Hyeon Su Heo

Bio-oil production from fast pyrolysis of waste furniture sawdust in a fluidized bed

The amount of waste furniture generated in Korea was over 2.4 million tons in the past 3 years, which can be used for renewable energy or fuel feedstock production. Fast pyrolysis is available for thermo-chemical conversion of the waste wood mostly into bio-oil. In this work, fast pyrolysis of waste furniture sawdust was investigated under various reaction conditions (pyrolysis temperature, particle size, feed rate and flow rate of fluidizing medium) in a fluidized-bed reactor. The optimal pyrolysis temperature for increased yields of bio-oil was 450 degrees C. Excessively smaller or larger feed size negatively affected the production of bio-oil. Higher flow and feeding rates were more effective for the production of bio-oil, but did not greatly affect the bio-oil yields within the tested ranges. The use of product gas as the fluidizing medium had a potential for increased bio-oil yields.

Clean bio-oil production from fast pyrolysis of sewage sludge: Effects of reaction conditions and metal oxide catalysts

Fast pyrolysis of sewage sludge was carried out under different reaction conditions, and its effects on bio-oil characteristics were studied. The effect of metal oxide catalysts on the removal of chlorine in the bio-oil was also investigated for four types of catalysts. The optimal pyrolysis temperature for bio-oil production was found to be 450 degrees C, while much smaller and larger feed sizes adversely influenced production. Higher flow and feeding rates were more effective but did not greatly affect bio-oil yields. The use of the product gas as the fluidizing medium gave an increased bio-oil yield. Metal oxide catalysts (CaO and La2O3) contributed to a slight decrease in bio-oil yield and an increase in water content but were significantly effective in removal of chlorine from the bio-oil. The fixed catalyst bed system exhibited a higher removal rate than when metal oxide-supported alumina was used as the fluidized bed material.

Influence of operation variables on fast pyrolysis of Miscanthus sinensis var. purpurascens.

Fast pyrolysis of Miscanthus was investigated in a bench-scale fluidized bed reactor for production of bio-oil. Process conditions were varied for temperature (350-550 degrees C), particle size (0.3-1.3mm), feed rate and gas flow rate. Pyrolysis temperature was the most influential parameter upon the yield and properties of bio-oil. The highest bio-oil yield of 69.2wt.% was observed at a temperature of 450 degrees C which corresponded to the end of the thermal composition of hemicellulose and cellulose. In the bio-oil, the water content was 34.5wt.%, and the main compounds in the organic fraction were phenolics and oxygenates. With increasing temperature, the amount of oxygenates in the bio-oil decreased gradually while that of water and aromatics increased rapidly. The bio-oil yield was not significantly affected by particle sizes or feed rates. The use of product gases as a fluidizing medium aided in increasing bio-oil yield.

Catalytic upgrading of oil fractions separated from food waste leachate.

In this work, catalytic cracking of biomass waste oil fractions separated from food waste leachate was performed using microporous catalysts, such as HY, HZSM-5 and mesoporous Al-MCM-48. The experiments were carried out using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to allow the direct analysis of the pyrolytic products. Most acidic components, especially oleic acid, contained in the food waste oil fractions were converted to valuable products, such as oxygenates, hydrocarbons and aromatics. High yields of hydrocarbons within the gasoline-range were obtained when microporous catalysts were used; whereas, the use of Al-MCM-48, which exhibits relatively weak acidity, resulted in high yields of oxygenated and diesel-range hydrocarbons. The HZSM-5 catalyst produced a higher amount of valuable mono aromatics due to its strong acidity and shape selectivity. Especially, the addition of gallium (Ga) to HZSM-5 significantly increased the aromatics content.

The Hydrodeoxygenation of 2-Methoxyphenol over Ni/Kieselguhr Catalysts as a Model Reaction for Bio-oil Upgrading

Ni/kieselguhr catalysts were applied to hydrodeoxygenate 2-methoxyphenol as a model reaction for bio-oil upgrading in a batch reactor at 100°C and 1.36 MPa. The Ni(40 wt%)-MgO(1.8 wt%)/kieselguhr showed much higher activity in the 2-methoxyphenol hydrodeoxygenation, which could be attributed to the optimal nickel particle size, surface area, and reducibility of the catalyst. Of the Na2CO3 + Urea, NaHCO3, and (NH4)2CO3 precipitants, the Na2CO3 + Urea showed the highest activity because the dispersion and surface area of nickel, rather than the pore size of the catalyst, seems to play an important role in the 2-methoxyphenol hydrodeoxygenation.

The Copyrolysis of Block Polypropylene with Particle Board and Medium Density Fiber

Copyrolysis of two waste wood samples with block polypropylene were investigated for the reaction characteristics and properties of the pyrolytic oil. The thermal decomposition of the mixture led to an increase in the temperature range for the decomposition of polypropylene, which implied an interaction in the mixture. New tar compounds were also identified from the copyrolysis using pyrolysis gas chromatography/mass spectrometry. The oil produced from the mixtures in a batch type reactor had an increase in the mass yield, with higher C and H, and lower moisture contents.