Ibai Funcia has a Master’s Degree in Chemistry from the University of Navarra (UPNa), Spain; pursued a course in Pedagogical Aptitude from the same university and a Project Management Interuniversity Master's Degree by the University of La Rioja (Spain). He is currently developing his PhD thesis at the UPNa on Science and Industrial Technologies PhD Program. Since 2004 he has been working in Biomass Department, National Renewable Energy Centre, Spain as a Biomass Researcher in the following main lines: 1. Thermo-chemical route: biomass torrefaction, biomass combustion (ash behavior at high temperature) and biomass gasification (tar cleaning, sampling and analysis). 2. Biochemical route: biomass pretreatment, enzymatic hydrolysis and fermentation. 3. Biomass and Bio-fuel characterization. 4. Chromatography methods development. 5. Laboratory quality and assurance procedures implementation.
Thermochemical modeling seems a promising tool in the biomass combustion field to avoid ash-related problems during combustion: slagging, fouling and corrosion. Several authors have used thermochemical software packages to understand and validate their experimental results in different biomass combustion studies, focusing directly on ash composition or ash streams composition. Besides, most of these studies are focused on operational issues, especially on those concerning de-fluidization phenomena, in pilot scale combustion plants. In this work, a thermochemical model was developed to predict inorganic elements’ released during combustion and the melting behavior and composition of the fly ash in the downstream, allowing to evaluate the effect of biofuel composition on the ash composition and behavior. With the aid of experimental data obtained by common techniques, previously used in other studies, such as chemical fractionation and chemical analysis to understand elements distribution during combustion, the model could be validated by comparison with real data. The results obtained with the model presented in this work, reveal the importance of the S/Cl molar ratio to reduce ash deposition problems during gas cooling in the combustion of wheat straw using large scale vibrating grate technologies.
Shun Chang Yen, PhD received his BS Degree from Republic of China Air Force Academy, Taiwan in 1992 and MS and PhD in Mechanical Engineering from National Taiwan University of Science and Technology, Taiwan in 1998 and 2003 respectively. He is a Full Professor of Mechanical and Mechatronic Engineering Department at the National Taiwan Ocean University, Taiwan. His researches cover fluid mechanics, aerodynamics, combustion technology, chemically reacting flows and related fields.
In this study, astral-type bluff bodies were placed on a burner to control flow fields, enhance the combustion efficiency of the burner and achieve energy conservation. In the experiment, the astral-type bluff bodies were placed on a burner when fluids passed the bluff bodies. The axial kinetic energy of the flow field was transformed into radial kinetic energy. The radial motion created a vortex flow structure that increased heat release and improved combustion efficiency. Furthermore, the astral-type mechanism was utilized to improve the mixing between fuel and air, and then reduce the formation of hydrocarbon. The experimental methods such as thermocouples and photography techniques were used to obtain the characteristic flame patterns, flame heights, temperature distribution, heat release rate, and the concentration of combusted exhaust gases. In this study, four bluff bodies (disk-shaped, concentric, three astral- type, and six astral-type) were utilized. The flame fields were divided into the following modes: jet flame, flickering flame, swirling flame, and lifted flame. The six- astral-type bluff body increased heat release by 44%, 35% increase by the concentric bluff body and 12.4% increase by the three astral-type bluff body. A gas analyzer was used to measure the concentration of exhaust gases (O2, CO2, C3H8, CO and NO) in the burner region. In comparison to that of a concentric bluff body, a 23% lower carbon monoxide (CO) concentration was generated when a six astral-type bluff body was used, whereas 40% CO was generated for a three astral-type bluff body.