## 3 Literature Review
### Peat Processing Technologies and Peat Applications
#### 3.2.1 Technologies and Technological Processes in Peat Processing  
Peat can serve as a replacement for fossil-based resources. The potential applications of peat biomass include using it as a raw material for building materials, in the food industry, and even as pharmaceutical products. Only a limited perspective can be found in the scientific literature on how peat can be processed for use in innovative products and materials as the key component or additive [57; 117; 149]. Peat can be used for energy production through gasification, direct combustion to produce electricity, or methane production [150]. Direct combustion for power production is a simple method for converting biomass energy into electrical energy. The process involves converting chemical energy into steam and then using this steam to rotate the turbine and generate power [150].  
Gaseous and liquid substances are transformed at high and elevated temperatures in the gasification process. The thermochemical processes include drying, pyrolysis, combustion, cracking, and reduction. Biomass is converted into gaseous biofuels. It is a more complicated method than direct combustion [150].  
Peat methane utilisation is a processing method for use with methane fuels, converting biogenic gas into electricity. The actual collection of CH\({}_{4}\) from peatlands is meant here [150].  
Processing techniques for energy peat are summarised in Figure 3.  
In Finland, 3-5% is used as a fuel resource [150]. However, peat is also used as a raw material in agriculture and livestock farming [150]. In northern Europe, peatlands are often transformed into grasslands, which can be used for dairy and livestock farming. In recent years, the bioeconomy has become a possible solution for the more sustainable use of peatlands [36; 46; 126]. The use of peat for energy purposes is evaluated with the lowest added value [33]. Developing technologies that can convert biomass into liquid biofuels, such as hydrothermal liquefaction, pyrolysis, and gasification, is an active area of research. Volatile organic compounds and carbon found in peat biomass can be converted into liquid biofuel [102; 151].  
Using different methods, peat can produce thermal insulation and raw materials in various construction materials substrates, and pharmaceutical products [152; 153; 154; 155; 156]. Also, an agro-industrial resource, peat, has a high but not fully used potential [57; 58]. The following section discusses technologies and processing processes for producing non-energy peat materials and products. Before peat can be used as a raw material in products or materials, peat must undergo chemical and thermal treatment processes [55; 98; 102]. Various methods can be applied to process non-energy peat, such as extraction, pyrolysis, hydrolysis, thermal dissolution, and chemical modification [95; 150]. Peat hydrolysis allows for the extraction of biologically active compounds from organic matter. Peat wax with valuable properties can be obtained for industry and medicinal applications. Pyrolysis produces liquid fuel, coke, and fuel gas [95; 150]. The processing methods of non-energy peat are shown in Figure 4.