US 4,655,904 AGranted

Thermal cracking process for selectively producing olefins and aromatic hydrocarbons from hydrocarbons

AssigneeMitsubishi Jukogyo Kabushiki Kaisha

InventorsToshiro Okamoto, Michio Ohshima

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Abstract

A process for selectively producing olefins and aromatic hydrocarbons by thermal cracking of hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding a heavy hydrocarbon to the hot gas to thermally crack the heavy hydrocarbon under conditions of a temperature not lower than 1000.degree. C., a pressure not higher than 100 kg/cm.sup.2 g, and a residence time of from 5 to 20 milliseconds; further feeding a light hydrocarbon downstream of the feed of the heavy hydrocarbon in such a way that a light hydrocarbon with a lower boiling point is fed at a lower temperature side downstream of the feed of the heavy hydrocarbon, thereby thermally cracking the light hydrocarbon under conditions of a reactor outlet temperature at not lower than 650.degree. C., a pressure at not higher than 100 kg/cm.sup.2 g, and a residence time at 5 to 1000 milliseconds; and quenching the resulting reaction product.

Claims5

Dependent claims

A thermal cracking process for selectively producing olefins and aromatic hydrocarbons which comprises the steps of:

(a) burning a hydrocarbon with oxygen in the presence of steam to give a hot gas of from 1300.degree. to 3000.degree. C. comprising steam;
(b) feeding the hot gas to a reaction zone to create higher and lower temperature sections in the reaction zone;
(c) feeding a starting heavy hydrocarbon comprising hydrocarbon components having boiling points above 350.degree. C. to the higher temperature section of the reaction zone under conditions of temperature not lower than 1000.degree. C., a pressure of not higher than 100 kg/cm.sup.2 g, and for a residence time of 5 to 20 milliseconds to thermally crack said hydrocarbon components;
(d) feeding a light hydrocarbon comprising hydrocarbon components having boiling points lower than 350.degree. C. to the lower temperature section of the reaction zone so as to thermally crack said light hydrocarbon under conditions of temperature at the outlet of the reactor of no lower than 650.degree. C., a pressure not higher 100 kg/cm.sup.2 g, and a residence time ranging from 5 to 1000 milliseconds;
and
(e) quenching the resulting product.

3 more elements

Dependencies are inferred from the claim text.