input to take advantage of the exothermic reaction and optimize the required energy. BACKGROUND INFORMATION [0003] In the United States, each resident discards approximately one waste tire annually. Discard of tires resulted in accumulation of approximately 242 million wasted tires nationwide in 1990 alone, exclusive of retreads. Waste tires are a minor portion of...

AI Technical Summary

Benefits of technology

[0015] The present invention solves the above need by providing a low energy method of pyrolysis of hydrocarbon material, including rubber, in which the hydrocarbon material is heated under vacuum conditions, using a clay catalyst. With the method of the present invention an improved solid reaction product can be achieved; carbon black is released from the rubber tires, rather than being created during the pyrolytic process. The addition of a catalyst, in combination with negative pressure conditions, allows the process to proceed at a more rapid rate than other prior art methods. In addition, by drawing the oil and gases to the surface of the rubber during the course of the reaction, the oil and gases are more easily removed from the system. Use of a clay catalyst provides reactive sites within layers of the clay wherein the sites can share electrons with carbon and sulfur molecules in the rubber molecules. This sharing of electrons strains the adjacent carbon-carbon, carbon-sulfur, and / or sulfur-sulfur bonds, destabilizing them and decreasing the energy, and thus the temperature required to promote thermal cracking. The breakage of the bonds involves either free radical formation, ion formation or polarization or a combination of these. Additionally, the catalyst causes steric strain on the bonds which makes them more susceptible to cleavage.

[0018] It is an object of the present invention, therefore, to provide a low energy method of pyrolysis of rubber, tar sands, coal or other hydrocarbon materials.

[0020] It is an additional object of the present invention to provide a low energy method of pyrolysis which produces higher quality reaction products.

Problems solved by technology

This sharing of electrons strains the adjacent carbon-carbon, carbon-sulfur, and / or sulfur-sulfur bonds, destabilizing them and decreasing the energy, and thus the temperature required to promote thermal cracking.

Additionally, the catalyst causes steric strain on the bonds which makes them more susceptible to cleavage.

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