Kinetics of CO release from bark and medium density fibreboard pyrolysis R.J.M. Bastiaans*, A. Toland, A. Holten, L.P.H. de Goey Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands article info Article history: Received 26 March 2009 Accepted 12 January 2010 Available online 2 February 2010 Keywords: CO kinetics Pine bark MDF Grid reactor Absorption measurement abstract The apparent rate of CO release during pyrolysis, from bark and Medium Density Fibre- board (MDF) particles was measured. The method used was a pre heated wire grid tech- nique. Experiments were performed under ambient nitrogen and at atmospheric pressure conditions over a temperature range 620–940 K. The temperature history of each pyrolysis experiment has been recorded. The CO release was monitored using a tunable diode laser set to a single infrared absorption line of 2082 cm 1 . The release followed a typical growth curve in time to a steady state level. Curves were fitted using a simple first order kinetic analysis and Arrhenius parameters were extracted. Both uncertainties in applied temperature and release rate were taken into account. The calculated apparent activation energies E a were 64  6 kJ mol 1 for bark and 71  6 kJ mol 1 for MDF, uncertainties are determined on a very conservative basis. A single apparent rate seems to be a fair description although two time scales can be identified. ª 2010 Elsevier Ltd. All rights reserved. 1. Introduction In recent years there has been a renewed emphasis on the use of sustainable forms of energy to replace, at least in part, dwindling fossil fuel resources. However it is not solely on account of economic factors that this upsurge in interest is happening but also due to a widespread awareness of the harmful impact our reliance on fossil fuel is having on our environment. With this in mind, European governments have set targets for increasing the relative contribution from sustainable energy to national power output over the coming years ([1]). One of the major forms of sustainable energy is biomass, a source that can be reaped and replenished in reasonably short time scales and is considered CO 2 neutral. Research and development in this area has received intermittent emphasis over the years, (e.g. [2]), however, the topic is now in a period of more sustained growth. The by-products of the wood processing industry make a significant contribution to total biomass stocks. This is, therefore, a major source of renew- able energy for adapted or purpose built electricity generating plants. An electricity generating plan that is adaptable to variable fuel loads is a more viable economic investment. A variable feedstock means fluctuating levels of CO released from the fuel layer during the pre-combustion, thermal decomposition of the fuel particle or pyrolysis. Pyrolysis is a process whereby a material is thermally decomposed in the absence of an oxidant. In the case of biomass (or coal) the result is the formation of char, tar and gas. Interest is ongoing in the development of kinetic models to accurately describe the release of CO, amongst other species, from the fuel layer (e.g. the European OPTICOMB project, [3,4]). In the study of Albrecht et al., [5], a correlation based on quite coarse exper- imental observations is used for the volatile release from a fuel bed, to investigate the gaseous combustion in a grate furnace with computational fluid dynamics. For developing * Corresponding author. Tel.: þ314024836; fax: þ31402433445. E-mail address: r.j.m.bastiaans@tue.nl (R.J.M. Bastiaans). Available at www.sciencedirect.com http://www.elsevier.com/locate/biombioe biomass and bioenergy 34 (2010) 771–779 0961-9534/$ – see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.biombioe.2010.01.020