| 1. |
- Lin, Leteng, 1980-, et al.
(författare)
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High-temperature Kinetics of Fine Biomass Char Particles in Air and CO2
- 2010
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Ingår i: 18th European Biomass Conference and Exhibition.
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Konferensbidrag (refereegranskat)abstract
- Knowledge of reliable chemical kinetics of char always plays significant roles in the modelling, design and optimization of processes during biofuel thermochemical conversions.The determination of reaction kinetics of char in the high-temperature range still highly depends on the extrapolation of results from kinetic data determined at lower temperatures due to mass and heat transfer limitations. In this work an aerosol-based method was used to investigate the reactivity of singly-distributed char particles with aerodynamic diameters between 0.5-10 mm. The conversion of char particles in the reactor at varying temperatures and residence time was determined by comparing the particle size distributions before and after passing the reactor, using an aerodynamic particle sizer (APS) spectrometer. The results of char particles reacted with air, CO2 and steam indicate that the aerosol-based method can be used to determine reaction kinetics of char particles in the high temperature range where reaction is controlled by diffusion limitation if using conventional thermogravimetric analysis (TGA). By combining the aerosol-based method and conventional TGA, the oxidation and gasification kinetic parameters of biomass char can be derived in the temperature range of 350-800ºC, and 800-1200ºC respectively. The aerosol-based method shows the potential of on-line measuring the char reactivity.
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| 2. |
- Pettersson, Jens, 1960-, et al.
(författare)
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Charging and removal efficiency of an ESP in a 250 kW biomass boiler
- 2012
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Ingår i: International Journal of Plasma Environmental Science and Technology. - : The Institute of Electrostatics Japan. - 1881-8692 .- 2435-0125. ; 6:3, s. 204-209
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Tidskriftsartikel (refereegranskat)abstract
- The combustion of biomass creates ultra-fine particulate matter which is not precipitated by traditional multi cyclone technique, usually adopted on small scale plants. In Sweden the number of small bio fuelled plants is increasing and there is a need for cost effective means to precipitate the ultra-fine particles formed. One such technique may be electrostatic precipitation, but the economy of scale is a constraining factor for systems commercially available today. This paper describes field tests of a low cost electrostatic precipitator, ESP, including not only investigation of collection efficiency, but also measurement of charging effectiveness. The aim of the tests was to determine the potential for the low cost ESP design to form part of an electrostatic precipitation system for use on bio fuelled plants in the megawatt scale. The charges acquired by the particles have been measured using a low pressure cascade impactor, ELPI. Measurements of charges were carried out on particles escaping from the ESP. The results of the measurements of particle charges indicates that the method may correctly reflect the mean charge levels of particles of the different sizes usually found within the fine particle mode of flue gases from biomass combustion.
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