Determination of kinetic parameters of pyrolysis of wheat straw using thermogravimetry and mathematical models

In many countries of the Central and Eastern Europe which have huge economic and energy potential of the straw, this agricultural waste becomes to be attractive material which can be utilized near to place of the production in the heating devices as well as in the gasifying facilities. Unfortunately straw is characterized by strongly various properties, which depends on type of straw, geographic location of growing as well as methods of the cultivation. Due to this fact, comprehensive approach to studies of the straw from given region is required to obtain information necessary to perform reliable simulations of its thermochemical conversion, what allows to carry out the optimisation of operation of the heating devices and the gasifiers. The paper presents methodology and results of the studies of the wheat straw from the southern Poland. The analysed properties were selected in order to use them for further development of the numerical simulation of the heterogeneous combustion of the considered fuel. Proximate and ultimate analysis as well as determination of the higher heating value (HHV) have been performed and compared with data presented in literature. Then thermogravimetry was carried out to determine content as well as dynamics of the decomposition of the pseudocomponents in the fuel. Selected approaches to model fitting and model-free methods described in this paper have been applied to find kinetic parameters of the straw pyrolysis.