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Upgrading biomass pyrolysis vapour over faujasite catalysts. T.S. Nguyen, A. Imran, L. Lefferts, G. Brem, K. Seshan. Introduction. Motivation. Pyrolysis. 500˚C, 1 atm, < 2 sec. World fossil reserves are being depleted. Bio-oil. Biomass is a “Sustainable feedstock”.
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Upgrading biomass pyrolysis vapour over faujasite catalysts T.S. Nguyen, A. Imran, L. Lefferts, G. Brem, K. Seshan
Introduction Motivation Pyrolysis 500˚C, 1 atm, < 2 sec • World fossil reserves are being depleted Bio-oil • Biomass is a “Sustainable feedstock” Biomass waste/residue • Bio-oil allows easier storage and transport
Introduction Conceptual design • Integration with crude oil refineries • Generation of green fuel, take advantage of existed infrastructure
Introduction Problems identification Characteristic Bio-oil Heavy Fuel Oil Water content (w%) 15-35 0.1 C (w%, dry) 50-64 85 H (w%, dry) 5.2-7 11.1 O (w%, dry) 35-40 1.0 N (w%, dry) 0.05-0.4 0.3 S (w%, dry) 0.05-0.3 2.3 Energy content (MJ/kg) 16 – 19* 40 Viscosity (cP at 50oC) 40-150 180 pH 2.4 -- • Higher oxygen content in Bio-oil causes the problems
introduction goal • Catalytic design to selectively remove oxygen from biomass
Introduction Experimental set-up Gas preheater IR furnace To GC Catalyst bed Condensers • Fixed bed reactor/ catalyst mixed with biomass • H-FAU, Na-FAU and Na0.2H0.8-FAU, SiO2/Al2O3 = 5.2 • RT – 500 ºC ramp in 8 sec (fast pyrolysis)
Results & discussion Product yields • Acid sites facilitated cracking reactions, resulted in the formation of coke and gas
Abundance Pyrolysis TIC: US wood 01.D\data.ms 750000 700000 650000 600000 550000 500000 450000 400000 350000 300000 250000 200000 150000 100000 50000 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 Time--> GC-MS analysis of bio-oil Results& Discussion • Chemical composition of bio-oil were investigated • Components in bio-oil reflect the decomposition of the three components: cellulose, hemicellulose, and lignin
Ketones, aldehydes, acids Results& Discussion How are they formed? Cellulose Furan derivatives
Results& Discussion How are they formed? Sugars Ketones, aldehydes, acids Furan derivatives Hemicellulose
Results& Discussion How are they formed? Phenol derivatives Lignin
Results& Discussion Acidity of bio-oil • Carboxylic acids, phenols and sugars all contribute to acidity of bio-oil
Results& Discussion Acidity of bio-oil- what determines acidity? • Acids contribute the most
Results& Discussion Acidity of bio-oil Pt catalyst + H2 • Decrease acidity of bio-oil by decreasing acids and sugars, • Phenols less acidic but have high energy content • Hydrogenation is an option
Results& Discussion Stability of bio-oil- How is aging happen? • During aging process, low-molecular-weight components react with each other to form heavy fraction, increase viscosity. • In most of the reactions which occurs during this process, aldehydes react with itself or other components such as phenol or alcohol and form water.
Results& Discussion Stability of bio-oil • Using the catalysts, the concentration of carbonyls is decreased and hence higher stability is expected
Results& Discussion Energy content of bio-oil • Due to the low H/C in biomass, the obtained HCs in bio-oil are mostly aromatics • These aromatics are formed from both cellulose, hemicellulose and lignin • Na0.2H0.8-FAU favours the formation of HCs and hence improve the energy content of bio-oil
Conclusions& Planning Bio-oil bulk analysis • Quality of bio-oil in terms of : stability, acidity and energy content have been improved. • The extent of the improvement is not high enough.
Conclusions& planning sodium based catalysts- Future plan • With sodium-based catalysts, it is possible to decrease the oxygen content in bio-oil down to 11 wt.% and resulted in a high energy oil (almost fuel oil ~ 40 MJ/kg). • Future plan: • Carry out hydrogenation to further improve quality of bio-oil. • Finding another source of cheaper [H]
Acknowledgement • B.G. Geerdink and K. Altena- Schildkamp for technical support • M. Zabeti and A. Imran for fruitful discussions • GSPT (STW) for financial support GSPT Green & Smart Process Technologies THANK YOU!
Results& Discussion Gas analysis • CO and CO2 are the main products • The yield of CO2 maximized with Na0.2H0.8-FAU catalyst • Hydrocarbons can be recycled as a [H] source
Results& Discussion Coke and Char analysis • Coke and char are oxygen-containing oligomeric species • Coke is aromatic in nature (molar C:H=7:6)