## 1 Introduction
The expected production volume of biogas with a content of approximately 55% methane (CH\({}_{4}\)) in the digester is 0.97\(\cdot\)10\({}^{-3}\) to 13.8\(\cdot\)10\({}^{-3}\) m\({}^{3}\cdot\)s\({}^{-1}\). Corresponding to this amount of biogas, the electrical power of the micro-biogas plant is approximately 7-10 kW\({}_{\rm{el}}\) (reference value). The designed fermentation chamber with insulation and external cover in the form of trapezoidal sheets does not generally exceed the dimensions of a 40-foot elevated shipping container. The total capacity is approx. 70 m\({}^{3}\), and the capacity of the filling with substrates is approx. 60 m\({}^{3}\). A biogas buffer store with a capacity of approximately 15 m\({}^{3}\), covered with a roof made of trapezoidal sheet metal, is planned to be placed on top of the container. The chamber is fed with substrates through a covered injection channel in the upper part of the container. The substrates delivered through the injection channel fall down the inclined plate into the interior of the chamber. The chamber does not have a mixer, and periodic spraying with percolate (fermented slurry) is used. The produced biogas, collected in the biogas buffer storage, is directed to the engine of the cogenerationunit, where the biogas energy is converted into electricity and heat. The cogeneration system is located on the KMR7 service platform, in a separate soundproofed container or in designated rooms of the farm. KMR7 is equipped with a standard connection system to the low-voltage network, including a switch, a connection cabinet with control and protection equipment, and the required telemechanics installation (telesignaling and telemeasurements). One of the main advantages of the structure is the possibility of transporting it without the need to obtain special permits, including construction [12]. It was assumed that in order to meet the demand of investors of pico-installations and biogas micro-installations, the basic element should be an agricultural micro-biogas plant container from the company Mega Sp. z o. o. [13] (Figure 1b), retrofitted with devices for initial hydrolysis of the feedstock and with devices used to improve the electrical efficiency of the power generator. The purpose of the AB Biogas System micro-biogas plant (Figure 1c) is to feed organic waste to the biological fermentation plant and make the resulting biogas available for further use [14]. The resulting fermentation residue can be used as a liquid soil improv (e.g., fertilizer). In this case, organic waste in the amount of 1.15\(\cdot\)10\({}^{-3}\)-11.57\(\cdot\)10\({}^{-3}\) kg\(\cdot\)s\({}^{-1}\) can be recycled and obtain biogas 1.38\(\cdot\)10\({}^{-3}\) m\({}^{3}\cdot\)s\({}^{-1}\). For logistical reasons, the entire micro-biogas plant is mounted in a 20-foot cargo container. Upon delivery, the gas storage facility is mounted on the roof of the container. Any number of micro-biogas plants that can operate  
Figure 1: Mobile installations for agricultural biogas production: (**a**) agricultural micro-biogas plant KMR7 container [12], (**b**) micro-biogas plant container [13], (**c**) micro-biogas plant [14], (**d**) MB-30 agricultural micro-biogas plant [15], (**e**) MB-50 agricultural micro-biogas plant [15]. in parallel to each other is possible. The introduction of organic waste takes place using a shredding unit. The shredder is mounted at the front and (like all other controls) accessible by opening the container door. Further feeding of shredded waste into the digestion space takes place automatically using a pumping system. The fermenter is equipped with a heater and a paddle mixer. The heating must be externally powered to maintain a constant temperature in the digester, especially during the colder months. The demand for thermal energy depends on the ambient temperature. The paddle mixer is driven by an electric motor via a flange gear and operates at a constant speed. The engine is controlled via an integrated control. The actual fermentation is fully automatic.