Pyrolytic hydrocarbon growth from cyclopentadiene

Area of Science:

• Chemical kinetics
• Combustion chemistry
• Organic chemistry

Background:

• Aromatic hydrocarbons are crucial in combustion and industrial processes.
• Understanding their formation pathways is essential for controlling reactions.
• Cyclopentadiene is a key precursor in aromatic hydrocarbon synthesis.

Purpose of the Study:

• To investigate the formation of aromatic hydrocarbons from cyclopentadiene (CPD) in a high-temperature, oxygen-free environment.
• To elucidate the dominant reaction pathways and mechanisms involved in CPD-based aromatic growth.
• To validate computational studies through experimental observations.

Main Methods:

• Utilized a laminar flow reactor for experiments.
• Operated within a temperature range of 550-950 °C.
• Conducted reactions in an oxygen-free atmosphere.

Main Results:

• Identified benzene, indene, and naphthalene as major products of CPD reactions.
• Observed a crossover in indene and naphthalene yields around 775 °C, aligning with computational predictions.
• Detected methylindene and dihydronaphthalene intermediates, supporting CPD dimerization as the primary pathway.
• Confirmed the significance of CPD in carbon growth through reactions with other aromatics.

Conclusions:

• CPD dimerization via radical-molecule and/or radical-radical pathways is the dominant route to indene and naphthalene.
• Experimental results strongly support previous computational findings on CPD reaction mechanisms.
• CPD plays a vital role in the formation of larger aromatic structures through subsequent reactions.