Biomass products are used as an energy source in many fields of industry and households. One such source can be pellets or briquettes made of wood chips, ideally made of waste wood. The final quality of these products is affected by many parameters, not only the process (production) parameters but also the material properties are important. A common aim of the research is to maximize the calorific value and minimize the emission of greenhouse gases, which is mainly influenced by the particle size distribution of the raw material. A mixture containing very fine grains will not allow the flow of oxygen, which will make it more difficult to burn the briquette, and conversely, if the percentage of the coarse fraction is high, there will be a larger proportion of oxygen, causing a greater emission of contaminating gases. In addition, particle size distribution may also affect the production of briquettes and pellets, and therefore such analysis is necessary before the wood chips are processed.
In the case of wood chips, the irregular–flaky shape is not the most ideal in terms of analysis. During the measurement, there is an effort to characterize each particle with one dimension. There are many ways to achieve this one dimension, while the result of each method of analysis may be different. For this reason, it is necessary to conduct a series of experiments on several devices to evaluate these measurements and compare the results. The first device used is Malvern’s Mastersizer 3000, which uses the laser diffraction technique to measure the particle size. The second device used is Malvern’s Morphologi G3, which measures the size and shape of the particle by static image analysis. The third usable device is Microtrac’s PartAn 3D, which uses the dynamic image analysis method. The sieve analysis with the Retsch AS200 is employed to compare the results by laser and optical methods.