COMPARATIVE STUDY OF PURE AND COMMERCIAL BIOMASS DURING PYROLYSIS

摘要

Due to the current scarcity of fossil fuels (among other drawbacks), renewable energy sources haverecently gained prominence. Thus, nowadays biomass plays a more and more important role. There are manyagricultural wastes that can be used as energy sources in Extremadura region, such as Grape pomace and Pyreneanoak. On the other hand, commercial biomass feedstock is widely used, being its composition quite heterogeneouscompared to the latter raw materials. During pyrolysis, some pollutants are evolved, some of them with harmfuleffects over human health and the environment. The aim of this work was to assess some evolved compounds (CO_2,NO_x, benzene and toluene) during pyrolysis of two different raw materials and a commercial biomass using a thermogravimetric-mass spectrometry system. Some kinetic parameters were also measured, based on the Coats-Redfern andCriado methods. Therefore, a comparative study between raw materials and commercial biomass was carried out.Regarding TG behaviour, it was found that commercial material started its degradation at lower temperature,indicating a higher reactivity at the first stage of decomposition. Subsequently, both pure biomass materials showed afaster degradation rate for higher conversions. These trends were consistent with kinetics data; for the first andsecond stages of pyrolysis, the commercial biomass exhibited higher activation energies (60.65 and 82.27,respectively). Concerning the emissions, carbon dioxide associated signal showed a very good agreement with DTGprofiles. Also NO_x emissions were higher for commercial sample. As far as organic compounds are concerned, therewere no significant differences between the samples in study.