Correlation of the colour of straw fuel pellets to the compressive properties

Abstract

The aim of the manuscript was the evaluation of the compressive properties of straw pellets in relation to the colour differences between them. Modulus of elasticity and failure strength of the pellets at the compression were determined. A testing machine Andilog Stentor 1000 (Andilog Technologies, Vitrolles, France) was employed for uniaxial compression tests. L*, a*, b* colour coordinates of CIE LAB 3D colour space were used for the characterization of the pellet's colour. Two sorts of pellets were measured: made from wheat straw and made from the mixed wheat and barley straw. Samples were measured by a spectrophotometer 3NH YS3020 and computed as the mean of twenty samples. The correlation of the pellet colour with the mechanical properties, mainly modulus of elasticity and failure strength of the pellets at the compression were realized to obtain a relation of the deformation process to the pellet's colour of different sorts of pellets.