| Abstract [eng] |
The possibilities to increase biogas potential during centralized treatment municipal biodegradable waste (BDW) within mechanical biological treatment (MBT) plant with anaerobic formation are evaluated in this Master’s thesis. The hypothesis of this work is that the source separation of food waste and centralized treatment in MBT equipment increases biogas yield, therefore, better quality compost is produced. This decision has to be economic beneficial to the regional level due to reducing the cost of mixed municipal waste management. Utena region was selected for detailed analysis in this research work. During analysis of scientific, practical literature and review of legal documents in are of municipal BDW management and biogas production, it was determined that: • widely used methods for biogas regeneration from municipal BDW are as follows: wet (moisture content of municipal waste – up to 85%), dry (moisture content – up to 80%), complete dry (moisture content – up to 50%); • source separation of municipal food BDW and separate treatment, is one of the priority of municipal BDW management; • biogas potential of source separated BDW is several times bigger (up to 220 m3 tonne-1 of BDW) in comparison with centralized municipal BDW; • also, the energetic volume of municipal BDW has to be increased by mixing with other BDW (manure, grass, etc.) or by insertion such microelement as Se. Existing municipal BDW management system in Utena region was analyzed. Up to 49,76 thousand tonnes of mixed municipal waste are generated in this region, incl. 30 thousand tonnes, which are collected by container system. In 2016, over 26 thousand tonnes of municipal waste, incl. 10 thousand tonnes of municipal BDW, were processed within centralized MBT plant; biogas yield was 24.21 m3 tonne-1 of municipal BDW. Technical capacity of biological treatment (fermentation and aerobic processing) is up to 15 thousand tonnes per year. This MBT equipment has to be partly used for MBT of source separated municipal BDW. In addition, shredding and sterilization line for food waste pretreatment has to be implemented. Separate collection of food BDW, for example, from the individual households in cities and towns (up to 3500 tonnes per year) and treatment within centralized MBT equipment can be alternative of existing municipal BDW management system. It was evaluated that number of run for municipal BDW collected will be increased up to 1 – 2,5 times per week (in depends on municipality and average distance till MBT plant). It was evaluated that biogas potential of such BDW reaches 107.04 m3 tonne-1 of food BDW. Despite municipal waste transportation cost increases, the implementation of work proposed alternatives for surplus power generation and the production of compost, which can be used, for example, to energy crop fertilization, MBT operating cost reduce on average 1,42 EUR/t of municipal waste. In master’s thesis are offered in regions where are installed municipal waste MBT devices with anaerobic digestion, increase the efficiency of source separation food waste from 11 % to 50 %. In other scientific work analyze alternative to food waste source separation not only from individual houses. |
