Удосконалення біотехнології переробки харчових відходів готельно-ресторанного комплексу

Abstract

The dissertation is devoted to the theoretical and experimental substantiation of the improvement of biotechnology for the processing of food waste in the hotel and restaurant complex by varying the parameters of the anaerobic degradation process to optimise and obtain the main valuable product - biogas, and the secondary product - compost, using biochar from waste coffee grounds as an additive. The current state of the waste management sector and the possibilities of processing food waste from the hotel and restaurant complex into secondary products in Ukraine and the world are analysed. The author emphasises the expediency of using biotechnology in hotel and restaurant complexes, which are one of the significant producers of food waste that cannot be properly processed and is most often disposed of in landfills, which carries an anthropogenic burden on the environment through the process of decay of organic matter and the release of harmful substances into the air, soil and groundwater. Environmental protection technologies cover a significant part of waste treatment and disposal, which is a huge niche that needs to be improved to create a better environmental situation in the country. Given the low level of public awareness of solid waste sorting at home and the inability to track this process, it is much easier and more efficient to work with hospitality businesses that are accountable for environmental protection, namely waste generation and disposal. Sorting and processing food waste is relevant not only in the environmental sector, but also in the energy and economic sectors, as the anaerobic degradation process produces biogas and a secondary product called vermicompost, the former used alongside natural gas in the EU to generate heat and electricity, and the latter for agricultural land. The symbiosis of biotechnology and business is very promising for the country's development in a new paradigm, namely, the preservation of the environment, which suffers too much from human activity. Therefore, the development and implementation of biotechnologies for processing food waste into valuable secondary products in the hotel and restaurant industry is rational and saves resources, which is important for the sustainability of enterprises, the economy and the preservation of environmental components from uncontrolled pollution. The processes of obtaining biochar from waste coffee grounds by thermal and microwave pyrolysis (irradiation) were investigated, the influence of the production method on the biopolymer and granular composition, structural characteristics, sorption, acid-base and ion-exchange properties of raw materials and biochar was analysed. Differential infrared spectroscopy and comprehensive thermal analysis of raw materials and biochar were also carried out. It was found that the biochar samples obtained by microwave pyrolysis have similar and/or improved performance compared to traditional thermal pyrolysis (composition, structural characteristics, sorption, acid-base and ion exchange properties), but the production cost is significantly reduced due to the use of microwave ovens that do not require significant electricity consumption. The processes of anaerobic digestion of food waste from a hotel and restaurant complex with the use of biochar from spent coffee grounds obtained by thermal and microwave pyrolysis as an additive were investigated, improved and optimised. It has been determined that in the preparation of a mixture for anaerobic degradation from cow manure, food waste and biochar, methane makes up 80% of the biogas obtained, which is analogous to natural gas and can be used to meet the energy needs of the enterprise. Technological and vector diagrams of production processes for the production of biochar from waste coffee grounds and anaerobic digestion of food waste from the hotel and restaurant complex into biogas have been developed. On the basis of the obtained results, the economic efficiency of the project for implementation at the enterprise with additional profitability from waste processing and biofuel production is calculated.