Bo-Sung Kang

Stabilization of bio-oil over a low cost dolomite catalyst

A low cost alkaline catalyst of dolomite (CaMg(CO3)2) was used to stabilize acacia sawdust bio-oil mixed with methanol. The upgrading efficiency was evaluated in terms of the total acid number (TAN) and viscosity. A change in the dolomite calcination temperature from 700 to 900 °C led to a significant change in the TAN and viscosity of the methanol-added bio-oil. Dolomite activated at higher temperatures had larger amounts of active CaO and MgO species due to the enhanced decarboxylation of calcium and magnesium carbonates. An increase in the dolomite content (1-5 wt%) decreased the TAN value of bio-oil remarkably. A thermal aging test of the methanol-added bio-oil upgraded using dolomite (calcined at 900 °C) at 50 °C for 24 h was carried out by storing the bio-oil at 80 °C for one week. Although the TAN value increased after the aging process, it was still lower than the TAN of raw bio-oil. In addition, increasing the methanol content (10-30 wt%) decreased the TAN and viscosity of the bio-oil significantly.

Catalytic Pyrolysis of Organosolv and Klason Lignin Over Al-SBA-15

The catalytic pyrolysis of two types of lignin, organosolv and klason lignin, which were extracted from miscanthus, over Al-SBA-15 was carried out using a thermogravimetric (TG) analyzer and a pyroyzer-gas chromatography/mass spectrometry (Py-GC/MS). Although Al-SBA-15 has weak acidity, the large molecular phenolic pyrolyzates of lignin were converted effectively into small molecular phenols and aromatic hydrocarbons due to the large pore size of Al-SBA-15. Compared to klason lignin, organosolv lignin produced larger amounts of valuable chemicals, such as mono-phenol, mono-aromatics, and furans, by catalytic pyrolysis over Al-SBA-15.

Removal of Food Waste Odor Using Nanoporous Carbon Adsorbents

The removal of acetaldehyde, which is one of main components of food waste odor was investigated using biomass char as a nanoporous carbon absorbent. The biomass char adsorbent obtained from the pyrolysis of Geodae-Uksae was modified by the water and KOH treatment. The modified char absorbent had a higher acetaldehyde removal efficiency than nanoporous CMK-8 possibly due to its high oxygen and nitrogen functional groups.

Hydrodeoxygenation of Pyrolysis Bio-Oil Over Ni Impregnated Mesoporous Materials

The catalytic hydrodeoxygenation (HDO) of bio-oil over Ni-supported mesoporous materials was performed using a high pressure autoclave reactor. The actual pyrolysis oil of cork oak wood was used as a sample, and Ni/Al-SBA-15 and Ni/Al-MSU-F were used as catalysts. In addition, supercritical ethanol was added as solvent. Both Ni-supported mesoporous catalysts showed efficient HDO reaction ability. A higher heating value and pH of bio-oil were achieved by the HDO reaction over both catalysts and upgraded bio-oil had a lower viscosity. Compared to Ni/Al-MSU-F, Ni/Al- SBA-15 produced more upgraded bio-oil with a lower oxygen content and higher heating value via a catalytic HDO process.

Catalytic Pyrolysis of Municipal Plastic Film Wastes Over Nanoporous Al-MCM-41

A mesoporous material, Al-MCM-41, was applied to the catalytic pyrolysis of municipal plastic film waste (MPFW) to produce large amounts of valuable hydrocarbons. Compared to non-catalytic pyrolysis, the catalytic pyrolysis of MPFW over Al-MCM-41 revealed a lower decomposition temperature and activation energy upon thermogravimetric analysis. Heavy aliphatic hydrocarbons, which are the major products of non-catalytic pyrolysis, were cracked into small hydrocarbons and converted efficiently to aromatic hydrocarbons by catalytic pyrolysis over Al-MCM-41. The activity of catalytic conversion was enhanced by increasing the catalyst to reactant ratio.