## 2 Potential of Municipal Waste to Energy Production--Review
For example, THERMOSEL 2002 (opened)/2006 (closed), DBA 2001/2010, EDDITH 2002/2009 and Schwel-Brenn 1997/2000 [52; 53]. Group No III comprises biodegradable waste, i.e., waste that can be subjected to biological gasification in the methane fermentation process. During decomposition of organic matter under controlled anaerobic conditions, biogas is generated, which contains flammable components, including methane. The share of biogas production in European Union countries makes up 136.6 million tons of oil equivalent [54]. The content of methane, depending on the raw material, is 50-75% and the calorific value is, on average, 22 MJ/m\({}^{3}\)[55; 56]. In the case of the organic fraction separated from municipal waste, the yield of biogas volume in the plants that use the methane fermentation process in low \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Components**} & \multicolumn{2}{c}{**Mixed (1)**} & \multicolumn{2}{c}{**>80–90 mm (1)**} & \multicolumn{2}{c}{**<80–90 mm (1)**} \\ \cline{3-6}  & & **\%(w/w)** & **\%(w/w)** & **Group, No** & **\%(w/w)** & **Group, No** \\ \hline
1 & Kitchen (BIO1) & 25.1 & 0.9 & III & 12.7 & III \\
2 & Park, garden (BIO2) & 0.3 & 0.6 & III & 0.3 & III \\
3 & Organic (BIO3) & 0.6 & 5.9 & III & 34.7 & III \\
4 & Wood & 0.6 & 1.3 & II & 0.6 & II \\
5 & Paper & 14.6 & 22.4 & I & 9.8 & II \\
6 & Plastic & 14.1 & 32.6 & I & 5.7 & II \\
7 & Glass & 8.6 & 1.4 & I & 11.1 & I \\
8 & Textiles & 39 & 12.7 & II & 0.6 & II \\
9 & Metals & 2 & 1.4 & I & 1.3 & I \\
10 & Multicomponent & 3.6 & 6.5 & II & 1.5 & II \\
11 & Other & 9.5 & 14.2 & IV & 21.7 & IV \\  & \textless{}20 mm & 17.7 & - & - & - & - \\ \hline \hline \end{tabular} \({}^{(1)}\) Own study.  
\end{table} 
Table 1: Percentage shares of waste components and classification into four different groups. hydration conditions (DFI) reaches 339 m\({}^{3}\) CH\({}_{4}\)/Mg organic matter [57]. A possibility to generate biogas, resulting in a reduction in waste processing costs will be, in future, the primary factor deciding the selection of this biological waste processing method. Waste that is also suitable for the methane transformation process is sewage sludge (SS), originating from municipal wastewater treatment plants. In 2018 in Poland, 640,000 t of dry matter from sewage sludge was generated. This is equivalent to approx. 25 million tons of mechanically dehydrated sludge to 80% humidity on average [36]. The volume of methane generated during the fermentation process carried out in separate chambers in high-hydration conditions is 0.19-0.24 m\({}^{3}\)/kg organic matter [58]. The application of the thermal method for the disposal of sewage sludge requires a reduction in its humidity to at least 10%. This means that the consumption of energy for mechanical dehydration, then water evaporation from sludge with an initial humidity of 98%, is very high. Other sorts of waste, which due to their properties may constitute a raw material for energy generating processes in various forms, are generated in populated areas; they comprise, among other things, waste from selective collection, including biowaste, organic waste from green area cultivation and biodegradable waste from production and foodstuff processing as well as flammable packaging waste with low value as recyclable material. The diversity of municipal waste means that optimisation of the system of energy generation from waste should take into account not just waste fuel properties but also its morphological features. This also means there is a necessity to apply various methods for the preparation of the raw material earmarked for the generation of energy in the form of heat, electricity and gas. Using (i) available techniques and (ii) applying the principle of cooperation between the waste generating and processing entities [59], an ERWP model was developed; it allows for assessment of the volume of energy generated from the processing of amassed waste independently of its volume, type and specific features.