Temperature profile prediction within selected materials heated by microwaves at 2.45GHz

Abstract This work presents a three-dimensional mathematical model to simulate temperature profiles inside a material heated by electromagnetic waves (EMW) at 2.45GHz. COMSOL-Multiphysics was used to simulate transient temperature profiles of pinewood, carbon, Pyrex, and combinations of such under different conditions. The model predicts that, upon exposing an 86mm wooden cube to 2.45GHz EMW for 300 s, the core temperature reached 595 K at a setting of 60 K/min, while the outer surface 365 K at 15 K/min. By mixing 50% carbon with the wooden block, the model anticipated the cube core to reach 990 K at 140 K/min, compared to 1350 K at 212 K/min with 75% carbon at the same power and after the same time. By inserting a 125cm3 carbon cube inside the wood cube, the core reaches 3200 K, while the outer surface was 375 K and 636 K for free convection (FC) and perfect insulator (PI), respectively. Placing the same volume of carbon on the surface of the wood cube yielded a maximum temperature of 660 K under FC, compared to 1280 K with PI. Changing the material of the core cube from Carbon to Pyrex yields a temperature of 324 K in the core, with 365 K and 605 K on the outer surface in the case of FC or PI, respectively. The average percentage relative error between the measured and the predicted temperatures was ±4% and ±15% inside the pinewood and carbon respectively.

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

[2]  Ashim K. Datta,et al.  Modeling the heating uniformity contributed by a rotating turntable in microwave ovens , 2007 .

[3]  J. J. Pis,et al.  Microwave-induced pyrolysis of sewage sludge. , 2002, Water research.

[4]  J. A. Menéndez,et al.  Microwave pyrolysis of sewage sludge: analysis of the gas fraction , 2004 .

[5]  L. Campañone,et al.  Mathematical analysis of microwave heating process , 2005 .

[6]  David Rooney,et al.  Dilute Acid Hydrolysis of Cellulose and Cellulosic Bio-Waste Using a Microwave Reactor System , 2007 .

[7]  H. Ramaswamy,et al.  Modeling of temperature profiles under continuous tube-flow microwave and steam heating conditions , 2000 .

[8]  B. Moghtaderi,et al.  Dielectric Properties of Typical Australian Wood-Based Biomass Materials at Microwave Frequency , 2010 .

[9]  Q. Gou,et al.  Advances and Applications of Microwave Spectroscopy , 2008 .

[10]  C. Blasi,et al.  Numerical simulation of the electromagnetic field and the heat and mass transfer processes during microwave-induced pyrolysis of a wood block , 2010 .

[11]  J. J. Pis,et al.  Investigations into the characteristics of oils produced from microwave pyrolysis of sewage sludge , 2005 .

[12]  B. Ondruschka,et al.  Multimode Microwave Reactor for Heterogeneous Gas‐Phase Catalysis , 2003 .

[13]  P. Rattanadecho,et al.  Analysis of microwave induced natural convection in a single mode cavity (Influence of sample volume, placement, and microwave power level) , 2012 .

[14]  Sundaram Gunasekaran,et al.  Temperature profiles in a Cylindrical model food during pulsed microwave heating , 2001 .

[15]  J. Clark,et al.  Microwave assisted decomposition of cellulose: A new thermochemical route for biomass exploitation. , 2010, Bioresource technology.

[16]  Jacqueline M.R. Bélanger,et al.  Microwave applications to oil sands and petroleum: A review , 2010 .

[17]  K. E. Harfi.  Pyrolysis of the Moroccan (Tarfaya) oil shales under microwave irradiation , 2000 .

[18]  Gennaro Cuccurullo,et al.  IR temperature measurements in microwave heating , 2002 .

[19]  David E. Clark,et al.  Processing materials with microwave energy , 2000 .

[20]  Manoj Gupta,et al.  Microwaves and Metals , 2007 .

[21]  S. Gabriel,et al.  Dielectric parameters relevant to microwave dielectric heating , 1998 .

[22]  Ashim K. Datta,et al.  Infrared and hot-air-assisted microwave heating of foods for control of surface moisture , 2002 .

[23]  Bo Zhang,et al.  Microwave-assisted pyrolysis of biomass: Catalysts to improve product selectivity , 2009 .

[24]  Yuanxin Wu,et al.  Microwave-assisted Alkali Pre-treatment of Wheat Straw and its Enzymatic Hydrolysis , 2006 .

[25]  Yuejin Wu,et al.  Enhanced enzymatic saccharification of rice straw by microwave pretreatment. , 2009, Bioresource technology.

[26]  V. M. Puri,et al.  Finite element modeling of heat and mass transfer in food materials during microwave heating — Model development and validation , 1995 .

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

[28]  A. Bliek,et al.  Impregnated carbon as a susceptor material for low loss oxides in dielectric heating , 2003 .

[29]  Toyoji Kakuchi,et al.  Rapid pyrolysis of wood block by microwave heating , 2004 .

[30]  A. Oloyede,et al.  The influence of microwave heating on the mechanical properties of wood , 2000 .

[31]  N. J. Miles,et al.  Microwave heating applications in environmental engineering—a review , 2002 .

[32]  A. Stankiewicz,et al.  Microwaves in Heterogeneous Gas‐Phase Catalysis: Experimental and Numerical Approaches , 2009 .

[33]  Pedro Fito,et al.  Application of microwaves dielectric spectroscopy for controlling pork meat (Longissimus dorsi) salting process , 2010 .

[34]  J. Kennedy,et al.  Rapid esterification of wheat straw hemicelluloses induced by microwave irradiation. , 2008, Carbohydrate polymers.

[35]  Shaojin Wang,et al.  Temperature and moisture dependent dielectric properties of legume flour associated with dielectric heating , 2010 .

[36]  J. Robinson,et al.  Microwave Pyrolysis of Wood Pellets , 2010 .

[37]  Yaobin Zhang,et al.  Microwave thermal remediation of crude oil contaminated soil enhanced by carbon fiber. , 2009, Journal of environmental sciences.

[38]  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.

[39]  H. S. Kol.  THERMAL AND DIELECTRIC PROPERTIES OF PINE WOOD IN THE TRANSVERSE DIRECTION , 2009 .

[40]  R. B. Pandit,et al.  Finite element analysis of microwave heating of potato––transient temperature profiles , 2003 .

[41]  Ashley J. Wilson,et al.  The preparation of high-grade bio-oils through the controlled, low temperature microwave activation of wheat straw. , 2009, Bioresource technology.

[42]  Sundaram Gunasekaran,et al.  Effect of experimental parameters on temperature distribution during continuous and pulsed microwave heating , 2007 .

[43]  E. Chiavaro,et al.  Microwave heating of different commercial categories of olive oil: Part II. Effect on thermal properties , 2009 .

[44]  Phadungsak Rattanadecho,et al.  Non-commercial Research and Educational Use including without Limitation Use in Instruction at Your Institution, Sending It to Specific Colleagues That You Know, and Providing a Copy to Your Institution's Administrator. All Other Uses, Reproduction and Distribution, including without Limitation Comm , 2022 .

[45]  W. McWhinnie,et al.  Rapid microwave pyrolysis of coal: Methodology and examination of the residual and volatile phases , 1995 .