Flash hydrogenation of a bituminous coal.

Area of Science:

• Chemical Engineering
• Materials Science
• Organic Chemistry

Background:

• Coal conversion technologies are crucial for energy production.
• Understanding hydrocarbon formation during coal pyrolysis is essential for optimizing processes.
• Illinois coal presents unique characteristics for thermochemical conversion.

Purpose of the Study:

• To investigate the rapid pyrolysis of Illinois coal under high-pressure hydrogen.
• To quantify the yield of specific hydrocarbon products, including methane, ethane, and aromatics.
• To determine the fate of carbon during flash heating and its distribution into various products.

Main Methods:

• Flash heating of Illinois coal to 700°C in 1 second.
• Pyrolysis conducted in flowing hydrogen at 100 atmospheres pressure.
• Controlled vapor residence time at peak temperature (3 seconds).

Main Results:

• 14% of coal carbon converted to methane.
• 7% of coal carbon converted to ethane.
• 10% of coal carbon converted to benzene, toluene, and xylenes (BTX).
• Coke is the primary remaining solid product.
• Heavy tar formation is less than 3%.

Conclusions:

• Rapid, high-pressure hydrogen treatment of Illinois coal is effective for producing light hydrocarbons.
• The process favors the formation of methane, ethane, and BTX aromatics.
• Minimal formation of heavy tar suggests a cleaner conversion pathway.