Myung Lang Yoo

Pyrolysis of Suncheon-Bay wild reed over zeolite catalysts

The catalytic fast pyrolysis of wild reed was carried out over HZSM-5 zeolite catalysts with two different SiO2/Al2O3 ratios, 23 and 280. The effects of the pyrolysis temperature and catalyst on the bio-oil yield were examined using a laboratory-scale batch-type quartz reactor for the pyrolysis experiments over the temperature range, 440–560 °C. The highest bio-oil yield was obtained between 520 °C and 560 °C depending on the catalytic conditions. The bio-oil yields obtained from catalytic pyrolysis were generally lower than those obtained from non-catalytic pyrolysis because of the cracking of large-molecular-mass products into gaseous species. Further experiments were carried out using the pyrolysis-gas chromatography/mass spectrometry at 550 °C for the in-situ analysis of the species distribution of the product bio-oil. Regardless of the use of catalyst, oxygenates were the most abundant products from the pyrolysis of wild reed, followed by phenolics. The fraction of total oxygenates was reduced consid...

Effects of acid characteristics of nanoporous MCM-48 on the pyrolysis product distribution of waste pepper stem

Nanoporous catalysts Si-MCM-48 and Al-MCM-48 were applied for the first time to the catalytic pyrolysis of waste pepper stem. Pyrolysis experiments were conducted at 550°C using Py-GC/MS to examine the product distribution rapidly. Phenolics were shown to be the most abundant product species of noncatalytic pyrolysis, whereas aliphatic and aromatic hydrocarbons were produced marginally. On the other hand, much larger quantities of furans and aliphatic and aromatic hydrocarbons were produced from the catalytic pyrolysis over MCM-48, while the production of phenolics was suppressed significantly. Al-MCM-48 showed a much higher catalytic activity than Si-MCM-48, which was attributed to its much higher acidity. The results of this study indicate that valuable chemicals can be produced from waste pepper stem using catalytic pyrolysis over an acidic nanoporous catalyst.