Influence of feed characteristics on the microwave-assisted pyrolysis used to produce syngas from biomass wastes

A series of biomass wastes (sewage sludges, coffee hulls and glycerol) were subjected to pyrolysis experiments under conventional and microwave heating. The influence of the initial characteristics of the raw materials upon syngas production was studied. Glycerol yielded the highest concentration of syngas, but the lowest H2/CO ratio, whereas sewage sludges produced the lowest syngas production with the highest H2/CO molar ratio. Coffee hull displayed intermediate values for both parameters. Microwave heating produced greater gas yields with elevated syngas content than conventional pyrolysis. Moreover, microwave pyrolysis always achieved the desired effect with temperature increase upon the pyrolysis products, whatever biomass material was employed. This could be due to the hot spot phenomenon, which only occurs under microwave heating. In addition, a comparison of the energy consumption of the traditional and microwave-assisted pyrolysis is also presented. Results point at microwave system as less time and energy consuming in comparison to conventional system.

[1]  André Faaij,et al.  Bio-energy in Europe: changing technology choices , 2006 .

[2]  D. Meier,et al.  Volatile products of catalytic flash pyrolysis of celluloses , 2001 .

[3]  Ilknur Alibas,et al.  Energy Consumption and Colour Characteristics of Nettle Leaves during Microwave, Vacuum and Convective Drying , 2007 .

[4]  C. Braekman-Danheux,et al.  Municipal waste pyrolysis (1). The behaviour of chlorine with cellulose and lignin , 2000 .

[5]  Y. F. Huang,et al.  Total recovery of resources and energy from rice straw using microwave-induced pyrolysis. , 2008, Bioresource technology.

[6]  José M. Encinar,et al.  Pyrolysis of various biomass residues and char utilization for the production of activated carbons. , 2009 .

[7]  Tsu-Wei Chou,et al.  Microwave processing: fundamentals and applications , 1999 .

[8]  J. A. Menéndez,et al.  Pyrolysis of glycerol over activated carbons for syngas production , 2009 .

[9]  N. Petrov,et al.  Biomass conversion to carbon adsorbents and gas , 2001 .

[10]  J. A. Menéndez,et al.  Conventional and microwave induced pyrolysis of coffee hulls for the production of a hydrogen rich fuel gas , 2007 .

[11]  A. Demirbas,et al.  Yields of hydrogen-rich gaseous products via pyrolysis from selected biomass samples , 2001 .

[12]  S. Salvador,et al.  Failure of the component additivity rule to predict gas yields of biomass in flash pyrolysis at 950 °C , 2009 .

[13]  J. A. Menéndez,et al.  Bio-syngas production with low concentrations of CO2 and CH4 from microwave-induced pyrolysis of wet and dried sewage sludge. , 2008, Chemosphere.

[14]  Suresh Prasad,et al.  Specific energy consumption in microwave drying of garlic cloves , 2006 .

[15]  Jenny M. Jones,et al.  Phosphorus catalysis in the pyrolysis behaviour of biomass , 2008 .

[16]  J. J. Pis,et al.  Production of bio-fuels by high temperature pyrolysis of sewage sludge using conventional and microwave heating. , 2006, Bioresource technology.

[17]  Rafael Font,et al.  Kinetic models for the pyrolysis and combustion of two types of sewage sludge , 2005 .

[18]  Juan A. Conesa,et al.  Evolution of gases in the primary pyrolysis of different sewage sludges , 1998 .

[19]  J. A. Menéndez,et al.  Microwave Heating Applied to Pyrolysis , 2011 .

[20]  Islam Ahmed,et al.  Syngas yield during pyrolysis and steam gasification of paper , 2009 .

[21]  Xavier Py,et al.  Contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and steam activated carbons from various lignocellulosic precursors. , 2009, Bioresource technology.

[22]  Raf Dewil,et al.  Fundamentals, kinetics and endothermicity of the biomass pyrolysis reaction , 2010 .

[23]  S. Salvador,et al.  Is it possible to predict gas yields of any biomass after rapid pyrolysis at high temperature from its composition in cellulose, hemicellulose and lignin? , 2009 .

[24]  L. Schmidt,et al.  Oxidation of Methanol over Polycrystalline Rh and Pt: Rates, OH Desorption, and Model , 1996 .

[25]  J. J. Pis,et al.  Evidence of self-gasification during the microwave-induced pyrolysis of coffee hulls , 2007 .

[26]  José M. Encinar,et al.  Pyrolysis/gasification of agricultural residues by carbon dioxide in the presence of different additives: influence of variables , 1998 .

[27]  S. Grundas,et al.  Advances in Induction and Microwave Heating of Mineral and Organic Materials , 2011 .

[28]  Nicholas H. Florin,et al.  The influence of supported Ni catalysts on the product gas distribution and H2 yield during cellulose pyrolysis , 2009 .

[29]  Paul J. Dauenhauer,et al.  Renewable hydrogen by autothermal steam reforming of volatile carbohydrates , 2006 .

[30]  Juan A. Conesa,et al.  KINETIC STUDY OF THE PYROLYSIS OF SEWAGE SLUDGE , 1997 .