Možnosti energetického využití kompostu z domácích kuchyňských bioodpadů

Abstract

The dissertation discusses the prospects of energy use of domestic kitchen bio waste, bringing a detailed overview of the current state of the issue and solutions with regard to minimise landfilling. In the doctoral thesis, I focused on the use of biodegradable municipal waste coming from households, I identified undesirable input components that may influence energy use. In the context of the current trend of decarbonization of energy and the search for ways to energy self-sufficiency, the possibilities of biomethane production were examined and the research to obtain new products from food waste was processed.The composition of household kitchen waste (HFW) was monitored in detail with an emphasis on the possibilities of its use in the application of the principles of circular economy. For the processing of HFW, modern composting technology was used in automatic composters that produce a "product" with problematic use. Parameters were identified in this product that limits its "traditional use" as compost for agricultural purposes (stability, high NaCl content, conductivity, phytotoxicity and toxicity on aquatic organisms, non-breakable pesticides, etc.). Within the framework of the doctoral thesis, another possibility of using these "composts" was sought, namely energy use. Parameters influencing combustion processes were monitored (course of thermal decomposition of this non-traditional raw material with high starch content, risk of slagging and fouling, etc.) and anaerobic digestion. The work presents the results of laboratory tests of composts (aqueous liquor analyses), the content of the majority of elements in the dry matter, the element composition and the course of TGA analysis concerning non-traditional raw material inputs (starches). Using X-ray fluorescence, the element composition of composts was determined for subsequent calculations of the ash caking index, the results of the elementary analysis were used to calculate the gross calorific value of composts and the raw material. The results showed that the loss of organic matter, the decrease of carbon and the reduction of the gross calorific value during composting in automatic composters is very low. Automatic composters can be recommended as a pre-treatment technology before further use of "composts", they are suitable for removing moisture and ensure the hygiene of the final product, which should be further processed by another technology. The solution of the work shows that anaerobic digestion is the most suitable option.