Patent ID: 7238847

Claim:
In a pyrolysis process in which a known amount of a hydrocarbon feed containing a known amount of an inert gas tracer, a hydrocarbon feed carbon content and a hydrocarbon feed hydrogen content, is charged to a pyrolysis furnace operated under pyrolysis cracking process conditions to yield a pyrolysis product wherein said pyrolysis product comprises a liquid fraction and a gas fraction, wherein said liquid fraction comprises a liquid fraction hydrogen content and a liquid fraction carbon content to thereby provide a liquid fraction hydrogen-to-carbon ratio, and wherein said gas fraction comprises a gas fraction inert gas tracer concentration, a gas fraction hydrogen content and a gas fraction carbon content, a method is provided for determining said liquid fraction hydrogen-to-carbon ratio, said method comprising the steps of: (a) determining said hydrocarbon feed hydrogen content and said hydrocarbon feed carbon content; (b) determining said gas fraction hydrogen content and said gas fraction carbon content by determining said gas fraction inert gas tracer concentration, utilizing the thus determined gas fraction inert gas tracer concentration to determine the proportion of said pyrolysis product that is said gas fraction, and utilizing the thus determined proportion of said pyrolysis product that is said gas fraction in determining said gas fraction hydrogen content and said gas fraction carbon content; and (c) determining said liquid fraction hydrogen-to-carbon ratio by subtracting the determined value for said gas fraction hydrogen content from the determined value for said hydrocarbon feed hydrogen content to give said liquid fraction hydrogen content, subtracting the determined value for said gas fraction carbon content from the determined value for said hydrocarbon feed carbon content to give said liquid fraction carbon content, and calculating the value for said liquid fraction hydrogen-to-carbon ratio.