## 2 Materials and Methods
### Characteristics of the Samples  
Chosen samples of the raw material from the processing plants were acquired directly from producers in the region of South Moravia in the Czech Republic according to ISO 18135 [21]. Table 1 has been obtained from Situation and outlook reports--Fruit and Grape vine and wine [22; 23] and it shows the available waste material in the Czech Republic for the year 2022, showing the amount of potential waste material that could be treated and burned to generate heat. The volume of the material shown reflects material harvested and processed, with the exception of almonds, dates and pistachio nuts, which are imported and only processed in the country. These materials represent commonly occurring waste materials in the processing industry and have so far been used for energy production only to a limited extent. These materials (Figure 1) are, however, produced in relatively large quantities during the processing season. The pomace of raspberries, sea-buckthorn and grapes is the result of pressing the fruit to produce juice. The pomace consists of seeds, pulp, skins and minimally the stems. It also contains residual water. The applied pressure of the press governs the residual moisture content (the higher the pressure, the more compact the pomace and the lower the moisture content). Processing of raw almonds yields, as a by-product, shells and sometimes seed coats when the seeds (nuts) are treated. The almond shell is dry, relatively hard material, and prior to consumption is always removed. On the other hand, the seed coat is thin and does not need to be removed when producing raw almonds. For use in confectionery, it is removed by blanching. The blanching process produces waste that is quite moist. The stones of peach, plum and date are obtained from the raw fruit and are separated relatively easily from the fruit without adhering pulp. The stones are relatively dry and also contain inside approximately 30% oil, which can potentially add to the calorific value of the waste. This waste material is encountered in the canning and distilling industries or in the press production of juices. Pistachio shells are produced by shelling the kernel; the shells are hard and dry and are therefore suitable for incineration. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{3}{*}{**Fruit**} & **Processed** & \begin{tabular}{c} **Amount of Harvest or** \\ **Inport in the Czech** \\ **Republic** \\ **(Tonnes)** \\ \end{tabular} & \begin{tabular}{c} **Content of** \\ **Waste Products** \\ **in the Fruit** \\ **(g\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Potential** \\ **Amount of** \\ **Waste Material** \\ **(Tonnes)** \\ \end{tabular} \\ \hline
\begin{tabular}{c} Raspberries \\ (_Rubus ideaus_) \\ Sea-buckthorn \\ (_Hippothe_ \\ _Humuoides_) \\ Grape vine \\ (_Vitis vinifera_) \\ Grape vine \\ (_Vitis vinifera_) \\ Grape vine \\ (_Vitis vinifera_) \\ Almond \\ (_Prumus dulcis_) \\ Pistachio \\ (_Pistaci rerio_) \\ Almond \\ (_Prunus dulcis_) \\ (_Prunus dulcis_) \\ Peach \\ (_Prunus pexica_) \\ Plum \\ (_Prunus dulcis_) \\ Plum \\ (_Prunus domestic_) \\ Date \\ (_Phoenix_ \\ _dactylifera_) \\ Sum & 239,145 \\ \hline \hline \end{tabular} Note: The data source is the report on fruit production in the Czech Republic 2022 [22,23].  
\end{table} 
Table 1: Volume of waste materials production in the Czech Republic or imported to the country in one calendar year. Grape seed cakes are produced when grape seeds are pressed to produce oil. The solid residue, the cakes, still contains a portion of residual oil that can increase calorific value of the waste material. Characterised waste products:  
The materials were collected separately for the individual experiment variants (approximately 50 kg per variant) directly from producers in the South Moravia region of the Czech Republic.